JP4894604B2 - Air-core type insulation transformer, signal transmission circuit and power conversion device using air-core type insulation transformer - Google Patents

Description

  The present invention relates to an air-core insulated transformer, a signal transmission circuit and a power conversion device using the air-core insulated transformer, and in particular, a transformer that transmits a rising edge of a pulse signal and a transformer that transmits a falling edge of a pulse signal are separately provided. It is suitable for application to a provided signal transmission circuit.

In recent vehicle equipment, in order to achieve high efficiency and energy saving measures, a step-up / down converter and an inverter are mounted on a drive system of an electric motor that generates drive force.
FIG. 14 is a block diagram showing a schematic configuration of a vehicle drive system using a conventional buck-boost converter.
In FIG. 14, the vehicle drive system includes a power supply 101 that supplies power to the buck-boost converter 102, a buck-boost converter 102 that boosts and boosts the voltage, and an inverter that converts the voltage output from the buck-boost converter 102 into a three-phase voltage. 103 and an electric motor 104 for driving the vehicle are provided. In addition, the power supply 101 can be comprised from the power supply voltage from an overhead wire, or the battery connected in series.

  When the vehicle is driven, the step-up / down converter 102 boosts the voltage of the power source 101 (eg, 280 V) to a voltage suitable for driving the electric motor 104 (eg, 750 V), and supplies the boosted voltage to the inverter 103. Then, by switching on / off the switching element, the voltage boosted by the step-up / down converter 102 is converted into a three-phase voltage, current is passed through each phase of the motor 104, and the switching frequency is controlled to control the vehicle. The speed of the can be changed.

  On the other hand, at the time of braking of the vehicle, the inverter 103 performs a rectifying operation by performing on / off control of the switching element in synchronization with the voltage generated in each phase of the electric motor 104 to convert it into a DC voltage, and then the buck-boost converter 102. The step-up / down converter 102 can perform a power regeneration operation by stepping down the voltage (eg, 750 V) generated from the electric motor 104 to the voltage (eg, 280 V) of the power supply 101.

FIG. 15 is a block diagram showing a schematic configuration of the buck-boost converter of FIG.
In FIG. 15, the buck-boost converter 102 includes a reactor L for storing energy, a capacitor C for storing charge, switching elements SW1 and SW2, and switching elements SW1 and SW2 for energizing and interrupting current flowing into the inverter 103. Control circuits 111 and 112 are provided for generating control signals instructing conduction and non-conduction, respectively.

  The switching elements SW1 and SW2 are connected in series, and a power source 101 is connected to a connection point of the switching elements SW1 and SW2 via a reactor L. Here, the switching element SW1 is provided with an IGBT (Insulated Gate Bipolar Transistor) 105 that performs a switching operation in accordance with a control signal from the control circuit 111, and the flywheel diode D1 that flows a current in a direction opposite to the current flowing in the IGBT 105 is the IGBT 105. Connected in parallel.

  Further, the switching element SW2 is provided with an IGBT 106 that performs a switching operation in accordance with a control signal from the control circuit 112, and a flywheel diode D2 that flows a current in a direction opposite to the current flowing through the IGBT 106 is connected in parallel to the IGBT 106. The collector of the IGBT 106 is connected to both the capacitor C and the inverter 103.

FIG. 16 is a diagram showing a waveform of a current flowing through reactor L in FIG. 15 during the boosting operation.
16, the step-up operation, IGBT 105 of the switching element SW1 is a result on (conductive), a current I flows through the reactor L through the IGBT 105, the energy of the LI ^2/2 is stored in the reactor L.
Next, when the IGBT 105 of the switching element SW1 is turned off (non-conducting), a current flows through the flywheel diode D2 of the switching element SW2, and the energy stored in the reactor L is sent to the capacitor C.

On the other hand, in the step-down operation, IGBT 106 of the switching element SW2 is turned on (conducting) Then a current I flows through the reactor L through the IGBT 106, the energy of the LI ^2/2 is stored in the reactor L.
Next, when the IGBT 106 of the switching element SW2 is turned off (non-conducting), a current flows through the flywheel diode D1 of the switching element SW1, and the energy stored in the reactor L is regenerated to the power source 101.

Here, the voltage of the step-up / step-down can be adjusted by changing the ON time (ON Duty) of the switching element, and the approximate voltage value can be obtained by the following equation (1).
V _L / V _H = ON Duty (%) (1)
However, V _L is the power supply voltage, V _H is the voltage after step-up / step-down, and ON Duty is the ratio of the conduction period to the switching period of the switching elements SW1 and SW2.

Here, the actual variation of the load, since there is such fluctuations in the power supply voltage V _L, monitors the voltage V _H after buck, so that the voltage V _H after buck becomes a target value, the switching element SW1 , SW2 ON time (ON Duty) is controlled.
In addition, the control circuits 111 and 112 that are grounded to the vehicle body casing have a low voltage, and the arm that is connected to the switching elements SW1 and SW2 has a high voltage. Therefore, even if an accident such as destruction of the switching elements SW1 and SW2 occurs, the arm side is connected to the control circuits 111 and 112 using an insulating transformer so that the human body is not exposed to danger. Signals are exchanged while being electrically insulated.

FIG. 17 is a plan view showing a schematic configuration of a conventional signal transmission insulating transformer.
In FIG. 17, the insulating transformer is provided with a magnetic core MC, and a primary winding M1 and a secondary winding M2 are wound around the magnetic core MC. The magnetic core MC can be composed of a ferromagnetic material such as ferrite or permalloy. Then, the magnetic flux φ generated by the current applied to the primary winding M1 is focused by the magnetic core MC, passes through the magnetic core MC, and links the secondary winding M2, and then the secondary winding. A voltage of dφ / dT is generated at both ends of M2. Here, a closed magnetic circuit can be formed by using the magnetic core MC, and the coupling coefficient between the primary winding M1 and the secondary winding M2 can be increased while reducing the influence of the external magnetic field. it can.

Patent Document 1 discloses a method of transmitting an NRZ data signal via an interface composed of an isolation barrier disposed between a first device and a second device interconnected via a bus. A method using a pulse transformer as an isolation barrier is disclosed.
Japanese Patent No. 3399950

  However, the method using a cored transformer as an insulating transformer for signal transmission is affected by the temperature characteristics of the magnetic permeability of the magnetic material, and the temperature dependence of the coupling coefficient is large, and it is difficult to reduce the cost and size. There was a problem. In addition, the PWM signal itself cannot be sent directly through a transformer with a core, and it is necessary to demodulate after receiving a modulated signal modulated at a high frequency with a secondary winding, which increases the circuit scale. there were.

On the other hand, in the method using an air core transformer as an insulation transformer for signal transmission, since a magnetic core is not used, the price can be reduced and the size can be reduced. There was a risk of causing malfunction due to easy superimposition on the line.
Accordingly, an object of the present invention is to reduce the influence of noise caused by an external magnetic flux while reducing the temperature dependence of the coupling coefficient, and to exchange signals while electrically insulating the low voltage side and the high voltage side. It is an object to provide an air-core type insulating transformer, a signal transmission circuit using the air-core type insulating transformer, and a power conversion device.

In order to solve the above-described problem, according to the air-core type insulated transformer according to claim 1, a set insulating transformer for transmitting a rising side of a pulse signal and a reset insulating transformer for transmitting a falling side of a pulse signal. The secondary winding of the set insulating transformer and the secondary winding of the reset insulating transformer cancel each other an electromotive voltage generated by an external magnetic flux interlinking the secondary winding, and the secondary winding. It is characterized in that at least a plurality of windings configured to reinforce the electromotive voltage due to the signal magnetic flux interlinking the wires are provided.
Here, the set insulation transformer is provided with a primary winding for setting, a first winding of the secondary winding for setting, and a second winding of the secondary winding for setting. The transformer is provided with a primary winding for resetting, a first winding of a secondary winding for resetting, and a second winding of a secondary winding for resetting. The first winding of the secondary winding and the second winding of the secondary winding for resetting are coaxially arranged, and the primary winding for resetting and the first winding of the secondary winding for resetting are arranged. The winding and the second winding of the set secondary winding are arranged coaxially.

  As a result, it is possible to cancel out the electromotive voltage caused by the external magnetic flux interlinked with the secondary winding, and even when the pulse width of the pulse signal is long, current is passed through the primary winding and the secondary winding. The period can be shortened. For this reason, even when an air-core transformer is used as an insulating transformer for signal transmission, it is possible to reduce the external magnetic flux from being superimposed on the secondary winding as noise, and to avoid the risk of causing a malfunction. Even when the conductor cross-sectional areas of the primary and secondary windings are reduced, the average current flowing in the primary and secondary windings can be made less than the allowable DC current, resulting from Joule heat. It is possible to prevent the primary winding and the secondary winding from fusing.

Even when the isolation transformer is divided into a set and a reset, it is possible to cancel the electromotive voltage due to the external magnetic flux interlinked with the secondary winding while canceling the primary winding and the secondary winding. One winding and the second winding can be stacked. For this reason, while suppressing the increase in the mounting area occupied by the insulating transformer, it is possible to reduce the external magnetic flux from being superimposed on the secondary winding as noise, and to avoid the risk of causing a malfunction. The average current flowing through the secondary winding and the secondary winding can be made equal to or less than the allowable DC current, and the primary winding and the secondary winding due to Joule heat can be prevented from fusing.

Further, according to the air-core type insulated transformer according to claim 2, the winding direction of the second winding of the first winding and the reset secondary winding of the secondary winding for the set are different from each other, wherein The winding directions of the first winding of the resetting secondary winding and the second winding of the setting secondary winding are different from each other.
This makes it possible to make the electromotive voltage generated in the first winding of the secondary winding for setting and the electromotive voltage generated in the second winding of the secondary winding for resetting out of phase with each other, The electromotive voltage generated in the first winding of the resetting secondary winding and the electromotive voltage generated in the second winding of the setting secondary winding can be in opposite phases.

  For this reason, the primary winding for setting, the first winding of the secondary winding for setting, and the second winding of the secondary winding for resetting are arranged coaxially, the primary winding for resetting, and the resetting Since the first winding of the secondary winding for winding and the second winding of the secondary winding for setting are coaxially arranged, the phase of the secondary winding on the reset side is also in reverse phase during signal transmission on the set side The signal transmission timing can be shifted even in the case where the signal is transmitted at the reset side and the signal transmission at the reset side is also transmitted to the secondary winding on the set side in the opposite phase. As a result, by detecting the timing of these signal transmissions, signals are transmitted in the opposite phase to the secondary winding on the reset side by signal transmission on the set side, or on the set side by signal transmission on the reset side. It is possible to prevent signals from being transmitted in the opposite phase to the secondary winding.

According to a signal transmission circuit using an air core type insulated transformer according to claim 3, a conversion circuit for generating a pulse current corresponding to a rising edge and a falling edge of a pulse signal, and a rising edge of the pulse signal Insulating transformer for setting that transmits a corresponding pulse current, an insulating transformer for reset that transmits a pulse current corresponding to a falling edge of the pulse signal, a secondary winding of the insulating transformer for setting, and the insulating transformer for resetting And a restoration circuit that restores the pulse signal based on the level of the voltage pulse generated in the secondary winding, and the secondary winding of the set insulating transformer and the secondary winding of the reset insulating transformer include: While canceling the electromotive force caused by the external magnetic flux interlinking the secondary winding, the electromotive force caused by the signal magnetic flux interlinking the secondary winding And a plurality of windings configured to constructive the pressure is at least provided.
Here, the set insulation transformer is provided with a primary winding for setting, a first winding of the secondary winding for setting, and a second winding of the secondary winding for setting. The transformer is provided with a primary winding for resetting, a first winding of a secondary winding for resetting, and a second winding of a secondary winding for resetting. The first winding of the secondary winding and the second winding of the secondary winding for resetting are coaxially arranged, and the primary winding for resetting and the first winding of the secondary winding for resetting are arranged. The winding and the second winding of the set secondary winding are arranged coaxially.

  As a result, it is possible to cancel out the electromotive voltage caused by the external magnetic flux interlinked with the secondary winding, and even when the pulse width of the pulse signal is long, current is passed through the primary winding and the secondary winding. The period can be shortened. For this reason, even when an air-core transformer is used as an insulating transformer for signal transmission, it is possible to reduce the external magnetic flux from being superimposed on the secondary winding as noise, and to avoid the risk of causing a malfunction. The average current flowing through the primary winding and the secondary winding can be made equal to or less than the allowable DC current, and the primary winding and the secondary winding due to Joule heat can be prevented from fusing.

Further, the time according to the signal transmission circuit using the air-core type insulated transformer according to claim 4, wherein, the set side receives the voltage detected by the pre-Symbol Set for secondary winding reaches the set for judgment threshold level, A comparison circuit that compares the reset-side received voltage detected by the reset secondary winding with a time when the reset determination threshold reaches the reset determination threshold, and a time when each reaches the set determination threshold or the reset determination threshold. It further comprises a determination circuit that validates the earlier set-side received voltage or reset-side received voltage.

  Thus, the primary winding for setting, the first winding of the secondary winding for setting, and the second winding of the secondary winding for resetting are coaxially arranged, and the primary winding for resetting and the resetting Since the first winding of the secondary winding for winding and the second winding of the secondary winding for setting are coaxially arranged, the phase of the secondary winding on the reset side is also in reverse phase during signal transmission on the set side Even when the signal is transmitted in the opposite phase to the secondary winding on the set side in the signal transmission on the reset side, the signal transmitted in the opposite phase can be invalidated. The original pulse signal can be restored while suppressing an increase in the mounting area occupied by the insulating transformer.

According to the power conversion device of claim 5, the switching element for energizing and interrupting the current flowing into the load, the control circuit for generating a control signal instructing conduction and non-conduction of the switching element, and the control A drive circuit for driving the control terminal of the switching element based on a signal; a set insulating transformer for transmitting a pulse current corresponding to the rising edge of the control signal to the drive circuit; and a falling edge of the control signal A reset insulating transformer for transmitting a corresponding pulse current to the drive circuit side, and the secondary winding is chained to the secondary winding of the set insulating transformer and the secondary winding of the reset insulating transformer. It is configured to cancel the electromotive voltage caused by the external magnetic flux that intersects, and to strengthen the electromotive voltage caused by the signal magnetic flux interlinking the secondary winding. The number of windings, characterized in that it is at least provided.
Here, the set insulation transformer is provided with a primary winding for setting, a first winding of the secondary winding for setting, and a second winding of the secondary winding for setting. The transformer is provided with a primary winding for resetting, a first winding of a secondary winding for resetting, and a second winding of a secondary winding for resetting. The first winding of the secondary winding and the second winding of the secondary winding for resetting are coaxially arranged, and the primary winding for resetting and the first winding of the secondary winding for resetting are arranged. The winding and the second winding of the set secondary winding are arranged coaxially.

  Thus, by providing a plurality of windings as the secondary winding, it is possible to cancel the electromotive voltage caused by the external magnetic flux interlinked with the secondary winding, and the external magnetic flux is generated as noise without using a magnetic core. It is possible to reduce superimposition on the secondary winding, and it is possible to shorten the period during which current flows in the primary winding and the secondary winding even when the pulse width of the control signal is long. . Therefore, it is possible to exchange signals while electrically insulating the control circuit side and the switching element side while avoiding the risk of causing a malfunction, and the primary winding and the secondary winding. Even when the conductor cross-sectional area of the coil becomes small, the average current flowing through the primary winding and the secondary winding can be reduced to an allowable DC current or less, and the primary winding and the secondary winding caused by Joule heat. Can be prevented from fusing.

  As described above, according to the present invention, it is possible to cancel the electromotive voltage caused by the external magnetic flux interlinked with the secondary winding, and shorten the period during which the excitation current is supplied to the primary winding. It becomes possible to pass an electric current. For this reason, even when an air-core transformer is used as an insulating transformer for signal transmission, it is possible to reduce the external magnetic flux from being superimposed on the secondary winding as noise, and to avoid the risk of causing a malfunction. The average excitation current flowing through the primary winding can be made equal to or less than the allowable DC current, and the primary winding can be prevented from being melted due to Joule heat.

Hereinafter, an air core type insulating transformer according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of an intelligent power module (IPM) for a buck-boost converter to which an air core type insulating transformer according to an embodiment of the present invention is applied.
In FIG. 1, the intelligent power module for the buck-boost converter generates control signals for instructing conduction and non-conduction of switching elements SWU, SWD and switching elements SWU, SWD for energizing and interrupting the current flowing into the load, respectively. A circuit 1 is provided. Here, the control circuit 1 can be configured by a CPU 4 or a logic IC, or a system LSI on which the logic IC and the CPU are mounted.

  The switching elements SWU and SWD are connected in series so as to operate for the upper arm 2 and the lower arm 3, respectively. The switching element SWU is provided with an IGBT 6 that performs a switching operation based on the gate signal SU4, and a flywheel diode DU1 that allows a current to flow in a direction opposite to the current that flows in the IGBT 6 is connected in parallel to the IGBT 6. The chip on which the IGBT 6 is formed has a main circuit in which the emitter current of the IGBT 6 is shunted through the temperature sensor using the VF change of the diode DU2 due to the temperature change of the chip as a measurement principle and the resistors RU1 and RU2. A current sensor for detecting current is provided.

  Further, the switching element SWD is provided with an IGBT 5 that performs a switching operation in accordance with the gate signal SD4, and a flywheel diode DD1 that allows a current to flow in a direction opposite to the current that flows through the IGBT 5 is connected in parallel to the IGBT 5. The chip on which the IGBT 5 is formed includes a temperature sensor that uses the VF change of the diode DD2 due to the temperature change of the chip as a measurement principle, and the emitter current of the IGBT 5 is shunted through the resistors RD1 and RD2, and the main circuit A current sensor for detecting current is provided.

  The upper arm 2 has a protection function for generating the gate signal SU4 for driving the control terminal of the IGBT 6 while monitoring the overheat detection signal SU6 from the temperature sensor and the overcurrent detection signal SU5 from the current sensor. A gate driver IC 8 is provided, and an analog PWM converter CU that generates a PWM signal corresponding to the temperature of the IGBT 6 is provided. Note that the gate driver IC 8 with a protective function can be provided with a self-diagnosis circuit that generates state signals of the switching elements SWD and SWU, and the self-diagnosis circuit can generate state signals of the switching elements SWD and SWU.

  The lower arm 3 has a protection function for generating a gate signal SD4 for driving the control terminal of the IGBT 5 while monitoring the overheat detection signal SD6 from the temperature sensor and the overcurrent detection signal SD5 from the current sensor. A gate driver IC 7 is provided, and an analog PWM converter CD that generates a PWM signal corresponding to the temperature of the IGBT 5 is provided.

The control circuit 1 also includes conversion circuits KU1 and KD1 that generate pulse signals SU1 and SD1 corresponding to the rising and falling edges of the gate drive PWM signals SU0 and SD0 output from the CPU 4, respectively, and air-core type insulation. Restoration circuits PU1 and PD1 for restoring the gate drive PWM signals SU0 and SD0 based on the level of the voltage pulse generated in the secondary windings of the transformers TU1 and TD1 are provided.
Air-core insulating transformers TU1 to TU3 and TD1 to TD3 are inserted between the control circuit 1 side grounded to the vehicle body casing and the upper arm 2 side and the lower arm 3 side, which are at high pressure, respectively. In the control circuit 1, signals are exchanged using the air-core type insulating transformers TU1 to TU3 and TD1 to TD3 while being electrically insulated from the upper arm 2 side and the lower arm 3 side.

  That is, on the upper arm 2 side, the pulse signal SU1 corresponding to the rising edge and the falling edge of the gate drive PWM signal SU0 is input to the restoration circuit PU1 via the air-core insulated transformer TU1. Further, the alarm signal SU2 output from the gate driver IC 8 with a protective function is input to the CPU 4 via the air core type insulating transformer TU2. Further, the IGBT chip temperature PWM signal SU3 output from the analog PWM converter CU is input to the CPU 4 via the air core type insulating transformer TU3.

  On the other hand, on the lower arm 3 side, the pulse signal SD1 corresponding to the rising edge and the falling edge of the gate drive PWM signal SD0 is input to the restoration circuit PD1 through the air-core insulating transformer TD1. The alarm signal SD2 output from the gate driver IC 7 with a protective function is input to the CPU 4 via the air core type insulating transformer TD2. The IGBT chip temperature PWM signal SD3 output from the analog PWM converter CD is input to the CPU 4 via the air-core type insulating transformer TD3.

  Here, the air-core insulating transformers TU1 to TU3 and TD1 to TD3 are respectively provided with a primary winding on the transmission side and a secondary winding on the reception side. The secondary windings of the air-core type insulating transformers TU1 to TU3 and TD1 to TD3 cancel out the electromotive voltage caused by the external magnetic flux interlinking the secondary windings, and the signal magnetic flux interlinking the secondary windings. A plurality of windings are provided so as to reinforce the electromotive voltage caused by the. The primary winding and the secondary winding of the air-core type insulating transformers TU1 to TU3 and TD1 to TD3 can be laminated with each other through an insulating layer, and the air-core type insulating transformers TU1 to TU3 and TD1 to TD3 are stacked. Can be formed by a fine processing technique such as a semiconductor process technique.

  The air-core insulated transformer TU1 includes a set insulated transformer and a reset insulated transformer that separately transmit pulse signals SU1 corresponding to the rising and falling edges of the gate drive PWM signal SU0 output from the CPU 4, respectively. The air core type isolation transformer TD1 includes a set isolation transformer that separately transmits the pulse signal SD1 corresponding to the rising edge and the falling edge of the gate drive PWM signal SD0 output from the CPU 4. And an insulating transformer for reset may be provided.

  Then, the CPU 4 generates the gate drive PWM signals SD0 and SU0 for instructing the conduction or non-conduction of the IGBTs 5 and 6, respectively, and inputs them to the conversion circuits KD1 and KU1, respectively. When the gate drive PWM signals SD0 and SU0 are input from the CPU 4, the conversion circuits KD1 and KU1 receive the gate drive pulse signals SU1 corresponding to the rising and falling edges of the gate drive PWM signals SU0 and SD0, SD1 is generated respectively, and based on the gate drive pulse signals SU1 and SD1, the air-core insulated transformers TD1 and TU1 can be driven so that an exciting current flows through the primary windings of the insulated transformers TD1 and TU1. .

  When the isolation transformers TD1 and TU1 are driven based on the gate drive pulse signals SD1 and SU1, the air-core type isolation transformers TD1 and TU1 transfer the gate drive pulse signals SD1 and SU1 to the restoration circuits PU1 and PD1. Insulate and transmit each. Then, when the gate drive pulse signals SD1 and SU1 are insulated and transmitted through the air-core type insulated transformers TD1 and TU1, respectively, the restoration circuits PU1 and PD1 return the original signals based on the gate drive pulse signals SD1 and SU1. The gate drive PWM signals SD0 and SU0 are restored and input to the gate drivers IC 7 and 8 with protection functions, respectively. Then, the gate driver ICs 7 and 8 with protection functions generate the gate signals SD4 and SU4 based on the PWM signals SD0 and SU0 for gate drive, respectively, and drive the control terminals of the IGBTs 5 and 6, respectively. Each is switched.

  Here, the overheat detection signals SD6 and SU6 output from the temperature sensor are input to the gate driver ICs 7 and 8 with protection function, respectively, and the overcurrent detection signals SD5 and SU5 output from the current sensor are the gate driver with protection function. Input to ICs 7 and 8, respectively. Then, the gate drivers IC 7 and 8 with protection functions transmit alarm signals SD2 and SU2 to the CPU 4 via the air-core type insulating transformers TD2 and TU2, respectively, when the threshold values that the IGBTs 5 and 6 do not break are exceeded. When the CPU 4 receives the alarm signals SD2 and SU2 from the gate driver ICs 7 and 8 with protection functions, the CPU 4 stops the generation of the gate drive PWM signals SD1 and SU1, respectively, thereby cutting off the current flowing through the IGBTs 5 and 6. .

Note that the gate driver ICs 7 and 8 with protective functions are below the threshold at which the IGBT does not break down based on the overheat detection signals SD6 and SU6 output from the temperature sensor and the overcurrent detection signals SD5 and SU5 output from the current sensor. If it is determined, the alarm signals SD2 and SU2 are canceled after a certain time has elapsed.
Further, when performing fine monitoring, the overheat detection signals SD6 and SU6 output from the temperature sensor are input to the analog PWM converters CD and CU, respectively. Then, the analog PWM converters CD and CU generate the IGBT chip temperature PWM signals SD3 and SU3, respectively, by converting the analog values of the overheat detection signals SD6 and SU6 into digital signals, respectively, and the air-core insulated transformer TD3, The IGBT chip temperature PWM signals SD3 and SU3 are transmitted to the CPU 4 via the TU3, respectively. Then, the CPU 4 calculates the chip temperatures of the IGBTs 5 and 6 from the IGBT chip temperature PWM signals SD3 and SU3, respectively, and performs a stepwise decrease in the switching frequency of the IGBTs 5 and 6 according to a predetermined number of thresholds. Or switching can be stopped.

  Here, by providing a plurality of windings as the secondary windings of the air-core type insulating transformers TU1 to TU3, TD1 to TD3, it is possible to cancel the electromotive voltage due to the external magnetic flux interlinked with the secondary winding, Without using the magnetic core, it is possible to reduce the external magnetic flux from being superimposed on the secondary winding as noise. For this reason, while avoiding the risk of causing a malfunction, it is possible to exchange signals while electrically insulating the control circuit 1 side from the upper arm 2 side and the lower arm 3 side, It is possible to reduce the price and size of the intelligent power module for the converter.

  Further, the primary winding and the secondary winding of the air-core type insulating transformers TU1 to TU3 and TD1 to TD3 are formed by a fine processing technique, thereby reducing the winding diameters of the primary winding and the secondary winding. And the distance between the primary winding and the secondary winding can be reduced. For this reason, while increasing the coupling coefficient between the primary winding and the secondary winding, the area where the magnetic flux interlinks with the primary winding and the secondary winding can be reduced, and noise caused by external magnetic flux It is possible to reduce the effects of noise, and it is no longer necessary to use a photocoupler to transmit and receive signals while electrically insulating the low-voltage side and high-voltage side. It becomes possible to improve the property.

  Further, pulse signals SU1 and SD1 corresponding to the rising and falling edges of the gate drive PWM signals SU0 and SD0 are transmitted through the air-core type insulated transformers TU1 and TD1, and the two air-core type insulated transformers TU1 and TD1 are transmitted. By restoring the gate drive PWM signals SU0 and SD0 on the secondary side, even when the pulse width of the gate drive PWM signals SU0 and SD0 is long, the primary winding and secondary of the air-core type insulated transformers TU1 and TD1 It is possible to shorten the period during which current flows through the winding. For this reason, since the primary winding and the secondary winding of the air-core type insulating transformers TU1, TD1 are formed by the fine processing technique, the primary winding and the secondary winding of the air-core type insulating transformers TU1, TD1 are formed. Even when the conductor cross-sectional area is reduced, the average excitation current flowing in the primary windings of the air-core type insulating transformers TU1 and TD1 can be reduced to an allowable DC current or less, and the primary winding caused by Joule heat can be reduced. Fusing can be prevented.

FIG. 2 is a block diagram showing a schematic configuration of a signal transmission circuit using the air-core type insulated transformer according to the first embodiment of the present invention.
In FIG. 2, the control signal S11 is input to one input terminal of the exclusive OR circuit 202 via the delay element 201, and the control signal S11 is directly input to the other input terminal of the exclusive OR circuit 202. Entered. The output from the exclusive OR circuit 202 is input to one input terminal of the AND circuit 204, and the control signal S11 is directly input to the other input terminal of the AND circuit 204. Further, the output from the exclusive OR circuit 202 is input to one input terminal of the AND circuit 205, and the control signal S 11 is input to the other input terminal of the AND circuit 204 via the inverter 203. Entered.

The drain of the N-channel field effect transistor 207 is connected to one end of the primary winding of the setting isolation transformer 210 via the resistor 206, and the drain of the N-channel field effect transistor 209 is connected via the resistor 208. It is connected to one end of the primary winding of the reset insulating transformer 218.
The output of the AND circuit 204 is connected to the gate of the N-channel field effect transistor 208, and the output of the AND circuit 205 is connected to the gate of the N-channel field effect transistor 209. Further, the other end of the primary winding of the set insulating transformer 210 and the other end of the primary winding of the reset insulating transformer 218 are fixed to the power supply voltage Vcc1. Further, both ends of the secondary winding of the setting insulating transformer 210 are connected to each other via a resistor 211, and both ends of the secondary winding of the reset insulating transformer 218 are connected to each other via a resistor 219. One end of the resistor 212 is connected to the power supply voltage Vcc2, and the resistors 212 and 213 are connected in series so that the potential at the connection point of the resistors 212 and 213 is Vth.

The non-inverting input terminals of the comparators 215 and 216 are fixed to the potential of Vth, the inverting input terminal of the comparator 215 is connected to one end of the secondary winding of the setting insulating transformer 210, and the inverting input terminal of the comparator 216 is set. Is connected to one end of the secondary winding of the reset isolation transformer 218. The output of the comparator 215 is connected to the set terminal of the flip-flop 217, and the output of the comparator 216 is connected to the reset terminal of the flip-flop 217.
The secondary winding of the set insulation transformer 210 and the secondary winding of the reset insulation transformer 218 cancel out the electromotive voltage caused by the external magnetic flux interlinking these secondary windings. It is possible to provide a plurality of windings configured to reinforce the electromotive voltage due to the signal magnetic flux interlinking the next windings.

  Then, a control signal S11 that instructs conduction and non-conduction of the switching elements SWD and SWU of FIG. 1 and a signal obtained by delaying the control signal S11 by the delay element 201 are input to the exclusive OR circuit 202, By taking the exclusive OR in the OR circuit 202, the edge of the control signal S11 is synchronized with the edge from S0-1 to “1” and the edge signal S12-1 is synchronized with the edge from “1” to “0”. The edge signal S12-2 thus extracted is extracted. These edge signals S12-1 and S12-2 are input to the logical product circuits 204 and 205, and the logical product circuit 204 performs a logical product with the control signal S11, thereby generating a rising edge pulse S13. At the same time, the logical product circuit 205 performs a logical product with the inverted signal of the control signal S11, whereby the logical product circuit 205 generates the falling edge pulse S14.

The rising edge pulse S13 generated by the AND circuit 204 is input to the gate of the N-channel field effect transistor 209, and the falling edge pulse S14 generated by the AND circuit 205 is the N-channel field effect. The timing of the pulse current flowing in the primary winding of the set isolation transformer 210 and the primary winding of the reset isolation transformer 218 is different between the rise and fall of the control signal S11 input to the gate of the type transistor 207 Such an operation can be performed.
The electromotive force generated on the secondary winding side of the insulating transformer for setting 210 and the secondary winding side of the insulating transformer for resetting 218 is guided to the comparators 215 and 216 set to the threshold value of Vth, respectively.

  At the rising edge of the control signal S11, a pulse S15 is sent from the comparator 215 along with the change in the terminal voltage level of the secondary winding of the setting isolation transformer 210, and at the falling edge of the control signal S11, A pulse S16 is output from the comparator 216 in accordance with a change in the level of the terminal voltage of the secondary winding of the reset isolation transformer 218. When these pulses S15 and S16 are input to the RS flip-flop 217, the RS flip-flop 217 is set by the pulse S15 from the comparator 215, and the RS flip-flop 217 is set by the pulse S16 from the comparator 216. The control signal S17 that has been reset and the control signal S11 on the transmission side is restored can be generated on the reception side.

FIG. 3 is an external view showing a schematic configuration of an air-core type insulating transformer applied to the signal transmission circuit of FIG.
3, the air-core insulated transformers TU1 and TD1 in FIG. 1 are provided with a primary winding M11 that plays the role of the transmitting side, and a first winding M21 of the secondary winding that plays the role of the receiving side, and Each of the second windings M22 can be provided. Here, the first winding M21 and the second winding M22 of the secondary winding cancel out the electromotive voltage caused by the external magnetic flux interlinking the secondary winding, and the signal magnetic flux interlinking the secondary winding. Can be configured to strengthen each other.

  For example, the winding directions of the first winding M21 and the second winding M22 of the secondary winding are made different from each other, and the first winding M21 and the second winding M22 of the secondary winding are arranged close to each other. be able to. Furthermore, the primary winding M11 and the first winding M21 of the secondary winding are arranged coaxially, and the winding direction of the primary winding M11 and the first winding M21 of the secondary winding is the same. be able to. Further, the end of the first winding M21 of the secondary winding is connected to the start of the second winding M22, or the start of the first winding M21 of the secondary winding is connected to the end of the second winding M22. can do. The number of turns of the first winding M21 and the second winding M22 of the secondary winding is preferably substantially the same.

  Thus, by causing the winding directions of the first winding M21 and the second winding M22 provided in the secondary winding to be different from each other, it is possible to cancel the electromotive voltage caused by the external magnetic flux interlinked with the secondary winding. it can. For this reason, even when the air-core type insulation transformers TU1 and TD1 are used as the signal transmission insulation transformer, it is possible to reduce the external magnetic flux from being superimposed on the secondary winding as noise, which may cause a malfunction. While avoiding this, it is possible to reduce the cost and size of the intelligent power module for the buck-boost converter.

FIG. 4 is a diagram showing a linkage state of external magnetic fluxes in the air-core type insulating transformer of FIG.
In FIG. 4, the external magnetic flux Φo is linked approximately equally from both the first winding M21 and the second winding M22 of the secondary winding from the same direction.
FIG. 5 is a diagram showing a state of linkage of signal magnetic flux in the air-core type insulating transformer of FIG.
In FIG. 5, the signal magnetic flux Φs formed by the signal current flowing through the primary winding M11 is formed so as to circulate around the axis of the primary winding M11, and is arranged on the same axis as the primary winding M11. Most of the first winding M21 of the secondary winding is interlinked, and a part of the second winding M22 of the secondary winding is interlinked.
In addition, when the magnetic flux linked to the winding which changes is changed, the voltage generated at both ends of the winding can be expressed by the following Faraday's law.

  As can be seen from equation (2), the factors affecting the sign of the voltage generated by the change in magnetic flux are the winding direction (dS) of the winding and the direction (B) of the magnetic flux. The electromotive force generated by the external magnetic flux Φo generated by the main circuit current is different in sign direction from the first winding M21 and the second winding M22 of the secondary winding. Can cancel each other. The cancellation of the electromotive voltages is most effective when the number of turns of the first winding M21 and the second winding M22 of the secondary winding is substantially equal.

  On the other hand, for the signal magnetic flux Φs, an electromotive voltage is generated in the same direction in both the first winding M21 and the second winding M22 of the secondary winding, and the electromotive voltage level increases. By using the configuration as described above, the electromotive voltage level due to the signal magnetic flux Φs can be increased, and the electromotive voltage level due to the external magnetic flux Φo of the main circuit current can be suppressed, and the air-core type insulated transformers TU1, TD1 in FIG. Even when the signal is used, the S / N ratio of the signal can be increased.

  In the above-described embodiment, the winding directions of the first winding M21 and the second winding M22 of the secondary winding are made different from each other, and the termination of the first winding M21 of the secondary winding is the second winding. The method of connecting to the start end of M22 or connecting the start end of the first winding M21 of the secondary winding to the end of the second winding M22 has been described. The winding direction of the two windings M22 is the same, and the starting end of the first winding M21 of the secondary winding is connected to the starting end of the second winding M22, or the first winding M21 of the secondary winding The terminal end may be connected to the terminal end of the second winding M22.

In the embodiment described above, the winding direction of the primary winding M11 and the first winding M21 of the secondary winding is the same, but the winding direction of these windings may be reversed. Only the sign of the output voltage due to the signal magnetic flux Φs changes, and the effect of suppressing the influence of the external magnetic flux Φo does not change.
Moreover, although the winding shown in FIG. 3 is formed in the vertical direction, a planar coil formed by a fine processing technique may be used.

  6A1 is a cross-sectional view illustrating a schematic configuration of the insulating transformer for setting according to the second embodiment of the present invention, and FIG. 6A2 illustrates a schematic configuration of the insulating transformer for setting of FIG. 6A1. FIG. 6B1 is a cross-sectional view showing a schematic configuration of the reset insulating transformer according to the second embodiment of the present invention, and FIG. 6B2 is a schematic diagram of the reset insulating transformer in FIG. 6B1. It is a top view which shows a structure.

  6 (a1) and 6 (a2), the insulating transformer for setting is provided with a substrate 11a and a substrate 21a. A lead wiring layer 12a is embedded in the substrate 11a, and a primary coil pattern 14a is formed on the substrate 11a. The primary coil pattern 14a is connected to the lead wiring layer 12a via the lead portion 13a. Then, a planarizing film 15a is formed on the primary coil pattern 14a, a secondary coil pattern 17a is formed on the planarizing film 15a via an insulating layer 16a, and the secondary coil pattern 17a is a protective film 18a. Covered with

On the other hand, a lead wiring layer 22a is embedded in the substrate 21a, and a secondary coil pattern 24a is formed on the substrate 21a. The secondary coil pattern 24a is connected to the lead wiring layer 22a through the lead portion 23a. The secondary coil pattern 24a is covered with a protective film 25a.
Here, the primary coil pattern 14a and the secondary coil pattern 17a set the winding direction clockwise, the secondary coil pattern 24a sets the winding direction counterclockwise, and the secondary coil patterns 17a and 24a are mutually connected. Can be placed close together. Furthermore, the end of the secondary coil pattern 17a can be connected to the start of the secondary coil pattern 24a, or the start of the secondary coil pattern 17a can be connected to the end of the secondary coil pattern 24a.

  In this case, the external magnetic flux Φo is linked to both the secondary coil patterns 17a and 24a of the setting insulating transformer almost uniformly from the same direction. On the other hand, the signal magnetic flux Φs formed by the signal current flowing in the primary coil pattern 14a of the insulating transformer for setting is formed to circulate around the axis of the primary coil pattern 14a, and is coaxial with the primary coil pattern 14a. Most of the secondary coil pattern 17a arranged above is linked, and a part of the secondary coil pattern 24a is linked. For this reason, the electromotive voltage level due to the signal magnetic flux Φs of the insulating transformer for setting can be increased, the electromotive voltage level due to the external magnetic flux Φo of the main circuit current can be suppressed, and the S / N ratio of the signal can be increased. .

  In addition, the winding diameter of the primary coil pattern 14a and the secondary coil patterns 17a and 24a of the insulating transformer for setting can be reduced, and the interval between the primary coil pattern 14a and the secondary coil pattern 17a can be reduced. be able to. For this reason, while increasing the coupling coefficient between the primary coil pattern 14a and the secondary coil pattern 17a of the insulating transformer for setting, the influence of noise due to the external magnetic flux Φo can be reduced, and the S / N ratio is improved. Can do.

  In FIGS. 6B1 and 6B2, the reset insulating transformer is provided with a substrate 11b and a substrate 21b. A lead wiring layer 12b is embedded in the substrate 11b, and a primary coil pattern 14b is formed on the substrate 11b. The primary coil pattern 14b is connected to the lead wiring layer 12b through the lead portion 13b. A planarizing film 15b is formed on the primary coil pattern 14b, a secondary coil pattern 17b is formed on the planarizing film 15b via an insulating layer 16b, and the secondary coil pattern 17b is a protective film 18b. Covered with

On the other hand, a lead wiring layer 22b is embedded in the substrate 21b, and a secondary coil pattern 24b is formed on the substrate 21b. The secondary coil pattern 24b is connected to the lead wiring layer 22b through the lead portion 23b. The secondary coil pattern 24b is covered with a protective film 25b.
Here, the primary coil pattern 14b and the secondary coil pattern 17b of the reset insulating transformer set the winding direction clockwise, and the secondary coil pattern 24b sets the winding direction counterclockwise. 17b and 24b can be arranged close to each other. Further, the end of the secondary coil pattern 17b of the insulating transformer for reset can be connected to the start of the secondary coil pattern 24b, or the start of the secondary coil pattern 17b can be connected to the end of the secondary coil pattern 24b.

  In this case, the external magnetic flux Φo is linked almost equally from both sides of the secondary coil patterns 17b and 24b of the reset insulating transformer from the same direction. On the other hand, the signal magnetic flux Φs formed by the signal current flowing through the primary coil pattern 14b of the reset insulating transformer is formed to circulate around the axis of the primary coil pattern 14b, and is coaxial with the primary coil pattern 14b. Most of the secondary coil pattern 17b disposed above is linked, and a part of the secondary coil pattern 24b is linked. For this reason, the electromotive voltage level by the signal magnetic flux Φs of the insulating transformer for reset can be increased, the electromotive voltage level by the external magnetic flux Φo of the main circuit current can be suppressed, and the S / N ratio of the signal can be increased. .

  In addition, the winding diameter of the primary coil pattern 14b and the secondary coil patterns 17b and 24b of the reset insulating transformer can be reduced, and the interval between the primary coil pattern 14b and the secondary coil pattern 17b can be reduced. be able to. For this reason, while increasing the coupling coefficient between the primary coil pattern 14b and the secondary coil pattern 17b of the reset insulating transformer, the influence of noise due to the external magnetic flux Φo can be reduced, and the S / N ratio is improved. Can do.

7 and 8 are cross-sectional views illustrating a method of manufacturing an air core type insulated transformer according to the third embodiment of the present invention.
In FIG. 7A, by selectively injecting impurities such as As, P, and B into the semiconductor substrate 51, the extraction diffusion layer 52 for extracting from the center of the primary coil pattern 55a is formed on the semiconductor substrate. 51. The material of the semiconductor substrate 51 can be selected from, for example, Si, Ge, SiGe, SiC, SiSn, PbS, GaAs, InP, GaP, GaN, or ZnSe.

Next, as shown in FIG. 7B, an insulating layer 53 is formed on the semiconductor substrate 51 on which the extraction diffusion layer 52 is formed by a method such as plasma CVD. As the material of the insulating layer 53, for example, a silicon oxide film or a silicon nitride film can be used.
Next, as shown in FIG. 7C, by using a photolithography technique, the resist pattern 54 provided with the opening 54a corresponding to the lead-out portion from the center of the primary coil pattern 55a is formed into the insulating layer 53. Form on top.

Next, as shown in FIG. 7D, the insulating layer 53 is etched using the resist pattern 54 in which the opening 54a is formed as a mask, so that the opening corresponding to the lead-out portion from the center of the primary coil pattern 55a. A portion 53 a is formed in the insulating layer 53.
Next, as shown in FIG. 7E, the resist pattern 54 is peeled off from the insulating layer 53 with chemicals.
Next, as shown in FIG. 7F, a conductive film 55 is formed on the insulating layer 53 by a method such as sputtering or vapor deposition. In addition, as a material of the electrically conductive film 55, metals, such as Al and Cu, can be used.

Next, as shown in FIG. 7G, a resist pattern 56 corresponding to the primary coil pattern 55a is formed by using a photolithography technique.
Next, as illustrated in FIG. 7H, the conductive coil 55 is etched using the resist pattern 56 as a mask, thereby forming a primary coil pattern 55 a on the insulating layer 53.
Next, as shown in FIG. 7I, the resist pattern 56 is peeled off from the primary coil pattern 55a with a chemical.

Next, as shown in FIG. 7J, a planarizing film 57 is formed on the insulating layer 53 on which the primary coil pattern 55a is formed by a method such as plasma CVD. As a material of the planarizing film 57, for example, a silicon oxide film or a silicon nitride film can be used.
Next, as shown in FIG. 7 (k), the planarization film 57 is planarized by a method such as oblique etching or CMP (Chemical Mechanical Polishing), and unevenness on the surface of the planarization layer 57 is removed.
Next, as shown in FIG. 7L, the resist pattern 58 provided with the opening 58a corresponding to the wiring extraction portion at the outer end of the secondary coil pattern 60a is flattened by using a photolithography technique. Formed on the film 57.

Next, as shown in FIG. 8A, the planarizing film 57 is etched using the resist pattern 58 provided with the opening 58a as a mask, thereby corresponding to the wiring extraction portion at the outer end of the secondary coil pattern 60a. The opening 57a thus formed is formed in the planarizing film 57.
Next, as shown in FIG. 8B, the resist pattern 58 is peeled off from the planarizing film 57 by chemicals.

Next, as illustrated in FIG. 8C, a separation layer 59 of the primary coil pattern 55 a and the secondary coil pattern 60 a is formed on the planarizing film 57. As a method for forming the separation layer 59, a method of applying a polyimide layer on the planarizing film 57 can be used.
Next, as shown in FIG. 8D, a conductive film 60 is formed on the separation layer 59 by a method such as sputtering or vapor deposition. In addition, as a material of the electrically conductive film 60, metals, such as Al and Cu, can be used.

Next, as shown in FIG. 8E, a resist pattern 61 corresponding to the secondary coil pattern 60a is formed by using a photolithography technique.
Next, as shown in FIG. 8 (f), the secondary coil pattern 60 a is formed on the separation layer 59 by etching the conductive film 60 using the resist pattern 61 as a mask.
Next, as shown in FIG. 8G, the resist pattern 61 is peeled off from the secondary coil pattern 60a with a chemical.

Next, as shown in FIG. 8H, a protective film 62 is formed on the separation layer 59 on which the secondary coil pattern 60a is formed by a method such as plasma CVD. As the material of the protective film 62, for example, a silicon oxide film or a silicon nitride film can be used. Then, by patterning the protective film 62 using a photolithography technique and an etching technique, the end portion and the center portion of the secondary coil pattern 60a are exposed.
Thereby, the secondary coil pattern 60a can be laminated on the primary coil pattern 55a by the fine processing technique, and the winding diameters of the primary coil pattern 55a and the secondary coil pattern 60a can be reduced. The interval between the primary coil pattern 55a and the secondary coil pattern 60a can be reduced.

FIG. 9 is a cross-sectional view showing a schematic configuration of an air-core type insulated transformer according to the fourth embodiment of the present invention.
In FIG. 9, substrates 131 and 151 are provided in the insulating transformer for setting and the insulating transformer for resetting. A lead wiring layer 132 is embedded in the substrate 131, and a reset secondary coil second winding pattern 134 is formed on the substrate 131. The reset secondary coil second winding pattern 134 is connected to the lead-out wiring layer 132 via the lead-out portion 133. A flattening film 135 is formed on the reset secondary coil second winding pattern 134, and a set secondary coil first winding pattern 139 is formed on the flattening film 135 via an insulating layer 136. Is formed.

  The set secondary coil pattern first winding 139 is connected to the lead-out wiring layer 137 via the lead-out portion 138. A flattening film 140 is formed on the set secondary coil pattern first winding 139, and a set primary coil pattern 142 is formed on the flattening film 140 via the insulating layer 141. The primary coil pattern 142 for use is covered with a protective film 143.

  On the other hand, a lead-out wiring layer 152 is embedded in the substrate 151, and a set secondary coil second winding pattern 154 is formed on the substrate 151. The set secondary coil second winding pattern 154 is connected to the lead-out wiring layer 152 via the lead-out portion 153. A flattening film 155 is formed on the set secondary coil second winding pattern 154, and a reset secondary coil first winding pattern 159 is formed on the flattening film 155 via an insulating layer 156. Is formed.

  The reset secondary coil first winding pattern 159 is connected to the lead wiring layer 157 via the lead portion 158. A flattening film 160 is formed on the reset secondary coil first winding pattern 159, and a reset primary coil pattern 162 is formed on the flattening film 160 via an insulating layer 161. The primary coil pattern 162 for use is covered with a protective film 163.

  As the substrates 131 and 151, for example, the semiconductor substrates 131 and 151, the lead-out wiring layers 132 and 152, for example, a high-concentration impurity diffusion layer, and as the lead-out wiring layers 137 and 157, for example, an Al wiring layer, flat For example, a silicon oxide film, a protective film 143, 163, for example, a silicon nitride film, and an insulating layer 141, 161, for example, a polyimide film can be used as the insulating films 135, 140, 155, 160 and the insulating layers 136, 156. Can be used.

  Here, in the set insulating transformer, the set secondary coil first winding pattern 139 and the set secondary coil second winding pattern 154 cancel each other the electromotive voltage caused by the external magnetic flux, and the set secondary coil. The coil pattern first winding pattern 139 and the set secondary coil second winding pattern 154 can be configured to reinforce the electromotive voltage caused by the signal magnetic flux interlinking. Further, in the reset insulating transformer, the reset secondary coil second winding pattern 134 and the reset secondary coil first winding pattern 159 cancel each other the electromotive voltage caused by the external magnetic flux, and the reset secondary coil. The second winding pattern 134 and the resetting secondary coil first winding pattern 159 can be configured to reinforce the electromotive voltage caused by the signal magnetic flux interlinking.

  Further, in the setting insulating transformer and the reset insulating transformer, the winding directions of the setting secondary coil first winding pattern 139 and the resetting secondary coil second winding pattern 134 are different from each other. The winding directions of the two-winding pattern 154 and the resetting secondary coil first winding pattern 159 may be different from each other.

  For example, the setting primary coil pattern 142 and the setting secondary coil first winding pattern 139 set the winding direction clockwise, and the setting secondary coil second winding pattern 154 counterclockwise the winding direction. And the set secondary coil first winding pattern 139 and the set secondary coil second winding pattern 154 can be arranged close to each other. Further, the end of the setting secondary coil first winding pattern 139 is connected to the starting end of the setting secondary coil second winding pattern 154, or the starting end of the setting secondary coil first winding pattern 139 is set. The secondary coil can be connected to the end of the second winding pattern 154.

  The reset primary coil pattern 162 and the reset secondary coil first winding pattern 159 set the winding direction clockwise, and the reset secondary coil second winding pattern 134 counterclockwise. The reset secondary coil second winding pattern 134 and the reset secondary coil first winding pattern 159 can be arranged close to each other. Further, the end of the reset secondary coil first winding pattern 159 is connected to the start of the reset secondary coil second winding pattern 134 or the start of the reset secondary coil second winding pattern 134 is reset. The secondary coil can be connected to the end of the second winding pattern 154.

FIG. 10A is a diagram showing the state of linkage of magnetic flux when the transmission coil for setting the air-core insulated transformer of FIG. 9 is operated, and FIG. 10B is for resetting the air-core insulated transformer of FIG. It is a figure which shows the linkage state of the magnetic flux at the time of transmission coil operation | movement.
In FIG. 10A, the external magnetic flux Φo is generated by the setting secondary coil first winding pattern 139, the second winding pattern 154, the resetting secondary coil second winding pattern 134, and the second winding pattern 159. In both cases, they are linked evenly from the same direction. On the other hand, the signal magnetic flux Φs1 formed by the signal current flowing in the setting primary coil pattern 142 is formed so as to circulate around the axis of the setting primary coil pattern 142. The set secondary coil first winding pattern 139 and the reset secondary coil second winding pattern 134, which are arranged on the same axis, are mostly interlinked, and the set secondary coil second winding pattern 154 and reset. A part of the secondary coil first winding pattern 159 is interlinked. Therefore, the electromotive voltage level due to the signal magnetic flux Φs1 can be increased, the electromotive voltage level due to the external magnetic flux Φo of the main circuit current can be suppressed, and the S / N ratio of the signal can be increased.

  In addition, it is possible to reduce the winding diameters of the primary coil pattern 142 for setting and the primary winding pattern 139 and the secondary winding pattern 154 for the secondary coil for setting, and the primary coil pattern 142 for setting and the set The distance from the secondary coil first winding pattern 139 can be reduced. For this reason, while increasing the coupling coefficient between the primary coil pattern 142 for setting and the first winding pattern 139 for secondary coil for setting, the influence of noise due to the external magnetic flux Φo can be reduced, and the S / N ratio can be reduced. Can be improved.

  In FIG. 10B, the external magnetic flux Φo is applied to the setting secondary coil first winding pattern 139, the second winding pattern 154, the resetting secondary coil second winding pattern 134, and the second winding pattern 159. In both cases, they are linked evenly from the same direction. On the other hand, the signal magnetic flux Φs2 formed by the signal current flowing in the reset primary coil pattern second winding pattern 162 is formed so as to circulate around the axis of the reset primary coil pattern 162. The setting secondary coil second winding pattern 154 and the resetting secondary coil first winding pattern 159, which are arranged on the same axis as the coil pattern 162, are mostly linked to each other, and the setting secondary coil first winding. A part of the pattern 139 and the reset secondary coil second winding pattern 134 are linked. Therefore, the electromotive voltage level due to the signal magnetic flux Φs2 can be increased, the electromotive voltage level due to the external magnetic flux Φo of the main circuit current can be suppressed, and the S / N ratio of the signal can be increased.

  Further, it is possible to reduce the winding diameters of the primary coil pattern for reset 162, the secondary coil pattern for reset secondary coil 134, and the second coil pattern 159, and the primary coil pattern for reset 162 and reset. The space | interval with the secondary coil 1st winding pattern 159 for use can be made small. For this reason, while increasing the coupling coefficient between the reset primary coil pattern 162 and the reset secondary coil first winding pattern 159, the influence of noise due to the external magnetic flux Φo can be reduced, and the S / N ratio can be reduced. Can be improved.

  Even when a set insulating transformer and a reset insulating transformer are used for insulating transmission of the pulse signal, the setting secondary coil first winding pattern 139, the second winding pattern 154, and the resetting secondary coil are used. While making it possible to cancel the electromotive voltage caused by the external magnetic flux interlinking with the second winding pattern 134 and the second winding pattern 159, the secondary coil for setting is placed on the secondary winding pattern 134 for reset. The first winding pattern 139 and the primary coil pattern for setting 142 are sequentially laminated, and the secondary coil for resetting first coil pattern 159 and the primary coil pattern for resetting are set on the secondary coil for winding second coil pattern 154 for setting. 162 can be sequentially stacked.

  Therefore, the secondary coil first winding pattern 139, the second winding pattern 154 and the resetting secondary coil 139 are set as noise while the increase in the mounting area occupied by the setting insulating transformer and the reset insulating transformer is suppressed. The secondary coil second winding pattern 134 and the second winding pattern 159 for use can be reduced and the risk of causing a malfunction can be avoided, and the primary coil pattern 142 for setting and resetting can be avoided. The average current flowing through the primary coil pattern 162 can be made equal to or less than the allowable DC current, and the fusing of the setting primary coil pattern 142 and the resetting primary coil pattern 162 due to Joule heat can be prevented.

  Further, the winding directions of the setting secondary coil first winding pattern 139 and the resetting secondary coil second winding pattern 134 are different from each other, and the setting secondary coil second winding pattern 154 and the resetting secondary coil By configuring the winding directions of the first winding pattern 159 to be different from each other, an electromotive voltage generated in the setting secondary coil first winding pattern 139 and a reset secondary coil second winding pattern 134 are generated. The electromotive voltages can be reversed from each other, and the electromotive voltage generated in the setting secondary coil second winding pattern 154 and the electromotive voltage generated in the reset secondary coil first winding pattern 159 can be mutually reduced. It becomes possible to make it into a reverse phase.

  Therefore, the setting secondary coil first winding pattern 139 and the setting primary coil pattern 142 are sequentially laminated on the resetting secondary coil second winding pattern 134 and the setting secondary coil second winding. Since the reset secondary coil first winding pattern 159 and the reset primary coil pattern 162 are sequentially laminated on the pattern 154, the reset secondary coil second winding pattern 134 is also transmitted by signal transmission on the set side. Even when the signal is transmitted in the opposite phase and the signal is transmitted in the opposite phase to the set secondary coil second winding pattern 154 by the signal transmission on the reset side, the timing of the signal transmission can be shifted. . As a result, by detecting the timing of these signal transmissions, the signal is transmitted in the opposite phase to the reset secondary coil second winding pattern 134 by the signal transmission on the set side, or the signal transmission on the reset side. Thus, it is possible to prevent the signal transmission to the secondary coil second winding pattern 154 for setting in reverse phase.

FIG. 11 is a block diagram showing a schematic configuration of a signal transmission circuit using the air-core type insulating transformer of FIG.
In FIG. 11, the control signal S 21 is input to one input terminal of the exclusive OR circuit 302 via the delay element 301, and the control signal S 21 is directly input to the other input terminal of the exclusive OR circuit 302. Entered. The output from the exclusive OR circuit 302 is input to one input terminal of the AND circuit 304, and the control signal S 21 is directly input to the other input terminal of the AND circuit 304. Further, the output from the exclusive OR circuit 302 is input to one input terminal of the AND circuit 305, and the control signal S 21 is input to the other input terminal of the AND circuit 304 via the inverter 303. Entered.

  The set insulating transformer 310 is provided with the set primary coil pattern 142, the set secondary coil first winding pattern 139, and the second winding pattern 154 shown in FIG. Are provided with a reset primary coil pattern 162, a reset secondary coil pattern first winding 134, and a second winding 159 shown in FIG.

The drain of the N-channel field effect transistor 307 is connected to the terminal end of the primary coil pattern 142 for setting of the insulating transformer for setting 310 via the resistor 306, and the starting end of the primary coil pattern for setting 142 is the power supply voltage. Connected to Vcc1.
The drain of the N-channel field effect transistor 309 is connected to the end of the reset primary coil pattern 162 via the resistor 308, and the start of the reset primary coil pattern 162 is connected to the power supply voltage Vcc1. .

  The output of the AND circuit 304 is connected to the gate of the N-channel field effect transistor 308, and the output of the AND circuit 305 is connected to the gate of the N-channel field effect transistor 309. The terminal ends of the set secondary coil first winding pattern 139 and the second winding pattern 154 are connected to each other via a resistor 311, and the set secondary coil first winding pattern 139 and the second winding The start ends of the pattern 154 are directly connected to each other, the reset secondary coil second winding pattern 134 and the end of the second winding pattern 159 are connected to each other via a resistor 319, and the setting secondary coil first winding The starting ends of the line pattern 134 and the second winding pattern 159 are directly connected to each other. One end of the resistor 312 is connected to the power supply voltage Vcc2, and the resistors 312 and 313 are connected in series so that the potential at the connection point of the resistors 312 and 313 is Vth.

The non-inverting input terminals of the comparators 315 and 316 are fixed to the potential of Vth, and the inverting input terminal of the comparator 315 is connected to the starting end of the setting secondary coil first winding pattern 139 and the inverting input of the comparator 316 is input. The terminal is connected to the starting end of the reset secondary coil first winding pattern 159.
The output of the comparator 315 is connected to the D terminal of the flip-flop 319 via the mono multivibrator 317 and also connected to the clock terminal of the flip-flop 320, and the output of the comparator 316 is flip-flops via the mono multivibrator 318. It is connected to the D terminal of 320 and to the clock terminal of the flip-flop 319. The output terminal Q of the flip-flop 319 is connected to the clock terminal of the flip-flop 322, the output terminal Q of the flip-flop 320 is connected to the input terminal of the mono multivibrator 321, and the output terminal of the mono multivibrator 321 is the flip-flop 319. , 320, and 322, and the D terminal of the flip-flop 322 is connected to the power supply voltage Vcc2.

FIG. 12 is a diagram showing signal waveforms at various parts of the signal transmission circuit of FIG.
In FIG. 12, a control signal S21 that instructs conduction and non-conduction of the switching elements SWD and SWU in FIG. 1 and a signal obtained by delaying the control signal S21 by the delay element 301 are input to the exclusive OR circuit 302. The exclusive OR circuit 302 obtains the exclusive OR, whereby the edge signal S22-1 synchronized with the edge from “0” to “1” of the control signal S21 and the edge from “1” to “0” The edge signal S22-2 synchronized with is extracted. These edge signals S22-1 and S22-2 are input to the AND circuits 304 and 305, and the AND circuit 304 ANDs the control signal S21 to generate a rising edge pulse S23. At the same time, the logical product circuit 305 performs a logical product with the inverted signal of the control signal S21, so that the logical product circuit 305 generates the falling edge pulse S24.

  The rising edge pulse S23 generated by the AND circuit 304 is input to the gate of the N-channel field effect transistor 307 (FIG. 12B), and the falling edge generated by the AND circuit 305 is used. The pulse S24 is input to the gate of the N-channel field effect transistor 309 (FIG. 12 (c)), and the primary coil pattern 142 for setting and resetting of the insulating transformer 310 for setting are performed when the control signal S21 rises and falls. An operation in which the timings of the pulse currents flowing through the reset primary coil pattern 162 of the insulating transformer 318 are different from each other can be performed.

At time t1, when the rising edge pulse S23 is input to the gate of the N-channel field effect transistor 307, a current flows through the set primary coil pattern 142 via the N-channel field effect transistor 307, The primary coil pattern 142 is excited.
When the set primary coil pattern 142 is excited, as shown in FIG. 10A, the set secondary coil first winding pattern 139, the second winding pattern 154, and the resetting secondary coil first The external magnetic flux Φo is linked from both the two winding pattern 134 and the second winding pattern 159 almost equally from the same direction, and the signal magnetic flux Φs1 is set to the set secondary coil first winding pattern 139 and the resetting coil. Most of the secondary coil second winding pattern 134 is linked, and part of the setting secondary coil second winding pattern 154 and the resetting secondary coil first winding pattern 159 is linked.

  As a result, an electromotive voltage generated by the external magnetic flux Φo interlinked with the setting secondary coil first winding pattern 139, the second winding pattern 154, the resetting secondary coil second winding pattern 134, and the second winding pattern 159. While canceling each other, a large electromotive voltage having a level opposite to each other is generated in the setting secondary coil first winding pattern 139 and the resetting secondary coil second winding pattern 134 (FIG. 12D). 12 (g)), an electromotive voltage having a small phase opposite to each other is generated in the setting secondary coil second winding pattern 154 and the resetting secondary coil first winding pattern 159 (FIG. 12E). 12 (f)).

  At time t1, the electromotive voltages generated in the set secondary coil first winding pattern 139 and second winding pattern 154 are applied to the non-inverting input terminal of the comparator 315 while strengthening each other, and the comparator 315 outputs a pulse S25. Is output (FIG. 12 (h)), and at time t2, the electromotive voltages generated in the reset secondary coil second winding pattern 134 and the second winding pattern 159 strengthen each other while the comparator 316 is not inverted. Applied to the input terminal, a pulse S26 is output from the comparator 316 (FIG. 12 (i)).

  At time t1, when the pulse S25 is output from the comparator 315, the pulse S25 is input to the mono multivibrator 317 and input to the clock terminal of the flip-flop 320, and the pulse S27 is output from the mono multivibrator 317. (FIG. 12 (j)). The pulse S27 output from the mono multivibrator 317 is input to the D terminal of the flip-flop 319.

  Further, when the pulse S26 is output from the comparator 316 at time t2, the pulse S26 is input to the mono multivibrator 318 and also to the clock terminal of the flip-flop 319, and the pulse S28 is output from the mono multivibrator 318. (FIG. 12 (k)). The pulse S28 output from the mono multivibrator 318 is input to the D terminal of the flip-flop 320.

  Here, when the pulse S27 output from the mono multivibrator 317 is input to the D terminal of the flip-flop 319 at time t1, the pulse S26 from the comparator 316 is not input to the clock terminal of the flip-flop 319. The pulse S27 output from the multivibrator 317 is not taken into the flip-flop 319, and the pulse S25 from the comparator 315 can be invalidated.

  At time t2, the pulse S26 from the comparator 316 is input to the clock terminal of the flip-flop 319, and the pulse S27 output from the mono multivibrator 317 is taken into the flip-flop 319, whereby the output of the flip-flop 319 is output. It changes from the low level to the high level (FIG. 12 (l)). When the output of the flip-flop 319 changes from the low level to the high level, the output of the flip-flop 322 changes from the low level to the high level with the change, and the rising edge of the control signal S21 on the transmission side is restored. The control signal S29 can be generated on the receiving side (FIG. 12 (o)).

  At time t3, the secondary coil first winding pattern 139 for setting, the second winding pattern 154, and the resetting coil are reset by the main circuit current flowing through the main terminals and bonding wires of the intelligent power module for the buck-boost converter in FIG. The external magnetic flux Φo is linked to the secondary coil second winding pattern 134 and the second winding pattern 159 (FIG. 12A).

  When the external magnetic flux Φo is linked to the setting secondary coil first winding pattern 139, the second winding pattern 154, the resetting secondary coil second winding pattern 134, and the second winding pattern 159, the set The secondary coil first winding pattern 139, the second winding pattern 154, the resetting secondary coil second winding pattern 134, and the second winding pattern 159 generate an electromotive voltage due to the external magnetic flux Φo (see FIG. 12 (d), FIG. 12 (e), FIG. 12 (f), and FIG. 12 (g)), since these electromotive voltages are canceled out, the pulses S25 and S26 are not output from the comparators 315 and 316. (FIG. 12 (h), FIG. 12 (i)).

When the falling edge pulse S24 is input to the gate of the N-channel field effect transistor 309 at time t4, a current flows through the reset primary coil pattern 162 via the N-channel field effect transistor 309, and the reset is performed. The primary coil pattern 162 is excited.
When the reset primary coil pattern 162 is excited, as shown in FIG. 10B, the set secondary coil first winding pattern 139, the second winding pattern 154, and the reset secondary coil Both the two-winding pattern 134 and the second winding pattern 159 are linked with the external magnetic flux Φo almost equally from the same direction, while the signal magnetic flux Φs2 is set to the secondary coil second winding pattern 154 for setting and the resetting. Most of the secondary coil first winding pattern 159 is interlinked, and part of the setting secondary coil first winding pattern 139 and the resetting secondary coil second winding pattern 134 is interlinked.

  As a result, an electromotive voltage generated by the external magnetic flux Φo interlinked with the setting secondary coil first winding pattern 139, the second winding pattern 154, the resetting secondary coil second winding pattern 134, and the second winding pattern 159. While canceling each other, a large electromotive voltage with a phase opposite to each other is generated in the setting secondary coil second winding pattern 154 and the resetting secondary coil first winding pattern 159 (FIG. 12E). 12 (f)), an electromotive voltage having a small phase opposite to each other is generated in the setting secondary coil first winding pattern 139 and the resetting secondary coil second winding pattern 134 (FIG. 12D). 12 (g)).

  At time t4, the electromotive voltages generated in the reset secondary coil second winding pattern 134 and the second winding pattern 159 are applied to the non-inverting input terminal of the comparator 316 while strengthening each other, and the comparator 316 outputs a pulse S26. Is output (FIG. 12 (h)), and at time t5, the electromotive voltages generated in the setting secondary coil first winding pattern 139 and the second winding pattern 154 strengthen each other and the comparator 315 is non-inverted. Applied to the input terminal, the comparator 315 outputs a pulse S25 (FIG. 12 (i)).

  At time t4, when the pulse S26 is output from the comparator 316, the pulse S26 is input to the mono multivibrator 318 and also to the clock terminal of the flip-flop 319, and the pulse S28 is output from the mono multivibrator 318. (FIG. 12 (k)). The pulse S28 output from the mono multivibrator 318 is input to the D terminal of the flip-flop 320.

  At time t5, when the pulse S25 is output from the comparator 315, the pulse S25 is input to the mono multivibrator 317 and also input to the clock terminal of the flip-flop 320, and the pulse S27 is output from the mono multivibrator 317. (FIG. 12 (j)). The pulse S27 output from the mono multivibrator 317 is input to the D terminal of the flip-flop 319.

  Here, when the pulse S28 output from the mono multivibrator 318 is input to the D terminal of the flip-flop 320 at time t4, the pulse S25 from the comparator 315 is not input to the clock terminal of the flip-flop 320. The pulse S28 output from the multivibrator 318 is not taken into the flip-flop 320, and the pulse S26 from the comparator 316 can be invalidated.

  At time t5, the pulse S25 from the comparator 315 is input to the clock terminal of the flip-flop 320, and the pulse S28 output from the mono multivibrator 318 is taken into the flip-flop 320, whereby the output of the flip-flop 320 is output. It changes from the low level to the high level (FIG. 12 (l)). When the output of the flip-flop 320 changes from low level to high level, a clear signal is output from the mono multivibrator 321 to the flip-flops 319, 320, and 322 (FIG. 12 (n)). When the clear signal is output from the mono multivibrator 321 to the flip-flops 319, 320, and 322, the outputs of the flip-flops 319, 320, and 322 change from the low level to the high level (FIG. 12 (l), FIG. 12). (M), FIG. 12 (o)), the control signal S29 in which the falling edge of the control signal S21 on the transmission side is restored can be generated on the reception side (FIG. 12 (o)).

  At time t6, the set secondary coil first winding pattern 139, the second winding pattern 154, and the resetting coil are driven by the main circuit current flowing through the main terminals and bonding wires of the intelligent power module for the buck-boost converter in FIG. The external magnetic flux Φo is linked to the secondary coil second winding pattern 134 and the second winding pattern 159 (FIG. 12A).

  When the external magnetic flux Φo is linked to the setting secondary coil first winding pattern 139, the second winding pattern 154, the resetting secondary coil second winding pattern 134, and the second winding pattern 159, the set The secondary coil first winding pattern 139, the second winding pattern 154, the resetting secondary coil second winding pattern 134, and the second winding pattern 159 generate an electromotive voltage due to the external magnetic flux Φo (see FIG. 12 (d), FIG. 12 (e), FIG. 12 (f), and FIG. 12 (g)), since these electromotive voltages are canceled out, the pulses S25 and S26 are not output from the comparators 315 and 316. (FIG. 12 (h), FIG. 12 (i)).

FIG. 13: is sectional drawing which shows the mounting state of the intelligent power module for buck-boost converters concerning 3rd Embodiment of this invention.
In FIG. 13, an IGBT chip 73 a and an FWD chip 73 b are mounted on a copper base 71 that plays a role of heat dissipation via an insulating ceramic substrate 72. The IGBT chip 73a and the FWD chip 73b are connected to each other via bonding wires 74a to 74c, and are connected to a main terminal 77 that extracts a main circuit current. Further, a circuit board 75 for performing gate drive and monitoring of the IGBT is disposed on the IGBT chip 73a and the FWD chip 73b, and the IGBT chip 73a, the FWD chip 73b and the circuit board 75 are sealed with a mold resin 76. . Here, the IGBT chip 73a and the FWD chip 73b can constitute a switching element for energizing and interrupting the current flowing into the load, and the switching elements are connected in series so as to operate for the upper arm and the lower arm. be able to. Further, the circuit board 75 can be provided with a control circuit that generates a control signal that instructs conduction and non-conduction of the switching element.

  The main circuit current flows not only to the main terminal 77 but also to the bonding wires 74a to 74c that connect the main terminal 77 to the IGBT chip 73a and the FWD chip 73b, but the bonding wires 74a to 74c are in the immediate vicinity of the circuit board 75. Therefore, the influence of the magnetic field generated by the main circuit current flowing through the bonding wires 74a to 74c is greater. The main circuit current is about 250 A at the maximum during normal operation, but may flow at 900 A or more, for example, at the time of starting or a load after idling.

  Here, an air core type insulation transformer is inserted between the control circuit side grounded to the vehicle body casing and the upper arm side and the lower arm side which become high pressure, respectively. Signals are exchanged using a transformer while being electrically insulated from the upper arm side and the lower arm side. The secondary winding of the air-core type insulated transformer cancels the electromotive voltage caused by the external magnetic flux interlinking the secondary winding, and strengthens the electromotive voltage caused by the signal magnetic flux interlinking the secondary winding. A plurality of configured windings can be provided.

  As a result, even when a large current of the main circuit flows through the bonding wires 74a to 74c that electrically connect the IGBT chip 73a, the FWD chip 73b, and the main terminal 77, the secondary winding on the receiving side of the air-core insulating transformer. The signal level at the output voltage of the line can be made sufficiently higher than the noise level due to the main circuit current, and even when an air-core type insulating transformer is used, signal transmission without malfunction is possible.

  In addition, as an air-core type insulation transformer, a set insulation transformer that transmits the rising side of the pulse signal and a reset insulation transformer that transmits the falling side of the pulse signal are provided, and the rising edge and falling edge of the pulse signal are provided. The corresponding pulse current is generated on the primary side, and the pulse current corresponding to the rising edge and the falling edge of the pulse signal is transmitted through the set insulating transformer and the reset insulating transformer, respectively. The pulse signal can be restored.

  As a result, even when the pulse width of the pulse signal is long, it is possible to shorten the period during which current flows through the primary winding and the secondary winding. For this reason, even when the conductor cross-sectional areas of the primary winding and the secondary winding are reduced, the average current flowing through the primary winding and the secondary winding can be reduced to an allowable DC current or less, and Joule heat It is possible to prevent the primary winding and the secondary winding from being melted due to the above.

1 is a block diagram showing a schematic configuration of an intelligent power module for a buck-boost converter to which an air core type insulating transformer according to an embodiment of the present invention is applied. 1 is a block diagram showing a schematic configuration of a signal transmission circuit using an air-core type insulated transformer according to a first embodiment of the present invention. It is an external view which shows schematic structure of the air core type | mold insulation transformer applied to the signal transmission circuit of FIG. It is a figure which shows the linkage state of the external magnetic flux in the air core type | mold insulation transformer of FIG. It is a figure which shows the linkage state of the signal magnetic flux in the air core type | mold insulation transformer of FIG. 6A1 is a cross-sectional view illustrating a schematic configuration of the insulating transformer for setting according to the second embodiment of the present invention, and FIG. 6A2 illustrates a schematic configuration of the insulating transformer for setting of FIG. 6A1. FIG. 6B1 is a cross-sectional view showing a schematic configuration of the reset insulating transformer according to the second embodiment of the present invention, and FIG. 6B2 is a schematic diagram of the reset insulating transformer in FIG. 6B1. It is a top view which shows a structure. It is sectional drawing which shows the manufacturing method of the air core type | mold insulation transformer which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the air core type | mold insulation transformer which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows schematic structure of the air-core type insulation transformer which concerns on 4th Embodiment of this invention. FIG. 10A is a diagram showing the state of linkage of magnetic flux when the transmission coil for setting the air-core insulated transformer of FIG. 9 is operated, and FIG. 10B is for resetting the air-core insulated transformer of FIG. It is a figure which shows the linkage state of the magnetic flux at the time of transmission coil operation | movement. FIG. 10 is a block diagram illustrating a schematic configuration of a signal transmission circuit using the air-core type insulating transformer of FIG. 9. It is a figure which shows the signal waveform of each part of the signal transmission circuit of FIG. It is sectional drawing which shows the mounting state of the intelligent power module for buck-boost converters concerning 3rd Embodiment of this invention. It is a block diagram which shows schematic structure of the vehicle drive system using the conventional buck-boost converter. It is a block diagram which shows schematic structure of the buck-boost converter of FIG. It is a figure which shows the waveform of the electric current which flows into the reactor of FIG. 15 at the time of pressure | voltage rise operation. It is a top view which shows schematic structure of the conventional isolation transformer for signal transmission.

Explanation of symbols

1 Control Circuit 2 Upper Arm 3 Lower Arm 4 CPU
5, 6 IGBT
7, 8 Gate driver IC
TU1 to TU3, TD1 to TD3 Air-core insulating transformer DU1, DU2, DD1, DD2 Diode RU1, RU2, RD1, RD2 Resistor CU, CD PWM converter KU1, KD1 conversion circuit PU1, PD1 Restoration circuit M11 Primary winding M21 Secondary winding first winding M22 Secondary winding second winding 11a, 21a, 11b, 21b, 131, 151 Substrate 12a, 22a, 12b, 22b, 132, 152, 137, 157 Lead-out wiring layer 13a , 23a, 13b, 23b, 133, 153, 138, 158 Lead-out part 14a, 14b, 55a, 134, 154 Primary coil pattern 15a, 15b, 57, 135, 155, 140, 160 Planarization film 16a, 16b, 53 136, 156, 141, 161 Insulating layer 17a, 24a, 17b, 4b, 60a Secondary coil pattern 18a, 25a, 18b, 25b, 62, 143, 163 Protective film 134 Secondary coil for winding second winding pattern 159 Secondary coil for resetting First winding pattern 139 Secondary coil for setting First winding pattern 154 Secondary coil for setting Second winding pattern 142 Primary coil pattern for setting 162 Primary coil pattern for reset 51 Semiconductor substrate 52 Diffusion layer 54, 56, 58, 61 Resist pattern 54a, 57a, 58a Opening 55, 60 Conductive film 59 Separation layer 71 Copper base 72 Insulating ceramic substrate 73a IGBT chip 73b FWD chip 74a-74c Bonding wire 75 Circuit board 76 Mold resin 77 Main terminal 201, 301 Delay element 202, 302 Exclusive logic Sum circuit 203, 303 Inverter 204, 205, 304, 305 AND circuit 206, 208, 211, 212, 213, 219, 306, 308, 311, 312, 313, 319 Resistor 207, 209, 307, 309 N-channel electric field Effect transistor 210, 310 Set isolation transformer 211, 311 Reset isolation transformer 215, 216, 315, 316 Comparator 217, 319, 320, 322 Flip-flop 317, 318, 321 Mono multivibrator

Claims (5)

A set isolation transformer that transmits the rising edge of the pulse signal;
With a reset isolation transformer that transmits the falling edge of the pulse signal,
The secondary winding of the set insulating transformer and the secondary winding of the reset insulating transformer cancel out the electromotive voltage caused by the external magnetic flux interlinking the secondary winding, and the secondary winding is interlinked. A plurality of windings configured to reinforce the electromotive voltage due to the signal magnetic flux is provided ,
The insulating transformer for setting is provided with a primary winding for setting, a first winding of a secondary winding for setting, and a second winding of a secondary winding for setting,
The insulating transformer for reset is provided with a primary winding for resetting, a first winding of a secondary winding for resetting, and a second winding of a secondary winding for resetting,
The primary winding for setting, the first winding of the secondary winding for setting, and the second winding of the secondary winding for resetting are coaxially arranged, and the primary winding for resetting An air-core type insulated transformer , wherein the first winding of the resetting secondary winding and the second winding of the setting secondary winding are coaxially arranged . The winding directions of the first winding of the resetting secondary winding and the second winding of the resetting secondary winding are different from each other, and the first winding of the resetting secondary winding and the setting 2 air-core type insulated transformer according to claim 1, characterized in that the winding direction of the second winding of the next winding different from each other. A conversion circuit that generates a pulse current according to the rising edge and falling edge of the pulse signal;
An insulating transformer for setting that transmits a pulse current corresponding to a rising edge of the pulse signal;
An insulating transformer for reset that transmits a pulse current according to a falling edge of the pulse signal;
A restoration circuit that restores the pulse signal based on the level of the voltage pulse generated in the secondary winding of the insulating transformer for set and the secondary winding of the insulating transformer for reset,
The secondary winding of the set insulating transformer and the secondary winding of the reset insulating transformer cancel out the electromotive voltage caused by the external magnetic flux interlinking the secondary winding, and the secondary winding is interlinked. A plurality of windings configured to reinforce the electromotive voltage due to the signal magnetic flux is provided ,
The insulating transformer for setting is provided with a primary winding for setting, a first winding of a secondary winding for setting, and a second winding of a secondary winding for setting,
The insulating transformer for reset is provided with a primary winding for resetting, a first winding of a secondary winding for resetting, and a second winding of a secondary winding for resetting,
The primary winding for setting, the first winding of the secondary winding for setting, and the second winding of the secondary winding for resetting are coaxially arranged, and the primary winding for resetting A signal transmission using an air-core type insulated transformer, wherein the first winding of the resetting secondary winding and the second winding of the setting secondary winding are coaxially arranged. circuit. And time the set side receives the voltage detected by the pre-Symbol Set for secondary winding reaches the set for judgment threshold level, the reset side receives the voltage detected by the secondary winding the reset is the reset determination threshold A comparison circuit for comparing the time of arrival;
The air core according to claim 3 , further comprising a determination circuit that validates the set-side reception voltage or the reset-side reception voltage that arrives at the set determination threshold or the reset determination threshold earlier. A signal transmission circuit using an insulated transformer. A switching element for energizing and interrupting the current flowing into the load;
A control circuit for generating a control signal instructing conduction and non-conduction of the switching element;
A drive circuit for driving a control terminal of the switching element based on the control signal;
An insulating transformer for setting that transmits a pulse current corresponding to the rising edge of the control signal to the drive circuit;
An insulation transformer for reset that transmits a pulse current corresponding to a falling edge of the control signal to the drive circuit side;
The secondary winding of the set insulating transformer and the secondary winding of the reset insulating transformer cancel out the electromotive voltage caused by the external magnetic flux interlinking the secondary winding, and the secondary winding is interlinked. A plurality of windings configured to reinforce the electromotive voltage due to the signal magnetic flux is provided ,
The insulating transformer for setting is provided with a primary winding for setting, a first winding of a secondary winding for setting, and a second winding of a secondary winding for setting,
The insulating transformer for reset is provided with a primary winding for resetting, a first winding of a secondary winding for resetting, and a second winding of a secondary winding for resetting,
The primary winding for setting, the first winding of the secondary winding for setting, and the second winding of the secondary winding for resetting are coaxially arranged, and the primary winding for resetting The power converter is characterized in that the first winding of the resetting secondary winding and the second winding of the setting secondary winding are arranged coaxially .

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