Bidirectional on-board charger, on-board power system and electric vehicle

Abstract

The present application provides a bidirectional on-board charger, an on-board power system and an electric vehicle, wherein the bidirectional on-board charger includes a DC bus, two bus capacitors, a power factor correction circuit and a controller, wherein the power factor correction circuit includes: a first bridge arm, connected in series between the positive and negative poles of the DC bus, the midpoint of the first bridge arm is connected to the series connection point of the two bus capacitors through a first switch; three second bridge arms, respectively connected in series between the positive and negative poles of the DC bus. The controller is used to: control the first switch to be disconnected, and control at least one second bridge arm to output DC power to charge the power battery; control the first switch to be turned on, and control the midpoint of at least one second bridge arm to output AC power to power the AC load. In the present application, the forward charging function for charging the power battery and the reverse discharge function for powering the AC load are compatible, which greatly reduces the circuit cost, has strong application flexibility and strong applicability.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a bidirectional on-board charger, an on-board power system and an electric vehicle. Background Art

[0002] At present, an on-board charger (OBC) refers to a charger fixedly installed on an electric vehicle, the AC side of which is connected to the AC power grid, and the DC side of which is connected to the power battery, wherein the on-board charger is used to convert the output voltage of the AC power grid into a DC voltage to charge the power battery. However, when the AC side of the on-board charger is connected to an external load, the on-board charger cannot be compatible with the demand for charging the external load, and has poor applicability. Summary of the invention

[0003] The present application provides a bidirectional on-board charger, an on-board power system and an electric vehicle, which are compatible with the forward charging function for charging the power battery and the reverse discharging function for supplying power to the AC load, greatly reducing the circuit cost, and having strong flexibility and applicability.

[0004] In a first aspect, the present application provides a bidirectional on-board charger for charging a power battery using a three-phase AC power supply or for supplying power to an AC load using a power battery. The bidirectional on-board charger includes:

[0005] DC bus, used to transmit direct current;

[0006] Two bus capacitors are connected in series between the positive and negative poles of the DC bus;

[0007] A power factor correction (PFC) circuit is used to receive one-phase AC power or three-phase AC power provided by a three-phase AC power source, or to receive DC power provided by a power battery. The power factor correction circuit includes:

[0008] A first bridge arm is connected in series between the positive and negative electrodes of the DC bus, and a midpoint of the first bridge arm is connected to a series connection point of two bus capacitors through a first switch;

[0009] The three second bridge arms are respectively connected in series between the positive and negative poles of the DC bus, and the midpoint of at least one second bridge arm is used to receive a single-phase AC power; or the midpoints of the three second bridge arms are used to receive a three-phase AC power; or at least one second bridge arm is used to receive a DC power;

[0010] Controller for:

[0011] Controlling the first switch to be disconnected, and controlling at least one second bridge arm to output direct current to charge the power battery;

[0012] The first switch is controlled to be turned on, and the midpoint of at least one second bridge arm is controlled to output alternating current to supply power to the AC load.

[0013] In the present application, the first switch and the three second bridge arms can be controlled to cooperate with each other to realize the forward charging function of charging the power battery and the reverse discharging function of powering the AC load, which greatly reduces the circuit cost, has strong application flexibility and strong applicability.

[0014] In combination with the first aspect, in a first possible implementation, the first bridge arm includes two diodes connected in series, and the series connection point of the two diodes serves as the midpoint of the first bridge arm, so that the bridge arm cost is lower; the second bridge arm includes a second switch and a third switch connected in series, and the series connection point of the second switch and the third switch serves as the midpoint of the second bridge arm.

[0015] Controller for:

[0016] Controlling the second switch and the third switch in at least one second bridge arm to be turned on alternately to convert one-phase AC power into DC power or convert DC power into AC power;

[0017] The second switches and the third switches in the three second bridge arms are controlled to be turned on alternately to convert the three-phase alternating current into direct current.

[0018] In the present application, by controlling the movement of some or all of the three second bridge arms, one-phase AC power can be converted into DC power, or DC power can be converted into AC power, or three-phase AC power can be converted into DC power, thereby meeting the different working requirements of the bidirectional on-board charger and having strong application flexibility.

[0019] In combination with the first possible implementation of the first aspect, in a second possible implementation, the bidirectional on-board charger includes three fourth switches corresponding to the three second bridge arms, and the midpoint of one second bridge arm is connected to a live wire of the three-phase AC power supply or the first connection end of the AC load through the fourth switch corresponding to the second bridge arm. The midpoints of the three second bridge arms, the three fourth switches, and the three live wires of the three-phase AC power supply correspond to and are connected one by one.

[0020] Controller for:

[0021] Controlling any one of the fourth switches to be turned on, and controlling the other two fourth switches to be turned off, so that the midpoint of at least one second bridge arm receives one-phase alternating current or outputs alternating current;

[0022] The three fourth switches are controlled to be turned on so that the midpoints of the three second bridge arms receive the three-phase alternating current.

[0023] In the present application, by controlling any one of the three fourth switches or all of the fourth switches to be turned on, the midpoint of the second bridge arm can receive one-phase AC power, or output AC power, or receive three-phase AC power, thereby meeting the different working requirements of the bidirectional on-board charger and having strong application flexibility.

[0024] In combination with the second possible implementation of the first aspect, in a third possible implementation, the three second bridge arms include two other second bridge arms except the second bridge arm corresponding to any fourth switch; the bidirectional on-board charger includes a fifth switch. The midpoint of any second bridge arm of the other two second bridge arms is connected to the first connection end of any fourth switch through the fifth switch, and the first connection end of any fourth switch is connected to a live wire of a three-phase AC power supply or a first connection end of an AC load.

[0025] Controller for:

[0026] Controlling any one of the fourth switch and the fifth switch to be turned on, and controlling the other two fourth switches to be turned off, so that the midpoint of at least one second bridge arm receives one-phase alternating current or outputs alternating current;

[0027] The three fourth switches are controlled to be disconnected, and the fifth switch is controlled to be turned on, so that the midpoint of at least one second bridge arm receives one-phase alternating current or outputs alternating current.

[0028] In the present application, by controlling each of the three fourth switches and one fifth switch to be turned on or off, the midpoint of the second bridge arm can receive one-phase AC power or output AC power, thereby meeting the different working requirements of the bidirectional on-board charger and having strong application flexibility.

[0029] In combination with the second possible implementation of the first aspect, in a fourth possible implementation, the three second bridge arms include the other two second bridge arms except the second bridge arm corresponding to any one of the fourth switches; the bidirectional on-board charger includes two fifth switches corresponding to the other two second bridge arms. The midpoint of one of the other two second bridge arms is connected to the first connection end of any one of the fourth switches through the fifth switch corresponding to the second bridge arm, and the first connection end of any one of the fourth switches is connected to a live wire of a three-phase AC power supply or a first connection end of an AC load. The midpoints of the other two second bridge arms correspond to and are connected to the two fifth switches one by one.

[0030] Controller for:

[0031] Controlling any one of the fourth switches and two of the fifth switches to be turned on, and controlling the other two fourth switches to be turned off, so that the midpoint of at least one of the second bridge arms receives one-phase alternating current or outputs alternating current;

[0032] The three fourth switches are controlled to be disconnected, and the two fifth switches are controlled to be turned on, so that the midpoint of at least one second bridge arm receives one-phase alternating current or outputs alternating current.

[0033] In the present application, by controlling each of the three fourth switches and the two fifth switches to be turned on or off, the midpoint of the second bridge arm can receive one-phase AC power or output AC power, thereby meeting the different working requirements of the bidirectional on-board charger and having strong application flexibility.

[0034] In combination with any one of the first possible implementation manner of the first aspect to the fourth possible implementation manner of the first aspect, in a fifth possible implementation manner, the bidirectional on-board charger includes a sixth switch, and the midpoint of any one of the second bridge arms is connected to the neutral line of the three-phase AC power supply through the sixth switch; the bidirectional on-board charger is used to charge the power battery using the three-phase AC power supply;

[0035] Controller for:

[0036] The sixth switch is controlled to be disconnected to realize the forward charging function of charging the power battery.

[0037] In combination with any one of the first possible implementation manner of the first aspect to the fourth possible implementation manner of the first aspect, in a sixth possible implementation manner, the bidirectional on-board charger includes a sixth switch, and the midpoint of any one of the second bridge arms is connected to the second connection end of the AC load through the sixth switch; the bidirectional on-board charger is used to use the power battery to power the AC load;

[0038] Controller for:

[0039] The sixth switch is controlled to be turned on to realize the reverse discharge function of supplying power to the AC load.

[0040] In combination with the sixth possible implementation of the first aspect, in the seventh possible implementation, the two bus capacitors include a positive bus capacitor and a negative bus capacitor. The controller is used to: collect the voltage of the positive bus capacitor and the voltage of the negative bus capacitor in the process of charging the load based on the DC voltage provided by the power battery; further, when the difference between the voltage of the positive bus capacitor and the voltage of the negative bus capacitor is greater than or equal to the first threshold, control the second switch in the second bridge arm connected to the sixth switch to conduct, so as to balance the voltage of the positive bus capacitor and the voltage of the negative bus capacitor, thereby suppressing the voltage fluctuation at the midpoint of the bus capacitor to improve the power supply stability of the bidirectional on-board charger, and the applicability is stronger. Among them, the difference is the value obtained by subtracting the voltage of the negative bus capacitor from the voltage of the positive bus capacitor.

[0041] In combination with the seventh possible implementation of the first aspect, in an eighth possible implementation, the controller is used to: when the difference between the voltage of the negative bus capacitor and the voltage of the positive bus capacitor is greater than or equal to the second threshold, control the third switch in the second bridge arm connected to the sixth switch to be turned on to balance the voltage of the positive bus capacitor and the voltage of the negative bus capacitor, thereby suppressing the voltage fluctuation at the midpoint of the bus capacitor to improve the power supply stability of the bidirectional on-board charger, and having stronger applicability. The difference is the value obtained by subtracting the voltage of the positive bus capacitor from the voltage of the negative bus capacitor.

[0042] In the second aspect, the present application provides a vehicle-mounted power system, including a power battery and a vehicle-mounted charger provided in any one of the possible implementations of the first aspect to the eighth aspect; the vehicle-mounted charger is used to charge the power battery. Since the bidirectional vehicle-mounted charger is compatible with the forward charging function and the reverse discharge function of a single three-phase input, the working efficiency of the vehicle-mounted power system can be improved, and the circuit cost of the vehicle-mounted power system is greatly reduced, and the applicability is strong.

[0043] In a third aspect, the present application provides an electric vehicle, comprising a power battery, a drive motor, and an on-board charger provided in any one of the first aspect to the eighth possible implementation manner as described above; the on-board charger is used to power the power battery; and the power battery is used to power the drive motor.

[0044] In this application, the forward charging function and reverse discharging function of a single three-phase input are compatible, which greatly reduces the circuit cost, has strong application flexibility and strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a structural schematic diagram of an electric vehicle provided by the present application;

[0046] Figure 2 It is a structural schematic diagram of the bidirectional on-board charger provided by the present application;

[0047] Figure 3A It is a circuit diagram of a bidirectional on-board charger provided by the present application;

[0048] Figure 3B is another circuit diagram of the bidirectional on-board charger provided by the present application;

[0049] Figure 4A is another circuit diagram of the bidirectional on-board charger provided by the present application;

[0050] Figure 4B is another circuit diagram of the bidirectional on-board charger provided by the present application;

[0051] Figure 5Ais another circuit diagram of the bidirectional on-board charger provided by the present application;

[0052] Figure 5B is another circuit diagram of the bidirectional on-board charger provided by the present application;

[0053] Fig. 6A is another circuit diagram of the bidirectional on-board charger provided by the present application;

[0054] Figure 6B is another circuit diagram of the bidirectional on-board charger provided by the present application;

[0055] Fig. 7A is another circuit diagram of the bidirectional on-board charger provided by the present application;

[0056] Figure 7B is another circuit diagram of the bidirectional on-board charger provided by the present application;

[0057] Fig. 8A is another circuit diagram of the bidirectional on-board charger provided by the present application;

[0058] Figure 8B is another circuit diagram of the bidirectional on-board charger provided by the present application;

[0059] Fig. 9 It is a structural schematic diagram of the vehicle-mounted power system provided in this application. DETAILED DESCRIPTION

[0060] The on-board charger, on-board power system and electric vehicle provided by the present application will be described below with reference to the accompanying drawings.

[0061] Figure 1 Schematic diagram of a structure of an electric vehicle provided by the present application. Figure 1 As shown, the electric vehicle 1 includes a bidirectional on-board charger 10, a power battery 20 and a drive motor 30. The bidirectional on-board charger 10 is used to receive an input voltage V provided by a three-phase AC power source 2. in1 and provides an output voltage V out1 Power the power battery 20. The power battery 20 is used to provide an input voltage V for the drive motor 30. in2 To supply power to the driving motor 30 .

[0062] In one embodiment, the three-phase AC power source 2 may be an AC power grid, an AC charging station, or an uninterruptible power system (UPS).

[0063] like Figure 1 As shown, the bidirectional on-board charger 10 is also used to receive the input voltage V provided by the power battery 20. in2and provides an output voltage V out2 Power is supplied to the AC load 3. In one embodiment, the AC load 3 is disposed inside the electric vehicle 1, for example, the AC load 3 may be a compressor motor or other low-power motor. In another embodiment, the AC load 3 is disposed outside the electric vehicle 1, and the AC load 3 may be a mobile phone, a tablet, a laptop computer, a Bluetooth headset, a lamp, an induction cooker, a kettle, a game console, a power bank, or a smart wearable device.

[0064] The bidirectional on-board charger 10 provided in the embodiment of the present application is compatible with the forward charging function for charging the power battery 20 and the reverse discharging function for supplying power to the AC load 3, thereby simplifying the structural layout of the electric vehicle 1, with low cost, small size and high integration.

[0065] Figure 2 1 is a schematic diagram of the structure of the bidirectional on-board charger provided by the present application. The bidirectional on-board charger 10 is used to charge the power battery 12 using the three-phase AC power supply 11 or to power the AC load 13 using the power battery 12. When the bidirectional on-board charger 10 charges the power battery 12 using the three-phase AC power supply 11, the bidirectional on-board charger 10 operates in a forward charging mode. When the bidirectional on-board charger 10 powers the AC load 13 using the power battery 12, the bidirectional on-board charger 10 operates in a reverse discharge mode.

[0066] In one embodiment, the three-phase AC power source 11 can be an AC power grid, an AC charging station or an uninterruptible power system (UPS). The AC load 3 can be a compressor motor, other low-power motors, mobile phones, tablets, laptops, Bluetooth headsets, lamps, induction cookers, kettles, game consoles, power banks or smart wearable devices.

[0067] like Figure 2 As shown, the bidirectional on-board charger 10 includes a DC bus 100 , two bus capacitors, a first switch K1 , a power factor correction circuit 101 and a controller 102 .

[0068] The DC bus 100 is used to transmit DC power. When the bidirectional on-board charger 10 uses the three-phase AC power supply 11 to charge the power battery 12, the DC bus 100 is used to transmit DC power V out3 When the bidirectional on-board charger 10 uses the power battery 12 to supply power to the AC load 13, the DC bus 100 is used to transmit DC power V in5 .

[0069] The two bus capacitors include the positive bus capacitor C dc1 and negative bus capacitor C dc2, connected in series between the positive and negative electrodes of the DC bus 100. Among them, the positive bus capacitor C dc1 is the bus capacitor connected to the positive pole of the DC bus 100, and the negative bus capacitor C dc2 It is a bus capacitor connected to the negative electrode of the DC bus 100 .

[0070] The power factor correction circuit 101 is used to receive a single-phase AC power V provided by a three-phase AC power source 11. in3 Or three-phase AC V in4 , or for receiving the DC power V provided by the power battery 12 in5 The power factor correction circuit 101 includes a first bridge arm 1011 and three second bridge arms.

[0071] The first bridge arm 1011 is connected in series between the positive and negative electrodes of the DC bus 100, and the midpoint of the first bridge arm 1011 is connected to the positive bus capacitor C through the first switch K1. dc1 and negative bus capacitor C dc2 The first switch K1 can be a relay, and the positive bus capacitor C dc1 and negative bus capacitor C dc2 The series connection point can also be called the bus capacitor midpoint or the busbar capacitor midpoint.

[0072] The three second bridge arms include a second bridge arm 1012, a second bridge arm 1013 and a second bridge arm 1014, which are respectively connected in series between the positive and negative electrodes of the DC bus 100. The midpoint of at least one second bridge arm is used to receive a single-phase AC power V in3 or the midpoints of the second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014 are used to receive the three-phase alternating current V in4 ; or at least one second bridge arm is used to receive direct current V in5 .

[0073] The controller 102 may be a control board, a control chip or a software code. The controller 102 may establish a wired connection or a wireless connection with the first switch K1 and the power factor correction circuit 101. In one embodiment, the controller 102 is used to control the on or off of the first switch K1 and control the operation of the power factor correction circuit 101. Specifically, the controller 102 is used to control the action of each of the second bridge arms 1012, the second bridge arm 1013 and the second bridge arm 1014, thereby controlling the operation of the power factor correction circuit 101.

[0074] The controller 102 is configured to:

[0075] Control the first switch K1 to be disconnected, and control at least one second bridge arm to output a DC voltage V out3 Charging the power battery 12, at which time the bidirectional on-board charger 10 is in a forward charging mode;

[0076] Control the first switch K1 to be turned on, and control the midpoint of at least one second bridge arm to output AC power V out4 The AC load 13 is powered, and the bidirectional on-board charger 10 is in a reverse discharge mode.

[0077] The controller 102 provided in the present application is used to control the coordinated actions of the first switch K1, the second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014, so as to be compatible with the forward charging function of charging the power battery 12 and the reverse discharge function of powering the AC load 13, which greatly reduces the circuit cost and has strong flexibility and applicability.

[0078] In one embodiment, when the first switch K1 is turned on, the positive bus capacitor C dc1 Or negative bus capacitance C dc2 , the first switch K1 , the first bridge arm 1011 , the second bridge arm 1012 , the second bridge arm 1013 and the second bridge arm 1014 can constitute a reverse direct current (DC) / alternating current (AC) circuit for realizing a reverse discharge function for supplying power to the AC load 13 .

[0079] In one embodiment, the first bridge arm 1011 includes a diode D1 and a diode D2 connected in series, and the series connection point of the diode D1 and the diode D2 serves as the midpoint of the first bridge arm 1011, so that the bridge arm cost is lower. In another embodiment, the first bridge arm 1011 includes two switches connected in series, and the series connection point of the two switches serves as the midpoint of the first bridge arm 1011.

[0080] In one embodiment, the second bridge arm includes a second switch and a third switch connected in series, and the series connection point of the second switch and the third switch serves as the midpoint of the second bridge arm. For example, the second bridge arm 1012 includes a second switch S1 and a third switch S2 connected in series, and the series connection point of the second switch S1 and the third switch S2 serves as the midpoint of the second bridge arm 1012; the second bridge arm 1013 includes a second switch S3 and a third switch S4 connected in series, and the series connection point of the second switch S3 and the third switch S4 serves as the midpoint of the second bridge arm 1013; the second bridge arm 1014 includes a second switch S5 and a third switch S6 connected in series, and the series connection point of the second switch S5 and the third switch S6 serves as the midpoint of the second bridge arm 1014.

[0081] In one embodiment, the second switch and the third switch in each second bridge arm include but are not limited to: an insulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field-effect transistor (MOSFET). The second switch and the third switch in each second bridge arm may be made of silicon semiconductor material Si, or silicon carbide SiC, a third generation wide bandgap semiconductor material, or gallium nitride GaN, or other switch materials. For example, Figure 2 As shown, the second switch and the third switch in each second bridge arm are IGBTs.

[0082] In one embodiment, the second switch and the third switch in each second bridge arm are turned on complementarily, that is, the third switch is turned off when the second switch is turned on, or the third switch is turned on when the second switch is turned off.

[0083] In one embodiment, the controller 102 is used to control the second switch and the third switch in at least one second bridge arm to be turned on alternately to convert the single-phase AC power V in3 Convert to DC V out3 And charge the power battery 12, or convert the DC power V in5 Convert to AC V out4 and supply power to the AC load 13; controlling the second switch and the third switch in the second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014 to be turned on alternately to convert the three-phase AC power V in4 Convert to DC V out3 And charge the power battery 12.

[0084] In one embodiment, for a second bridge arm, the second switch and the third switch are alternately turned on, including: the second switch in the second bridge arm is turned on and the third switch is turned off in a time period, and the second switch in the second bridge arm is turned off and the third switch is turned on in another time period. The one time period and the other time period are in a switching cycle of the second bridge arm, and the other time period is after the one time period.

[0085] The controller 102 provided in the embodiment of the present application is used to control the actions of part of the second bridge arms 1012, the second bridge arms 1013, and the second bridge arms 1014, or all of the second bridge arms, so as to realize the conversion of a single-phase AC power V in3 Convert to DC V out3 , or direct current V in5 Convert to AC V out4 , or three-phase AC V in4 Convert to DC V out3, thereby meeting the different working requirements of the bidirectional on-board charger 10 and having strong flexibility in use.

[0086] In one embodiment, the bidirectional on-board charger 10 is used to charge the power battery 12 using a three-phase AC power supply 11, and the diode D1 and the diode D2 in the first bridge arm 1011 are alternately turned on. Specifically, when the diode D1 is turned on, the diode D2 is turned off, or when the diode D1 is turned off, the diode D2 is turned on.

[0087] In another embodiment, the bidirectional on-board charger 10 is used to use the power battery 12 to power the AC load 13, and the diode D1 and the diode D2 in the first bridge arm 1011 are both turned off.

[0088] Figure 3A Schematic diagram of a circuit of a bidirectional on-board charger provided by the present application. Figure 3A As shown, the three-phase AC power supply 11 is a power supply composed of three AC potentials with the same frequency, equal amplitude, and phase difference of 120 degrees. The three AC potentials include AC potential V ga , AC potential V gb and AC potential V gc The three live wires of the three-phase AC power supply 11 are respectively from the AC potential V ga , AC potential V gb and AC potential V gc Lead out, the neutral line of the three-phase AC power supply 11 is from the AC potential V ga , AC potential V gb and AC potential V gc The neutral point of the power supply is led out. The zero line can also be called the N line.

[0089] like Figure 3A As shown, the bidirectional on-board charger 10 includes three fourth switches corresponding to the second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014. Among them, the midpoint of one of the second bridge arms 1012, the second bridge arm 1013 and the second bridge arm 1014 is connected to a live wire of the three-phase AC power supply 11 through the fourth switch corresponding to the second bridge arm. The midpoints of the second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014, the three fourth switches and the three live wires of the three-phase AC power supply 11 correspond to each other and are connected one by one. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be seen in Figure 2 The corresponding embodiments will not be described in detail here.

[0090] Among them, the three fourth switches include the fourth switch K 2a , the fourth switch K 2b and the fourth switch K 2c The midpoint of the second bridge arm 1012 is connected via the fourth switch K 2aConnect to AC potential V ga The live wire is led out, and the midpoint of the second bridge arm 1013 passes through the fourth switch K 2b Connect the AC potential V gb The live wire is led out, and the midpoint of the second bridge arm 1014 passes through the fourth switch K 2c Connect the AC potential V gc Leading out the fire line.

[0091] In one embodiment, the bidirectional on-board charger 10 includes a filter inductor L a 、Filter inductor L b and filter inductor L c The midpoint of the second bridge arm 1012 is connected through the filter inductor L a and the fourth switch K 2a Connect to AC potential V ga The live wire is led out, and the midpoint of the second bridge arm 1013 passes through the filter inductor L b and the fourth switch K 2b Connect the AC potential V gb The live wire is led out, and the midpoint of the second bridge arm 1014 passes through the filter inductor L c and the fourth switch K 2c Connect the AC potential V gc Leading out the fire line.

[0092] Figure 3B is another circuit diagram of the bidirectional on-board charger provided by the present application. Figure 3B As shown above Figure 2 The bidirectional on-board charger 10 shown also includes three fourth switches corresponding to the second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014. Among them, the midpoint of one of the second bridge arms 1012, the second bridge arm 1013 and the second bridge arm 1014 is connected to the first connection end of the AC load 13 through the fourth switch corresponding to the second bridge arm. The midpoints of the second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014 correspond to and are connected to the three fourth switches one by one. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be seen in Figure 2 The corresponding embodiments will not be described in detail here.

[0093] Among them, the three fourth switches include the fourth switch K 2a , the fourth switch K 2b and the fourth switch K 2c The midpoint of the second bridge arm 1012 is connected via the fourth switch K 2a The first connection end is connected to the AC load 13, and the midpoint of the second bridge arm 1013 is connected to the AC load 13 through the fourth switch K 2b The first connection end is connected to the AC load 13, and the midpoint of the second bridge arm 1014 is connected to the AC load 13 through the fourth switch K2c The first connection terminal is connected to the AC load 13 .

[0094] In one embodiment, the bidirectional on-board charger 10 includes a filter inductor L a 、Filter inductor L b and filter inductor L c The midpoint of the second bridge arm 1012 is connected through the filter inductor L a and the fourth switch K 2a The first connection terminal of the AC load 13 is connected to the midpoint of the second bridge arm 1013 through the filter inductor L b and the fourth switch K 2b The first connection terminal of the AC load 13 is connected, and the midpoint of the second bridge arm 1014 is connected through the filter inductor L c and the fourth switch K 2c A first connection terminal connected to an AC load 13 .

[0095] In one embodiment, the controller 102 can be connected to the fourth switch K 2a , the fourth switch K 2b and the fourth switch K 2c Establish a wired connection or a wireless connection. The controller 102 is used to control the fourth switch K 2a , the fourth switch K 2b and the fourth switch K 2c Turn on or off so that the power factor correction circuit 101 receives a single-phase AC power V in3 , or receive three-phase AC power V in4 Or output AC V out4 .

[0096] Specifically, the controller 102 is used to control any one of the fourth switches to be turned on, and to control the other two fourth switches to be turned off, so that the midpoint of at least one second bridge arm receives a single-phase AC power V in3 Or output AC V out4 ; Control the fourth switch K 2a , the fourth switch K 2b and the fourth switch K 2c The second bridge arm 1012, the second bridge arm 1013 and the midpoint of the second bridge arm 1014 receive the three-phase alternating current V in4 .

[0097] In one embodiment, any one of the fourth switches may be the fourth switch K 2a , the other two fourth switches include the fourth switch K 2b and the fourth switch K 2c , at least one second bridge arm includes the second bridge arm 1012. In another embodiment, any one of the fourth switches may be the fourth switch K 2b, the other two fourth switches include the fourth switch K 2a and the fourth switch K 2c , at least one second bridge arm includes the second bridge arm 1013. In another embodiment, any one of the fourth switches may be the fourth switch K 2c , the other two fourth switches include the fourth switch K 2a and the fourth switch K 2b , at least one second bridge arm includes a second bridge arm 1014 .

[0098] It can be seen that the controller 102 is used to control the fourth switch K 2a , the fourth switch K 2b and the fourth switch K 2c Any one of the fourth switches or all of the fourth switches are turned on, so that the midpoint of the second bridge arm receives a single-phase alternating current V in3 , or receive three-phase AC power V in4 , or output AC power V out4 , thereby meeting the different working requirements of the bidirectional on-board charger 10 and having strong flexibility in use.

[0099] Figure 4A is another circuit diagram of the bidirectional on-board charger provided by the present application. Figure 4A As shown, the bidirectional on-board charger 10 includes a fifth switch K 3a The second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014 include the other two second bridge arms except the second bridge arm corresponding to any one of the fourth switches. The midpoint of any one of the other two second bridge arms is connected to the fifth switch K. 3a The first connection end of any fourth switch is connected to a live wire of the three-phase AC power source 11. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be seen in Figure 3A The corresponding embodiments will not be described in detail here.

[0100] In one embodiment, any fourth switch is a fourth switch K 2a , the second bridge arm corresponding to any one of the fourth switches is the second bridge arm 1012, the other two second bridge arms include the second bridge arm 1013 and the second bridge arm 1014, and any one of the other two second bridge arms is the second bridge arm 1013. The midpoint of the second bridge arm 1013 is connected to the fifth switch K 3a Connected to the fourth switch K 2a The first connection end of the fourth switch K 2a The first connection end is connected to the AC potential V ga Lead out live wire connection.

[0101] Figure 4B is another circuit diagram of the bidirectional on-board charger provided by the present application. Figure 4B As shown, the bidirectional on-board charger 10 includes a fifth switch K 3a The second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014 include the other two second bridge arms except the second bridge arm corresponding to any one of the fourth switches. The midpoint of any one of the other two second bridge arms is connected to the fifth switch K. 3a The first connection end of any fourth switch is connected to the first connection end of the AC load 13. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be seen in Figure 3B The corresponding embodiments will not be described in detail here.

[0102] In one embodiment, any fourth switch is a fourth switch K 2a , the second bridge arm corresponding to any one of the fourth switches is the second bridge arm 1012, the other two second bridge arms include the second bridge arm 1013 and the second bridge arm 1014, and any one of the other two second bridge arms is the second bridge arm 1013. The midpoint of the second bridge arm 1013 is connected to the fifth switch K 3a Connected to the fourth switch K 2a The first connection end of the fourth switch K 2a The first connection end is connected to the first connection end of the AC load 13.

[0103] The controller 102 provided in the embodiment of the present application can be connected to the fourth switch K 2a , the fourth switch K 2b , the fourth switch K 2c and the fifth switch K 3a Establish a wired connection or a wireless connection. In one embodiment, the controller 102 is used to control the fourth switch K 2a , the fourth switch K 2b , the fourth switch K 2c and the fifth switch K 3a Turn on or off so that the power factor correction circuit 101 receives a single-phase AC power V in3 , or receive three-phase AC power V in4 Or output AC V out4 .

[0104] The power factor correction circuit 101 provided in the embodiment of the present application is used to receive a single-phase alternating current V in3 Or output AC V out4 The controller 102 is used to control the fourth switch K 2a and the fifth switch K 3aThe second bridge arm is turned on and the other two fourth switches are controlled to be turned off, so that the midpoint of at least one second bridge arm receives a single-phase AC power V in3 Or output AC V out4 , wherein the other two fourth switches include a fourth switch K 2b and the fourth switch K 2c , at least one second bridge arm includes a second bridge arm 1012 and a second bridge arm 1013; controlling the fourth switch K 2a , the fourth switch K 2b and the fourth switch K 2c Disconnect and control the fifth switch K 3a is turned on so that the midpoint of at least one second bridge arm receives a single-phase alternating current V in3 Or output AC V out4 , wherein the at least one second bridge arm includes a second bridge arm 1013 .

[0105] It can be seen that the controller 102 is used to control the fourth switch K 2a , the fourth switch K 2b , the fourth switch K 2c and the fifth switch K 3a Each switch in the bridge is turned on or off, so that the midpoint of the second bridge arm receives a single-phase AC power V in3 Or output AC V out4 , thereby meeting the different working requirements of the bidirectional on-board charger 10 and having strong flexibility in use.

[0106] The power factor correction circuit 101 provided in the embodiment of the present application is used to receive a three-phase alternating current V in4 The controller 102 is used to control the fourth switch K 2a , the fourth switch K 2b and the fourth switch K 2c is turned on and controls the fifth switch K 3a The second bridge arm 1012, the second bridge arm 1013 and the midpoint of the second bridge arm 1014 receive the three-phase alternating current V in4 .

[0107] Figure 5A is another circuit diagram of the bidirectional on-board charger provided by the present application. Figure 5A As shown, the power factor correction circuit 101 includes a filter inductor L a 、Filter inductor L b and filter inductor L c The corresponding three filter capacitors include filter capacitor C a 、Filter capacitor C b And filter capacitor C c Among them, the filter inductor L a Connect filter capacitor Ca The first connection terminal, the filter inductor L b Connect filter capacitor C b The first connection terminal, the filter inductor L c Connect filter capacitor C c The first connection terminal of the filter capacitor C a 、Filter capacitor C b And filter capacitor C c The second connection end of each filter capacitor is connected to the positive bus capacitor C dc1 and negative bus capacitor C dc2 series connection point.

[0108] The bidirectional on-board charger 10 includes a bidirectional DC / DC conversion circuit 103, which is connected in series between the positive and negative electrodes of the DC bus 100. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be seen in Figure 4A The corresponding embodiments will not be described in detail here.

[0109] In one embodiment, the filter inductor L a 、Filter inductor L b 、Filter inductor L c 、Filter capacitor C a 、Filter capacitor C b And filter capacitor C c A filter circuit can be formed, and the first bridge arm 1011, the second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014 can form a bridge arm conversion circuit. The bidirectional on-board charger 10 provided in the embodiment of the present application is used to charge the power battery 12 using the three-phase AC power supply 11. The filter circuit is used to in3 Or three-phase AC V in4 Filtering is performed and the DC voltage V is output through the bridge arm conversion circuit. OUT3 The power battery 12 is charged, thereby reducing the switching ripple of the bidirectional vehicle charger 10, and the applicability is strong. In one embodiment, the bidirectional DC / DC conversion circuit 103 is used to receive the output voltage of the bridge arm conversion circuit and output a direct current V OUT3 The power battery 12 is charged.

[0110] See also Figure 5B , Figure 5B is another circuit diagram of the bidirectional on-board charger provided by the present application. Figure 5B As shown, the internal circuit structure of the bidirectional on-board charger 10 can be seen in Figure 5AThe corresponding embodiments are not described in detail here. The power factor correction circuit 101 provided in the embodiment of the present application is used to use the power battery 12 to power the AC load 13. The bridge arm conversion circuit is used to receive the DC power V provided by the power battery 12. in5 Or the power battery 12 outputs direct current through the bidirectional DC / DC conversion circuit 103, and outputs alternating current V after filtering by the filter circuit OUT4 Power is supplied to the AC load 13, thereby reducing the switching ripple of the bidirectional on-board charger 10, and the applicability is strong.

[0111] Fig. 6A is another circuit diagram of the bidirectional on-board charger provided by the present application. Fig. 6A As shown, the bidirectional on-board charger 10 further includes a sixth switch K4, and the midpoint of any second bridge arm is connected to the neutral line of the three-phase AC power supply 11 through the sixth switch K4. In one embodiment, any second bridge arm can be the second bridge arm 1014. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be referred to Figure 5A The corresponding embodiments will not be described in detail here.

[0112] The bidirectional on-board charger 10 provided in the embodiment of the present application is used to charge the power battery 12 using the three-phase AC power supply 11. The controller 102 is used to: control the sixth switch K4 to be disconnected. The specific control method of other switches in the bidirectional on-board charger 10 can be referred to the above Figure 4A The corresponding embodiments will not be described in detail here.

[0113] Figure 6B is another circuit diagram of the bidirectional on-board charger provided by the present application. Figure 6B As shown, the bidirectional on-board charger 10 further includes a sixth switch K4, and the midpoint of any second bridge arm is connected to the second connection end of the AC load 13 through the sixth switch K4. In one embodiment, any second bridge arm can be the second bridge arm 1014. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be referred to Figure 5B The corresponding embodiments will not be described in detail here.

[0114] The bidirectional on-board charger 10 provided in the embodiment of the present application is used to use the power battery 12 to power the AC load 13. The controller 102 is used to: control the sixth switch K4 to be turned on. The specific control method of other switches in the bidirectional on-board charger 10 can be referred to above. Figure 4B The corresponding embodiments will not be described in detail here.

[0115] In one embodiment, the second bridge arm 1014 connected to the sixth switch K4 may be a positive bus capacitor C dc1 and negative bus capacitor C dc2The balanced bridge arm is used to balance the positive bus capacitance C dc1 The voltage and negative bus capacitance C dc2 When the power battery 12 supplies power to the AC load 13, the controller 102 is used to collect the voltage of the positive bus capacitor C dc1 The voltage and negative bus capacitance C dc2 The voltage at the positive bus capacitor C dc1 The voltage of the negative bus capacitor C dc2 When the difference between the voltages of and is greater than or equal to the first threshold, the second switch S5 in the second bridge arm 1014 connected to the sixth switch K4 is controlled to be turned on, thereby balancing the positive bus capacitor C dc1 The voltage and negative bus capacitance C dc2 The voltage at the midpoint of the bus capacitor is suppressed to suppress the voltage fluctuation, thereby improving the power supply stability of the bidirectional on-board charger 10.

[0116] The current output from the positive terminal of the power battery 12 flows through the second switch S5, the sixth switch K4, the first switch K1 and the negative bus capacitor C dc2 Return to the negative terminal of the power battery 12 to form a balancing circuit, and the balancing circuit is used to balance the positive bus capacitance C dc1 The voltage and negative bus capacitance C dc2 The specific conduction time of the second switch S5 can be determined by the difference, which is the positive bus capacitor C dc1 The voltage minus the negative bus capacitance C dc2 The first threshold is a threshold set by a user or a threshold configured by the controller 102. For example, the first threshold is 10V or other values.

[0117] In one embodiment, when collecting the positive bus capacitance C dc1 The voltage and negative bus capacitance C dc2 After the voltage of the negative bus capacitor C dc2 The voltage of the positive bus capacitor C dc1 When the difference between the voltages of and is greater than or equal to the second threshold, the third switch S6 in the second bridge arm 1014 connected to the sixth switch K4 is controlled to be turned on, thereby balancing the positive bus capacitor C dc1 The voltage and negative bus capacitance C dc2 The voltage at the midpoint of the bus capacitor is suppressed to suppress the voltage fluctuation, thereby improving the power supply stability of the bidirectional on-board charger 10.

[0118] Among them, the current output from the positive terminal of the power battery 12 flows through the positive bus capacitor C dc1, the first switch K1, the sixth switch K4 and the third switch S6 return to the negative terminal of the power battery 12 to form a balancing circuit, and the balancing circuit is used to balance the positive bus capacitor C dc1 The voltage and negative bus capacitance C dc2 The specific conduction time of the third switch S6 can be determined by the difference, which is the negative bus capacitor C dc2 The voltage minus the positive bus capacitance C dc1 The second threshold is a threshold set by a user or a threshold configured by the controller 102. In one embodiment, the first threshold and the second threshold may be the same or different.

[0119] In one embodiment, the second bridge arm connected to the sixth switch K4 may be the second bridge arm 1013. The controller 102 is configured to: control the fifth switch K 3a In another embodiment, the second bridge arm connected to the sixth switch K4 may be the second bridge arm 1012. The controller 102 is configured to: control the fourth switch K 2a Turn off. It can be seen that when the second bridge arm connected to the sixth switch K4 and the second bridge arm connected to the fourth switch or the fifth switch are the same bridge arm, the fourth switch or the fifth switch is turned off; when the second bridge arm connected to the sixth switch K4 and the second bridge arm connected to the fourth switch or the fifth switch are different bridge arms, the fourth switch or the fifth switch can be turned on or off. It should be noted that the specific control method of other switches in the bidirectional on-board charger 10 can be referred to the above Figure 4B The corresponding embodiments will not be described in detail here.

[0120] Fig. 7A is another circuit diagram of the bidirectional on-board charger provided by the present application. Fig. 7A As shown, the second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014 include the other two second bridge arms except the second bridge arm corresponding to any one of the fourth switches, and the bidirectional on-board charger 10 includes two fifth switches corresponding to the other two second bridge arms, and the two fifth switches include the fifth switch K 3a and the fifth switch K 3b The midpoint of one of the other two second bridge arms is connected to the first connection end of any fourth switch through the fifth switch corresponding to the second bridge arm, and the first connection end of any fourth switch is connected to a live wire of the three-phase AC power supply 11. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be seen in Figure 3A The corresponding embodiments will not be described in detail here.

[0121] In one embodiment, any fourth switch is a fourth switch K 2aThe second bridge arm corresponding to any one of the fourth switches is the second bridge arm 1012, and the other two second bridge arms include the second bridge arm 1013 and the second bridge arm 1014. The midpoint of the second bridge arm 1013 passes through the fifth switch K corresponding to the second bridge arm 1013. 3a Connected to the fourth switch K 2a The midpoint of the second bridge arm 1014 passes through the fifth switch K corresponding to the second bridge arm 1014. 3b Connected to the fourth switch K 2a The first connection end of the fourth switch K 2a The first connection end is connected to the AC potential V ga Lead out live wire connection.

[0122] Figure 7B is another circuit diagram of the bidirectional on-board charger provided by the present application. Figure 7B As shown, the second bridge arm 1012, the second bridge arm 1013 and the second bridge arm 1014 include the other two second bridge arms except the second bridge arm corresponding to any one of the fourth switches. Figure 3B The bidirectional on-board charger 10 shown in the figure further includes a fifth switch K corresponding to the other two second bridge arms. 3a and the fifth switch K 3b The midpoint of one of the other two second bridge arms is connected to the first connection end of any fourth switch through the fifth switch corresponding to the second bridge arm, and the first connection end of any fourth switch is connected to the first connection end of the AC load 13. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be seen in Figure 3B The corresponding embodiments will not be described in detail here.

[0123] In one embodiment, any one of the fourth switches may be the fourth switch K 2a The second bridge arm corresponding to any one of the fourth switches is the second bridge arm 1012, and the other two second bridge arms include the second bridge arm 1013 and the second bridge arm 1014. The midpoint of the second bridge arm 1013 passes through the fifth switch K corresponding to the second bridge arm 1013. 3a Connected to the fourth switch K 2a The midpoint of the second bridge arm 1014 passes through the fifth switch K corresponding to the second bridge arm 1014. 3b Connected to the fourth switch K 2a The first connection end of the fourth switch K 2a The first connection end is connected to the first connection end of the AC load 13.

[0124] The controller 102 provided in the embodiment of the present application can be connected to the fourth switch K 2a , the fourth switch K 2b , the fourth switch K 2c, the fifth switch K 3a and the fifth switch K 3b Establish a wired connection or a wireless connection. The controller 102 is used to control the fourth switch K 2a , the fourth switch K 2b , the fourth switch K 2c , the fifth switch K 3a and the fifth switch K 3b Turn on or off so that the power factor correction circuit 101 receives a single-phase AC power V in3 , or receive three-phase AC power V in4 Or output AC V out4 .

[0125] The power factor correction circuit 101 provided in the embodiment of the present application is used to receive a single-phase alternating current V in3 Or output AC V out4 The controller 102 is used to control the fourth switch K 2a , the fifth switch K 3a and the fifth switch K 3b The second bridge arm is turned on and the other two fourth switches are controlled to be turned off, so that the midpoint of at least one second bridge arm receives a single-phase AC power V in3 Or output AC V out4 , wherein the other two fourth switches include a fourth switch K 2b and the fourth switch K 2c , at least one second bridge arm includes a second bridge arm 1012, a second bridge arm 1013 and a second bridge arm 1014; controlling the fourth switch K 2a , the fourth switch K 2b and the fourth switch K 2c Disconnect and control the fifth switch K 3a and the fifth switch K 3b is turned on so that the midpoint of at least one second bridge arm receives a single-phase alternating current V in3 Or output AC V out4 , wherein the at least one second bridge arm includes a second bridge arm 1013 and a second bridge arm 1014 .

[0126] It can be seen that the controller 102 is used to control the fourth switch K 2a , the fourth switch K 2b , the fourth switch K 2c , the fifth switch K 3a and the fifth switch K 3b Each switch in the bridge is turned on or off, so that the midpoint of the second bridge arm receives a single-phase AC power V in3 Or output AC V out4 , thereby meeting the different working requirements of the bidirectional on-board charger 10 and having strong flexibility in use.

[0127] The power factor correction circuit 101 provided in the embodiment of the present application is used to receive a three-phase alternating current V in4 The controller 102 is used to control the fourth switch K 2a , the fourth switch K 2b and the fourth switch K 2c is turned on and controls the fifth switch K 3a and the fifth switch K 3b The second bridge arm 1012, the second bridge arm 1013 and the midpoint of the second bridge arm 1014 receive the three-phase alternating current V in4 .

[0128] Fig. 8A is another circuit diagram of the bidirectional on-board charger provided by the present application. Fig. 8A As shown, the bidirectional on-board charger 10 includes a sixth switch K4, and the midpoint of the second bridge arm 1014 is connected through a filter inductor L c The sixth switch K4 is connected to the neutral line of the three-phase AC power source 11. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be seen in Fig. 7A The corresponding embodiments will not be described in detail here.

[0129] The bidirectional on-board charger 10 provided in the embodiment of the present application is used to charge the power battery 12 using the three-phase AC power supply 11. The controller 102 is used to: control the sixth switch K4 to be disconnected. The specific control method of other switches in the bidirectional on-board charger 10 can be referred to the above Fig. 7A The corresponding embodiments will not be described in detail here.

[0130] Figure 8B is another circuit diagram of the bidirectional on-board charger provided by the present application. Figure 8B As shown, the bidirectional on-board charger 10 includes a sixth switch K4, and the midpoint of the second bridge arm 1014 is connected through a filter inductor L c The sixth switch K4 is connected to the second connection end of the AC load 13. It should be noted that the connection relationship between other components in the bidirectional on-board charger 10 can be seen in Figure 7B The corresponding embodiments will not be described in detail here.

[0131] The bidirectional on-board charger 10 provided in the embodiment of the present application is used to use the power battery 12 to supply power to the AC load 13. The controller 102 is used to: control the fifth switch K 3a The sixth switch K4 is turned on and the fifth switch K 3b The specific control method of other switches in the bidirectional on-board charger 10 can be referred to above. Figure 7B The corresponding embodiments will not be described in detail here.

[0132] In one embodiment, the second bridge arm 1014 may be a positive bus capacitor Cdc1 and negative bus capacitor C dc2 The balanced bridge arm is used to balance the positive bus capacitance C dc1 The voltage and negative bus capacitance C dc2 The specific working principle of the balanced bridge arm can be found in Figure 6B The corresponding embodiments will not be described in detail here.

[0133] In the bidirectional on-board charger 10 provided in the present application, a single-phase AC power V provided by a three-phase AC power source 11 can be used. in3 Or three-phase AC V in4 Charge the power battery 12, or use the DC power V provided by the power battery 12 in5 Power is supplied to the AC load 13, thereby being compatible with the forward charging function and the reverse discharging function of the single three-phase input, greatly reducing the circuit cost, and making the application more flexible and more applicable.

[0134] Fig. 9 Schematic diagram of the structure of the vehicle power system provided by this application. Fig. 9 As shown, the vehicle power system 4 includes a power battery 40 and a bidirectional vehicle charger 41, and the bidirectional vehicle charger 41 is used to charge the power battery 40. Since the bidirectional vehicle charger 41 is compatible with the forward charging function and the reverse discharging function of the single three-phase input, the working efficiency of the vehicle power system 4 can be improved, and the circuit cost of the vehicle power system 4 is greatly reduced, and the applicability is strong.

[0135] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A bidirectional on-board charger, used to charge a power battery using a three-phase AC power supply or to supply power to an AC load using the power battery, characterized in that: The bidirectional on-board charger comprises: A DC bus, wherein the DC bus is used to transmit direct current; A positive bus capacitor and a negative bus capacitor, wherein the positive bus capacitor and the negative bus capacitor are connected in series between the positive and negative electrodes of the DC bus; A power factor correction circuit, the power factor correction circuit is used to receive one-phase AC power or three-phase AC power provided by the three-phase AC power supply or to receive the DC power provided by the power battery, the power factor correction circuit includes a first bridge arm, the first bridge arm is connected in series between the positive and negative poles of the DC bus, the first bridge arm includes two diodes connected in series, the series connection point of the two diodes serves as the midpoint of the first bridge arm, the midpoint of the first bridge arm is connected to the series connection point of the positive bus capacitor and the negative bus capacitor through a first switch, the power factor correction circuit includes three second bridge arms, the three second bridge arms are respectively connected in series between the positive and negative poles of the DC bus, the midpoint of at least one second bridge arm is used to receive the one-phase AC power, or the midpoints of three second bridge arms are used to receive the three-phase AC power, or at least one second bridge arm is used to receive the DC power, the second bridge arm includes a second switch and a third switch connected in series, and the series connection point of the second switch and the third switch serves as the midpoint of the second bridge arm; a controller, the controller being used to control the first switch to be disconnected and to control at least one of the second bridge arms to output the direct current to charge the power battery, the controller being used to control the first switch to be turned on and to control the midpoint of at least one of the second bridge arms to output alternating current to power the alternating current load; a sixth switch, wherein the midpoint of any one of the second bridge arms is connected to the second connection end of the AC load through the sixth switch, the second connection end of the AC load is connected to the midpoint of the first bridge arm, and the midpoint of any one of the second bridge arms is connected to the neutral line of the three-phase AC power supply through the sixth switch; The controller is used to control the sixth switch and the second switch in the second bridge arm connected to the sixth switch to be turned on when the difference obtained by subtracting the voltage of the negative bus capacitor from the voltage of the positive bus capacitor is greater than or equal to a first threshold, so as to balance the voltage of the positive bus capacitor and the voltage of the negative bus capacitor; The controller is used to control the sixth switch and the third switch in the second bridge arm connected to the sixth switch to be turned on when the difference obtained by subtracting the voltage of the positive bus capacitor from the voltage of the negative bus capacitor is greater than or equal to a second threshold, so as to balance the voltage of the positive bus capacitor and the voltage of the negative bus capacitor; The bidirectional on-board charger is used to utilize the power battery to supply power to the AC load.

2. The bidirectional on-board charger according to claim 1, characterized in that: The controller is used to: Controlling the second switch and the third switch in at least one of the second bridge arms to be alternately turned on to convert the one-phase alternating current into the direct current or convert the direct current into the alternating current; The second switches and the third switches in the three second bridge arms are controlled to be turned on alternately to convert the three-phase alternating current into the direct current.

3. The bidirectional on-board charger according to claim 2, characterized in that: The bidirectional on-board charger includes three fourth switches corresponding to the three second bridge arms, a midpoint of one second bridge arm is connected to a live wire of the three-phase AC power supply or a first connection end of the AC load through the fourth switch corresponding to the second bridge arm, and the controller is used for: Controlling any one of the fourth switches to be turned on, and controlling the other two fourth switches to be turned off, so that a midpoint of at least one of the second bridge arms receives the one-phase alternating current or outputs the alternating current; The three fourth switches are controlled to be turned on so that the midpoints of the three second bridge arms receive the three-phase alternating current.

4. The bidirectional on-board charger according to claim 3, characterized in that: The three second bridge arms include the other two second bridge arms except the second bridge arm corresponding to any one of the fourth switches, the bidirectional on-board charger includes a fifth switch, the midpoint of any one of the other two second bridge arms is connected to the first connection end of any one of the fourth switches through the fifth switch, the first connection end of any one of the fourth switches is connected to a live wire of the three-phase AC power supply or the first connection end of the AC load, and the controller is used for: Controlling any one of the fourth switch and the fifth switch to be turned on, and controlling the other two fourth switches to be turned off, so that a midpoint of at least one of the second bridge arms receives the one-phase alternating current or outputs the alternating current; The three fourth switches are controlled to be disconnected, and the fifth switch is controlled to be turned on, so that a midpoint of at least one of the second bridge arms receives the one-phase alternating current or outputs the alternating current.

5. The bidirectional on-board charger according to claim 3, characterized in that: The three second bridge arms include the other two second bridge arms except the second bridge arm corresponding to any one of the fourth switches, the bidirectional on-board charger includes two fifth switches corresponding to the other two second bridge arms, the midpoint of one of the second bridge arms of the other two second bridge arms is connected to the first connection end of any one of the fourth switches through the fifth switch corresponding to the second bridge arm, the first connection end of any one of the fourth switches is connected to a live wire of the three-phase AC power supply or the first connection end of the AC load, and the controller is used for: Controlling any one of the fourth switches and two of the fifth switches to be turned on, and controlling the other two of the fourth switches to be turned off, so that a midpoint of at least one of the second bridge arms receives the one-phase alternating current or outputs the alternating current; The three fourth switches are controlled to be disconnected, and the two fifth switches are controlled to be turned on, so that a midpoint of at least one of the second bridge arms receives the one-phase alternating current or outputs the alternating current.

6. The bidirectional on-board charger according to any one of claims 1 to 5, characterized in that: The controller is used to control the sixth switch to be disconnected, and the bidirectional on-board charger is used to charge the power battery using the three-phase AC power supply.

7. A vehicle-mounted power system, characterized in that: The vehicle-mounted power system includes a power battery and a bidirectional vehicle-mounted charger as described in any one of claims 1 to 6, and the bidirectional vehicle-mounted charger is used to charge the power battery using the three-phase AC power supply.

8. An electric vehicle, characterized in that: The electric vehicle includes a power battery, a drive motor and a bidirectional on-board charger as described in any one of claims 1 to 6, wherein the bidirectional on-board charger is used to charge the power battery using the three-phase AC power supply, and the power battery is used to power the drive motor.

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