JP6702202B2 - Rotating electrical machine system - Google Patents

Description

  The present invention relates to a rotary electric machine system including a rotary electric machine and a power conversion device that converts direct current into alternating current and supplies the alternating current to the rotary electric machine.

  BACKGROUND ART Conventionally, as a rotary electric machine system that includes a rotary electric machine and a power conversion device that converts direct current into alternating current and supplies the alternating current to the rotary electric machine, for example, there is a rotary electric machine system disclosed in Patent Document 1 shown below.

  The rotary electric machine system of Patent Document 1 includes a brushless DC motor, one step-down converter circuit, and one voltage source inverter circuit. The brushless DC motor corresponds to a rotating electric machine. The step-down converter circuit and the voltage source inverter circuit correspond to the power converter.

  The brushless DC motor has one 3-phase winding. The step-down converter circuit is controlled so that the output current becomes a predetermined current, and steps down and outputs the direct current supplied from the direct current power supply. The voltage source inverter circuit converts the direct current supplied from the step-down converter circuit into a three-phase alternating current and supplies the three-phase winding. That is, the step-down converter circuit and the voltage-type inverter circuit function as a current-type inverter circuit, convert DC supplied from the DC power supply into three-phase AC, and supply the DC to the rotating electric machine. Therefore, even when the impedance of the three-phase winding is very small and it is difficult to control the current flowing by controlling the voltage supplied to the three-phase winding, the current flowing in the three-phase winding is appropriately adjusted. Can be controlled.

Japanese Patent No. 3278188

  By the way, in the rotary electric machine, the counter electromotive voltage also increases as the rotation speed increases. When the counter electromotive voltage of the rotating electric machine becomes high, the counter electromotive voltage is subtracted from the DC power supply voltage, so that the voltage applied to the three-phase winding becomes small. Even if the step-down converter circuit is not used, the voltage source inverter circuit allows the three-phase winding. You will be able to control the current flowing through the line.

  However, in the rotary electric machine system described above, the step-down converter circuit is always operated regardless of the magnitude of the back electromotive force. Therefore, the loss of the rotary electric machine system increases and the efficiency decreases.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a rotary electric machine system capable of suppressing loss and improving efficiency by performing appropriate control according to the situation. ..

A first aspect of the present invention made to solve the above problems is to provide a rotating electric machine having at least one multiphase winding, a DC power supply, and a DC power supply provided for each multiphase winding and supplied from the DC power supply. What is claimed is: 1. A rotary electric machine system comprising: a power conversion device that converts the AC power to be supplied to a rotary electric machine; and a control device that controls the power conversion device, wherein the power conversion device steps down the direct current supplied from a DC power supply. A step-down converter circuit, a voltage source inverter circuit that converts direct current supplied from the step-down converter circuit into alternating current and supplies the alternating-current electric machine, and a bypass switch connected between an input end and an output end of the step-down converter circuit. When the counter electromotive voltage of the rotating electric machine is less than the threshold voltage, the control device turns off the bypass switch, the output current of the step-down converter circuit becomes a predetermined current, and the step-down converter circuit is supplied with direct current (DC). The step-down converter circuit is controlled to step down the voltage, and the voltage-type inverter circuit controls the voltage-type inverter circuit to convert the direct current supplied from the step-down converter circuit to alternating current. In the above cases, the bypass switch is turned on, the operation of the step-down converter circuit is stopped, and the voltage source inverter circuit controls the voltage source inverter circuit so as to convert the direct current supplied from the DC power supply via the bypass switch to alternating current. Further, even if the back electromotive voltage of the rotating electric machine is less than the threshold voltage, if the voltage at the output end of the step-down converter circuit is higher than the voltage at the input end, the bypass switch is turned on .
In the rotating electric machine, the counter electromotive voltage also increases as the rotation speed increases. When the counter electromotive voltage of the rotating electric machine becomes high, the voltage applied to the multiphase winding becomes small, and the current flowing through the multiphase winding can be controlled by the voltage source inverter circuit without using the step-down converter circuit. According to this configuration, the power conversion device includes the bypass switch connected between the input end and the output end of the step-down converter circuit. When the counter electromotive voltage of the rotary electric machine is equal to or higher than the threshold voltage, the control device turns on the bypass switch to stop the operation of the step-down converter circuit. Then, the voltage source inverter circuit controls the voltage source inverter circuit so as to convert the direct current supplied from the direct current power source through the bypass switch into the alternating current. Therefore, AC can be supplied from the voltage source inverter circuit to the rotating electric machine without operating the step-down converter circuit. Therefore, it is possible to suppress the loss of the step-down converter circuit and improve the efficiency.
With this configuration, the control device turns on the bypass switch even when the back electromotive voltage of the rotating electric machine is lower than the threshold voltage and when the voltage at the output end of the step-down converter circuit is higher than the voltage at the input end. Put in a state. Therefore, even if the voltage at the output end of the step-down converter circuit becomes higher than the voltage at the input end due to the switching of the voltage source inverter circuit, a current flows from the output end of the step-down converter circuit to the input end via the bypass switch. be able to. Therefore, the voltage rise at the output end of the step-down converter circuit is suppressed, and damage to the step-down converter circuit and the voltage source inverter circuit can be prevented.

A second aspect of the present invention made to solve the above problem is to provide a rotating electric machine having at least one polyphase winding, a DC power supply, and a DC power supply provided for each polyphase winding and supplied from the DC power supply. What is claimed is: 1. A rotary electric machine system comprising: a power converter that converts the AC power to be supplied to a rotating electric machine; and a control device that controls the power converter, wherein the power converter steps down the DC supplied from a DC power supply. A step-down converter circuit, a voltage source inverter circuit that converts direct current supplied from the step-down converter circuit to alternating current and supplies the alternating-current electric machine, and a bypass switch connected between an input end and an output end of the step-down converter circuit. When the counter electromotive voltage of the rotating electric machine is less than the threshold voltage, the control device turns off the bypass switch, the output current of the step-down converter circuit becomes a predetermined current, and the step-down converter circuit is supplied with DC power. The step-down converter circuit is controlled to step down the voltage, and the voltage-type inverter circuit controls the voltage-type inverter circuit to convert the direct current supplied from the step-down converter circuit to alternating current. In the above cases, the bypass switch is turned on, the operation of the step-down converter circuit is stopped, and the voltage source inverter circuit controls the voltage source inverter circuit so as to convert the direct current supplied from the direct current power supply via the bypass switch to alternating current. At that time, the phase of the alternating current supplied from the voltage source inverter circuit to the rotary electric machine is adjusted.
In the rotating electric machine, the counter electromotive voltage also increases as the rotation speed increases. When the counter electromotive voltage of the rotating electric machine becomes high, the voltage applied to the multiphase winding becomes small, and the current flowing through the multiphase winding can be controlled by the voltage source inverter circuit without using the step-down converter circuit. According to this configuration, the power conversion device includes the bypass switch connected between the input end and the output end of the step-down converter circuit. When the counter electromotive voltage of the rotary electric machine is equal to or higher than the threshold voltage, the control device turns on the bypass switch to stop the operation of the step-down converter circuit. Then, the voltage source inverter circuit controls the voltage source inverter circuit so as to convert the direct current supplied from the direct current power source through the bypass switch into the alternating current. Therefore, AC can be supplied from the voltage source inverter circuit to the rotating electric machine without operating the step-down converter circuit. Therefore, it is possible to suppress the loss of the step-down converter circuit and improve the efficiency.
According to this configuration, when the counter electromotive voltage of the rotary electric machine is equal to or higher than the threshold voltage, the control device adjusts the phase of the alternating current supplied from the voltage source inverter circuit to the rotary electric machine. Therefore, even when DC is supplied from the battery to the voltage source inverter circuit via the bypass switch, the current supplied to the rotating electric machine can be controlled.

It is a circuit diagram of the rotary electric machine system of 1st Embodiment. It is a waveform diagram of each part for explaining the operation of the rotating electrical machine system of the first embodiment. It is a circuit diagram of the rotary electric machine system of the 1st modification in 1st Embodiment. It is a circuit diagram of the rotary electric machine system of the 2nd modification in 1st Embodiment. It is a circuit diagram of the rotary electric machine system of the 3rd modification in 1st Embodiment. It is a circuit diagram of the rotary electric machine system of 2nd Embodiment. It is a circuit diagram of the rotary electric machine system of 3rd Embodiment.

  Next, the present invention will be described in more detail with reference to embodiments.

(First embodiment)
First, the rotary electric machine system of the first embodiment will be described with reference to FIG.

  A rotary electric machine system 1 shown in FIG. 1 is a system that converts direct current supplied from a battery 11 into alternating current and supplies the alternating current to the rotary electric machine 10 to generate torque in the rotary electric machine 10. The rotary electric machine system 1 includes a rotary electric machine 10, a battery 11, a capacitor 12, a power conversion device 13, a current sensor 15, and a control device 17.

  The rotary electric machine 10 is a device that generates torque by being supplied with an alternating current. The rotary electric machine 10 includes a three-phase winding 100 and a rotation sensor 102.

  The three-phase winding 100 is a member that generates magnetic flux by being supplied with a three-phase alternating current. The three-phase winding 100 is configured by connecting the phase windings 100a to 100c in a Y connection. One ends of the phase windings 100a to 100c are commonly connected, and the other ends are connected to the power conversion device 13, respectively. Although not shown, the three-phase winding 100 is provided on the stator of the rotary electric machine 10.

  The rotation sensor 102 is a sensor that detects a rotation angle and a rotation speed of the rotary electric machine 10. Although not shown, the sensor is a sensor that detects the rotation angle and the rotation speed of the rotor of the rotary electric machine 10. Specifically, it is a sensor that outputs three types of pulse signals according to the rotation angle and the rotation speed. The rotation angle can be detected by the levels of the three types of pulse signals, and the rotation speed can be detected by the frequency of the pulse signal. The rotation sensor 102 is arranged so as to detect the rotation angle and the rotation speed of the rotor. The output end of the rotation sensor 102 is connected to the control device 17.

  The battery 11 is a DC power supply that supplies DC. The positive electrode end and the negative electrode end of the battery 11 are connected to the capacitor 12, respectively.

  The capacitor 12 is an element that smoothes the direct current supplied from the battery 11. One end of the capacitor 12 is connected to the positive terminal of the battery 11, and the other end is connected to the negative terminal of the battery 11.

  The power conversion device 13 is a device that steps down the direct current supplied from the battery 11 via the capacitor 12, converts it into a three-phase alternating current, and supplies it to the three-phase winding 100. The power conversion device 13 includes a step-down converter circuit 130, a voltage source inverter circuit 131, a bypass switch 132, and a diode 133.

  The step-down converter circuit 130 is a circuit that steps down the direct current supplied from the battery 11 via the capacitor 12. The step-down converter circuit 130 includes FETs 130a and 130b, a reactor 130c, and a capacitor 130d.

  The FETs 130a and 130b are converter switching elements that are switched to store energy in the reactor 130c or release the stored energy from the reactor 130c. The FETs 130a and 130b are connected in series. Specifically, the source of the FET 130a is connected to the drain of the FET 130b. The drain of the FET 130a is connected to one end of the capacitor 12, and the source of the FET 130b is connected to the other end of the capacitor 12. The series connection point of the FETs 130a and 130b is connected to the reactor 130c. The gates of the FETs 130a and 130b are connected to the control device 17, respectively.

  The reactor 130c is an element that stores energy or emits the stored energy. One end of the reactor 130c is connected to the series connection point of the FETs 130a and 130b, and the other end is connected to the capacitor 130d.

  The capacitor 130d is an element that smoothes the reduced direct current. One end of the capacitor 130d is connected to the other end of the reactor 130c, and the other end is connected to the source of the FET 130b.

  The voltage type inverter circuit 131 is a circuit that converts the stepped-down direct current supplied from the step-down converter circuit 130 into a three-phase alternating current and supplies the three-phase winding 100. The voltage type inverter circuit 131 includes FETs 131a to 131f.

  The FETs 131a to 131f are switching elements for inverters that convert DC into three-phase AC by switching. The FETs 131a and 131b, the FETs 131c and 131d, and the FETs 131e and 131f are connected in series. The three sets of FETs 131a, 131b, FETs 131c, 131d and FETs 131e, 131f connected in series are connected in parallel and are connected to the step-down converter circuit 130. Specifically, the sources of the FETs 131a, 131c, 131e are connected to the drains of the FETs 131b, 131d, 131f, respectively. The drains of the FETs 131a, 131c and 131e are commonly connected to one end of the capacitor 130d, and the sources of the FETs 131b, 131d and 131f are commonly connected to the other end of the capacitor 130d. The series connection points of three sets of FETs 131a, 131b, FETs 131c, 131d and FETs 131e, 131f connected in series are connected to the three-phase winding 100, respectively. Specifically, they are respectively connected to the other ends of the phase windings 100a, 100b, 100c.

  The bypass switch 132 is an element that is connected between the input end and the output end of the step-down converter circuit 130 and connects the input end and the output end or disconnects the input end and the output end. The bypass switch 132 supplies direct current from the battery 11 to the voltage source inverter circuit 131 by connecting the input end and the output end of the step-down converter circuit 130. The bypass switch 132 includes a FET 132a. The FET 132a is a bypass switching element having a parasitic diode 132b. The anode of the parasitic diode 132b is connected to the source of the FET 132a, and the cathode is connected to the drain of the FET 132a. The source of the FET 132a is connected to one end of the capacitor 130d that is the positive output side of the step-down converter circuit 130, and the cathode is connected to the drain of the FET 130a that is the positive side input end of the step-down converter circuit 130.

  The diode 133 is an element that allows a current to flow from the output end of the step-down converter circuit 130 to the input end. Specifically, it is the parasitic diode 132b. The anode of the diode 133 is connected to one end of the capacitor 130d which is the output end of the step-down converter circuit 130, and the cathode is connected to the drain of the FET 130a which is the input end of the step-down converter circuit 130.

  The current sensor 15 is a sensor that detects the output current of the step-down converter circuit 130. The current sensor 15 is provided in the wiring that connects the step-down converter circuit 130 and the voltage source inverter circuit 131. Specifically, it is provided in the wiring that connects the capacitor 130d and the FETs 131b, 131d, and 131f. The output end of the current sensor 15 is connected to the control device 17.

  The control device 17 is a device that controls the step-down converter circuit 130, the voltage source inverter circuit 131, and the bypass switch 132 based on the command input from the external device and the detection results of the rotation sensor 102 and the current sensor 15.

  The controller 17 turns off the bypass switch 132 when the counter electromotive voltage of the rotary electric machine 10 is less than the threshold voltage. Then, based on the command input from the external device and the detection result of the current sensor 15, the output current of the step-down converter circuit 130 becomes a predetermined current, and the step-down converter circuit 130 steps down the direct current supplied from the battery 11. The step-down converter circuit 130 is controlled. Specifically, the FETs 130a and 130b are complementarily switched at a predetermined timing. Further, based on the command input from the external device and the detection result of the rotation sensor 102, the voltage source inverter circuit 131 converts the DC supplied from the step-down converter circuit 130 into a three-phase AC corresponding to the rotation angle of the rotary electric machine 10. The voltage source inverter circuit 131 is controlled so that Specifically, the FETs 131a to 131f are driven so that the 120-degree rectangular wave conduction having the conduction angle of 120 degrees is performed. Here, 120-degree rectangular wave energization is a well-known energization method in which a positive and negative alternating current is energized in a section of 120 degrees in electrical angle.

  On the other hand, when the back electromotive force voltage of the rotating electric machine is equal to or higher than the threshold voltage, the control device 17 turns on the bypass switch 132 to stop the switching operation of the FETs 130a and 130b of the step-down converter circuit 130 and turn off the FET 130a of the step-down converter circuit 130. Turn on. Then, based on the command input from the external device and the detection result of the rotation sensor 102, the voltage source inverter circuit 131 supplies the direct current supplied from the battery 11 via the bypass switch 132, and the FET 130a and the reactor 130c. The voltage source inverter circuit 131 is controlled so as to convert the direct current supplied from the battery 11 into the three-phase alternating current according to the rotation angle of the rotary electric machine 10. At that time, the control device 17 controls the current by adjusting the conduction angle of the three-phase alternating current supplied from the voltage source inverter circuit 131 to the rotary electric machine 10. Specifically, the FETs 131a to 131f are driven so that the rectangular-wave conduction is smaller than the conduction angle of 120 degrees. Further, the voltage is controlled by providing a non-conduction period within the conduction angle of the three-phase alternating current supplied from the voltage source inverter circuit 131 to the rotary electric machine 10.

  When the counter electromotive voltage of the rotary electric machine 10 increases, the voltage applied to the three-phase winding 100 decreases, and the voltage source inverter circuit 131 can control the current flowing through the three-phase winding 100 without using the step-down converter circuit 130. Like The threshold voltage is set to a counter electromotive voltage value of the rotary electric machine 10 that allows the voltage source inverter circuit 131 to control the current flowing through the three-phase winding 100 without using the step-down converter circuit 130.

  The control device 17 is connected to the output end of the rotation sensor 102 and the output end of the current sensor 15, respectively. Further, it is connected to the step-down converter circuit 130 and the voltage source inverter circuit 131. Specifically, they are respectively connected to the gates of the FETs 130a, 130b, 131a to 131f.

  The control device 17 includes a counter electromotive voltage determination circuit 170 and a drive circuit 173.

  The counter electromotive voltage determination circuit 170 is a circuit that determines whether the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than a threshold voltage and outputs a signal according to the determination result to the drive circuit 173. The counter electromotive voltage of the rotary electric machine 10 is proportional to the rotation speed of the rotary electric machine 10. Specifically, the counter electromotive voltage determination circuit 170 determines whether or not the rotation speed of the rotating electric machine 10 is equal to or higher than the rotation speed at which the counter electromotive voltage becomes the threshold voltage, and outputs a signal according to the determination result to the drive circuit. It is a circuit for outputting to 173. The counter electromotive voltage determination circuit 170 includes an F/V conversion circuit 170a, a reference power source 170b, and a comparator 170c.

  The F/V conversion circuit 170a is a circuit that converts the pulse signal output from the rotation sensor 102 into a voltage according to the frequency and outputs the voltage to the comparator 170c. That is, it is a circuit that outputs a voltage according to the rotation speed of the rotating electrical machine 10 to the comparator 170c. The input end of the F/V conversion circuit 170a is connected to the output end of the rotation sensor 102, and the output end is connected to the comparator 170c.

  The reference power supply 170b is a power supply that outputs a voltage serving as a reference for determining whether the rotation speed of the rotating electric machine 10 is equal to or higher than the threshold rotation speed Nth at which the back electromotive voltage becomes the threshold voltage. The reference power source 170b is connected to the comparator 170c.

  The comparator 170c is a circuit that determines whether the output of the F/V conversion circuit 170a is equal to or higher than the voltage of the reference power source 170b and outputs a signal according to the determination result to the drive circuit 173. The comparator 170c outputs a high level signal when the output of the F/V conversion circuit 170a is equal to or higher than the voltage of the reference power supply 170b. On the other hand, when the output of the F/V conversion circuit 170a is lower than the voltage of the reference power source 170b, a low level signal is output. That is, when the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than the threshold voltage, a high level signal is output, and when the counter electromotive voltage of the rotary electric machine 10 is less than the threshold voltage, a low level signal is output. The non-inverting input terminal of the comparator 170c is connected to the output terminal of the F/V conversion circuit 170a, the inverting input terminal thereof is connected to the reference power source 170b, and the output terminal thereof is connected to the drive circuit 173.

  The drive circuit 173 is a circuit that turns on or off the FET 132a based on the output of the comparator 170c. The drive circuit 173 turns on the FET 132a when the output of the comparator 170c is at a high level. On the other hand, when the output of the comparator 170c is low level, the FET 132a is turned off. That is, when the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than the threshold voltage, the FET 132a is turned on, and when the counter electromotive voltage of the rotary electric machine 10 is lower than the threshold voltage, the FET 132a is turned off. The input end of the drive circuit 173 is connected to the output end of the comparator 170c, and the output end is connected to the gate of the FET 132a.

  The capacitor 12, the power conversion device 13, the current sensor 15, and the control device 17 are fixed to and integrated with the rotating electric machine 10.

  Next, the operation of the rotary electric machine system according to the first embodiment will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 2, when the rotation speed of the rotary electric machine 10 is less than the threshold rotation speed Nth, the comparator 170c shown in FIG. 1 outputs a low level signal. The drive circuit 173 turns off the FET 132a because the output of the comparator 170c is at a low level. Since the FET 132a is off, no direct current is supplied from the battery 11 to the voltage source inverter circuit 131 via the FET 132a.

  In this case, the control device 17 sets the output current of the step-down converter circuit 130 to a predetermined current based on the command input from the external device and the detection result of the current sensor 15, and the step-down converter circuit 130 is supplied from the battery 11. The FETs 130a and 130b are complementarily switched at a predetermined timing so as to reduce the direct current. As a result, the step-down converter circuit 130 outputs a predetermined current and also steps down and outputs the direct current supplied from the battery 11.

  Further, the control device 17 causes the voltage source inverter circuit 131 to reduce the step-down direct current supplied from the step-down converter circuit 130 based on the command input from the external device and the detection result of the rotation sensor 102. The FETs 131a to 131f are driven so as to be converted into three-phase AC corresponding to the above. Specifically, it is driven so that 120-degree rectangular wave energization is performed. As a result, the voltage source inverter circuit 131 supplies to the three-phase winding 100 a three-phase alternating current by 120-degree rectangular wave energization according to the rotation angle of the rotary electric machine 10.

  When the output voltage of the step-down converter circuit 130 becomes higher than the input voltage, the diode 133 supplies a current from the output end of the step-down converter circuit 130 to the input end to suppress the increase of the output voltage.

  The three-phase winding 100 generates a magnetic flux by being supplied with a three-phase alternating current by 120-degree rectangular wave energization according to the rotation angle of the rotary electric machine 10. As a result, the rotary electric machine 10 generates torque.

  As shown in FIG. 2, when the rotation speed of the rotary electric machine 10 increases and reaches the threshold rotation speed Nth at time t1, the comparator 170c shown in FIG. 1 outputs a high level signal. Since the output of the comparator 170c is at the high level, the drive circuit 173 turns on the FET 132a. As a result, direct current is supplied from the battery 11 to the voltage source inverter circuit 131 via the FET 132a.

  In this case, the control device 17 stops the switching operation of the FETs 130a and 130b of the step-down converter circuit 130 and turns on the FET 130a of the step-down converter circuit 130. Specifically, the complementary switching of the FETs 130a and 130b is stopped and the FET 130a is turned on. As a result, direct current is supplied from the battery 11 to the voltage source inverter circuit 131 via the FET 130a.

  In the control device 17, the voltage source inverter circuit 131 uses the direct current supplied from the battery 11 via the FET 132a and the FET 130a and the reactor 130c based on the command input from the external device and the detection result of the rotation sensor 102. The FETs 131a to 131f are driven so as to convert the direct current supplied from the battery 11 into the three-phase alternating current according to the rotation angle of the rotary electric machine 10. At that time, the control device 17 controls the current by adjusting the conduction angle of the three-phase alternating current supplied from the voltage source inverter circuit 131 to the rotary electric machine 10. Specifically, the driving is performed so that the rectangular wave has an energization angle of less than 120 degrees. For example, control is performed so that the rectangular wave is energized at 110 degrees. Further, the voltage is controlled by providing a non-conduction period within the conduction angle of the three-phase alternating current supplied from the voltage source inverter circuit 131 to the rotary electric machine 10. For example, a non-energization period of a predetermined width is provided near the center within an energization angle of 110 degrees. As a result, the voltage source inverter circuit 131 supplies the three-phase AC current according to the rotation angle of the rotary electric machine 10 to the three-phase winding 100.

  The three-phase winding 100 generates a magnetic flux by being supplied with a three-phase alternating current according to the rotation angle of the rotary electric machine 10. As a result, the rotary electric machine 10 continuously generates torque.

  Next, effects of the rotary electric machine system according to the first embodiment will be described.

  According to the first embodiment, the rotary electric machine system 1 is provided for the rotary electric machine 10 having the three-phase winding 100, the battery 11, and the three-phase winding 100, and supplies the direct current supplied from the battery 11 to the A power conversion device 13 that converts the power into a phase alternating current and supplies the rotary electric machine 10 and a control device 17 that controls the power conversion device 13 are provided. The power conversion device 13 includes a step-down converter circuit 130 that steps down the direct current supplied from the battery 11, and a voltage source inverter circuit 131 that converts the direct current supplied from the step-down converter circuit 130 into three-phase alternating current and supplies the three-phase alternating current to the rotating electric machine 10. And a bypass switch 132 connected between the input end and the output end of the step-down converter circuit 130.

  The controller 17 turns off the bypass switch 132 when the counter electromotive voltage of the rotary electric machine 10 is less than the threshold voltage. Then, the output current of the step-down converter circuit 130 becomes a predetermined current, the step-down converter circuit 130 controls the step-down converter circuit 130 to step down the direct current supplied from the battery 11, and the voltage source inverter circuit 131 causes the step-down converter circuit 131 to step down. The voltage source inverter circuit 131 is controlled so that the direct current supplied from 130 is converted into alternating current. On the other hand, when the counter electromotive voltage of the rotating electric machine is equal to or higher than the threshold voltage, the bypass switch 132 is turned on to stop the switching operation of the FETs 130a and 130b of the step-down converter circuit 130. Then, the voltage source inverter circuit 131 controls the voltage source inverter circuit 131 so that the direct current supplied from the battery 11 via the bypass switch 132 is converted into alternating current.

  In the rotary electric machine 10, the counter electromotive voltage also increases as the rotation speed increases. When the counter electromotive voltage of the rotary electric machine 10 increases, the voltage applied to the three-phase winding 100 decreases, and the voltage source inverter circuit 131 can control the current flowing through the three-phase winding 100 without using the step-down converter circuit 130. Like The power conversion device 13 includes a bypass switch 132 connected between an input end on the positive side and an output end on the positive side of the step-down converter circuit 130. When the back electromotive voltage of the rotary electric machine 10 is equal to or higher than the threshold voltage, the control device 17 turns on the bypass switch 132 to stop the switching operation of the FETs 130a and 130b of the step-down converter circuit 130. Then, the voltage source inverter circuit 131 controls the voltage source inverter circuit 131 so as to convert the direct current supplied from the battery 11 via the bypass switch 132 into the three-phase alternating current. Therefore, the three-phase alternating current can be supplied from the voltage source inverter circuit 131 to the rotary electric machine 10 while controlling the current without switching the FETs 130a and 130b of the step-down converter circuit 130. Therefore, the switching loss of the FET due to the step-down converter circuit 130 can be suppressed and the efficiency can be improved.

  According to the first embodiment, the step-down converter circuit 130 has the FET 130a having one end connected to the input end and the other end connected to the output end via the reactor 130c. When the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than the threshold voltage, the control device 17 turns on the FET 130a and converts the direct current supplied from the battery 11 to the alternating current through the FET 130a and the reactor 130c into a voltage source inverter circuit. Control 131. Therefore, when the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than the threshold voltage, direct current can be supplied from the battery 11 to the voltage-type inverter circuit 131 via not only the FET 132a but also the FET 130a. That is, it is possible to increase the number of paths for supplying direct current from the battery 11 to the voltage source inverter circuit 131. As a result, the current flowing through each path can be reduced. As a result, it is possible to suppress the loss in the path through which the current flows, as compared with the case where the direct current is supplied from the battery 11 to the voltage type inverter circuit 131 via only the FET 132a.

  According to the first embodiment, the power conversion device 13 includes the diode 133 that is connected between the input end and the output end of the step-down converter circuit 130 so that the current flows from the output end toward the input end. There is. Therefore, even if the voltage at the output end of the step-down converter circuit 130 becomes higher than the voltage at the input end due to the switching of the FETs 131a to 131f of the voltage source inverter circuit 131, the output end of the step-down converter circuit 130 is output via the diode 133. A current can flow from the input terminal to the input terminal. Therefore, the voltage increase at the output end of the step-down converter circuit 130 is suppressed, and the step-down converter circuit 130 and the voltage source inverter circuit 131 can be prevented from being damaged.

  According to the first embodiment, the bypass switch 132 is the FET 132a having the parasitic diode 132b. The diode 133 is a parasitic diode 132b. Therefore, it is not necessary to purposely provide another diode as the diode 133. Therefore, the configuration of the power conversion device 13 can be simplified.

  According to the first embodiment, the control device 17 adjusts the conduction angle of the three-phase AC supplied from the voltage source inverter circuit 131 to the rotating electric machine 10 when the counter electromotive voltage of the rotating electric machine 10 is equal to or higher than the threshold voltage. Therefore, even when direct current is supplied from the battery 11 to the voltage source inverter circuit 131 via the bypass switch 132, the current supplied to the rotary electric machine 10 can be controlled.

  According to the first embodiment, when the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than the threshold voltage, the control device 17 does not energize within the conduction angle of the three-phase AC supplied from the voltage source inverter circuit 131 to the rotary electric machine 10. Set a period. Therefore, even when direct current is supplied from the battery 11 to the voltage source inverter circuit 131 via the bypass switch 132, the voltage supplied to the rotating electrical machine 10 is supplied to the voltage source inverter circuit 131 via the step-down converter circuit 130. The state can be controlled in the same manner as when the direct current is supplied to the inverter circuit 131.

  According to the first embodiment, the rotary electric machine 10 has the three-phase winding 100 having three phases. Therefore, as the voltage source inverter circuit that constitutes the power conversion device 13, the three-phase voltage source inverter circuit 131 that is generally widely used can be used. Therefore, the power conversion device 13 can be easily configured as compared with the case where a plurality of multi-phase windings whose number of phases is not a multiple of 3 are provided.

  According to the first embodiment, the power conversion device 13 and the control device 17 are fixed to the rotary electric machine 10. Therefore, the rotary electric machine system 1 can be downsized.

  In the first embodiment, the bypass switch 132 is the FET 132a having the parasitic diode 132b and the diode 133 is the parasitic diode 132b. However, the present invention is not limited to this. As shown in FIG. 3, the power conversion device 13 may have an external diode 134 faster than the parasitic diode 132b externally attached to the FET 132a, and the diode 133 may be the parasitic diode 132b and the external diode 134. Through the external diode 134, a current can flow at high speed from the output end of the step-down converter circuit 130 to the input end. Therefore, the voltage increase at the output end of the step-down converter circuit 130 can be immediately suppressed. Therefore, it is possible to reliably prevent the step-down converter circuit 130 and the voltage source inverter circuit 131 from being damaged.

  According to the first embodiment, when the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than the threshold voltage, the control device 17 adjusts the conduction angle of the three-phase AC supplied from the voltage source inverter circuit 131 to the rotary electric machine 10. However, the present invention is not limited to this. When the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than the threshold voltage, the control device 17 may adjust the phase of the three-phase alternating current supplied from the voltage source inverter circuit 131 to the rotary electric machine 10. Similar to the case of adjusting the conduction angle of the three-phase alternating current, even when the direct current is supplied from the battery 11 to the voltage source inverter circuit 131 via the bypass switch 132, the current supplied to the rotary electric machine 10 is controlled. can do.

  In the first embodiment, an example in which the counter electromotive voltage determination circuit 170 determines whether or not the rotation speed of the rotary electric machine 10 is a rotation speed at which the counter electromotive voltage is equal to or higher than the threshold voltage is given. It is not limited. The counter electromotive voltage determination circuit 170 may directly determine whether the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than a threshold voltage. In the case of rectangular wave energization, the counter electromotive voltage of the rotary electric machine 10 can be detected at the input end of the voltage source inverter circuit 131. As shown in FIG. 4, the counter electromotive voltage determination circuit 170 may include an operational amplifier 170d, a low-pass filter circuit 170e, a reference power supply 170f, and a comparator 170g. The operational amplifier 170d is connected to the input end of the voltage source inverter circuit 131 and amplifies and outputs the counter electromotive voltage of the rotary electric machine 10 appearing at the input end. The low pass filter circuit 170e removes the high frequency component included in the output of the operational amplifier 170d. The reference power source 170f outputs a reference voltage corresponding to the threshold voltage for determining whether the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than the threshold voltage. When the output of the low-pass filter circuit 170e is larger than the voltage of the reference power source 170f, the comparator 170g outputs a high-level signal indicating that the counter electromotive voltage of the rotary electric machine 10 is equal to or higher than the threshold voltage. On the other hand, when the output of the low-pass filter circuit 170e is equal to or lower than the voltage of the reference power source 170f, the low-level signal indicating that the counter electromotive voltage of the rotary electric machine 10 is less than the threshold voltage is output. This makes it possible to directly determine whether the back electromotive force of the rotary electric machine 10 is equal to or higher than the threshold voltage.

  In the first embodiment, an example in which the rotary electric machine 10 has the three-phase winding 100 is given, but the present invention is not limited to this. The rotary electric machine 10 may have multi-phase windings other than three phases. In that case, the number of phases of the multiphase winding may be a multiple of three. A three-phase voltage source inverter circuit that is generally widely used can be used as the voltage source inverter circuit that constitutes the power conversion device.

  In the first embodiment, the example in which the step-down converter circuit 130 is composed of the FETs 130a and 130b, the reactor 130c, and the capacitor 130d is given, but the present invention is not limited to this. The step-down converter circuit 130 may be configured by connecting a plurality of small-capacity step-down converter circuits in parallel. As shown in FIG. 5, the step-down converter circuit 130 includes a small-capacity step-down converter circuit including FETs 130e and 130f, a reactor 130g, and a capacitor, and a small-capacity step-down converter circuit including FETs 130i and 130j, a reactor 130k, and a capacitor. May be connected in parallel. Here, the capacitor 130h is a combination of the capacities of the capacitors of the two small capacity step-down converter circuits. In this case, the current flows in a distributed manner in the small-capacity converter circuits, so that heat generation of the step-down converter circuit 130 can be suppressed.

(Second embodiment)
Next, the rotating electrical machine system of the second embodiment will be described. The rotating electrical machine system of the second embodiment is different from the rotating electrical machine system of the first embodiment in that the voltage at the output end of the step-down converter circuit is the input end even when the back electromotive voltage of the rotating electrical machine is less than the threshold voltage. When the voltage is higher than the voltage of, the bypass switch is controlled.

  The rotating electrical machine system of the second embodiment is the same as the rotating electrical machine system of the first embodiment except that the bypass switch is controlled based on the voltage at the input/output terminal of the step-down converter circuit. Therefore, only the configuration and operation of controlling the bypass switch based on the voltage at the input/output terminal of the step-down converter circuit will be described with reference to FIG. 6, and description of the other parts will be omitted. In addition, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

  First, with reference to FIG. 6, a configuration for controlling the bypass switch based on the voltage at the input/output terminal of the step-down converter circuit in the rotary electric machine system according to the second embodiment will be described.

  As shown in FIG. 6, the rotary electric machine system 2 includes a control device 17. The control device 17 performs the same control as in the first embodiment. Further, even when the back electromotive voltage of the rotary electric machine 10 is less than the threshold voltage, if the voltage at the output end of the step-down converter circuit 130 is higher than the voltage at the input end, the bypass switch 132 is turned on, and the bypass switch 132 is turned on. A current flows from the output end to the input end via 132. The control device 17 includes an input/output voltage determination circuit 171 and an OR circuit 172.

  The input/output voltage determination circuit 171 is a circuit that determines whether or not the voltage at the output end of the step-down converter circuit 130 is higher than the voltage at the input end, and outputs a signal according to the determination result to the OR circuit 172. The input/output voltage determination circuit 171 includes a comparator 171a.

  The comparator 171a is a circuit that determines whether the voltage at the output end of the step-down converter circuit 130 is higher than the voltage at the input end and outputs a signal according to the determination result to the OR circuit 172. The comparator 171a outputs a high level signal when the voltage at the output end of the step-down converter circuit 130 is higher than the voltage at the input end. On the other hand, when the voltage at the output end of the step-down converter circuit 130 is equal to or lower than the voltage at the input end, a low level signal is output. The non-inverting input end of the comparator 171a is connected to one end of the capacitor 130d which is the output end of the step-down converter circuit 130, the inverting input end is connected to the drain of the FET 130a which is the input end of the step-down converter circuit 130, and the output end is connected to the OR circuit 172, respectively. Has been done.

  The OR circuit 172 is a circuit that calculates the logical sum of the outputs of the comparators 170c and 171a and outputs the calculation result to the drive circuit 173. The OR circuit 172 outputs a high level signal when the output of at least one of the comparators 170c and 171a is high level. On the other hand, when the outputs of the comparators 170c and 171a are both low level, a low level signal is output. That is, when the counter electromotive voltage of the rotating electric machine 10 is equal to or higher than the threshold voltage, or when the voltage at the output end of the step-down converter circuit 130 is higher than the voltage at the input end, a high-level signal is output, In other cases, a low level signal is output. One input end of the OR circuit 172 is connected to the output end of the comparator 170c, the other input end is connected to the output end of the comparator 171a, and the output end is connected to the input end of the drive circuit 173.

  The drive circuit 173 turns on the FET 132a when the output of the OR circuit 172 is at a high level. On the other hand, when the output of the OR circuit 172 is low level, the FET 132a is turned off.

  Next, the operation of controlling the bypass switch based on the voltage at the input/output terminal of the step-down converter circuit in the rotary electric machine system according to the second embodiment will be described with reference to FIG.

  When the voltage at the output end of the step-down converter circuit 130 shown in FIG. 6 is higher than the voltage at the input end, the comparator 171a outputs a high level signal. Since the output of the comparator 171a is high level, the OR circuit 172 outputs a high level signal even if the output of the comparator 170c is low level. The drive circuit 173 turns on the FET 132a because the output of the OR circuit 172 is at a high level. The FET 132a is turned on, and a current is caused to flow from the output end of the step-down converter circuit 130 to the input end thereof to suppress an increase in the output voltage. That is, even if the back electromotive voltage of the rotary electric machine 10 is less than the threshold voltage, the control device 17 turns on the FET 132a if the voltage at the output end of the step-down converter circuit 130 is higher than the voltage at the input end. , A current is passed from the output end to the input end via the FET 132a to suppress an increase in the output voltage.

  Next, effects of the rotary electric machine system according to the second embodiment will be described.

  According to the second embodiment, by having the same configuration as the first embodiment, it is possible to obtain the same effect corresponding to the same configuration.

  According to the second embodiment, even if the counter electromotive voltage of the rotary electric machine 10 is lower than the threshold voltage, the control device 17 determines that the voltage at the output end of the step-down converter circuit 130 is higher than the voltage at the input end. , FET 132a is turned on. Therefore, even if the voltage at the output end of the step-down converter circuit 130 becomes higher than the voltage at the input end due to the switching of the FETs 131a to 131f of the voltage-source inverter circuit 131, the output end of the step-down converter circuit 130 is changed via the FET 132a. A current can be applied to the input end. Therefore, the voltage increase at the output end of the step-down converter circuit 130 is suppressed, and the step-down converter circuit 130 and the voltage source inverter circuit 131 can be prevented from being damaged. Moreover, the loss can be suppressed as compared with the case where a current is passed through the parasitic diode 132b.

(Third Embodiment)
Next, a rotating electrical machine system according to the third embodiment will be described. The rotating electric machine system according to the third embodiment drives a rotating electric machine having one three-phase winding, whereas the rotating electric machine system according to the first embodiment has two rotating three-phase windings. A step-down converter circuit, a voltage source inverter circuit, and a bypass switch are added so as to drive, and a part of the control method is changed accordingly.

  The rotating electrical machine system of the third embodiment is the rotating electrical machine of the first embodiment except for the added three-phase winding, the step-down converter circuit, the voltage source inverter circuit, the bypass switch, and the partially changed control method. It is the same as the system. Therefore, referring to FIG. 7, only the added three-phase winding, the step-down converter circuit, the voltage source inverter circuit, the bypass switch, and the partially changed control method will be described, and the other parts will be described. Omit it. In addition, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

  First, the added three-phase winding, the step-down converter circuit, the voltage source inverter circuit, and the bypass switch in the rotary electric machine system according to the third embodiment will be described with reference to FIG. 7.

  As shown in FIG. 7, the rotary electric machine system 3 includes a rotary electric machine 10, a battery 11, a capacitor 12, power conversion devices 13 and 14, current sensors 15 and 16, and a control device 17.

  The rotary electric machine 10 includes three-phase windings 100 and 101.

  The three-phase winding 101 is a member that generates magnetic flux by being supplied with a three-phase alternating current. The three-phase winding 101 is configured by connecting the phase windings 101a to 101c in a Y connection. One ends of the phase windings 101a to 101c are commonly connected, and the other ends thereof are connected to the power conversion device 14, respectively. Although not shown, the three-phase winding 101 is provided on the stator of the rotary electric machine 10.

  The three-phase winding 100 and the three-phase winding 101 are arranged so as to have different phases.

  The power converters 13 and 14 are provided for each of the three-phase windings 100 and 101. The power converter 13 is provided for the three-phase winding 100, and the power converter 14 is provided for the three-phase winding 101.

  The power conversion device 14 is a device that steps down the direct current supplied from the battery 11 via the capacitor 12, converts it into a three-phase alternating current, and supplies it to the three-phase winding 101. The power conversion device 14 includes a step-down converter circuit 140, a voltage source inverter circuit 141, a bypass switch 142, and a diode 143.

  The step-down converter circuit 140 is a circuit that steps down the direct current supplied from the battery 11 via the capacitor 12. The step-down converter circuit 140 includes FETs 140a and 140b, a reactor 140c, and a capacitor 140d. The FETs 140a and 140b, the reactor 140c, and the capacitor 140d are the same elements as the FETs 130a and 130b, the reactor 130c, and the capacitor 130d, and have the same configuration.

  The voltage source inverter circuit 141 is a circuit that converts the stepped-down direct current supplied from the step-down converter circuit 140 into a three-phase alternating current and supplies the three-phase winding 101. The voltage type inverter circuit 141 includes FETs 141a to 141f. The FETs 141a to 141f are the same elements as the FETs 131a to 131f and have the same configuration.

  The bypass switch 142 is an element that is connected between the input end and the output end of the step-down converter circuit 140 and connects the input end and the output end or disconnects the input end and the output end. The bypass switch 142 includes a FET 142a. The FET 142a is a bypass switching element having a parasitic diode 142b. The FET 142a is the same element as the FET 132a and has the same configuration.

  The diode 143 is an element that causes a current to flow from the output end of the step-down converter circuit 140 to the input end. Specifically, it is the parasitic diode 142b. The diode 143 is configured similarly to the diode 133.

  The current sensor 16 is a sensor that detects the output current of the step-down converter circuit 140. The current sensor 16 is provided in the wiring that connects the step-down converter circuit 140 and the voltage source inverter circuit 141. Specifically, it is provided on a wiring connecting the capacitor 140d and the FETs 141b, 141d, 141f.

  The control device 17 controls the step-down converter circuits 130, 140 voltage source inverter circuits 131, 141 and the bypass switches 132, 142 based on the command input from the external device and the detection results of the rotation sensor 102 and the current sensors 15, 16. It is a device that does. The controller 17 controls the step-down converter circuit 130, the voltage source inverter circuit 131, and the bypass switch 132 in the same manner as in the first embodiment. Further, the same control as in the first embodiment is performed on the step-down converter circuit 140, the voltage source inverter circuit 141, and the bypass switch 142. At that time, the voltage source inverter circuits 131, 141 are controlled so that the phase difference of the three-phase AC converted by the voltage source inverter circuits 131, 141 becomes a predetermined phase difference corresponding to the three-phase windings 100, 101.

  The capacitor 12, the power conversion devices 13 and 14, the current sensors 15 and 16, and the control device 17 are fixed to and integrated with the rotating electric machine 10.

  Next, the operation of the rotary electric machine system according to the third embodiment will be described with reference to FIG. 7.

  When the rotation speed of the rotary electric machine 10 shown in FIG. 7 is less than the threshold rotation speed Nth, the control device 17 turns off the FETs 132a and 132a. Since the FETs 132a and 142a are off, direct current is not supplied from the battery 11 to the voltage source inverter circuits 131 and 141 via the FETs 132a and 142a.

  In this case, the control device 17 causes the output currents of the step-down converter circuits 130 and 140 to become a predetermined current based on the command input from the external device and the detection results of the current sensors 15 and 16, and the step-down converter circuits 130 and 140 are The FETs 130a and 130b are complementarily switched at a predetermined timing and the FETs 140a and 140b are complementarily switched at a predetermined timing so as to reduce the direct current supplied from the battery 11. As a result, the step-down converter circuits 130 and 140 output the same predetermined current and step-down and output the direct current supplied from the battery 11.

  Further, the control device 17 causes the voltage-source inverter circuits 131 and 141 to generate the step-down direct current supplied from the step-down converter circuits 130 and 140 on the basis of the command input from the external device and the detection result of the rotation sensor 102. The FETs 131a to 131f are driven and the FETs 141a to 141f are driven so as to be converted into three-phase alternating current according to the rotation angle of 10. Specifically, it is driven so that 120-degree rectangular wave energization is performed. At that time, the FETs 131a to 131f are driven so that the phase difference of the three-phase AC converted by the voltage source inverter circuits 131 and 141 becomes a predetermined phase difference corresponding to the three-phase windings 100 and 101, and the FETs 141a to 141f are turned on. To drive. As a result, the voltage source inverter circuits 131 and 141 supply the three-phase alternating currents having a predetermined phase difference due to the 120-degree rectangular wave energization to the three-phase windings 100 and 101 according to the rotation angle of the rotary electric machine 10.

  When the output voltage of the step-down converter circuits 130, 140 becomes higher than the input voltage, the diodes 133, 143 allow a current to flow from the output terminal of the step-down converter circuits 130, 140 to the input terminal and suppress the rise of the output voltage.

  The three-phase windings 100 and 101 generate magnetic flux by being supplied with a three-phase alternating current having a predetermined phase difference due to 120-degree rectangular wave energization according to the rotation angle of the rotary electric machine 10. As a result, the rotary electric machine 10 generates torque.

  When the rotation speed of the rotary electric machine 10 increases and reaches the threshold rotation speed Nth, the control device 17 turns on the FETs 132a and 132a. As a result, direct current is supplied from the battery 11 to the voltage type inverter circuit 131 via the FET 132a and direct current is supplied from the battery 11 to the voltage type inverter circuit 141 via the FET 142a.

  In this case, the control device 17 stops the switching operation of the FETs 130a, 130b, 140a, 140b of the step-down converter circuits 130, 140, turns on the FET 130a of the step-down converter circuit 130, and turns on the FET 140a of the step-down converter circuit 140. Put in a state. Specifically, the complementary switching of the FETs 130a and 130b and the complementary switching of the FETs 140a and 140b are stopped, and the FETs 130a and 140a are turned on. As a result, direct current is supplied from the battery 11 to the voltage type inverter circuit 131 via the FET 130a and direct current is supplied from the battery 11 to the voltage type inverter circuit 141 via the FET 140a.

  The control device 17 supplies the stepped-down direct current supplied from the step-down converter circuits 130 and 140 to the rotary electric machine 10 by the voltage source inverter circuits 131 and 141 based on a command input from an external device and a detection result of the rotation sensor 102. The FETs 131a to 131f are driven and the FETs 141a to 141f are driven so as to be converted into three-phase alternating current according to the rotation angle. At that time, the control device 17 controls the current by adjusting the conduction angle of the three-phase alternating current supplied from the voltage source inverter circuits 131 and 141 to the rotary electric machine 10. Specifically, the driving is performed so that the rectangular wave has a conduction angle of less than 120 degrees. Further, the voltage is controlled by providing a non-energization period within the energization angle of the three-phase alternating current supplied from the voltage source inverter circuits 131 and 141 to the rotary electric machine 10. Further, the FETs 131a to 131f are driven and the FETs 141a to 141f are driven so that the phase difference of the three-phase alternating current converted by the voltage source inverter circuits 131 and 141 becomes a predetermined phase difference corresponding to the three-phase windings 100 and 101. To do. As a result, the voltage source inverter circuits 131 and 141 supply the three-phase alternating currents having the predetermined phase difference according to the rotation angle of the rotary electric machine 10 to the three-phase windings 100 and 101.

  The three-phase windings 100 and 101 generate magnetic flux by being supplied with a three-phase alternating current having a predetermined phase difference according to the rotation angle of the rotary electric machine 10. As a result, the rotary electric machine 10 continuously generates torque.

  Next, effects of the rotary electric machine system according to the third embodiment will be described.

  According to the third embodiment, by having the same configuration as the first embodiment, it is possible to obtain the same effect corresponding to the same configuration.

  According to the third embodiment, even in the rotary electric machine system including the rotary electric machine 10 having the two three-phase windings 100 and 101, it is possible to suppress the loss due to the step-down converter circuits 130 and 140 and improve the efficiency.

  According to the third embodiment, the rotary electric machine 10 has the three-phase windings 100 and 101 having three phases. Therefore, three-phase voltage source inverter circuits 131 and 141 that are generally widely used can be used as the voltage source inverter circuits that form the power conversion devices 13 and 14. Therefore, the power conversion device 13 can be easily configured as compared with the case where a plurality of multi-phase windings whose number of phases is not a multiple of 3 are provided.

  According to the third embodiment, the power conversion devices 13 and 14 and the control device 17 are fixed to the rotating electric machine 10. Therefore, the rotary electric machine system 3 can be downsized.

  In addition, in the third embodiment, an example in which the rotary electric machine 10 has two three-phase windings 100 and 101 is given, but the present invention is not limited to this. The rotary electric machine 10 may have a plurality of multiphase windings. In that case, the number of phases of the multiphase winding may be a multiple of three. A three-phase voltage source inverter circuit that is generally widely used can be used as the voltage source inverter circuit that constitutes the power conversion device.

  Although the embodiment of the present invention and the modification thereof have been described above, the present invention is not limited to these embodiments. These forms may be combined and configured without departing from the scope of the present invention.

  DESCRIPTION OF SYMBOLS 1... Rotating electric machine system, 10... Rotating electric machine, 100... Three-phase winding, 11... Battery, 13... Power converter, 130... Step-down converter circuit, 131... Voltage source inverter circuit, 132... Bypass switch, 133... Diode, 17... Control device

Claims (12)

A rotating electric machine (10) having at least one polyphase winding;
DC power supply (11),
A power conversion device (13, 14) which is provided for each of the multi-phase windings and which converts direct current supplied from the direct current power source into alternating current and supplies the alternating current to the rotary electric machine;
A control device (17) for controlling the power conversion device,
A rotary electric machine system comprising:
The power conversion device,
A step-down converter circuit (130, 140) for stepping down the direct current supplied from the direct current power source;
A voltage source inverter circuit (131, 141) that converts direct current supplied from the step-down converter circuit into alternating current and supplies the alternating current to the rotating electric machine;
A bypass switch (132, 142) connected between the input terminal and the output terminal of the step-down converter circuit;
Have
When the counter electromotive voltage of the rotary electric machine is less than a threshold voltage, the control device turns off the bypass switch, the output current of the step-down converter circuit becomes a predetermined current, and the step-down converter circuit supplies the direct current power from the DC power supply. The step-down converter circuit is controlled so as to step down the direct current, and the voltage-type inverter circuit is controlled so that the voltage-type inverter circuit converts direct current supplied from the step-down converter circuit to alternating current, and the rotation is performed. When the back electromotive voltage of the electric machine is equal to or higher than the threshold voltage, the bypass switch is turned on to stop the operation of the step-down converter circuit, and the voltage source inverter circuit is supplied from the DC power supply through the bypass switch. The voltage source inverter circuit is controlled so as to convert direct current into alternating current, and further, even when the counter electromotive voltage of the rotating electric machine is less than the threshold voltage, the voltage at the output end of the step-down converter circuit is at the input end. The rotating electrical machine system turns on the bypass switch when the voltage is higher than the voltage . A rotating electric machine (10) having at least one polyphase winding;
DC power supply (11),
A power conversion device (13, 14) which is provided for each of the multi-phase windings and which converts direct current supplied from the direct current power source into alternating current and supplies the alternating current to the rotary electric machine;
A control device (17) for controlling the power conversion device,
A rotary electric machine system comprising:
The power conversion device,
A step-down converter circuit (130, 140) for stepping down the direct current supplied from the direct current power source;
A voltage source inverter circuit (131, 141) that converts direct current supplied from the step-down converter circuit into alternating current and supplies the alternating current to the rotating electric machine;
A bypass switch (132, 142) connected between the input terminal and the output terminal of the step-down converter circuit;
Have
When the counter electromotive voltage of the rotary electric machine is less than a threshold voltage, the control device turns off the bypass switch, the output current of the step-down converter circuit becomes a predetermined current, and the step-down converter circuit supplies the direct current power from the DC power supply. The step-down converter circuit is controlled so as to step down the direct current, and the voltage-type inverter circuit is controlled so that the voltage-type inverter circuit converts direct current supplied from the step-down converter circuit to alternating current, and the rotation is performed. When the back electromotive voltage of the electric machine is equal to or higher than the threshold voltage, the bypass switch is turned on to stop the operation of the step-down converter circuit, and the voltage source inverter circuit is supplied from the DC power supply through the bypass switch. A rotating electrical machine system for controlling the voltage source inverter circuit so as to convert direct current into alternating current, and adjusting the phase of alternating current supplied from the voltage source inverter circuit to the rotating electrical machine. Even when the counter electromotive voltage of the rotating electric machine is less than the threshold voltage, the control device turns on the bypass switch when the voltage at the output end of the step-down converter circuit is higher than the voltage at the input end. The rotary electric machine system according to claim 2 . The step-down converter circuit has converter switching elements (130a, 140a), one end of which is connected to an input end and the other end of which is connected to an output end via a reactor,
When the counter electromotive voltage of the rotating electric machine is equal to or higher than the threshold voltage, the control device turns on the converter switching element, and supplies a direct current supplied from the DC power supply via the converter switching element and the reactor. the rotary electric machine system according to any one of claims 1 to 3 for controlling the voltage inverter circuit to convert the AC. The diode (133, 143) connected so that a current flows from the output end to the input end, between the input end and the output end of the step-down converter circuit, according to any one of claims 1 to 4. Rotating electric machine system. The bypass switch is a bypass switching element (132a, 142a) having a parasitic diode,
The rotary electric machine system according to claim 5 , wherein the diode is the parasitic diode (132b, 142b). The bypass switch is a bypass switching element (132a, 142a) having a parasitic diode,
An external diode (134), which is external to the bypass switching element and has a higher speed than the parasitic diode,
The rotary electric machine system according to claim 5 , wherein the diodes are the parasitic diodes (132b, 142b) and the external diode. The control device, wherein when the counter electromotive voltage of the rotating electrical machine is equal to or higher than the threshold voltage, any one of claims 1 to 7 to adjust the conduction angle of the alternating current supplied from the voltage source inverter circuit to the rotating electrical machine The rotating electric machine system according to item 1.   The control device provides a non-energization period within a conduction angle of an alternating current supplied from the voltage source inverter circuit to the rotating electric machine when a counter electromotive voltage of the rotating electric machine is equal to or higher than the threshold voltage. The rotary electric machine system according to any one of items.   The rotary electric machine system according to any one of claims 1 to 9, wherein the rotary electric machine includes a plurality of the multiphase windings (100, 101).   The rotating electrical machine system according to any one of claims 1 to 10, wherein the number of phases of the multiphase winding is a multiple of three.   The rotary electric machine system according to any one of claims 1 to 11, wherein the power converter and the controller are fixed to the rotary electric machine.

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