Charging and discharging control method, system, device, electric vehicle and storage medium

Abstract

The present invention discloses a charge and discharge control method, system, device, electric vehicle, and storage medium, wherein the charge and discharge control method first determines the working mode of the power battery unit according to the charge and discharge requirements of the power battery unit, and when the working mode is determined to be any one of the AC isolation charging mode, the AC isolation discharging mode, the DC isolation charging mode, and the DC isolation discharging mode, the switch state of the controllable switch unit is controlled, and the DC / DC conversion unit, the motor control unit, the generator control unit, and some switch tubes in the isolation conversion unit are multiplexed and controlled to realize the isolated charge and discharge of the power battery unit. Therefore, the charge and discharge control method in this embodiment can reduce the weight and volume of the charge and discharge control circuit and improve the mileage and endurance of the electric vehicle.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a charge and discharge control method, a charge and discharge control system, an electric vehicle, a computer-readable storage medium, and a charge and discharge control device. Background Art

[0002] With the development of new energy vehicle technology, more and more users are starting to use new energy electric vehicles. However, whether it is a pure electric vehicle or a hybrid electric vehicle, new energy vehicles generally contain an OBC (On Board Charger) AC or DC charging circuit to meet the needs of AC or DC charging of electric vehicles. However, OBC is often only used when the vehicle is stationary. When the vehicle is in motion, the OBC component becomes a fixed load of the new energy vehicle.

[0003] In the related art, the power devices used to charge electric vehicle batteries with single-phase or three-phase AC power cannot be reused, and the charging circuit is often not electrically isolated, so the system safety cannot be effectively guaranteed, the overall weight of the vehicle cannot be reduced, and the cost is increased. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, one object of the present invention is to provide a charge and discharge control method that can reduce the weight and volume of the charge and discharge control circuit and improve the mileage and endurance of electric vehicles.

[0005] The second object of the present invention is to provide a charge and discharge control system.

[0006] A third object of the present invention is to provide an electric vehicle.

[0007] A fourth object of the present invention is to provide a computer-readable storage medium.

[0008] A fifth object of the present invention is to provide a charge and discharge control device.

[0009] To achieve the above-mentioned purpose, a first aspect of the present invention provides a charge and discharge control method, wherein the charge and discharge control circuit includes a power battery unit, an isolation conversion unit, a DC / DC conversion unit, a motor control unit, a generator control unit and a controllable switch unit, the DC / DC conversion unit, the motor control unit and the generator control unit are connected to each other, the DC / DC conversion unit is also connected to the power battery unit and the DC charge and discharge terminal, the isolation conversion unit is also connected to the power battery unit, the motor control unit and the generator control unit, the first end of the DC / DC conversion unit and the midpoint of the first phase bridge arm in the motor control unit are connected to the AC charge and discharge terminal, and the charge and discharge control method includes: when the power battery unit needs to be charged and discharged, controlling the controllable switch unit to operate in a preset working mode to realize the charging and discharging of the power battery unit; wherein the controllable switch unit operating in the working mode can use at least part of the switch tubes in the DC / DC conversion unit, the motor control unit, the generator control unit and the isolation conversion unit as part of the charging and discharging circuit of the power battery unit.

[0010] The charge and discharge control method of the present invention can first determine the working mode of the power battery unit according to the charge and discharge requirements of the power battery unit. When the working mode is determined to be any one of the AC isolation charging mode, the AC isolation discharging mode, the DC isolation charging mode and the DC isolation discharging mode, the switch state of the controllable switch unit is controlled, and the DC / DC conversion unit, the motor control unit, the generator control unit and some switch tubes in the isolation conversion unit are multiplexed and controlled to realize the isolated charge and discharge of the power battery unit. Therefore, the charge and discharge control method in this embodiment can reduce the weight and volume of the charge and discharge control circuit and improve the mileage and endurance of the electric vehicle.

[0011] To achieve the above-mentioned purpose, the second aspect of the present invention proposes a charge and discharge control system, which includes a memory, a processor, and a charge and discharge control program stored in the memory and executable on the processor. When the processor executes the charge and discharge control program, the charge and discharge control method described in the first aspect of the present invention is implemented.

[0012] The charge and discharge control system of the embodiment of the present invention includes a memory and a processor. The processor executes the charge and discharge control program stored in the memory, which can reduce the weight and volume of the charge and discharge control circuit and improve the mileage and endurance of the electric vehicle.

[0013] To achieve the above-mentioned object, a third aspect of the present invention provides an electric vehicle, which includes the charge and discharge control system in the above-mentioned embodiment.

[0014] The electric vehicle of the embodiment of the present invention can reduce the weight and volume of the electric vehicle and improve the driving mileage and endurance of the electric vehicle through the charge and discharge control system in the above embodiment.

[0015] To achieve the above-mentioned purpose, the fourth aspect of the present invention proposes a computer-readable storage medium, which stores a charge and discharge control program. When the charge and discharge control program is executed by a processor, it implements the charge and discharge control method described in the first aspect of the present invention.

[0016] The computer-readable storage medium of the embodiment of the present invention can reduce the weight and volume of the charge and discharge control circuit and improve the mileage and endurance of the electric vehicle by executing the charge and discharge control program stored thereon through a processor.

[0017] To achieve the above-mentioned purpose, a fifth embodiment of the present invention proposes a charge and discharge control device, wherein the charge and discharge control circuit includes a power battery unit, an isolation conversion unit, a DC / DC conversion unit, a motor control unit, a generator control unit and a controllable switch unit, wherein the DC / DC conversion unit, the motor control unit and the generator control unit are connected to each other, and the DC / DC conversion unit is also connected to the power battery unit and the DC charge and discharge terminal, the isolation conversion unit is also connected to the power battery unit, the motor control unit and the generator control unit, the first end of the DC / DC conversion unit and the midpoint of the first phase bridge arm in the motor control unit are connected to the AC charge and discharge terminal, and the charge and discharge control device includes: a charge and discharge control module, which is used to control the controllable switch unit to operate in a preset working mode when the power battery unit needs to be charged and discharged, so as to realize the charging and discharging of the power battery unit; wherein the controllable switch unit operating in the working mode can use at least part of the switch tubes in the DC / DC conversion unit, the motor control unit, the generator control unit and the isolation conversion unit as part of the charge and discharge circuit of the power battery unit.

[0018] The charge and discharge control device of the embodiment of the present invention includes a charge and discharge control module, wherein, when the power battery unit needs to be charged and discharged, the charge and discharge control device can control the switch state of the controllable switch unit when the working mode is determined to be any one of the AC isolation charging mode, the AC isolation discharging mode, the DC isolation charging mode and the DC isolation discharging mode, and multiplex control some switch tubes in the DC / DC conversion unit, the motor control unit, the generator control unit and the isolation conversion unit to realize the isolated charge and discharge of the power battery unit. Therefore, the charge and discharge control device in this embodiment can reduce the weight and volume of the charge and discharge control circuit and improve the driving mileage and endurance of the electric vehicle because it increases the reuse of the switch tube and reduces the switch devices that need to be set.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of a charging and discharging circuit structure according to an embodiment of the present invention;

[0021] Figure 2 is a flow chart of a charge and discharge control method according to an embodiment of the present invention;

[0022] Figure 3 is a flow chart of a charge and discharge control method according to a specific embodiment of the present invention;

[0023] Figure 4 is a schematic diagram of a charging and discharging circuit structure according to a specific embodiment of the present invention;

[0024] Figure 5 is a flow chart of a charge and discharge control method according to a specific embodiment of the present invention;

[0025] Figure 6 is a flow chart of a charge and discharge control method according to a specific embodiment of the present invention;

[0026] Figure 7 is a schematic diagram of a charging and discharging circuit structure according to a specific embodiment of the present invention;

[0027] Figure 8 is a flow chart of a charge and discharge control method according to a specific embodiment of the present invention;

[0028] Fig. 9 is a flow chart of a charge and discharge control method according to a specific embodiment of the present invention;

[0029] Fig.10 is a schematic diagram of a charging and discharging circuit structure according to a specific embodiment of the present invention;

[0030] Fig.11 is a flow chart of a charge and discharge control method according to a specific embodiment of the present invention;

[0031] Fig.12 is a flow chart of a charge and discharge control method according to a specific embodiment of the present invention;

[0032] Fig.13 is a schematic diagram of a charging and discharging circuit structure according to a specific embodiment of the present invention;

[0033] Fig.14 is a flow chart of a charge and discharge control method according to a specific embodiment of the present invention;

[0034] Fig.15 is a schematic diagram of a charging and discharging circuit structure according to a specific embodiment of the present invention;

[0035] Fig.16 is a flow chart of a charge and discharge control method according to a specific embodiment of the present invention;

[0036] Fig.17 is a structural block diagram of a charge and discharge control system according to an embodiment of the present invention;

[0037] Fig.18 is a structural block diagram of an electric vehicle according to an embodiment of the present invention;

[0038] Fig.19 4 is a structural block diagram of a charge and discharge control device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0040] The following describes the charge and discharge control method, system, device, and storage medium according to the embodiments of the present invention with reference to the accompanying drawings.

[0041] Figure 1 Schematic diagram of a charging and discharging circuit structure according to an embodiment of the present invention.

[0042] like Figure 1 As shown, the charge and discharge control circuit in the embodiment of the present invention includes a power battery unit 2, an isolation conversion unit 40, a DC / DC conversion unit 10, a motor control unit 20, a generator control unit 30, and a first controllable switch unit, a second controllable switch unit, a third controllable switch unit, a fourth controllable switch unit, and a fifth controllable switch unit. The DC / DC conversion unit 10, the motor control unit 20 and the generator control unit 30 are connected to each other through a DC bus. The DC / DC conversion unit 10 is also connected to the power battery unit 2 through the first controllable switch unit and to the DC charge and discharge terminal 3 through the third controllable switch unit. The isolation conversion unit 40 is connected to the power battery unit 2 through the second controllable switch unit and to the motor control unit 20 and the generator control unit 30 through the fifth controllable switch unit. The first end of the DC / DC conversion unit 10 and the midpoint of the first phase bridge arm in the motor control unit 20 are connected to the AC charge and discharge terminal 4 through the fourth controllable switch unit.

[0043] Specifically, Figure 1As shown in the figure, the controllable switch unit includes multiple switches. Since the distances between the switch positions are too different, the controllable switch unit is not described with reference numerals. Figure 1 It can be seen that the DC / DC conversion unit 10, the motor control unit 20 and the generator control unit 30 are connected through a DC bus, and the DC / DC conversion unit 10 includes four switch tubes, namely switch tube Q1, switch tube Q2, switch tube Q3 and switch tube Q4, wherein the four switch tubes form an H bridge, the switch tube Q1 and the switch tube Q2 are the first bridge arm of the DC / DC conversion unit 10, and the switch tube Q3 and the switch tube Q4 are the second bridge arm of the DC / DC conversion unit 10. The motor control unit 20 includes six switch tubes, namely switch tube M1, switch tube M2, switch tube M3, switch tube M4, switch tube M5 and switch tube M6, wherein the six switch tubes form a three-phase full-bridge circuit, the switch tube M1 and the switch tube M4 are the first phase bridge arm of the motor control unit 20, the switch tube M3 and the switch tube M6 are the second phase bridge arm of the motor control unit 20, and the switch tube M2 and the switch tube M5 are the third phase bridge arm of the motor control unit 20. The generator control unit 30 includes six switches, namely switch G1, switch G2, switch G3, switch G4, switch G5 and switch G6, wherein the six switches form a three-phase full-bridge circuit, switch G1 and switch G4 are the first phase bridge arm of the generator control unit 30, switch G3 and switch G6 are the second phase bridge arm of the generator control unit 30, and switch G2 and switch G5 are the third phase bridge arm of the generator control unit 30. The isolation conversion unit 40 includes four switches, namely switch B1, switch B2, switch B3 and switch B4, wherein the four switches form an H bridge, switch B1 and switch B2 are the first bridge arm of the isolation conversion unit 40, and switch B3 and switch B4 are the second bridge arm of the isolation conversion unit 40.

[0044] In this embodiment, by selecting and controlling the controllable switch unit, and multiplexing and controlling some switch tubes in the DC / DC conversion unit 10, the motor control unit 20, the generator control unit 30, and the isolation conversion unit 40, the energy isolation conversion between the power battery 2 and the external charging and discharging equipment can be realized. It can be understood that the switch tubes in the DC / DC conversion unit 10, the motor control unit 20, the generator control unit 30, and the isolation conversion unit 40 are all controlled by the controller, and the controller can control the working mode of the switch tube by controlling the change of the electrical signal at the control end of the switch tube, and the controller can also control the switch in the controllable switch unit.

[0045] It should be noted that the DC / DC conversion unit 10, the motor control unit 20, the generator control unit 30 and the isolation conversion unit 40 in this embodiment are all necessary for electric vehicles. That is to say, even if the electric vehicle is not equipped with an OBC to charge the electric vehicle, it is necessary to set up the DC / DC conversion unit 10, the motor control unit 20, the generator control unit 30 and the isolation conversion unit 40 to ensure the normal operation of the electric vehicle. Therefore, by reusing the switch tubes in the DC / DC conversion unit 10, the motor control unit 20, the generator control unit 30 and the isolation conversion unit 40, there is no need to add more power devices to reduce the fixed load of the vehicle, reduce the weight and volume of the vehicle, and help to improve the mileage of the electric vehicle and solve the current range anxiety problem in the use of electric vehicles.

[0046] More specifically, see Figure 1 In this embodiment, the first controllable switch unit may include a first switch S1 and a third switch S3, the second controllable switch unit may include a second switch S2 and a fourth switch S4, the third controllable switch unit may include a fifth switch S5 and a sixth switch S6, the fourth controllable switch unit may include a fifth switch S5 and a seventh switch S7, and the fifth controllable switch unit may include an eighth switch S8, wherein it should be noted that both the third controllable switch unit and the fourth controllable switch unit include the fifth switch S5, that is, the fifth switch S5 can be reused, and when the working mode of the power battery unit is any one of the AC isolation charging mode, the AC isolation discharging mode, the DC isolation charging mode and the DC isolation discharging mode, the fifth switch S5 is in a closed state, and the working state of the third controllable switch unit is specifically determined by the state of the sixth switch S6, and the working state of the fourth controllable switch unit is specifically determined by the state of the seventh switch S7.

[0047] like Figure 2 As shown, the present invention proposes a charge and discharge control method, which includes the following steps:

[0048] S10, when the power battery unit needs to be charged and discharged, the controllable switch unit is controlled to operate in a preset operating mode to realize the charging and discharging of the power battery unit; wherein, the controllable switch unit operating in the operating mode can use at least some of the switch tubes in the DC / DC conversion unit 10, the motor control unit 20, the generator control unit 30 and the isolation conversion unit 40 as part of the charging and discharging circuit of the power battery unit.

[0049] Specifically, in this embodiment, the vehicle controller can first determine whether the power battery unit has received a charge and discharge instruction, and the charge and discharge instruction can be detected by the detection device on the charge and discharge terminal. For example, when it is detected that the charging terminal is connected to the external power grid, it can be determined that the power battery unit has triggered the charge and discharge instruction. After determining the charge and discharge instruction of the power battery unit, the working mode of the power battery unit can be determined according to the charge and discharge instruction. The specific working mode can include an AC isolation charging mode, an AC isolation discharging mode, a DC isolation charging mode, and a DC isolation discharging mode. When it is determined that the working mode of the power battery unit is any one of the AC isolation charging mode, the AC isolation discharging mode, the DC isolation charging mode, and the DC isolation discharging mode, the states of the first to eighth switches are controlled respectively corresponding to different working modes, and the DC / DC conversion unit 10, the motor control unit 20, the generator control unit 30, and the isolation conversion unit 40 are reused to achieve the isolated charging and discharging of the power battery unit 2.

[0050] In some embodiments of the present invention, when the power battery unit operates in the AC isolation discharge mode, Figure 2 and Figure 3 As shown, in step S10, when the power battery unit needs to be charged and discharged, the controllable switch unit is controlled to work in a preset working mode to realize the charging and discharging of the power battery unit, including the following steps:

[0051] S301, when the power battery unit needs AC isolation discharge, control the first controllable switch unit and the third controllable switch unit to be disconnected, and control the second controllable switch unit, the fourth controllable switch unit and the fifth controllable switch unit to be closed. S302, control the isolation conversion unit 40 to perform DC-AC isolation conversion on the DC power provided by the power battery unit 2, output the first AC power, and control the H bridge composed of the second phase bridge arm in the motor control unit 20 and any one phase bridge arm in the generator control unit 30 to rectify the AC power output by the isolation conversion unit 40, and control the first phase bridge arm in the motor control unit 20 and the inverter circuit composed of the DC / DC conversion unit 10 to invert the DC power output by the H bridge, so as to provide AC power supply to the outside through the AC charge and discharge terminal 4.

[0052] Specifically, in this embodiment, the alternating current can be divided into a positive half-cycle and a negative half-cycle. In the positive half-cycle, the current flows out from the live wire L and flows back from the neutral wire N; in the negative half-cycle, the current flows out from the neutral wire N and flows back from the live wire L.

[0053] Figure 4 FIG. 1 is a circuit diagram of an AC discharge mode with a positive half cycle as a specific embodiment. Figure 4As shown, the power battery unit 2 outputs direct current through the second switch S2 and the fourth switch S4, and outputs alternating current after being inverted by the inverter H-bridge composed of the switch tubes B1-B4 in the isolation conversion unit 40. The alternating current is then isolated and transformed by the transformer T1 in the isolation conversion unit 40, and the first secondary winding inputs the alternating current into the H-bridge composed of the second phase bridge arm in the motor control unit 20 and the first phase bridge arm of the generator control unit 30 for rectification. After rectifying the alternating current, the H-bridge outputs direct current, and the direct current is then inverted by the inverter circuit composed of the first phase bridge arm in the motor control unit 20 and the first bridge arm and / or the second bridge arm in the DC / DC conversion unit 10, thereby inverting the direct current into alternating current, and then the alternating current is used to charge the external device through the AC charge and discharge terminal 4.

[0054] It should be noted that in the positive half cycle, in the inverter circuit composed of the first bridge arm in the motor control unit 20 and the first bridge arm and / or the second bridge arm in the DC / DC conversion unit 10, the switch tubes Q1, Q2, Q3, Q4 and M4 are in working state, and the switch tube M1 is in off state. Specifically, the switch tubes Q1 and Q2 are switched on and off alternately according to their working cycles, Q1 and Q2 are switched on and off complementary, and the switching on and off time of the switch tube Q3 is the switching signal of the switch tube Q1 delayed by half of the working cycle, and the switching on and off time of the switch tube Q4 is the switching signal of the switch tube Q2 delayed by half of the working cycle, and the switch tube M4 is always in the on state. The first bridge arm and the second bridge arm of the DC / DC conversion unit are parallel structures. It should be noted that only one of the bridge arms can work, or the two bridge arms can work in an interlaced parallel manner.

[0055] The H-bridge in this specific embodiment may also be composed of the second phase bridge arm in the motor control unit 20 and the second phase bridge arm or the third phase bridge arm of the generator control unit 30, which is not limited here.

[0056] More specifically, if Figure 5As shown, when determining that the vehicle is working in the AC isolation discharge mode, it can be first determined whether the vehicle is in a stopped state, specifically by detecting the speed of the vehicle and whether the vehicle gear is in the parking gear. If yes, it is determined that the vehicle is in a stopped state, and further detects whether the AC discharge cable has been connected to the AC charge and discharge terminal 4. Specifically, a corresponding detection circuit can be set in the AC charge and discharge terminal 4, so that when there is a cable access, a cable access signal is sent to the vehicle control system, thereby determining whether the AC discharge cable is connected to the AC charge and discharge terminal 4. If yes, it is further determined whether the electric vehicle is connected to the load by CAN (Controller Area Network) communication. If yes, the discharge current, voltage, frequency, power, discharge amount and other parameters can be set by both parties through CAN communication. It should be noted that it is not a necessary step to determine whether the vehicle is connected to the load by CAN communication. In the case where the load does not have the CAN communication function, the discharge current, voltage, frequency, power, discharge amount and other parameters can be directly set through the control panel of the discharge vehicle.

[0057] After determining the discharge current, voltage, frequency, power, discharge amount and other parameters, the switching logic of the switching tubes in the DC / DC conversion unit 10, the motor control unit 20, the generator control unit 30 and the isolation conversion unit 40 can be configured, which may specifically include the switching frequency, duty cycle, dead time and other parameters of the switching tubes. Specifically, in the inverter H-bridge in the isolation conversion unit 40, the motor control unit 20 and the H-bridge in the generator control unit 30, first, according to the LLC working principle, the stable output voltage value V2 on the bus capacitor is calculated according to the discharge voltage V1, the voltage value V2 is greater than the discharge voltage V1, the LLC circuit performs closed-loop control, and the voltage value V2 is used as the given voltage, and the voltage sampling value on the bus capacitor is used as the feedback value. After the difference between the two is PID adjusted and calculated, the frequency of the modulated voltage waveform of the switch tubes B1-B4, the switch tube M2, the switch tube M5, the switch tube G1 and the switch tube G4 can be obtained, and then the frequency of the modulated voltage waveform (generally sine and cosine) is compared with a triangular carrier of a fixed frequency (for example, 100kHz) to obtain the PWM waveform of the switch tubes B1-B4, the switch tube M2, the switch tube M5, the switch tube G1 and the switch tube G4, the waveform includes duty cycle information, and the dead time between the upper and lower bridge arms can be set by software. It should be noted that the switch tube B1 and the switch tube B4 are turned on at the same time, the switch tube B2 and the switch tube B3 are turned on at the same time, the switch tube M5 and the switch tube G4 are turned on at the same time, and the switch tube M2 and the switch tube G1 are turned on at the same time.

[0058] In the inverter conversion circuit composed of the switch tubes Q1-Q4, the switch tube M1 and the switch tube M4, the discharge voltage V1, the discharge current I1 and the frequency f can be used as given quantities, and the sampling values ​​of the AC output current and the AC output voltage can be used as feedback quantities for comparison, and the comparison difference can be calculated by PID adjustment to obtain the modulation voltage waveform of the switch tubes Q1-Q4, the switch tube M1 and the switch tube M4, and then the modulation voltage waveform (generally sine and cosine, frequency f) is compared with a triangular carrier with a fixed frequency (for example, 10kHz) to obtain the PWM waveform of the switch tubes Q1-Q4, the switch tube M1 and the switch tube M4, which includes duty cycle information, and the dead time between the upper and lower bridge arms can also be set by software. It should be noted that, among them, the switch tube Q1 and the switch tube Q3 are connected in parallel, and the switch tube Q2 and the switch tube Q4 are connected in parallel, and only one-phase bridge arm composed of the switch tube Q1 and the switch tube Q3 can be used; or only one-phase bridge arm composed of the switch tube Q2 and the switch tube Q4 can be used. The switch tubes Q1, Q2, Q3, Q4 and M4 are in working state, and the switch tube M1 is in off state. Specifically, the switch tubes Q1Q2 are switched on and off alternately according to their working cycles, and Q1 and Q2 are switched on and off complementarily. The switch tube Q3 is switched on and off when the switch signal of the switch tube Q1 is delayed by half a working cycle, and the switch tube Q4 is switched on and off when the switch signal of the switch tube Q2 is delayed by half a working cycle. The switch tube M4 is always in the on state.

[0059] In this embodiment, the isolation conversion unit 40 is also connected to the AC-DC conversion unit 50. When the isolation conversion unit 40 performs DC-AC isolation conversion on the DC power provided by the power battery unit 2, it also outputs a second AC power. The AC-DC conversion unit 50 is used to convert the second AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

[0060] Specifically, Figure 4 As shown, the AC / DC conversion unit 50 includes a first diode and a second diode, and a low-voltage battery unit is also connected to the second secondary winding of the transformer T1. Specifically, the anode of the first diode can be connected to the same-name end of the second secondary winding, and then the cathode of the first diode is connected to the positive electrode of the low-voltage battery unit, the opposite-name end of the second secondary winding is connected to the anode of the second diode, and then the cathode of the second diode is connected to the cathode of the first diode, and the tap of the second secondary winding is connected to the negative electrode of the low-voltage battery unit, so that the alternating current flowing out of the second secondary winding can charge the low-voltage battery unit in both the positive and negative half cycles. Of course, the low-voltage battery unit can also be replaced by a low-voltage electrical device to power the low-voltage electrical device, or the low-voltage battery unit and the low-voltage electrical device can be connected in parallel to power them simultaneously.

[0061] It should be noted that this specific embodiment only cites the case where the AC power is in the positive half cycle, and when the AC power is in the negative half cycle, simple reasoning can be performed referring to the above method, which will not be repeated here.

[0062] In some embodiments of the present invention, when the power battery unit operates in a DC isolation discharge mode, Figure 2 and Figure 6 As shown, in step S10, when the power battery unit needs to be charged and discharged, the controllable switch unit is controlled to work in a preset working mode to realize the charging and discharging of the power battery unit, including the following steps:

[0063] S601, when the power battery unit needs DC isolation discharge, control the first controllable switch unit and the fourth controllable switch unit to be disconnected, and control the second controllable switch unit, the third controllable switch unit and the fifth controllable switch unit to be closed. S602, control the isolation conversion unit to perform DC-AC isolation conversion on the DC power provided by the power battery unit, output the first AC power, and control the H-bridge composed of the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit to rectify the AC power output by the isolation conversion unit, and control the first switch tube and / or the third switch tube in the DC / DC conversion unit to be turned on, so that the DC power after the H-bridge rectification can be supplied to the outside through the DC charging and discharging terminal for DC power supply.

[0064] Specifically, the power battery unit in the embodiment of the present invention can be discharged in DC isolation mode or AC isolation mode, and different isolation discharge modes correspond to different control modes for each unit in the control system. Figure 6 and Figure 7 It can be seen that in the DC isolation discharge mode, that is, when the power battery unit 2 outputs DC power to the external charging and discharging device, the DC power output by the power battery unit 2 flows into the H-bridge composed of the switch tubes B1-B4 in the isolation conversion unit 40 through the second switch S2 and the fourth switch S4 for inversion processing, and is converted into AC power after the inversion processing and converted by the transformer T1, and then the AC power is input into the H-bridge composed of the third bridge arm in the motor control unit 20 and the first bridge arm of the generator control unit 30. After the H-bridge processing, DC power can be input into the DC / DC conversion unit 10 for step-down processing, and then the DC power after the step-down processing is input into the DC charging and discharging terminal 3 through the fifth switch S5 and the sixth switch S6, so as to supply power to the external charging and discharging device. Optionally, in this embodiment, the external charging and discharging device can be a DC power grid, a vehicle, or other DC power or storage device.

[0065] It should be noted that in some embodiments, the DC / DC conversion unit 10 may be controlled not to perform voltage regulation, that is, the DC / DC conversion unit 10 may not participate in the voltage regulation in the DC discharge mode, and the DC power output by the H-bridge may be directly output to the external charging and discharging device. At this time, the switch tube Q1 and / or the switch tube Q3 need to be kept turned on continuously.

[0066] More specifically, if Figure 8 As shown, the description of the flow chart can refer to the above embodiment for Figure 5 The description of the vehicle stop state judgment, cable connection and other steps are the same and will not be repeated here. It should be noted that in this embodiment, it is also judged whether the DC / DC conversion unit 10 is enabled, which can be judged based on the comparison result between the input voltage and the preset voltage. The specific judgment method is described in detail below.

[0067] It should be noted that the control method of the switch tubes B1-B4, switch tube M2, switch tube M5, switch tube G1 and switch tube G4 in this embodiment can refer to the specific control method of the switch tubes B1-B4, switch tube M2, switch tube M5, switch tube G1 and switch tube G4 in the above-mentioned AC isolation discharge mode, which will not be repeated here.

[0068] As for the control of the switch tubes Q1-Q4, in this embodiment, first, according to the set value of the discharge voltage V1, if the discharge voltage V1 is less than the stable output voltage value V2 on the bus capacitor, it is necessary to enable the DC / DC conversion unit 10 to make it work in the staggered parallel Buck circuit mode, and then use the discharge voltage V1 as the output voltage, and use the discharge current I1 as the given quantity, and the actual sampled values ​​of the output voltage and the output current as the feedback quantity, and the difference is PID (generally current inner loop closed-loop control, voltage outer loop closed-loop control) adjusted to obtain the modulation voltage waveform (generally real-time regulated DC quantity) of the switch tubes Q1-Q4, and then compare the modulation voltage waveform with a triangular carrier of a fixed frequency (for example, 10kHz) to obtain the PWM waveform of the switch tubes Q1-Q4, the waveform information includes duty cycle information, and the dead time between the upper and lower bridge arms can also be set by software. The switch tubes Q1 and Q2 are complementary to each other, the conduction timing of the switch tubes Q3 and Q1 is 180° different, and the conduction timing of the switch tubes Q4 and Q2 is 180° different, so that the two bridge arms are alternately turned on, thereby reducing the ripple of the output voltage and the output current and improving the quality of the output voltage and current. It should be noted that if the discharge voltage V1 is equal to the stable output voltage value V2 on the bus capacitor, there is no need to enable the DC / DC conversion unit 10, and the output of the DC voltage can be achieved by only keeping the switch tubes Q1 and Q3 constantly turned on.

[0069] In this embodiment, the isolation conversion unit 40 is also connected to the AC-DC conversion unit 50. When the isolation conversion unit 40 performs DC-AC isolation conversion on the DC power provided by the power battery unit 2, it also outputs a second AC power. The AC-DC conversion unit 50 is used to convert the second AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

[0070] It should be noted that the specific implementation of the isolation conversion unit 40 charging the low-voltage battery unit in the electric vehicle or supplying power to the low-voltage device can be found in the specific description of the above embodiment, which will not be repeated here.

[0071] In some embodiments of the present invention, when the power battery unit operates in an AC isolation charging mode, Figure 2 and Fig. 9 As shown, in step S10, when the power battery unit needs to be charged and discharged, the controllable switch unit is controlled to work in a preset working mode to realize the charging and discharging of the power battery unit, including the following steps:

[0072] S901, when the power battery unit requires an AC isolation charging mode, control the first controllable switch unit and the third controllable switch unit to be disconnected, and control the second controllable switch unit, the fourth controllable switch unit and the fifth controllable switch unit to be closed. S902, control the rectification and PFC circuit formed by the DC / DC conversion unit and the first phase bridge arm in the motor control unit to rectify and PFC correct the AC power provided through the AC charging and discharging terminal, output DC power, and control the inverter H-bridge formed by the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit to invert the DC power output by the rectification and PFC circuit, and control the isolation conversion unit to perform AC-DC isolation conversion on the first AC power output by the inverter H-bridge to charge the power battery unit.

[0073] Specifically, see Fig. 9 and Fig.10In this embodiment, the AC isolation charging mode is described in detail by taking the positive half cycle of AC power as an example. The negative half cycle can be derived according to the same principle and will not be described in detail. More specifically, first, the current can flow out from the live wire L, and then the power is corrected and rectified by the PFC circuit composed of the switch tubes Q1-Q4, the switch tube M1 and the switch tube M4. Specifically, in the positive half cycle, only one of the switch tubes M1 and the switch tube M4 is turned on, for example, the switch tube M4 is turned on, and in the negative half cycle, the switch tube M1 is turned on. In the positive half cycle, the switch tube Q1 and the switch tube Q2 are alternately switched on and off in a complementary manner, and the specific alternating cycle can be adjusted according to the actual application, while the switch tube Q3 is delayed by half of the alternating cycle relative to the state of the switch tube Q1, and the switch tube Q3 and the switch tube Q4 are also alternately switched in a complementary manner. Through the alternating operation of the switch tubes Q1-Q4, the switch tubes M1 and the switch tubes M4, the power factor correction for the external input AC power can be performed. At the same time, the PFC circuit can also rectify the external input AC power to obtain DC power. After the DC power is input into the inverter H-bridge composed of the third bridge arm in the motor control unit 20 and the first bridge arm in the generator control unit 30, it can be converted into AC power and input into the isolation conversion unit 40. The switch tubes B1-B4 in the isolation conversion unit 40 can form an H-bridge to rectify the AC power input from the inverter H-bridge to obtain DC power, and then the DC power is input into the power battery unit 2 to complete the charging of the power battery unit.

[0074] It should be noted that see Fig.10 It can be seen that a switch S0 is further provided in this embodiment, and the switch can pre-charge the bus voltage before the power battery unit performs AC isolation charging, so as to protect the components of the circuit during the AC isolation charging process.

[0075] More specifically, if Fig.11The detailed process of AC isolation charging of the vehicle is shown, wherein the relevant description of the same steps as in the above embodiment can refer to the specific description of the above embodiment, and it should be noted that during the charging process, after determining that the CAN communication connection is established between the vehicle and the charging terminal, the bus capacitor in the charging circuit of the power battery unit can be pre-charged to prevent the sudden high voltage from damaging the components in the charging circuit. Specifically, the switches S0 and S3 can be closed first to pre-charge the bus capacitor. When the voltage of the bus capacitor is greater than or equal to 85% (no specific value needs to be specified) of the battery voltage of the power battery unit 2, the pre-charge is determined to be completed for normal charging. After the charging is completed, it is necessary to wait for the discharge of the bus capacitor voltage to determine that the AC isolation charging process of the vehicle is completed. Specifically, when the voltage of the bus capacitor is discharged to the safe voltage of 60 volts (no specific value needs to be specified), it is determined that the voltage of the bus capacitor has been discharged. It should be noted that the values ​​85% and 60 volts can be adaptively modified according to actual needs and are not specifically limited here.

[0076] In this embodiment, the isolation conversion unit 40 is also connected to the AC-DC conversion unit 50. When the isolation conversion unit 40 performs AC-DC isolation conversion on the first AC power output by the inverter H-bridge, it also outputs a second AC power. The AC-DC conversion unit 50 is used to convert the AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

[0077] It should be noted that the specific implementation of the isolation conversion unit 40 charging the low-voltage battery unit in the electric vehicle or supplying power to the low-voltage device can be found in the specific description of the above embodiment, which will not be repeated here.

[0078] In some embodiments of the present invention, when the power battery unit needs to be charged or discharged, controlling the controllable switch unit to operate in a preset operating mode to realize the charging and discharging of the power battery unit includes the following steps:

[0079] S1201, when the power battery unit needs DC isolation charging, control the first controllable switch unit and the fourth controllable switch unit to be disconnected, and control the second controllable switch unit, the third controllable switch unit and the fifth controllable switch unit to be closed. S1202, control the inverter H-bridge composed of the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit to invert the DC power provided through the DC charging and discharging terminal, output the first AC power, and control the isolation conversion unit to perform AC-DC isolation conversion on the first AC power output by the inverter H-bridge to charge the power battery unit.

[0080] Specifically, see Fig.12 and Fig.13In the DC isolation charging mode, that is, the external charging and discharging device inputs DC power to the charging circuit of the power battery unit, and first flows into the boost circuit composed of the switch tubes Q1-Q4 in the DC / DC conversion unit 10 through the fifth switch S5 and the sixth switch S6 for voltage transformation. It should be noted that in some embodiments, the DC / DC conversion unit 10 can be controlled not to participate in the voltage regulation work, that is, the DC / DC conversion unit 10 can also not participate in the voltage regulation work in the DC charging mode, and the power flowing in from the external charging and discharging device is directly input through the body diodes of the switch tubes Q1 and Q3 into the inverter H bridge composed of the second bridge arm in the motor control unit 20 and the first bridge arm of the generator control unit 30. The inverter H bridge can invert the DC power input by the external charging and discharging device to obtain AC power, and output it to the isolation conversion unit 40. The H bridge composed of the transformer T1 and the switch tubes B1-B4 can isolate and transform the AC power to output DC power to charge the power battery unit 2 through the second switch S2 and the fourth switch S4.

[0081] It should be noted that see Fig.13 It can be seen that a switch S0 is further provided in this embodiment, and the switch can pre-charge the bus voltage before the power battery unit performs DC isolation charging, so as to protect the components of the circuit during the DC isolation charging process.

[0082] More specifically, Fig.14 The detailed process of the vehicle in DC isolation charging is shown, wherein the relevant description of the same steps as in the above embodiment can refer to the specific description of the above embodiment, and it should be noted that during the charging process, after determining that the CAN communication connection is established between the vehicle and the charging terminal, the bus capacitor in the charging circuit of the power battery unit can be pre-charged to prevent the sudden high voltage from damaging the components in the charging circuit. Specifically, the switches S0 and S3 can be closed first to pre-charge the bus capacitor. When the voltage of the bus capacitor is greater than or equal to 85% (no specific value needs to be specified) of the battery voltage of the power battery unit 2, the pre-charge is determined to be completed for normal charging. After the charging is completed, it is necessary to wait for the discharge of the bus capacitor voltage to determine that the AC isolation charging process of the vehicle is completed. Specifically, when the voltage of the bus capacitor is discharged to the safe voltage of 60 volts (no specific value needs to be specified), it is determined that the voltage of the bus capacitor has been discharged. It should be noted that the values ​​85% and 60 volts can be adaptively modified according to actual needs and are not specifically limited here.

[0083] In this embodiment, the isolation conversion unit 40 is also connected to the AC-DC conversion unit 50. When the isolation conversion unit 40 performs AC-DC isolation conversion on the first AC power provided by the inverter H-bridge, it also outputs a second AC power. The AC-DC conversion unit 50 is used to convert the second AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

[0084] It should be noted that the specific implementation of the isolation conversion unit 40 charging the low-voltage battery unit in the electric vehicle or supplying power to the low-voltage device can be found in the specific description of the above embodiment, which will not be repeated here.

[0085] In some embodiments of the present invention, the operating mode of the power battery unit also includes a non-isolated DC charging mode, wherein, when the power battery unit operates in the non-isolated DC charging mode, the first controllable switch unit and the third controllable switch unit are controlled to be closed, and the second controllable switch unit, the fourth controllable switch unit and the fifth controllable switch unit are controlled to be disconnected, so that the power battery unit is directly charged by the DC power provided by the DC charge and discharge terminals.

[0086] Specifically, Fig.15 As shown, in this embodiment, no isolation conversion unit is provided, but only a DC / DC conversion unit 10 is provided, and a bus capacitor is provided on the bus to meet the requirements of pre-charging and discharging the bus voltage.

[0087] More specifically, Fig.16 The following is a detailed description of the non-isolated DC charging process for the vehicle. Fig.16 , wherein each step has a corresponding step in the above embodiment for detailed description, and the details can be referred to the detailed description of the above embodiment, which will not be repeated here. In summary, the charge and discharge control method of the embodiment of the present invention can reduce the weight and volume of the charge and discharge control circuit and improve the mileage and endurance of the electric vehicle.

[0088] Fig.17 4 is a structural block diagram of a charge and discharge control system according to an embodiment of the present invention.

[0089] Furthermore, the present invention proposes a charge and discharge control system 100, which includes a memory 101, a processor 102, and a charge and discharge control program stored in the memory 101 and executable on the processor 102. When the processor 102 executes the charge and discharge control program, the charge and discharge control method according to the above embodiment is implemented.

[0090] The charge and discharge control system of the embodiment of the present invention includes a memory and a processor. The processor executes the charge and discharge control program stored in the memory, which can reduce the weight and volume of the charge and discharge control circuit and improve the mileage and endurance of the electric vehicle.

[0091] Fig.18 is a structural block diagram of an electric vehicle according to an embodiment of the present invention.

[0092] Furthermore, the present invention proposes an electric vehicle 200 , which includes the charge and discharge control system 100 in the above embodiment.

[0093] The electric vehicle of the embodiment of the present invention can reduce the weight and volume of the charge and discharge control circuit through the charge and discharge control system in the above embodiment, thereby improving the driving mileage and endurance of the electric vehicle.

[0094] Furthermore, the present invention proposes a computer-readable storage medium, which stores a charge and discharge control program. When the charge and discharge control program is executed by a processor, the charge and discharge control method according to the above embodiment is implemented.

[0095] The computer-readable storage medium of the embodiment of the present invention can reduce the weight and volume of the charge and discharge control circuit and improve the mileage and endurance of the electric vehicle by executing the charge and discharge control program stored thereon through a processor.

[0096] Fig.19 4 is a structural block diagram of a charge and discharge control device according to an embodiment of the present invention.

[0097] Furthermore, if Fig.18 As shown, the present invention proposes a charge and discharge control device 300 for a power battery unit, first of all, see Figure 1 As shown, the power battery unit includes a power battery unit 2, an isolation conversion unit 40, a DC / DC conversion unit 10, a motor control unit 20, a generator control unit 30, and a controllable switch unit. The DC / DC conversion unit 10, the motor control unit 20 and the generator control unit 30 are connected to each other through a DC bus. The DC / DC conversion unit 10 is also connected to the power battery unit 2 and the DC charge and discharge terminal 3. The isolation conversion unit 40 is also connected to the power battery unit 2, the motor control unit 20 and the generator control unit 30. The first end of the DC / DC conversion unit 10 and the midpoint of the first phase bridge arm in the motor control unit 20 are connected to the AC charge and discharge terminal 4. The control device 300 includes: a charge and discharge control module 301, wherein the charge and discharge control module 301 is used to control the controllable switch unit to work in a preset working mode when the power battery unit needs to be charged and discharged, so as to realize the charging and discharging of the power battery unit; wherein the controllable switch unit working in the working mode can use at least part of the switch tubes in the DC / DC conversion unit 10, the motor control unit 20, the generator control unit 30 and the isolation conversion unit 40 as part of the charge and discharge circuit of the power battery unit.

[0098] In some embodiments of the present invention, the controllable switch unit includes a first controllable switch unit, a second controllable switch unit, a third controllable switch unit, a fourth controllable switch unit and a fifth controllable switch unit, wherein the first controllable switch unit is arranged between the DC / DC conversion unit and the power battery unit, the second controllable switch unit is arranged between the isolation conversion unit and the power battery unit, the third controllable switch unit is arranged between the DC / DC conversion unit and the DC charge and discharge terminal, the fourth controllable switch unit is arranged between the AC charge and discharge terminal and the circuit composed of the DC / DC conversion unit and the first phase bridge arm in the motor control unit, and the fifth controllable switch unit is arranged between the isolation conversion unit and the motor control unit.

[0099] In some embodiments of the present invention, the first controllable switch unit includes a first switch and a third switch, the second controllable switch unit includes a second switch and a fourth switch, the third controllable switch unit includes a sixth switch, the fourth controllable switch unit includes a seventh switch, and the fifth controllable switch unit includes an eighth switch, wherein one end of the first switch is connected to the positive terminal of the power battery unit, the other end of the first switch is connected to the first end of the DC / DC conversion unit, one end of the third switch is connected to the negative terminal of the power battery unit, and the other end of the third switch is connected to the second end of the DC / DC conversion unit; one end of the second switch is connected to the positive terminal of the power battery unit, and the other end of the second switch is connected to the isolation conversion unit. one end of the eighth switch is connected to the first AC terminal or the second AC terminal of the isolation conversion unit, and the other end of the eighth switch is connected to the midpoint of the second phase bridge arm in the motor control unit or the midpoint of any one phase bridge arm in the generator control unit.

[0100] In some embodiments of the present invention, the charge and discharge control module 301 is specifically used to, when the power battery unit needs AC isolation discharge, control the first controllable switch unit and the third controllable switch unit to be disconnected, and control the second controllable switch unit, the fourth controllable switch unit and the fifth controllable switch unit to be closed; control the isolation conversion unit to perform DC-AC isolation conversion on the DC power provided by the power battery unit, output the first AC power, and control the H-bridge formed by the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit to rectify the AC power output by the isolation conversion unit, and control the inverter circuit formed by the first phase bridge arm in the motor control unit and the DC / DC conversion unit to invert the DC power output by the H-bridge so as to provide AC power to the outside through the AC charge and discharge terminals.

[0101] In some embodiments of the present invention, the isolation conversion unit is also connected to the AC-DC conversion unit. When the isolation conversion unit performs DC-AC isolation conversion on the DC power provided by the power battery unit, it also outputs a second AC power. The AC-DC conversion unit is used to convert the second AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

[0102] In some embodiments of the present invention, the charge and discharge control module 301 is specifically used to control the first controllable switch unit and the fourth controllable switch unit to be disconnected, and control the second controllable switch unit, the third controllable switch unit and the fifth controllable switch unit to be closed when the power battery unit needs DC isolation discharge; control the isolation conversion unit to perform DC-AC isolation conversion on the DC power provided by the power battery unit, output the first AC power, and control the H-bridge formed by the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit to rectify the AC power output by the isolation conversion unit, and control the first switch tube and / or the third switch tube in the DC / DC conversion unit to be turned on, so that the DC power after the H-bridge rectification can be supplied to the outside through the DC charge and discharge terminals for DC power supply.

[0103] In some embodiments of the present invention, the charge and discharge control module 301 is specifically used to control the DC / DC conversion unit to step down the DC current output by the H-bridge, specifically including controlling the first switch tube and the second switch tube in the DC / DC conversion unit to be alternately turned on with a difference of a first preset period, and controlling the third switch tube and the fourth switch tube to be alternately turned on with a difference of a first preset period, wherein the third switch tube is delayed by a second preset period compared with the first switch tube, and the fourth switch tube is delayed by a second preset period compared with the second switch tube.

[0104] In some embodiments of the present invention, the isolation conversion unit is also connected to the AC-DC conversion unit. When the isolation conversion unit performs DC-AC isolation conversion on the DC power provided by the power battery unit, it also outputs a second AC power. The AC-DC conversion unit is used to convert the second AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

[0105] In some embodiments of the present invention, the charge and discharge control module 301 is specifically used to control the first controllable switch unit and the third controllable switch unit to be disconnected, and control the second controllable switch unit, the fourth controllable switch unit and the fifth controllable switch unit to be closed when the power battery unit requires an AC isolated charging mode; control the rectification and PFC circuit formed by the DC / DC conversion unit and the first phase bridge arm in the motor control unit to rectify and perform PFC correction on the AC power provided through the AC charge and discharge terminals to output DC power, and control the inverter H-bridge formed by the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit to invert the DC power output by the rectification and PFC circuit, and control the isolation conversion unit to perform AC-DC isolation conversion on the first AC power output by the inverter H-bridge to charge the power battery unit.

[0106] In some embodiments of the present invention, the charge and discharge control module 301 is specifically used for the isolation conversion unit to be connected to the AC / DC conversion unit. When the isolation conversion unit performs AC-DC isolation conversion on the first AC power output by the inverter H-bridge, it also outputs a second AC power. The AC / DC conversion unit is used to convert the AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

[0107] In some embodiments of the present invention, the charge and discharge control module 301 is specifically used to control the first controllable switch unit and the fourth controllable switch unit to be disconnected, and control the second controllable switch unit, the third controllable switch unit and the fifth controllable switch unit to be closed when the power battery unit needs DC isolation charging; control the inverter H-bridge formed by the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit to invert the DC power provided through the DC charge and discharge terminal, output the first AC power, and control the isolation conversion unit to perform AC-DC isolation conversion on the first AC power output by the inverter H-bridge to charge the power battery unit.

[0108] In some embodiments of the present invention, the charge and discharge control module 301 is specifically used to control the DC / DC conversion unit to boost the DC power provided through the DC charge and discharge terminal.

[0109] In some embodiments of the present invention, the charge and discharge control module 301 is specifically used for the isolation conversion unit to be connected to the AC / DC conversion unit. When the isolation conversion unit performs AC-DC isolation conversion on the first AC power provided by the inverter H-bridge, it also outputs a second AC power. The AC / DC conversion unit is used to convert the second AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

[0110] In some embodiments of the present invention, the operating mode of the power battery unit also includes a non-isolated DC charging mode, wherein, when the power battery unit operates in the non-isolated DC charging mode, the charge and discharge control module 301 is specifically used to control the first controllable switch unit and the third controllable switch unit to close, and control the second controllable switch unit, the fourth controllable switch unit and the fifth controllable switch unit to open, so as to directly charge the power battery unit through the DC power provided by the DC charge and discharge terminals.

[0111] It should be noted that the specific implementation of the charge and discharge control device of the embodiment of the present invention can refer to the specific implementation of the charge and discharge control method in the above embodiment, which will not be repeated here.

[0112] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0113] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0114] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0115] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0116] In addition, the terms "first", "second", etc. used in the embodiments of the present invention are only used for descriptive purposes and should not be understood as indicating or implying relative importance, or implicitly indicating the number of technical features indicated in the present embodiment. Therefore, the features defined by the terms "first", "second", etc. in the embodiments of the present invention can explicitly or implicitly indicate that the embodiment includes at least one of the features. In the description of the present invention, the word "multiple" means at least two or two or more, such as two, three, four, etc., unless otherwise clearly and specifically defined in the embodiments.

[0117] In the present invention, unless otherwise clearly specified or limited in the embodiments, the terms "installed", "connected", "connected" and "fixed" etc. in the embodiments should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integrated connection. It can be understood that it can also be a mechanical connection, an electrical connection, etc.; of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements, or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific implementation situation.

[0118] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0119] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A charge and discharge control method, characterized in that: The charge and discharge control circuit includes a power battery unit, an isolation conversion unit, a DC / DC conversion unit, a motor control unit, a generator control unit and a controllable switch unit, wherein the DC / DC conversion unit, the motor control unit and the generator control unit are connected to each other, the DC / DC conversion unit is also connected to the power battery unit and the DC charge and discharge terminal, the isolation conversion unit is also connected to the power battery unit, the motor control unit and the generator control unit, the first end of the DC / DC conversion unit and the midpoint of the first phase bridge arm in the motor control unit or the generator control unit are connected to the AC charge and discharge terminal, and the method includes: When the power battery unit needs to be charged or discharged, the controllable switch unit is controlled to operate in a preset operating mode to realize the charging and discharging of the power battery unit; The controllable switch unit operating in the working mode can use at least some of the switch tubes in the DC / DC conversion unit, the motor control unit, the generator control unit and the isolation conversion unit as part of the charging and discharging circuit of the power battery unit; The controllable switch unit includes a first controllable switch unit, a second controllable switch unit, a third controllable switch unit, a fourth controllable switch unit and a fifth controllable switch unit, wherein: The first controllable switch unit is arranged between the DC / DC conversion unit and the power battery unit, the second controllable switch unit is arranged between the isolation conversion unit and the power battery unit, the third controllable switch unit is arranged between the DC / DC conversion unit and the DC charge and discharge terminal, the fourth controllable switch unit is arranged between the AC charge and discharge terminal and a circuit composed of the DC / DC conversion unit and the first phase bridge arm in the motor control unit, and the fifth controllable switch unit is arranged between the isolation conversion unit and the motor control unit.

2. The method according to claim 1, characterized in that The first controllable switch unit includes a first switch and a third switch, the second controllable switch unit includes a second switch and a fourth switch, the third controllable switch unit includes a sixth switch, the fourth controllable switch unit includes a seventh switch, and the fifth controllable switch unit includes an eighth switch, wherein: One end of the first switch is connected to the positive terminal of the power battery unit, the other end of the first switch is connected to the first end of the DC / DC conversion unit, one end of the third switch is connected to the negative terminal of the power battery unit, and the other end of the third switch is connected to the second end of the DC / DC conversion unit; One end of the second switch is connected to the positive terminal of the power battery unit, and the other end of the second switch is connected to the first DC terminal of the isolation conversion unit; one end of the fourth switch is connected to the negative terminal of the power battery unit, and the other end of the fourth switch is connected to the second DC terminal of the isolation conversion unit; One end of the sixth switch is connected to the negative electrode of the DC charge and discharge terminal, and the other end of the sixth switch is connected to the second end of the DC / DC conversion unit; One end of the seventh switch is connected to the neutral line of the AC charging and discharging terminal, and the other end of the seventh switch is connected to the midpoint of the first phase bridge arm in the motor control unit; One end of the eighth switch is connected to the first AC terminal or the second AC terminal of the isolation conversion unit, and the other end of the eighth switch is connected to the midpoint of the second phase bridge arm in the motor control unit or the midpoint of any phase bridge arm in the generator control unit.

3. The method according to claim 1, characterized in that: When the power battery unit needs to be charged or discharged, controlling the controllable switch unit to operate in a preset operating mode to realize the charging and discharging of the power battery unit includes: When the power battery unit needs AC isolated discharge, the first controllable switch unit and the third controllable switch unit are controlled to be disconnected, and the second controllable switch unit, the fourth controllable switch unit and the fifth controllable switch unit are controlled to be closed; The isolation conversion unit is controlled to perform DC-AC isolation conversion on the direct current provided by the power battery unit to output a first alternating current, and the H-bridge formed by the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit is controlled to rectify the alternating current output by the isolation conversion unit, and the inverter circuit formed by the first phase bridge arm in the motor control unit and the DC / DC conversion unit is controlled to invert the direct current output by the H-bridge so as to provide AC power supply to the outside through the AC charging and discharging terminals.

4. The method according to claim 3, characterized in that The isolation conversion unit is also connected to the AC-DC conversion unit. When the isolation conversion unit performs DC-AC isolation conversion on the DC power provided by the power battery unit, it also outputs a second AC power. The AC-DC conversion unit is used to convert the second AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

5. The method according to claim 1, characterized in that When the power battery unit needs to be charged or discharged, controlling the controllable switch unit to operate in a preset operating mode to realize the charging and discharging of the power battery unit includes: When the power battery unit needs DC isolation discharge, the first controllable switch unit and the fourth controllable switch unit are controlled to be disconnected, and the second controllable switch unit, the third controllable switch unit and the fifth controllable switch unit are controlled to be closed; The isolation conversion unit is controlled to perform DC-AC isolation conversion on the direct current provided by the power battery unit to output a first alternating current, and the H-bridge formed by the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit is controlled to rectify the alternating current output by the isolation conversion unit, and the first switch tube and / or the third switch tube in the DC / DC conversion unit are controlled to be turned on, so that the direct current after rectification by the H-bridge can be supplied to the outside through the DC charging and discharging terminals for DC power supply.

6. The method according to claim 5, characterized in that After controlling the H-bridge to rectify the alternating current output by the isolation conversion unit, the method further includes: Controlling the DC / DC conversion unit to step down the DC current output by the H-bridge specifically includes controlling the first switch tube and the second switch tube in the DC / DC conversion unit to be alternately turned on with a difference of a first preset period, and controlling the third switch tube and the fourth switch tube to be alternately turned on with a difference of a first preset period, wherein the third switch tube is delayed by a second preset period compared with the first switch tube, and the fourth switch tube is delayed by a second preset period compared with the second switch tube.

7. The method according to claim 5, characterized in that The isolation conversion unit is also connected to the AC-DC conversion unit. When the isolation conversion unit performs DC-AC isolation conversion on the DC power provided by the power battery unit, it also outputs a second AC power. The AC-DC conversion unit is used to convert the second AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

8. The method according to claim 1, characterized in that When the power battery unit needs to be charged or discharged, controlling the controllable switch unit to operate in a preset operating mode to realize the charging and discharging of the power battery unit includes: When the power battery unit requires an AC isolated charging mode, controlling the first controllable switch unit and the third controllable switch unit to be disconnected, and controlling the second controllable switch unit, the fourth controllable switch unit, and the fifth controllable switch unit to be closed; Control the rectification and PFC circuit formed by the DC / DC conversion unit and the first phase bridge arm in the motor control unit to rectify and perform PFC correction on the AC power provided through the AC charging and discharging terminals to output DC power, and control the inverter H-bridge formed by the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit to invert the DC power output by the rectification and PFC circuit, and control the isolation conversion unit to perform AC-DC isolation conversion on the first AC power output by the inverter H-bridge to charge the power battery unit.

9. The method according to claim 8, characterized in that The isolation conversion unit is also connected to the AC-DC conversion unit. When the isolation conversion unit performs AC-DC isolation conversion on the first AC power output by the inverter H-bridge, it also outputs a second AC power. The AC-DC conversion unit is used to convert the AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

10. The method according to claim 1, characterized in that When the power battery unit needs to be charged or discharged, controlling the controllable switch unit to operate in a preset operating mode to realize the charging and discharging of the power battery unit includes: When the power battery unit needs DC isolation charging, controlling the first controllable switch unit and the fourth controllable switch unit to be disconnected, and controlling the second controllable switch unit, the third controllable switch unit and the fifth controllable switch unit to be closed; The inverter H-bridge formed by the second phase bridge arm in the motor control unit and any one phase bridge arm in the generator control unit is controlled to invert the DC power provided through the DC charge and discharge terminals to output a first AC power, and the isolation conversion unit is controlled to perform AC-DC isolation conversion on the first AC power output by the inverter H-bridge to charge the power battery unit.

11. The method according to claim 10, characterized in that Before controlling the inverter H-bridge to invert the DC power provided by the DC charging and discharging terminal, the method further includes: The DC / DC conversion unit is controlled to boost the DC power provided through the DC charging and discharging terminal.

12. The method according to claim 10, characterized in that The isolation conversion unit is also connected to the AC-DC conversion unit. When the isolation conversion unit performs AC-DC isolation conversion on the first AC power provided by the inverter H-bridge, it also outputs a second AC power. The AC-DC conversion unit is used to convert the second AC power into DC power to charge the low-voltage battery unit or power the low-voltage device.

13. The method according to any one of claims 2 to 11, characterized in that: The working mode of the power battery unit also includes a non-isolated DC charging mode, wherein when the power battery unit works in the non-isolated DC charging mode, The first controllable switch unit and the third controllable switch unit are controlled to be closed, and the second controllable switch unit, the fourth controllable switch unit and the fifth controllable switch unit are controlled to be opened, so that the direct current provided by the direct current charging and discharging terminal can directly charge the power battery unit.

14. A charge and discharge control system, characterized in that: The invention comprises a memory, a processor and a charge and discharge control program stored in the memory and executable on the processor. When the processor executes the charge and discharge control program, the charge and discharge control method according to any one of claims 1 to 13 is implemented.

15. An electric vehicle, characterized in that: Includes the charge and discharge control system as described in claim 14.

16. A computer-readable storage medium, characterized in that: A charge and discharge control program is stored thereon, and when the charge and discharge control program is executed by a processor, a charge and discharge control method according to any one of claims 1 to 13 is implemented.

17. A charge and discharge control device, characterized in that: The charge and discharge control circuit includes a power battery unit, an isolation conversion unit, a DC / DC conversion unit, a motor control unit, a generator control unit and a controllable switch unit. The DC / DC conversion unit, the motor control unit and the generator control unit are connected to each other. The DC / DC conversion unit is also connected to the power battery unit and the DC charge and discharge terminal. The isolation conversion unit is also connected to the power battery unit, the motor control unit and the generator control unit. The first end of the DC / DC conversion unit and the midpoint of the first phase bridge arm in the motor control unit or the generator control unit are connected to the AC charge and discharge terminal. The device includes: A charge and discharge control module, used for controlling the controllable switch unit to operate in a preset operating mode when the power battery unit needs to be charged and discharged, so as to realize the charge and discharge of the power battery unit; wherein the controllable switch unit operating in the operating mode can use at least part of the switch tubes in the DC / DC conversion unit, the motor control unit, the generator control unit and the isolation conversion unit as part of the charge and discharge circuit of the power battery unit; The controllable switch unit includes a first controllable switch unit, a second controllable switch unit, a third controllable switch unit, a fourth controllable switch unit and a fifth controllable switch unit, wherein: The first controllable switch unit is arranged between the DC / DC conversion unit and the power battery unit, the second controllable switch unit is arranged between the isolation conversion unit and the power battery unit, the third controllable switch unit is arranged between the DC / DC conversion unit and the DC charge and discharge terminal, the fourth controllable switch unit is arranged between the AC charge and discharge terminal and a circuit composed of the DC / DC conversion unit and the first phase bridge arm in the motor control unit, and the fifth controllable switch unit is arranged between the isolation conversion unit and the motor control unit.

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