CN104702109A - Re-boost power conversion device with flyback mode - Google Patents

Abstract

The invention provides a re-boosting power conversion device with a flyback mode, which comprises a transformer, a primary side switch unit, a primary side switch control unit, a first unidirectional conductive unit, a first charge storage unit, a second unidirectional conductive unit, a mode switch unit and a mode switch control unit. When the mode switch control unit turns on the mode switch unit, the re-boosting power conversion device with the flyback mode has the function of a re-boosting power converter; when the mode switch control unit does not conduct the mode switch unit, the re-boosting type power conversion device with the flyback mode has the function of a flyback type power converter.

Description

Re-boost power conversion device with flyback mode

technical field

The invention relates to a re-boost power conversion device, in particular to a re-boost power conversion device with a flyback mode.

Background technique

The re-boost power conversion device has the advantages of high efficiency and high boost ratio; therefore, the re-boost power conversion device is widely used and is an excellent power conversion device.

Please refer to Fig. 1, which is a waveform diagram of an embodiment of the output voltage of a general step-up power conversion device; the shortcoming of the step-up power conversion device is that the minimum output voltage will be clamped by the input voltage; that is, the minimum output The voltage cannot be zero (because the input voltage is not zero), as shown in Figure 1.

Therefore, the general re-boost power conversion device can only be used as a boost converter, and cannot be applied to an AC output power supply, such as a micro inverter. Please refer to Figure 2, which is a waveform diagram of an embodiment of an output voltage that can be applied to an AC output power supply; please refer to Figure 3, which is a waveform diagram of the output voltage in Figure 2 after being converted; a general re-boost power supply The output voltage of the conversion device (as shown in Figure 1) cannot achieve a perfect zero crossing after being converted (as shown in Figure 3), so the general re-boost power conversion device cannot be applied to an AC output power supply.

Contents of the invention

In order to improve the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a re-boost power conversion device with a flyback mode.

In order to achieve the above object of the present invention, the re-boost power conversion device with flyback mode of the present invention includes: a power input terminal; a power output terminal; a power negative terminal; a transformer, the transformer is electrically connected to the Power supply input end; a primary side switch unit, the primary side switch unit is electrically connected to the transformer and the negative terminal of the power supply; a primary side switch control unit, the primary side switch control unit is electrically connected to the primary side switch unit; a first unidirectional conduction unit, the first unidirectional conduction unit is electrically connected to the transformer and the power supply output; a first charge storage unit, the first charge storage unit is electrically connected to the transformer and the power supply Power supply output end; a second charge storage unit, the second charge storage unit is electrically connected to the transformer, the first charge storage unit and the negative end of the power supply; a second unidirectional conduction unit, the second unidirectional conduction The unit is electrically connected to the transformer and the primary side switch unit; a mode switch unit is electrically connected to the second unidirectional conduction unit, the transformer, the first charge storage unit and the second a charge storage unit; and a mode switch control unit, the mode switch control unit is electrically connected to the mode switch unit. Wherein when the mode switch control unit is turned on the mode switch unit, the re-boost power conversion device with flyback mode has the function of a re-boost power converter; when the mode switch control unit is not turned on When the switch unit is switched in this mode, the re-boost power conversion device with flyback mode has the function of a flyback power converter.

The effect of the present invention is that the minimum output voltage of the re-boost power conversion device can be zero, so the re-boost power conversion device can be applied to an AC output power supply.

Description of drawings

FIG. 1 is an output voltage waveform diagram of a general re-boost power conversion device;

FIG. 2 is a waveform diagram of an embodiment in which the output voltage can be applied to an AC output power supply;

FIG. 3 is a waveform diagram of the output voltage of FIG. 2 after being converted;

4 is a block diagram of the first embodiment of the re-boost power conversion device with flyback mode of the present invention;

5 is a block diagram of a second embodiment of the re-boost power conversion device with flyback mode of the present invention;

6 is a block diagram of a third embodiment of the re-boost power conversion device with flyback mode of the present invention;

FIG. 7 is a block diagram of a fourth embodiment of the re-boost power conversion device with flyback mode of the present invention.

reference sign

10: Re-boost power conversion device with flyback mode

102: Power input terminal 104: Power output terminal

106: Negative terminal of power supply 108: Transformer

110: Primary side switch unit 112: Primary side switch control unit

114: the first one-way conduction unit 116: the first charge storage unit

118: The second charge storage unit 120: The second unidirectional conduction unit

122: Mode switching switch unit

124: Mode switching switch control unit 126: Second charge storage unit bypass circuit

10802: Transformer primary side 10804: Transformer secondary side

10806: The first pin of the transformer 10808: The second pin of the transformer

10810: The third pin of the transformer 10812: The fourth pin of the transformer

11002: The first pin of the primary side switch unit 11004: The second pin of the primary side switch unit

11006: The third pin of the primary side switch unit 11402: The first pin of the first one-way conductive unit

11404: the second pin of the first unidirectional conduction unit 11602: the first pin of the first charge storage unit

11604: The second pin of the first charge storage unit 11802: The first pin of the second charge storage unit

11804: The second pin of the second charge storage unit 12002: The first pin of the second unidirectional conduction unit

12004: The second pin of the second unidirectional conductive unit 12202: The first pin of the mode switch unit

12204: The second pin of the mode switch unit 12206: The third pin of the mode switch unit

12602: Bypass switch unit 12604: Bypass switch control unit

12606: The third one-way conductive unit 12608: Voltage detection unit

Detailed ways

Please refer to FIG. 4 , which is a block diagram of a first embodiment of the re-boost power conversion device with flyback mode of the present invention. A re-boost power conversion device 10 with flyback mode includes a power input terminal 102, a power output terminal 104, a power negative terminal 106, a transformer 108, a primary side switch unit 110, a primary side switch Control unit 112, a first unidirectional conduction unit 114, a first charge storage unit 116, a second charge storage unit 118, a second unidirectional conduction unit 120, a mode switch unit 122 and a mode switch control Unit 124.

The primary side switch unit 110 can be, for example but not limited to, a transistor switch; the first unidirectional conduction unit 114 can be, for example but not limited to, a diode (the cathode of the diode is electrically connected to the power output terminal 104; The anode is electrically connected to the transformer 108); the first charge storage unit 116 can be, for example but not limited to, a capacitor; the second charge storage unit 118 can be, for example but not limited to, a capacitor; the second unidirectional conduction The unit 120 can be, for example but not limited to, a diode (the cathode of the diode is electrically connected to the mode switch unit 122; the anode of the diode is electrically connected to the transformer 108); the mode switch unit 122 can be for example but not limited to is a transistor switch.

The transformer 108 is electrically connected to the power input terminal 102; the primary side switch unit 110 is electrically connected to the transformer 108 and the power supply negative terminal 106; the primary side switch control unit 112 is electrically connected to the primary side switch unit 110 ; the first unidirectional conduction unit 114 is electrically connected to the transformer 108 and the power output 104; the first charge storage unit 116 is electrically connected to the transformer 108 and the power output 104; the second charge storage unit 118 is electrically connected to the transformer 108, the first charge storage unit 116 and the power supply negative terminal 106; the second unidirectional conduction unit 120 is electrically connected to the transformer 108 and the primary side switch unit 110; the mode switching switch The unit 122 is electrically connected to the second unidirectional conduction unit 120, the transformer 108, the first charge storage unit 116 and the second charge storage unit 118; the mode switch control unit 124 is electrically connected to the mode switch Unit 122.

When the mode switch control unit 124 turns on the mode switch unit 122, the re-boost power conversion device 10 with flyback mode has the function of a re-boost power converter; when the mode switch control unit When the mode switch unit 122 is not turned on at 124 , the re-boost power conversion device 10 with flyback mode has the function of a flyback power converter.

Please refer to FIG. 1 again, which is an output voltage waveform diagram of a general step-up power conversion device. The difference between the re-boost power conversion device 10 with the flyback mode of the present invention and the general re-boost power conversion device is that when the output voltage of the general re-boost power conversion device changes with time ( When the absolute value of the output voltage is greater than the absolute value of the input voltage; the horizontal line part in the output voltage waveform in FIG. 1 is the voltage value of the input voltage), the mode switch control unit 124 turns on the mode switch unit 122 ( The re-boost power conversion device 10 with flyback mode is a boost power converter).

When the output voltage of the general re-boost power conversion device does not change with time (when the lowest output voltage is clamped by the input voltage), the mode switch control unit 124 does not conduct the mode switch unit 122 (which has The re-boost power conversion device 10 in flyback mode is a flyback power converter).

Therefore, an output voltage (not shown in FIG. 4 , the output voltage is output from the power supply output terminal 104 ) waveform of the re-boost power conversion device 10 with flyback mode of the present invention will be as shown in FIG. 2 , which is similar to that of FIG. 1 The output voltage waveforms of the typical re-boost power conversion devices shown are different; the re-boost power conversion device 10 with flyback mode of the present invention can be applied to an AC output power supply.

In other words, when the output voltage of the general re-boost power conversion device does not change with time (the lowest output voltage cannot be zero), the re-boost power conversion device 10 with flyback mode of the present invention changes to Flyback type power converter, so that the minimum output voltage can be lower than an input voltage (not shown in FIG. 4, the input voltage is input to the power supply input terminal 102), and the minimum output voltage can be zero; the present invention has a flyback mode The re-boost power conversion device 10 can be applied to an AC output power supply.

In a specific embodiment, the mode switch control unit 124 does not conduct the mode switch unit 122 at twice the frequency of the input voltage, so that the re-boost power conversion device 10 with flyback mode becomes a flyback mode. In the rest of the time, the mode switch control unit 124 turns on the mode switch unit 122, so that the re-boost power conversion device 10 with flyback mode becomes a boost power converter. For example, if the frequency of the input voltage is 60 Hz, then the mode switch control unit 124 does not conduct the mode switch unit 122 at 120 Hz.

In another specific embodiment, the re-boost power conversion device 10 with flyback mode further includes a power input terminal voltage detector (not shown in FIG. 4 ) and a power supply output terminal voltage detector (not shown in FIG. 4 ). The voltage detector at the power input end is electrically connected to the power input end 102 and the mode switch control unit 124; the power output end voltage detector is electrically connected to the power output end 104 and the mode switch control unit 124 . The power input voltage detector detects the voltage of the power input 102 and notifies the mode switch control unit 124 ; the power output voltage detector detects the voltage of the power output 104 and notifies the mode switch control unit 124 .

Thereby, the mode switch control unit 124 knows the voltage value of the input voltage and the voltage value of the output voltage; when the absolute value of the output voltage is greater than the absolute value of the input voltage, the mode switch control unit 124 leads Through the mode switch unit 122, the re-boost power conversion device 10 with flyback mode is a boost power converter; when the lowest value of the output voltage is clamped by the input voltage, and the output voltage When the target value of the input voltage is not greater than the input voltage (when the absolute value of the output voltage is not greater than the absolute value of the input voltage), the mode switch control unit 124 does not conduct the mode switch unit 122, the flyback mode The re-boost power conversion device 10 is a flyback power converter.

Furthermore, the re-boost power conversion device 10 with flyback mode of the present invention can be equipped with an AC converter circuit (such as a full bridge circuit) at the power input end 102 or the power output end 104; therefore, the present invention has The re-boost power conversion device 10 in the flyback mode can be applied in the field of direct current to direct current, direct current to alternating current (such as a micro-converter), alternating current to direct current or alternating current to alternating current. The primary side switch control unit 112 controls the primary side switch unit 110 in a pulse width modulation (such as DCM, CCM, BCM or QR mode, etc.) manner.

Please refer to FIG. 5 , which is a block diagram of a second embodiment of the re-boost power conversion device with flyback mode of the present invention. Where the content in FIG. 5 is the same as that in FIG. 4 will not be repeated. Moreover, the re-boost power conversion device 10 with flyback mode further includes a second charge storage unit bypass circuit 126; the second charge storage unit bypass circuit 126 is electrically connected to the transformer 108, the second charge storage unit bypass circuit 126, A charge storage unit 116 , the second charge storage unit 118 , the mode switch unit 122 and the power negative terminal 106 .

When the mode switch control unit 124 does not turn on the mode switch unit 122 , the second charge storage unit 118 correctly discharges the power negative terminal 106 according to the second charge storage unit bypass circuit 126 .

That is, when the re-boost power conversion device 10 with flyback mode is a flyback power converter, the second charge storage unit bypass circuit 126 provides a bypass path for the second charge storage unit 118 , to ensure that the voltage of the second charge storage unit 118 is zero, and prevent the second charge storage unit 118 from being subjected to a negative charging current so that its voltage is negative.

The second charge storage unit bypass circuit 126 includes a bypass switch unit 12602 , a bypass switch control unit 12604 and a voltage detection unit 12608 . The bypass switch unit 12602 is electrically connected to the transformer 108, the first charge storage unit 116, the second charge storage unit 118, the mode switching switch unit 122 and the power supply negative terminal 106; the bypass switch control unit 12604 Electrically connected to the bypass switch unit 12602 and the mode switch control unit 124; the voltage detection unit 12608 is electrically connected to the transformer 108, the first charge storage unit 116, the second charge storage unit 118, the mode Switching switch unit 122 , the bypass switch unit 12602 and the bypass switch control unit 12604 . The bypass switch unit 12602 can be, for example but not limited to, a transistor switch.

When the re-boost power conversion device 10 with flyback mode is a flyback power converter, the mode switch control unit 124 notifies the bypass switch control unit 12604, and the voltage detection unit 12608 detects the second The voltage of the charge storage unit 118 notifies the bypass switch control unit 12604 , and the bypass switch control unit 12604 determines the turn-on time point of the bypass switch unit 12602 according to the voltage of the second charge storage unit 118 .

When the re-boost power conversion device 10 with flyback mode is a boost power converter, the mode switching switch control unit 124 notifies the bypass switch control unit 12604, and the bypass switch control unit 12604 does not conduct Pass the bypass switch unit 12602.

The transformer 108 includes a transformer primary side 10802 and a transformer secondary side 10804; the transformer primary side 10802 is electrically connected to the power input terminal 102; the transformer secondary side 10804 is set relative to the transformer primary side 10802; the transformer primary side The side 10802 includes a transformer first pin 10806 and a transformer second pin 10808; the transformer first pin 10806 is electrically connected to the power input terminal 102; the transformer secondary side 10804 includes a transformer third pin 10810 and a fourth pin 10812 of a transformer.

The primary side switch unit 110 includes a first pin 11002 of the primary side switch unit, a second pin 11004 of the primary side switch unit and a third pin 11006 of the primary side switch unit; The pin 11002 is electrically connected to the second pin 10808 of the transformer; the second pin 11004 of the primary switch unit is electrically connected to the primary switch control unit 112; the third pin 11006 of the primary switch unit is electrically connected to to the negative terminal 106 of the power supply.

The first unidirectional conductive unit 114 includes a first pin 11402 of the first unidirectional conductive unit and a second pin 11404 of the first unidirectional conductive unit; the first pin 11402 of the first unidirectional conductive unit is electrically connected To the third pin 10810 of the transformer; the second pin 11404 of the first unidirectional conduction unit is electrically connected to the output terminal 104 of the power supply.

The first charge storage unit 116 includes a first charge storage unit first pin 11602 and a first charge storage unit second pin 11604; the first charge storage unit first pin 11602 is electrically connected to the power output terminal 104; the second pin 11604 of the first charge storage unit is electrically connected to the fourth pin 10812 of the transformer.

The second charge storage unit 118 includes a first pin 11802 of a second charge storage unit and a second pin 11804 of a second charge storage unit; the first pin 11802 of the second charge storage unit is electrically connected to the first pin 11802 of the transformer Four pins 10812 ; the second pin 11804 of the second charge storage unit is electrically connected to the negative terminal 106 of the power supply.

The second unidirectional conduction unit 120 includes a first pin 12002 of a second unidirectional conduction unit and a second pin 12004 of a second unidirectional conduction unit; the first pin 12002 of the second unidirectional conduction unit is electrically connected to the second pin 10808 of the transformer.

The mode switch unit 122 includes a first pin 12202 of the mode switch unit, a second pin 12204 of the mode switch unit and a third pin 12206 of the mode switch unit; the first pin 12202 of the mode switch unit Electrically connected to the second pin 12004 of the second unidirectional conductive unit; the second pin 12204 of the mode switch unit is electrically connected to the mode switch control unit 124; the third pin 12206 of the mode switch unit Connect to the fourth pin 10812 of the transformer.

Please refer to FIG. 6 , which is a block diagram of a third embodiment of the re-boost power conversion device with flyback mode of the present invention. Where the content in FIG. 6 is the same as that in FIG. 5 will not be repeated. The second charge storage unit bypass circuit 126 includes a third unidirectional conduction unit 12606; the third unidirectional conduction unit 12606 is electrically connected to the transformer 108, the first charge storage unit 116, and the second charge storage unit 118 . The mode switch unit 122 and the negative terminal 106 of the power supply. The third unidirectional conduction unit 12606 can be, for example but not limited to, a diode (the cathode of the diode is electrically connected to the transformer 108, the first charge storage unit 116, the second charge storage unit 118 and the mode switch unit 122; the anode of the diode is electrically connected to the negative terminal 106 of the power supply).

The key points of the present invention are as follows:

1. When the absolute value of the output voltage is greater than the absolute value of the input voltage, the mode switch control unit 124 turns on the mode switch unit 122, and the re-boost power conversion device 10 with flyback mode is a boost type power converter; the mode switch control unit 124 notifies the bypass switch control unit 12604 that the bypass switch control unit 12604 does not conduct the bypass switch unit 12602 .

2. When the lowest value of the output voltage is clamped by the input voltage, the mode switch control unit 124 does not conduct the mode switch unit 122, and the re-boost power conversion device 10 with flyback mode is a flyback mode. type power converter, so that the minimum output voltage can be lower than the input voltage, and the minimum output voltage can be zero, so the re-boost power conversion device 10 with flyback mode of the present invention can be applied to an AC output power supply; the The second charge storage unit 118 correctly discharges the power supply negative terminal 106 according to the second charge storage unit bypass circuit 126 .

The effect of the present invention is that the minimum output voltage of the re-boost power conversion device can be zero, so the re-boost power conversion device can be applied to an AC output power supply.

Please refer to FIG. 7 , which is a block diagram of a fourth embodiment of the re-boost power conversion device with flyback mode of the present invention. Furthermore, in a specific embodiment, at least two re-boost power conversion devices 10 with flyback mode operate in parallel.

However, the above descriptions are only preferred embodiments of the present invention, and should not limit the scope of the present invention, that is, all equivalent changes and modifications made according to the claims of the present invention should still belong to the scope of patent coverage of the present invention. scope of protection.

Claims (10)

1. A re-boost power conversion device with a flyback mode, characterized in that it comprises: a power input terminal; a power output terminal; a power supply negative terminal; a transformer electrically connected to the power input terminal; a primary side switch unit, the primary side switch unit is electrically connected to the transformer and the negative terminal of the power supply; a primary side switch control unit, the primary side switch control unit is electrically connected to the primary side switch unit; a first one-way conduction unit, the first one-way conduction unit is electrically connected to the transformer and the output end of the power supply; a first charge storage unit, the first charge storage unit is electrically connected to the transformer and the output terminal of the power supply; a second charge storage unit electrically connected to the transformer, the first charge storage unit and the negative terminal of the power supply; a second unidirectional conduction unit, the second unidirectional conduction unit is electrically connected to the transformer and the primary side switch unit; a mode switch unit, the mode switch unit is electrically connected to the second unidirectional conduction unit, the transformer, the first charge storage unit and the second charge storage unit; and a mode switch control unit, the mode switch control unit is electrically connected to the mode switch unit, Wherein when the mode switch control unit is turned on the mode switch unit, the re-boost power conversion device with flyback mode has the function of a re-boost power converter; when the mode switch control unit is not turned on When the switch unit is switched in this mode, the re-boost power conversion device with flyback mode has the function of a flyback power converter. 2. The re-boost power conversion device with flyback mode according to claim 1, further comprising: A second charge storage unit bypass circuit, the second charge storage unit bypass circuit is electrically connected to the transformer, the first charge storage unit, the second charge storage unit, the mode switch unit and the negative terminal of the power supply , Wherein when the mode switch control unit does not turn on the mode switch unit, the second charge storage unit correctly discharges the negative terminal of the power supply according to the second charge storage unit bypass circuit. 3. The re-boost power conversion device with flyback mode according to claim 2, wherein the second charge storage unit bypass circuit comprises: a bypass switch unit electrically connected to the transformer, the first charge storage unit, the second charge storage unit, the mode switching switch unit and the negative terminal of the power supply; and A bypass switch control unit, the bypass switch control unit is electrically connected to the bypass switch unit and the mode switching switch control unit. 4. The re-boost power conversion device with flyback mode according to claim 3, wherein the transformer comprises a transformer primary side and a transformer secondary side, and the transformer primary side is electrically connected to the power supply The input end, the secondary side of the transformer is arranged relative to the primary side of the transformer, the primary side of the transformer includes a first pin of the transformer and a second pin of the transformer, the first pin of the transformer is electrically connected to the input end of the power supply, The secondary side of the transformer includes a transformer third pin and a transformer fourth pin. 5. The re-boost power conversion device with flyback mode according to claim 4, wherein the primary side switch unit comprises a first pin of the primary side switch unit, a first pin of the primary side switch unit Two pins and a third pin of the primary switch unit, the first pin of the primary switch unit is electrically connected to the second pin of the transformer, and the second pin of the primary switch unit is electrically connected to the primary The side switch control unit, the third pin of the primary side switch unit is electrically connected to the negative terminal of the power supply. 6. The re-boost power conversion device with flyback mode according to claim 5, wherein the first unidirectional conduction unit comprises a first pin of the first unidirectional conduction unit and a first unit The second pin of the unidirectional conductive unit, the first pin of the first unidirectional conductive unit is electrically connected to the third pin of the transformer, and the second pin of the first unidirectional conductive unit is electrically connected to the output end of the power supply; The first charge storage unit includes a first pin of the first charge storage unit and a second pin of the first charge storage unit, the first pin of the first charge storage unit is electrically connected to the output end of the power supply, and the first pin of the first charge storage unit is electrically connected to the output end of the power supply. A second pin of a charge storage unit is electrically connected to the fourth pin of the transformer; the second charge storage unit includes a first pin of a second charge storage unit and a second pin of a second charge storage unit, the first charge storage unit The first pin of the second charge storage unit is electrically connected to the fourth pin of the transformer, and the second pin of the second charge storage unit is electrically connected to the negative terminal of the power supply; the second unidirectional conduction unit includes a second unit The first pin of the directional conduction unit and the second pin of a second unidirectional conduction unit, the first pin of the second unidirectional conduction unit is electrically connected to the second pin of the transformer. 7. The re-boost power conversion device with flyback mode according to claim 6, characterized in that, the mode switch unit comprises a first pin of the mode switch unit, a second pin of the mode switch unit pin and a third pin of a mode switch unit, the first pin of the mode switch unit is electrically connected to the second pin of the second unidirectional conduction unit, and the second pin of the mode switch unit is electrically connected to The mode switch control unit, the third pin of the mode switch unit is electrically connected to the fourth pin of the transformer. 8. The re-boost power conversion device with flyback mode according to claim 7, characterized in that the re-boost power conversion device with flyback mode is applied to direct current to direct current, direct current to alternating current, alternating current Convert to DC or AC to AC field. 9 . The re-boost power conversion device with flyback mode according to claim 8 , wherein at least two re-boost power conversion devices with flyback mode operate in parallel. 10. The re-boost power conversion device with flyback mode according to claim 2, wherein the second charge storage unit bypass circuit comprises: A third unidirectional conduction unit, the third unidirectional conduction unit is electrically connected to the transformer, the first charge storage unit, the second charge storage unit, the mode switch unit and the negative terminal of the power supply.