TWI719573B - Power converter and power converter control method - Google Patents

Abstract

A power converter includes a power converting circuit, an output current control circuit, a high-voltage control circuit, a low-voltage control circuit, and a driving circuit. The power converting circuit receives and converts a HV dc voltage from a HV side to a LV dc voltage to a LV side. The output current control circuit is configured to detect an output current and output a first control signal. The high-voltage control circuit is configured to detect the HV dc voltage and output a second control signal. The low-voltage control circuit is configured to detect the LV dc voltage and output a third control signal selectively according to the LV dc voltage, or the LV dc voltage and the first control signal, or the LV dc voltage and the second control signal. The driving voltage outputs a driving signal to drive the power converting circuit according to the third control signal.

Description

Power converter and control method of power converter

The present disclosure relates to a power converter and a control method of the power converter, and particularly relates to a high-voltage to low-voltage power converter and a control method thereof.

Recently, with the increase in environmental awareness, electric vehicles (Electric Vehicle, EV), Hybrid Electric Vehicle (HEV) or plug-in hybrid electric vehicle (Plug-in Hybrid Electric Vehicle, PHEV) is becoming more and more popular.

Generally, a hybrid electric vehicle is equipped with a set of high-voltage batteries and a set of low-voltage batteries. However, when the high-voltage battery fails abnormally or cannot work at extremely low temperatures, the generators in the system may not be able to balance the voltage, causing the entire system to be overwhelmed. The system stops working due to voltage or under-voltage, which reduces the reliability of the system and causes problems such as the inability of the vehicle to run.

Therefore, how to improve the current power conversion system is one of the important topics in this field.

An implementation aspect of the present disclosure relates to a power converter. The power converter includes a power conversion circuit, an output current control circuit, a high-voltage voltage control circuit, a low-voltage voltage control circuit, and a drive circuit. The power conversion circuit is used for receiving the high-voltage direct current voltage from the high-voltage side, converting the high-voltage direct current voltage into a low-voltage direct current voltage and outputting to the low-voltage side. The output current control circuit is electrically coupled to the low voltage side for detecting the output current of the power conversion circuit and outputting the first control signal according to the output current. The high-voltage voltage control circuit is electrically coupled to the high-voltage side for detecting the high-voltage direct current voltage and outputting the second control signal according to the high-voltage direct current voltage. The low-voltage voltage control circuit is electrically coupled to the low-voltage side for detecting low-voltage DC voltage, and selectively according to the low-voltage DC voltage, or according to the low-voltage DC voltage and the first control signal, or according to the low-voltage DC voltage and the second control signal , To output the third control signal. The driving circuit is electrically coupled to the low voltage control circuit for driving the power conversion circuit according to the third control signal output driving signal.

Another implementation aspect of the present disclosure relates to a control method of a power converter, including: a power conversion circuit converts a high-voltage DC voltage on a high-voltage side into a low-voltage DC voltage and outputs it to a low-voltage side; and a processing circuit selectively Start the low-voltage voltage control circuit, or the output current control circuit and the low-voltage voltage control circuit, or the high-voltage voltage control circuit and the low-voltage voltage control circuit; when the output current control circuit is started, the output current control circuit is used to detect the output current of the power conversion circuit And output the first control signal to the low voltage control circuit according to the output current; when the high voltage control circuit is activated, detect the high voltage direct current voltage through the high voltage control circuit and output the second control signal to the low voltage control circuit according to the high voltage direct current voltage; When the low voltage voltage control circuit is activated, the low voltage voltage control circuit detects the low voltage DC voltage and outputs the third control signal; and the drive circuit outputs the drive signal according to the third control signal to drive the power conversion circuit to correspond to the third control The signal controls low-voltage DC voltage, high-voltage DC voltage or output current.

The following is a detailed description of the embodiments in conjunction with the accompanying drawings to better understand the aspect of the case, but the provided embodiments are not intended to limit the scope covered by the disclosure, and the description of the structural operations is not intended to limit The order of execution, any recombination of components, and a device with an equal effect are all within the scope of this disclosure. In addition, according to industry standards and common practices, the drawings are only for the purpose of supplementary explanation, and are not drawn in accordance with the original dimensions. In fact, the dimensions of various features can be arbitrarily increased or decreased for ease of explanation. In the following description, the same elements will be described with the same symbols to facilitate understanding.

Unless otherwise specified, the terms used in the entire specification and the scope of the patent application usually have the usual meaning of each term used in this field, in the content disclosed here, and in the special content. Some terms used to describe the present disclosure will be discussed below or elsewhere in this specification to provide those skilled in the art with additional guidance on the description of the present disclosure.

In addition, the terms "include", "include", "have", "contain", etc. used in this article are all open terms, meaning "including but not limited to". In addition, the "and/or" used in this article includes any one of one or more of the related listed items and all combinations thereof.

In this text, when an element is referred to as "connection" or "coupling", it can refer to "electrical connection" or "electrical coupling". "Connected" or "coupled" can also be used to indicate that two or more components cooperate or interact with each other. In addition, although terms such as “first”, “second”, etc. are used herein to describe different elements, the terms are only used to distinguish elements or operations described in the same technical terms. Unless the context clearly indicates, the terms do not specifically refer to or imply order or sequence, nor are they used to limit the present invention.

Please refer to Figure 1. FIG. 1 is a schematic diagram of a power conversion system 100 according to some embodiments of the present application. As shown in Figure 1, in some embodiments, the power conversion system 100 includes a DC generator 110, a power converter 120, a high-voltage side energy storage device 130, a processing circuit 140, a low-voltage side energy storage device 150, and a low-voltage load device 170. In some other embodiments, the power conversion system 100 further includes a protection circuit 180.

In some embodiments, the power conversion system 100 can be used in a plug-in hybrid electric vehicle (PHEV) or hybrid electric vehicle (HEV) system, through the power converter 120 and The cooperative operation of the processing circuit 140 converts the high-voltage DC voltage V1 output by the DC generator 110 on the high-voltage side into a low-voltage DC voltage V2, and provides an output current Io to output to the low-voltage side energy storage device 150 and the low-voltage load device 170 on the low-voltage side. In this way, the power required by various devices in the vehicle system can be provided.

For example, in some embodiments, the DC generator 110 can output a high-voltage DC voltage V1 of about 48V. The power converter 120 can convert it into a low-voltage DC voltage V2 of about 12V, for example, to supply the power demand of the car audio system on the car, the car electronic device such as the driving recorder, and so on. It is worth noting that the above-mentioned values and applications are only examples and are not intended to limit the case.

As shown in FIG. 1, structurally, the power converter 120 includes a power conversion circuit 121, a low-voltage voltage control circuit 122, an output current control circuit 124, a high-voltage voltage control circuit 126, and a drive circuit 129. The high voltage side of the power conversion circuit 121 is electrically coupled to the high voltage side energy storage device 130 and the DC generator 110, and the low voltage side of the power conversion circuit 121 is electrically coupled to the low voltage side energy storage device 150 and the low voltage load device 170. The power conversion circuit 121 is used to receive the high voltage DC voltage V1 on the high voltage side, convert the high voltage DC voltage V1 into a low voltage DC voltage V2 and output to the low voltage side of the power conversion circuit 121.

Specifically, the power conversion circuit 121 can be implemented by various switched DC-DC converters. For example, the power conversion circuit 121 may be a non-isolated converter (Non-Isolated Converter), such as: Buck Converter, Buck-Boost Converter, and so on. Alternatively, the power conversion circuit 121 may also be implemented by an isolated converter (Isolated Converter).

Please refer to Figure 2. FIG. 2 is a schematic diagram of a power conversion circuit 121 according to some embodiments of the present disclosure. In some embodiments, as shown in FIG. 2, the power conversion circuit 121 may be a phase shifted full bridge converter. In this embodiment, the power conversion circuit 121 includes switch switches SW1 to SW4, a resonant inductor L1, a transformer, rectifier switches SW5, SW6, an output inductor Lo, and an output capacitor Co. The primary side of the transformer includes a set of primary windings Np. The stage side contains two sets of secondary windings Ns1 and Ns2.

Structurally, the first terminals of the switch switches SW1 and SW3 are electrically coupled to the positive terminal of the high-voltage DC voltage V1, and the second terminals of the switch switches SW1 and SW3 are electrically coupled to the first terminals of the switch switches SW2 and SW4. The second terminals of the switches SW2 and SW4 are electrically coupled to the negative terminal of the high-voltage DC voltage V1. The resonant inductor L1 is connected in series with the primary winding Np, one end of which is electrically coupled between the second end of the switch SW1 and the first end of the switch SW2, and the other end is electrically coupled to the second end of the switch SW3 and the switch Between the first end of the switch SW4. The start end of the secondary winding Ns2 is electrically coupled to the end end of the secondary winding Ns1, and is electrically coupled to the negative end of the output capacitor Co through the rectifier switches SW5 and SW6, respectively.

In operation, the control ends of the switch switches SW1 to SW4 are respectively used to receive corresponding drive signals (such as the drive signal PWM in Figure 1), so that the switch switches SW1 to SW4 are selectively turned on or off according to the corresponding drive signals. Accordingly, by adjusting the length of time that the switches SW1 and SW4 and the switches SW2 and SW3 are turned on in turn, the switching signals of different duty cycles can be generated, and the switching signals are input to the transformer through the resonant inductor L1 for transformation. . The secondary winding Ns1 and the secondary winding Ns2 in the transformer induce the secondary current outputted by the signal change on the primary winding Np. The rectifier switches SW5 and SW6 are used to synchronously rectify the secondary current output by the transformer to provide a low-voltage DC voltage V2 on both ends of the output capacitor Co.

It should be noted that the power conversion circuit 121 is only used as an example, and is not intended to limit the case. In other embodiments, the types of the power conversion circuit 121 and the transformer circuit, resonant circuit, and rectifier circuit in the power conversion circuit 121 can be implemented in any form well known to those skilled in the art.

Please continue to refer to Figure 1. As shown in FIG. 1, the output current control circuit 124 is electrically coupled to the low voltage side to detect the output current Io of the power conversion circuit 121 and output the first control signal CT1 according to the output current Io. The high-voltage voltage control circuit 126 is electrically coupled to the high-voltage side for detecting the high-voltage DC voltage V1 and correspondingly outputting the second control signal CT2.

The low voltage control circuit 122 is electrically coupled to the low voltage side, the output current control circuit 124 and the high voltage control circuit 126. The low-voltage voltage control circuit 122 is used to detect the low-voltage DC voltage V2, and selectively according to the low-voltage DC voltage V2, or according to the low-voltage DC voltage V2 and the first control signal CT1, or according to the low-voltage DC voltage V2 and the second control signal CT2 correspondingly outputs the third control signal CT3 to the driving circuit 129.

The driving circuit 129 is electrically coupled to the low voltage control circuit 122 for receiving the third control signal CT3 and outputting the driving signal PWM according to the third control signal CT3 to switch the switch in the power conversion circuit 121 in a pulse width modulation method SW1～SW4 are turned on and off. In this way, by adjusting the duty cycle of the driving signal PWM, the length of time during which the switching switches SW1 to SW4 in the power conversion circuit 121 are turned on in the complete cycle can be controlled, thereby controlling the operation of the power converter 120.

In some embodiments, at the same point in time, the low-voltage voltage control circuit 122 can be activated separately, or the output current control circuit 124 and the low-voltage control circuit 122 can be activated together, or the high-voltage voltage control circuit 126 and the low-voltage voltage control circuit 122 can be activated together. That is to say, in this embodiment, the three feedback paths all include the low-voltage voltage control circuit 122 (ie, the low-voltage control circuit 122 will remain activated). However, at the same time, only one of the three feedback paths will be activated.

In other words, in the low-voltage control mode, when the low-voltage control circuit 122 is individually activated and outputs the third control signal CT3, the output current control circuit 124 and the high-voltage control circuit 126 are decoupled accordingly. In the low voltage and output current parallel control mode, when the output current control circuit 124 activates and outputs the first control signal CT1, the low voltage control circuit 122 also activates and receives the first control signal CT1 and outputs the third control signal CT3, and The high voltage voltage control circuit 126 is decoupled accordingly. In the low voltage and high voltage parallel control mode, when the high voltage control circuit 126 activates and outputs the second control signal CT2, the low voltage control circuit 122 also activates and receives the second control signal CT2 and outputs the third control signal CT3, and The output current control circuit 124 is decoupled accordingly.

In this way, the power conversion system 100 can control the output current control circuit 124 and the high voltage voltage control circuit 126 through the processing circuit 140, which decoupling is activated, or both are decoupled, and the high voltage DC voltage V1 can be adjusted according to the corresponding command value. The voltage level, the voltage level of the low-voltage DC voltage V2, or the current magnitude of the output current Io are controlled. It is worth noting that the activation and decoupling of the control circuit does not limit whether the control circuit is closed, but only represents whether the control circuit is involved in control.

More specifically, the processing circuit 140 is electrically connected to the low-voltage voltage control circuit 122, the output current control circuit 124, and the high-voltage voltage control circuit 126. The processing circuit 140 respectively outputs a low-voltage voltage command LVcmd, an output current command Icmd, and a high-voltage voltage command HVcmd to the low-voltage voltage control circuit 122, the output current control circuit 124, and the high-voltage voltage control circuit 126 to control selectively activate only the low-voltage voltage control circuit 122 , Or start the low voltage voltage control circuit 122 and the output current control circuit 124, or start the low voltage voltage control circuit 122 and the high voltage control circuit 126. In other words, the power converter 120 can operate in a low-voltage voltage control mode, a low-voltage voltage and output current parallel control mode, or a low-voltage and high-voltage voltage parallel control mode according to the control of the processing circuit 140. Perform corresponding control according to the current system status.

In addition, as shown in Figure 1, the high-voltage side and the low-voltage side of the power converter 120 can be respectively coupled to the high-voltage side energy storage device 130 and the low-voltage side energy storage device 150 to perform necessary power compensation. In some embodiments, the high-voltage side energy storage device 130 and the low-voltage side energy storage device 150 may be implemented by energy storage batteries. For example, the low-voltage side energy storage device 150 is electrically coupled to the low-voltage load device 170 and the low-voltage side of the power conversion circuit 121. When the low-voltage load device 170 is under a light load, the low-voltage side energy storage device 150 can absorb the extra power output by the power converter 120a. In this way, when the low-voltage load device 170 is under heavy load or the power converter 120 is insufficient to supply the power required by the low-voltage load device 170, the low-voltage side energy storage device 150 can output the stored power to the low-voltage load device 170 , In order to maintain the balance of supply and demand on the power system.

Similarly, the high-voltage side energy storage device 130 is electrically coupled to the high-voltage side of the DC generator 110 and the power conversion circuit 121. In this way, the high-voltage side energy storage device 130 can also adjust the power output from the DC generator 110 to the power converter 120 to maintain the stability of the high-voltage DC voltage V1 on the high-voltage side.

However, when the high-voltage side energy storage device 130 is disconnected from the DC generator 110 or an abnormality occurs, the high-voltage side energy storage device 130 cannot adjust the high-voltage DC voltage V1 on the high-voltage side. For example, in an extremely low temperature environment. High-voltage batteries may not work due to low temperatures. In this situation, if the load terminal on the low-voltage side changes drastically, the response of the DC generator 110 will be slow, and the output power of the generator will be insufficient to adjust the generator’s output power in a timely manner. The corresponding action of the protection circuit leads to abnormal system operation, for example, the power system stops working.

In order to avoid the above situation, in some embodiments of the present disclosure, when the high-voltage side energy storage device 130 is disconnected from the DC generator 110 or abnormality occurs, the processing circuit 140 can output the corresponding high-voltage voltage command HVcmd to control the high-voltage voltage control circuit 126 outputs the second control signal CT2 to the low voltage control circuit 122 according to the high voltage voltage command HVcmd, so that the low voltage control circuit 122 generates a corresponding third control signal CT3 to control the high voltage DC voltage V1 to stabilize at a corresponding target voltage value. In this way, the activation of the over-voltage protection mechanism can be avoided.

For ease of description, the cooperative operation of the power converter 120 and the processing circuit 140 will be described in conjunction with FIGS. 3A to 3C. Please refer to Figure 3A~Figure 3C. 3A to 3C are respectively schematic diagrams of the operation of the power converter 120a according to some embodiments of the present disclosure. In some embodiments, the power converter 120a shown in FIG. 3A to FIG. 3C can be used to implement the power converter 120 in FIG. 1.

As shown in FIGS. 3A to 3C, the low-voltage voltage control circuit 122 includes a voltage detection circuit 220, an adder 123, a compensation circuit, and a comparison amplifier OP1. Structurally, the voltage detection circuit 220 is electrically coupled to the low voltage side for detecting the low voltage DC voltage V2 to output the voltage detection signal Vd2 to the adder 123. For example, the voltage detection circuit 220 may be a voltage divider circuit including voltage divider resistors connected in series with each other. By selecting an appropriate voltage divider resistance value, the voltage detection circuit 220 can divide the voltage and output a voltage detection signal Vd2 with an appropriate voltage range for the operation of the subsequent circuit.

The adder 123 is electrically coupled to the low voltage side, the output current control circuit 124 and the high voltage control circuit 126 for receiving the voltage detection signal Vd2, the first control signal CT1, and the second control signal CT2, and the received signal The output is summed up.

The compensation circuit is electrically coupled between the adder 123 and the driving circuit 129 for receiving the signal added by the adder 123. In some embodiments, as shown in FIG. 3A, the compensation circuit may include resistors R1, R2, R3 and capacitors C1, C2, C3, but the disclosure is not limited thereto. In other embodiments, the compensation circuit may include resistors and capacitors electrically connected in various forms to form RC circuit. In the embodiments shown in FIGS. 3A to 3C, one end of the resistors R1 and R2 is electrically coupled to the adder 123, and the other end is electrically coupled to the second end (eg, the negative end) of the comparison amplifier OP1. The resistor R3 and the capacitor C2 are connected in series and connected in parallel with the capacitor C3. One end of the resistor R3 is electrically coupled to the second terminal (eg, the negative terminal) of the comparison amplifier OP1, and the other end is electrically coupled to the output terminal of the comparison amplifier OP1.

The first terminal (eg, the positive terminal) of the comparison amplifier OP1 is electrically coupled to the processing circuit 140 for receiving the low voltage voltage command LVcmd. The second terminal (eg, the negative terminal) of the comparison amplifier OP1 is electrically coupled to the compensation circuit. The output terminal of the comparison amplifier OP1 is electrically coupled to the driving circuit 129 for outputting the third control signal CT3 to the driving circuit 129.

It is worth noting that in some other embodiments, the low-voltage voltage control circuit 122 can also achieve selective reception of the first control signal CT1 or the second control signal CT2 in other ways. Although in the embodiments shown in FIGS. 3A to 3C, the output current control circuit 124 and the high voltage control circuit 126 are both coupled to the adder 123 in the low voltage control circuit 122, in other embodiments, the power supply The converter 120 can also be provided with a switch, and selectively output one or both of the low voltage DC voltage V2, the first control signal CT1 and the second control signal CT2 to the low voltage control circuit 122 through the switch. Therefore, the embodiment shown in FIG. 3A to FIG. 3C is only one possible implementation manner of the present disclosure, and is not intended to limit the case.

Similarly, as shown in FIGS. 3A to 3C, in some embodiments, the output current control circuit 124 includes a current detection circuit 240, a compensation circuit, a comparison amplifier OP2, and a rectification element D1. Structurally, the current detection circuit 240 is electrically coupled to the low voltage side for outputting a current detection signal Id according to the output current Io. For example, in some embodiments, the current detection circuit 240 can be implemented by a current detection resistor.

In some embodiments, the compensation circuit is electrically coupled between the processing circuit 140 and the low voltage control circuit 122 for receiving the output current command Icmd or Icmd_dis. As shown in the figure, the compensation circuit may include resistors R4, R5, R6 and capacitors C4, C5, C6, but the present disclosure is not limited to this. In other embodiments, the compensation circuit may include resistors and capacitors electrically connected in various forms to form an RC circuit. In the embodiments shown in FIGS. 3A to 3C, one end of the resistors R4 and R5 is electrically coupled to the processing circuit 140, and the other end is electrically coupled to the second end (eg, the negative end) of the comparison amplifier OP2. The resistor R6 and the capacitor C5 are connected in series and connected in parallel with the capacitor C6. One end of the resistor R6 is electrically coupled to the second terminal (eg, the negative terminal) of the comparison amplifier OP2, and the other end is electrically coupled to the output terminal of the comparison amplifier OP2.

The first terminal (such as the positive terminal) of the comparison amplifier OP2 is used to receive the current detection signal Id, the second terminal (such as the negative terminal) of the comparison amplifier OP2 is electrically coupled to the compensation circuit, and the output terminal of the comparison amplifier OP2 transmits The rectifying element D1 is electrically coupled to the low voltage control circuit 122 for outputting the first control signal CT1 to the low voltage control circuit 122.

In some embodiments, the rectifying element D1 can be realized by a diode unit. As shown in FIGS. 3A to 3C, the anode terminal of the rectifying element D1 is coupled to the output terminal of the comparator OP2, and the cathode terminal of the rectifying element D1 is coupled to the low voltage control circuit 122. The rectifying element D1 is used to ensure that no current path is generated between the output current control circuit 124 and the low-voltage voltage control circuit 122 to cause interference.

Similarly, as shown in FIGS. 3A to 3C, in some embodiments, the high voltage control circuit 126 includes a voltage detection circuit 260, a compensation circuit, a comparison amplifier OP3, and a rectification element D2. Structurally, the voltage detection circuit 260 is electrically coupled to the high voltage side for detecting the high voltage DC voltage V1 to output the voltage detection signal Vd1. For example, similar to the voltage detection circuit 220, the voltage detection circuit 260 can also be a voltage divider circuit including voltage divider resistors connected in series with each other. By selecting an appropriate voltage divider resistance value, the voltage detection circuit 260 can divide the voltage and output a voltage detection signal Vd1 with an appropriate voltage range for the operation of the subsequent circuit.

In some embodiments, the compensation circuit is electrically coupled between the voltage detection circuit 260 and the low voltage control circuit 122 for receiving the voltage detection signal Vd1. In some embodiments, as shown in the figure, the compensation circuit may include resistors R7, R8, R9 and capacitors C7, C8, C9, but the present disclosure is not limited to this. In other embodiments, the compensation circuit may include resistors and capacitors electrically connected in various forms to form an RC circuit. In the embodiments shown in FIGS. 3A to 3C, one end of the resistors R7 and R8 is electrically coupled to the voltage detection circuit 260, and the other end is electrically coupled to the second end (eg, the negative terminal) of the comparison amplifier OP3 ). The resistor R9 and the capacitor C8 are connected in series and connected in parallel with the capacitor C9. One end of the resistor R9 is electrically coupled to the second terminal (eg, the negative terminal) of the comparison amplifier OP3, and the other end is electrically coupled to the output terminal of the comparison amplifier OP3.

The first terminal (eg, the positive terminal) of the comparison amplifier OP3 is electrically coupled to the processing circuit 140 for receiving the high voltage command HVcmd or HVcmd_dis. The second terminal (eg, the negative terminal) of the comparison amplifier OP3 is electrically coupled to the compensation circuit. The output terminal of the comparison amplifier OP3 is electrically coupled to the low voltage control circuit 122 through the rectifying element D2 for outputting the second control signal CT2 to the low voltage control circuit 122.

In some embodiments, similar to the rectifying element D1, the rectifying element D2 can be realized by a diode unit. As shown in FIGS. 3A to 3C, the anode terminal of the rectifying element D2 is coupled to the output terminal of the comparator OP3, and the cathode terminal of the rectifying element D2 is coupled to the low voltage control circuit 122. The rectifying element D2 is used to ensure that no current path is generated between the output current control circuit 124 and the high voltage voltage control circuit 126 causing interference.

In operation, as shown in FIG. 3A, when the high-voltage side energy storage device 130 operates normally, the processing circuit 140 can control the power converter 120a to operate in a low-voltage voltage control mode or a low-voltage voltage and output current parallel control mode according to actual requirements. When the processing circuit 140 makes the power converter 120a selectively operate in the low voltage voltage control mode, the processing circuit 140 outputs a corresponding low voltage voltage command LVcmd. At this time, the low voltage voltage control circuit 122 receives the low voltage voltage command LVcmd from the processing circuit 140 to output the third control signal CT3 to the drive circuit 129 according to the low voltage voltage command LVcmd, so that the drive circuit 129 controls the low voltage DC voltage V2 to stabilize at the corresponding target voltage value.

Specifically, as shown in FIG. 3A, the low-voltage voltage command LVcmd can be filtered through the RC filter circuit 230 first. The filtered low-voltage voltage command LVcmd serves as the reference voltage of the low-voltage voltage control circuit 122 and is input to the positive terminal of the comparison amplifier OP1. The voltage detection signal Vd2 detected and output by the voltage detection circuit 220 is input to the negative terminal of the comparison amplifier OP1 through the adder 123. In this way, the comparison amplifier OP1 can cooperate with the compensation circuit to output the third control signal CT3 to the driving circuit 129 according to the voltage error signal of the positive terminal and the negative terminal.

For example, in some embodiments, when the low-voltage DC voltage V2 increases, the voltage detection signal Vd2 that generates feedback also increases correspondingly. When the voltage detection signal Vd2 output to the negative terminal of the comparison amplifier OP1 is greater than the low voltage voltage command LVcmd as the reference voltage, the voltage value of the third control signal CT3 generated by the comparison amplifier OP1 will decrease. Because the output terminal of the comparison amplifier OP1 is electrically coupled to the Vcomp pin of the driving circuit 129. Therefore, at this time, the voltage value of the Vcomp pin is correspondingly reduced, so that the duty cycle of the driving signal PWM output by the driving circuit 129 is reduced. In this way, the low-voltage direct current voltage V2 drops accordingly to control the low-voltage direct current voltage V2 at the voltage level corresponding to the low-voltage voltage command LVcmd.

Correspondingly, at this time, the processing circuit 140 outputs the high-voltage voltage command HVcmd_dis and the output current command Icmd_dis to control the high-voltage voltage control circuit 126 and the output current control circuit 124 to decouple according to the corresponding high-voltage voltage command HVcmd_dis and the output current command Icmd_dis. For example, at this time, the high-voltage voltage command HVcmd_dis can be set to zero or a value approaching zero, and the output current command Icmd_dis can be set to the current command corresponding to the maximum output current. In this way, the circuits in the high-voltage voltage control circuit 126 and the output current control circuit 124 will not affect the third control signal CT3.

On the other hand, as shown in Figure 3B, when the processing circuit 140 allows the power converter 120a to selectively operate in the low-voltage voltage and output current parallel control mode, the processing circuit 140 can slightly increase the low-voltage voltage command LVcmd and output the corresponding Output current command Icmd. At this time, the output current control circuit 124 can receive the output current command Icmd from the processing circuit 140 to output the first control signal CT1 to the low voltage control circuit 122 according to the output current command Icmd, so that the low voltage control circuit 122 controls the output through the drive circuit 129 The current Io stabilizes at the target current value corresponding to the output current command Icmd.

Specifically, as shown in FIG. 3B, the output current command Icmd is used as the reference current of the output current control circuit 124 and is input to the negative terminal of the comparator OP2. The current detection signal Id outputted by the current detection circuit 240 is input to the positive terminal of the comparison amplifier OP2. In this way, the comparison amplifier OP2 can output the first control signal CT1 to the low voltage control circuit 122 according to the voltage error signal of the positive terminal and the negative terminal in conjunction with the compensation circuit.

For example, in some embodiments, when the output current Io increases, the current detection signal Id that generates feedback also increases accordingly. When the current detection signal Id output to the positive terminal of the comparison amplifier OP1 is greater than the output current command Icmd as the reference current, the voltage value of the first control signal CT1 generated by the comparison amplifier OP2 will increase. Since the output terminal of the comparison amplifier OP2 is electrically coupled to the adder 123 of the low voltage control circuit 122, the adder 123 inputs the summed signal of the voltage detection signal Vd2 and the first control signal CT1 to the low voltage control circuit 122 for comparison The negative terminal of amplifier OP1. Therefore, when the voltage value of the first control signal CT1 increases, the voltage value of the Vcomp pin decreases accordingly, so that the duty cycle of the driving signal PWM output by the driving circuit 129 decreases to reduce the output current Io.

In this way, the output current control circuit 124 can output the first control signal CT1 to the low voltage voltage control circuit 122 according to the output current command Icmd, so that the low voltage voltage control circuit 122 controls the output current Io through the drive circuit 129 to stabilize at the same level as the output current command Icmd The corresponding target current value. Correspondingly, at this time, the processing circuit 140 outputs a corresponding high voltage voltage command HVcmd_dis The high-voltage voltage control circuit 126 is controlled to be decoupled. The specific operation details have been described in detail in the previous embodiment, so it will not be repeated here.

On the other hand, in operation, as shown in Figure 3C, when the high-voltage side energy storage device 130 is disconnected from the DC generator 110 or an abnormality occurs, or when the processing circuit 140 makes the power converter 120a selectively operate at low voltage In the parallel control mode of voltage and high voltage voltage, the processing circuit 140 may slightly adjust the high and low voltage command LVcmd and output the corresponding high voltage command HVcmd. At this time, the high-voltage voltage control circuit 126 can receive the high-voltage command HVcmd from the processing circuit 140 to output the second control signal CT2 to the low-voltage control circuit 122 according to the high-voltage command HVcmd, so that the low-voltage control circuit 122 controls the high-voltage through the drive circuit 129 The DC voltage V1 is stabilized at the corresponding target voltage value.

Specifically, as shown in FIG. 3C, the detailed operation of the high voltage control circuit 126 is similar to the negative feedback control in the low voltage control circuit 122, and the high voltage command HVcmd can be filtered through the RC filter circuit 270 first. The filtered high-voltage voltage command HVcmd is used as the reference voltage of the high-voltage voltage control circuit 126 and input to the positive terminal of the comparator OP3. The voltage detection signal Vd1 detected by the voltage detection circuit 260 is input to the negative terminal of the comparison amplifier OP3. In this way, the comparison amplifier OP3 can output the second control signal CT2 to the low-voltage voltage control circuit 122 according to the voltage error signal at the positive terminal and the negative terminal in conjunction with the compensation circuit.

For example, in some embodiments, when the high-voltage DC voltage V1 decreases, the voltage detection signal Vd1 that generates the feedback is also decreased correspondingly. When the voltage detection signal Vd1 output to the negative terminal of the comparison amplifier OP3 is smaller than the high voltage command HVcmd as the reference voltage, the voltage value of the second control signal CT2 generated by the comparison amplifier OP3 will increase. Since the output terminal of the comparison amplifier OP3 is electrically coupled to the adder 123 of the low-voltage voltage control circuit 122, the adder 123 inputs the summed signal of the voltage detection signal Vd2 and the second control signal CT2 into the low-voltage voltage control circuit 122 for comparison The negative terminal of amplifier OP1. Therefore, when the voltage value of the second control signal CT2 increases (while the voltage detection signal Vd2 remains unchanged), the voltage value of the Vcomp pin decreases accordingly, so that the duty cycle of the driving signal PWM output by the driving circuit 129 decreases.

As a result, the output power of the power converter 120a is reduced accordingly, so as to control the high-voltage DC voltage V1 not to be further reduced and cause the under-voltage protection mechanism to start, so that the high-voltage DC voltage V1 can be controlled to remain stable. Correspondingly, at this time, the processing circuit 140 outputs a corresponding output current command Icmd_dis to control the decoupling of the output current control circuit 124. The specific operation details have been described in detail in the previous embodiment, so it will not be repeated here.

In this way, by the processing circuit 140 respectively outputting one or both of the low-voltage voltage command LVcmd, the output current command Icmd, and the high-voltage voltage command HVcmd, the low-voltage voltage control circuit 122, the output current control circuit 124, and the high-voltage voltage control can be controlled. Whether one or both of the circuits 126 are activated. In this way, when the high-voltage side energy storage device 130 and the DC generator 110 are disconnected or abnormal, the high-voltage DC voltage V1 can be stabilized at the corresponding target voltage value, and the high-voltage DC voltage V1 can be prevented from exceeding the safe range and causing system misoperation. It can also selectively control the low-voltage DC voltage V2 at the voltage level corresponding to the low-voltage voltage command LVcmd when the high-voltage side energy storage device 130 operates normally, and/or stabilize the output current Io at a voltage level corresponding to the output current command Icmd Target current value.

Please refer to Figure 4A to Figure 4C. 4A to 4C are respectively schematic diagrams of the operation of the power converter 120b according to some embodiments of the present disclosure. In some embodiments, the power converter 120b shown in FIG. 4A to FIG. 4C can be used to implement the power converter 120 in FIG. 1. In FIGS. 4A to 4C, similar elements related to the embodiments in FIGS. 3A to 3C are denoted by the same reference numerals for ease of understanding, and the specific principles of the similar elements have been described in detail in the previous paragraphs. If it is not necessary to introduce the elements that have a cooperative operation relationship with the elements in FIG. 4A to FIG. 4C, it will not be repeated here.

Compared with the embodiments in FIGS. 3A to 3C, in the embodiments in FIGS. 4A to 4C, the low-voltage voltage control circuit 122 includes an adder 123 and a subtractor 125. Structurally, the adder 123 is electrically coupled to the voltage detection circuit 220 and the output current control circuit 124 to receive the voltage detection signal Vd2 and the first control signal CT1, and output the sum of the two to the comparison amplifier OP1 The second terminal (such as the negative terminal). The subtractor 125 is electrically coupled to the processing circuit 140 and the high voltage control circuit 126 to receive the low voltage command LVcmd and the second control signal CT2, and subtract the second control signal CT2 from the low voltage command LVcmd and output to the comparison amplifier The first end of OP1 (such as the positive end).

In addition, in the embodiments shown in FIGS. 4A to 4C, the first terminal (eg, the positive terminal) of the comparator amplifier OP3 of the high-voltage voltage control circuit 126 is electrically coupled to the voltage detection circuit 260 for receiving the voltage detection circuit. Test signal Vd1. The second terminal (eg, the negative terminal) of the comparator OP3 of the high voltage control circuit 126 is electrically coupled to the processing circuit 140 through the compensation circuit and the RC filter circuit 270 for receiving the filtered high voltage command HVcmd or HVcmd_dis.

In operation, when the processing circuit 140 makes the power converter 120b selectively operate in the low voltage voltage control mode, as shown in FIG. 4A, similar to FIG. 3A, the processing circuit 140 outputs a corresponding low voltage voltage command LVcmd. At this time, the low voltage voltage control circuit 122 can receive the low voltage command LVcmd from the processing circuit 140 through the subtractor 125, and receive the voltage detection signal Vd2 from the voltage detection circuit 220 through the adder 123, so that the comparison amplifier OP1 is based on the positive and negative The extreme voltage error signal is combined with the compensation circuit to output the third control signal CT3 to the driving circuit 129. Correspondingly, at this time, the processing circuit 140 outputs the corresponding high-voltage voltage command HVcmd_dis and the output current command Icmd_dis to control the high-voltage voltage control circuit 126 and the output current control circuit 124 to decouple. The specific operation details are described in detail in the previous embodiment, so it will not be repeated here.

On the other hand, when the processing circuit 140 allows the power converter 120b to selectively operate in the low voltage and output current parallel control mode, as shown in Figure 4B, similar to Figure 3B, the processing circuit 140 can slightly increase the low voltage command LVcmd and output the corresponding output current command Icmd. At this time, the low-voltage voltage control circuit 122 can receive the low-voltage command LVcmd through the subtractor 125, and receive the sum of the voltage detection signal Vd2 and the first control signal CT1 through the adder 123, so that the comparison amplifier OP1 is based on the difference between the positive terminal and the negative terminal. The voltage error signal is combined with the compensation circuit to output the third control signal CT3 to the driving circuit 129. Correspondingly, at this time, the processing circuit 140 outputs a corresponding high-voltage voltage command HVcmd_dis to control the decoupling of the high-voltage voltage control circuit 126. The specific operation details are described in detail in the previous embodiment, so it will not be repeated here.

On the other hand, when the processing circuit 140 makes the power converter 120b selectively operate in the low voltage and high voltage parallel control mode, as shown in Figure 4C, the processing circuit 140 outputs the corresponding high voltage command HVcmd and slightly increases the low voltage. Voltage command LVcmd. At this time, the low-voltage voltage control circuit 122 can receive the difference between the low-voltage command LVcmd and the second control signal CT2 through the subtractor 125, and receive the voltage detection signal Vd2 through the adder 123, so that the comparison amplifier OP1 is based on the positive terminal and the negative terminal. The voltage error signal is matched with the compensation circuit to output the third control signal CT3 to the driving circuit 129. Correspondingly, at this time, the processing circuit 140 outputs a corresponding output current command Icmd_dis to control the decoupling of the output current control circuit 124.

For example, in some embodiments, when the high-voltage DC voltage V1 decreases, the voltage detection signal Vd1 that generates the feedback is also decreased correspondingly. When the voltage detection signal Vd1 output to the positive terminal of the comparison amplifier OP3 is smaller than the high voltage command HVcmd as the reference voltage, the voltage value of the second control signal CT2 generated by the comparison amplifier OP3 will decrease. Since the output terminal of the comparison amplifier OP3 is electrically coupled to the subtractor 125 of the low voltage control circuit 122, the subtractor 125 inputs the signal obtained by subtracting the low voltage command LVcmd and the second control signal CT2 into the comparison amplifier of the low voltage control circuit 122 The positive extreme of OP1. Therefore, the voltage value of the Vcomp pin is correspondingly reduced, so that the duty cycle of the driving signal PWM output by the driving circuit 129 is reduced.

As a result, in the embodiment shown in Fig. 4A to Fig. 4C, as described in the previous embodiment in Fig. 3A to Fig. 3C, the energy storage device 130 on the high-voltage side is disconnected from the DC generator 110 or an abnormality occurs. At this time, the power converter 120b can operate in a parallel control mode of low voltage and high voltage. On the other hand, when the high-voltage side energy storage device 130 operates normally, the processing circuit 140 can control the power converter 120b to operate in a low-voltage voltage control mode or a low-voltage voltage and output current parallel control mode according to actual requirements. As a result, the processing circuit 140 is used to output corresponding low-voltage voltage commands, output current commands, and high-voltage voltage commands to control the corresponding activation or decoupling of the low-voltage voltage control circuit 122, the output current control circuit 124, and the high-voltage voltage control circuit 126 to The low-voltage DC voltage V2, the output current Io, or the high-voltage DC voltage V1 is stabilized at the corresponding target voltage value and target current value.

Please refer to Figure 5. FIG. 5 is a flowchart of a control method 500 of the power converter 120 according to some embodiments of the present disclosure. For the sake of convenience and clarity, the following control method 500 of the power converter 120 is described in conjunction with the embodiments shown in Figures 1 to 4C, but is not limited to this. Anyone who is familiar with this skill will not depart from it. Within the spirit and scope of this case, various changes and modifications can be made. As shown in FIG. 5, the control method 500 of the power converter 120 includes operations S510, S520, S530, S540, S550, and S560.

First, in operation S510, the power conversion circuit 121 converts the high-voltage DC voltage V1 on the high-voltage side into a low-voltage DC voltage V2 and outputs it to the low-voltage side.

In operation S520, the processing circuit 140 selectively activates one or both of the low-voltage voltage control circuit 122, the output current control circuit 124, and the high-voltage voltage control circuit 126. Specifically, the processing circuit 140 can enable the power converter 120 to selectively operate in the low-voltage voltage control mode Mode1, the low-voltage voltage and output current parallel control mode Mode2, or the low-voltage voltage and high-voltage voltage parallel control mode Mode3, which of the three is Either.

In the low-voltage voltage and output current parallel control mode Mode2, enter operation S530. In operation S530, when the output current control circuit 124 is activated, the output current control circuit 124 detects the output current Io of the power conversion circuit 121 and outputs the first control signal CT1 to the low voltage control circuit 122 according to the output current Io. For example, the output current control circuit 124 can output the first control signal CT1 to the low voltage control circuit 122 according to the detected current detection signal Id and the output current command Icmd.

In the low-voltage and high-voltage parallel control mode Mode3, operation S540 is entered. In operation S540, when the high-voltage control circuit 126 is activated, the high-voltage control circuit 126 detects the high-voltage direct current voltage V1 and outputs the second control signal CT2 according to the high-voltage direct current voltage V1. For example, the high voltage control circuit 126 can output the second control signal CT2 to the low voltage control circuit 122 according to the detected voltage detection signal Vd1 and the high voltage command HVcmd.

After operation S530 and operation S540, or in the low voltage control mode Mode1, proceed to operation S550. In operation S550, when the low-voltage control circuit 122 is activated, the low-voltage control circuit 122 detects the low-voltage DC voltage V2 and outputs the third control signal CT3 accordingly. For example, in the low voltage control mode Mode1, the low voltage control circuit 122 can output the third control signal CT3 to the driving circuit 129 according to the detected voltage detection signal Vd2 and the low voltage command LVcmd. For another example, in the low voltage and output current parallel control mode Mode2, the low voltage control circuit 122 can output the third control signal CT3 to drive according to the detected voltage detection signal Vd2, the low voltage command LVcmd, and the first control signal CT1 Circuit 129. For another example, in the low-voltage and high-voltage parallel control mode Mode3, the low-voltage control circuit 122 can output the third control signal CT3 to the driver according to the detected voltage detection signal Vd2, the low-voltage voltage command LVcmd, and the second control signal CT2. Circuit 129. The specific content is explained in detail in the previous paragraph, so it will not be repeated here.

Finally, in operation S560, the driving circuit 129 outputs the driving signal PWM to drive the power conversion circuit 121 according to the third control signal CT3 to control the high-voltage direct current voltage V1, the low-voltage direct current voltage V2 or the output current Io corresponding to the third control signal CT3.

The above content includes exemplary operations. However, these operations do not have to be performed in sequence. The operations mentioned in this embodiment can be adjusted according to actual needs, and can even be performed simultaneously or partly, unless the order is specifically stated.

Those skilled in the art can directly understand how the control method 500 performs these operations and functions based on the power conversion system 100 in the various embodiments described above, so the details are not repeated here.

In addition, although the disclosed methods are shown and described herein as a series of operations or events, it should be understood that the sequence of these operations or events shown should not be construed in a limiting sense. For example, some operations may occur in a different order and/or simultaneously with other operations or events other than those shown and/or described herein. In addition, when implementing one or more aspects or embodiments described herein, not all operations shown here are necessary. In addition, one or more operations herein may also be performed in one or more separate steps and/or stages.

In addition, in some implementations, when the high voltage control circuit 126 is activated, if the voltage detection signal Vd1 is less than the high voltage command HVcmd as the reference voltage, the duty cycle of the driving signal PWM output by the driving circuit 129 is reduced. At this time, if the output power of the power converter 120 is reduced accordingly, so that the low-voltage DC voltage V2 output to the low-voltage side is smaller than the low-voltage side energy storage device 150, it may cause the low-voltage side current to flow back to the power conversion circuit 121, causing the power supply The conversion circuit 121 is damaged.

In order to avoid the above situation, in some embodiments of the present disclosure, as shown in FIG. 1, the protection circuit 180 is electrically coupled between the power conversion circuit 121 and the low-side energy storage device 150. For ease of description, please refer to Fig. 6A and Fig. 6B for the operation of the protection circuit 180. FIG. 6A and FIG. 6B are respectively schematic diagrams of the operation of the protection circuits 180a and 180b according to some embodiments of the present disclosure. The protection circuits 180a and 180b shown in FIGS. 6A and 6B can be used to implement the protection circuit 180 in FIG. 1. As shown in FIGS. 6A and 6B, the protection circuits 180a and 180b are coupled to the low-voltage side. When the reverse current Iz flowing from the low-voltage side to the power conversion circuit 121 is detected, the protection circuits 180a and 180b are used to output stop commands DIS to protect the power conversion circuit 121.

In some embodiments, as shown in FIG. 6A, the protection circuit 180a includes a reverse current detection circuit 620a. The reverse current detection circuit 620a is electrically coupled between the low voltage side and the power conversion circuit 121. When the reverse current detection circuit 620a detects the reverse current Iz, the reverse current detection circuit 620a is used to output the detection signal S1 to the driving circuit 129. When the driving circuit 129 receives the detection signal S1, the driving circuit 129 is used to output a stop command DIS to turn off a plurality of switches in the power conversion circuit 121 (such as the switch switches SW1 to SW4 shown in FIG. 2).

In other embodiments, as shown in FIG. 6B, the protection circuit 180b includes a reverse current detection circuit 620b, a protection switch SWp, and a protection switch driver 640. The reverse current detection circuit 620b is electrically coupled between the low voltage side and the protection switch driver 640. When the reverse current detection circuit 620b detects the reverse current Iz, the reverse current detection circuit 620b is used to output the detection signal S2 to the protection switch driver 640. When the protection switch driver 640 receives the detection signal S2, the protection switch driver 640 is used to output a stop command to turn off the protection switch SWp. Specifically, the protection switch SWp and the protection switch driver 640 may be implemented by a set of protection field effect transistors (Oring FET).

In this way, with the reverse current detection circuit 620a and/or 620b, when a reverse current Iz occurs, the switch and/or switch in the power conversion circuit 121 can be actively and quickly turned off through the detection signal S1 and/or S2. Or the protection switch SWp on the output current path to prevent the power conversion circuit 121 from being damaged.

It should be noted that, in the case of no conflict, the features and circuits in the various drawings, embodiments, and embodiments of the present disclosure can be combined with each other. The circuit shown in the figure is only an example, and is simplified to make the description concise and easy to understand, and is not intended to limit the case. In addition, the various devices, units, and components in the foregoing embodiments can be implemented by various types of digital or analog circuits, and can also be implemented by different integrated circuit chips, or integrated into a single chip. The foregoing is only an example, and the present disclosure is not limited thereto.

To sum up, in this case, by applying the above-mentioned various embodiments, when the high-voltage side energy storage device 130 is disconnected from the DC generator 110 or an abnormality occurs, the processing circuit 140 outputs the corresponding high-voltage voltage command HVcmd to control the high-voltage voltage control circuit 126 According to the high-voltage command HVcmd, the second control signal CT2 is output to the low-voltage control circuit 122, so that the low-voltage control circuit 122 controls the high-voltage DC voltage V1 to stabilize at the corresponding target voltage value through the drive circuit 129, so that the voltage abnormality protection mechanism can be prevented from being activated. In this way, when the high-voltage battery fails abnormally or the high-voltage battery cannot work due to the extremely low temperature environment, the power converter 120 can actively stabilize the high-voltage power supply to ensure that the vehicle can run normally, thereby improving the reliability of the system.

Although the content of this disclosure has been disclosed in the above manner, it is not intended to limit the content of this disclosure. Those with ordinary knowledge in the technical field can make various changes and modifications without departing from the spirit and scope of this disclosure. Therefore, this The scope of protection of the disclosed content shall be subject to the scope of the attached patent application.

100 Power Conversion System 110 DC generator 120, 120a, 120b Power converter 121 Power Conversion Circuit 122 Low voltage control circuit 123 Adder 124 Output current control circuit 126 High voltage voltage control circuit 129 Drive circuit 130 High-voltage side energy storage device 140 processing circuit 150 Low-voltage side energy storage device 170 Low-voltage load device 180, 180a, 180b Protection circuit V1 High voltage DC voltage V2 Low voltage DC voltage Io output current PWM drive signal CT1, CT2, CT3 control signal LVcmd Low voltage voltage command HVcmd, HVcmd_dis High voltage command Icmd, Icmd_dis output current command SW1～SW4 switch SW5, SW6 Rectifier switch L1 Resonant inductance Lo output inductance Co output capacitor Np primary winding Ns1, Ns2 secondary winding R1～R9 Resistance C1～C9 Capacitance OP1, OP2, OP3 Comparison amplifier D1, D2 Rectifier components 220, 260 Voltage detection circuit 230, 270 RC filter circuit 240 Current detection circuit Vd1, Vd2 voltage detection signal Id Current detection signal 500 control method S510, S520, S530, S540, S550, S560 Operation Mode1, Mode2, Mode3 Control mode Iz Reverse current 620a, 620b Reverse current detection circuit 640 Protection switch driver SWp protection switch S1, S2 detection signal DIS Stop command

FIG. 1 is a schematic diagram of a power conversion system according to some embodiments of the present disclosure. FIG. 2 is a schematic diagram of a power conversion circuit according to some embodiments of the present disclosure. 3A to 3C are respectively schematic diagrams of the operation of the power converter according to some embodiments of the present disclosure. 4A to 4C are respectively schematic diagrams of the operation of the power converter according to some embodiments of the present disclosure. FIG. 5 is a flowchart of the control method of the power converter according to some embodiments of the present disclosure. FIG. 6A and FIG. 6B are respectively schematic diagrams of the operation of the protection circuit according to some embodiments of the present disclosure.

100 Power Conversion System 110 DC generator 120 Power converter 121 Power Conversion Circuit 122 Low voltage control circuit 124 Output current control circuit 126 High voltage voltage control circuit 129 Drive circuit 130 High-voltage side energy storage device 140 processing circuit 150 Low-voltage side energy storage device 170 Low-voltage load device 180 Protection Circuit V1 High voltage DC voltage V2 Low voltage DC voltage Io output current PWM drive signal CT1, CT2, CT3 control signal LVcmd Low voltage voltage command HVcmd High voltage voltage command Icmd output current command

Claims (13)

A power converter includes: a power conversion circuit for receiving a high voltage DC voltage from a high voltage side, converting the high voltage DC voltage into a low voltage DC voltage and outputting to a low voltage side; an output current control circuit, electrical Is coupled to the low voltage side for detecting an output current of the power conversion circuit and outputting a first control signal according to the output current; a high voltage voltage control circuit is electrically coupled to the high voltage side for detecting Measure the high-voltage DC voltage, and output a second control signal according to the high-voltage DC voltage; a low-voltage voltage control circuit is electrically coupled to the low-voltage side for detecting the low-voltage DC voltage, and selectively the low-voltage The direct current voltage and the first control signal are summed to output a third control signal, or the low-voltage direct current voltage and the second control signal are summed to output the third control signal; and a driving circuit is electrically coupled to The low voltage control circuit is used for outputting a driving signal to drive the power conversion circuit according to the third control signal. The power converter according to claim 1, wherein the low-voltage voltage control circuit is further configured to receive a low-voltage voltage command from a processing circuit, so as to selectively respond to the low-voltage voltage command, the low-voltage DC voltage, and the first control signal , Or according to the low voltage voltage command, the low voltage direct current voltage and the second control signal to generate the third control signal. The power converter according to claim 2, wherein the low-voltage voltage control circuit includes: a first voltage detection circuit for detecting the low-voltage DC voltage to output a first voltage detection signal; A compensation circuit is electrically coupled between the first voltage detection circuit and the drive circuit for receiving the sum of the first voltage detection signal and the first control signal, or receiving the first voltage detection The summation of the signal and the second control signal; and a first comparison amplifier, a first end of the first comparison amplifier is used to receive the low voltage command, and a second end of the first comparison amplifier is electrically coupled In the first compensation circuit, an output terminal of the first comparison amplifier is electrically coupled to the driving circuit. The power converter according to claim 2, wherein the low-voltage voltage control circuit includes: a first voltage detection circuit for detecting the low-voltage DC voltage to output a first voltage detection signal; A compensation circuit is electrically coupled between the first voltage detection circuit and the drive circuit for receiving the sum of the first voltage detection signal and the first control signal; and a first comparison amplifier, the A first terminal of the first comparison amplifier is used to receive the low voltage command or the sum of the low voltage command and the second control signal, and a second terminal of the first comparison amplifier is electrically coupled to the first A compensation circuit, an output terminal of the first comparison amplifier is electrically coupled to the driver Moving circuit. The power converter according to claim 1, wherein the output current control circuit is further configured to receive an output current command from a processing circuit to generate the first control signal to the low voltage voltage according to the output current command and the output current Control circuit. The power converter according to claim 5, wherein the output current control circuit includes: a current detection circuit for outputting an output current detection signal according to the output current; and a second compensation circuit electrically coupled to Between the processing circuit and the low-voltage voltage control circuit, for receiving the output current command; and a second comparison amplifier, a first end of the second comparison amplifier for receiving the output current detection signal, the second A second terminal of the comparison amplifier is electrically coupled to the second compensation circuit, and an output terminal of the second comparison amplifier is electrically coupled to the low voltage control circuit. The power converter according to claim 1, wherein the high-voltage voltage control circuit is further configured to receive a high-voltage voltage command from a processing circuit to generate the second control signal to the low-voltage according to the high-voltage voltage command and the high-voltage DC voltage Voltage control circuit. The power converter according to claim 7, wherein the high voltage The voltage control circuit includes: a second voltage detection circuit for detecting the high-voltage DC voltage to output a second voltage detection signal; a third compensation circuit electrically coupled to the second voltage detection The circuit and the low-voltage voltage control circuit are used to receive the second voltage detection signal; and a third comparison amplifier. A second end of the amplifier is electrically coupled to the third compensation circuit, and an output end of the third comparison amplifier is electrically coupled to the low voltage control circuit. The power converter according to claim 7, wherein the high-voltage voltage control circuit includes: a second voltage detection circuit for detecting the high-voltage direct current voltage to output a second voltage detection signal; and a third A compensation circuit, electrically coupled between the processing circuit and the low voltage control circuit, for receiving the high voltage command; and a third comparison amplifier, a first end of the third comparison amplifier for receiving the first Two voltage detection signals, a second end of the third comparison amplifier is electrically coupled to the third compensation circuit, and an output end of the third comparison amplifier is electrically coupled to the low voltage control circuit. The power converter according to claim 1, further comprising: a protection circuit, coupled to the low voltage side, when a reverse current is detected, The protection circuit is used for outputting a stop command to protect the power conversion circuit. The power converter according to claim 10, wherein the protection circuit includes: a reverse current detection circuit coupled to the low voltage side, and when the reverse current flowing from the low voltage side to the power conversion circuit is detected, The reverse current detection circuit is used to output a detection signal; and a protection switch and a protection switch driver are coupled to the low voltage side. When receiving the detection signal, the protection switch driver is used to output the stop command to Turn off the protection switch. The power converter according to claim 10, wherein the protection circuit includes: a reverse current detection circuit coupled to the low voltage side, and when the reverse current flowing from the low voltage side to the power conversion circuit is detected, The reverse current detection circuit is used for outputting a detection signal, wherein when the driving circuit receives the detection signal, the driving circuit is used for outputting a stop command to turn off a plurality of switches in the power conversion circuit. A control method for a power converter includes: a power conversion circuit converts a high-voltage DC voltage on a high-voltage side into a low-voltage DC voltage and outputs it to a low-voltage side; a processing circuit selectively activates an output current at the same time Control circuit and a low-voltage voltage control circuit, or start a high-voltage voltage control circuit at the same time And the low voltage voltage control circuit; when the output current control circuit is activated, the output current control circuit detects an output current of the power conversion circuit and outputs a first control signal to the low voltage control circuit according to the output current ; When the high-voltage voltage control circuit is activated, the high-voltage voltage control circuit detects the high-voltage DC voltage and outputs a second control signal to the low-voltage voltage control circuit according to the high-voltage DC voltage; when the low-voltage control circuit is activated , Through the low-voltage voltage control circuit, detect the low-voltage DC voltage and output a third control signal; and a drive circuit outputs a drive signal according to the third control signal to drive the power conversion circuit to correspond to the third The control signal controls the low-voltage direct current voltage, the high-voltage direct current voltage or the output current.

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