Vehicle charging and discharging system

Abstract

The utility model provides a vehicle charging and discharging system. The vehicle charging and discharging system comprises a power supply module, a motor control module, a first switch switching module and an angle joint motor winding, when the power supply module is connected with the battery pack through the first switch switching module and the motor control module, a first direct charging loop can be formed; when the power supply module is connected with the battery pack through the first switch switching module, the angle joint motor winding and the motor control module, a first boost charging loop can be formed; when the battery pack is connected with the power supply module through the motor control module, the angle joint motor winding and the first switch switching module, a first step-down discharge loop can be formed. According to the vehicle charging and discharging system, high-voltage direct charging, boost charging and buck discharging can be achieved, additional boost and buck circuits do not need to be added, the structure is simple, and the cost advantage is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of electric vehicles, in particular to a vehicle charging and discharging system. Background Art

[0002] At present, due to the anxiety of "short driving range and slow charging" of 400V platform electric vehicles, 800V high-voltage platform electric vehicles have become the route of choice for more and more mainstream car companies at home and abroad to deeply deploy electrification. However, after the car is upgraded to the 800V voltage platform, it needs to be charged with the support of 800V charging piles. Currently, most charging piles are 400V charging piles, so 800V high-voltage platform electric vehicles face the pain point of difficult charging.

[0003] Therefore, a technical solution that can be compatible with 400V charging piles and 800V charging piles has emerged in the prior art to charge 800V electric vehicles, and at this stage, it is mainly equipped with a boost DC-DC module to increase the charging pile voltage to above 800V for charging the battery. However, due to the additional DC-DC module, this technical solution has the problem of large size and high cost. Utility Model Content

[0004] In view of this, the utility model aims to provide a vehicle charging and discharging system to solve the problem that the existing charging system needs to be equipped with an additional boost module, resulting in large volume and high cost.

[0005] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0006] A vehicle charging and discharging system includes a power supply module, a motor control module, a first switch switching module and a delta-connected motor winding;

[0007] The positive electrode of the power supply module can be connected to the positive electrode of the battery pack in the vehicle through the first switch switching module, the delta motor winding and the motor control module in sequence;

[0008] The negative electrode of the power supply module can be connected to the negative electrode of the battery pack;

[0009] When the power supply module is connected to the battery pack through the first switch switching module and the motor control module, a first direct charging loop can be formed;

[0010] When the power supply module is connected to the battery pack through the first switch switching module, the delta-connected motor winding and the motor control module, a first boost charging loop can be formed;

[0011] When the battery pack is connected to the power supply module through the motor control module, the delta-connected motor winding and the first switch switching module, a first step-down discharge circuit can be formed.

[0012] Further, the motor control module includes a first power tube, a second power tube, a third power tube, a fourth power tube, a fifth power tube and a sixth power tube and a second capacitor;

[0013] A first control branch formed by the first power tube and the fourth power tube connected in series, a second control branch formed by the third power tube and the sixth power tube connected in series, and a third control branch formed by the fifth power tube and the second power tube connected in series are connected in parallel;

[0014] The second capacitor is arranged in parallel between the battery pack and the first control branch;

[0015] The first power tube, the third power tube and the fifth power tube are connected to the positive electrode of the battery pack.

[0016] Further, the delta-connected motor winding includes a first winding, a second winding and a third winding;

[0017] The first end of the first winding is a current inflow end, the second end of the first winding is connected to the first end of the second winding, the second end of the second winding is connected to the first end of the third winding, and the second end of the third winding is a current outflow end;

[0018] The second end of the first winding is connected to the common end of the first power tube and the fourth power tube;

[0019] The second end of the second winding is connected to the common end of the third power tube and the sixth power tube;

[0020] The second end of the third winding is connected to a common end of the fifth power tube and the second power tube.

[0021] Further, the first switch switching module includes a first relay and a second relay;

[0022] The first end of the first relay is connected to the second end of the third winding, and the second end of the first relay is connected to the first end of the second relay;

[0023] A first end of the second relay is connected to a first end of the first winding, and a second end of the first relay is connected to a positive electrode of the power supply module.

[0024] Furthermore, the first direct charging circuit includes the first relay and the second relay that are closed in the first switch switching module, and the fifth power tube that is turned on in the motor control module.

[0025] Furthermore, the first boost charging circuit includes a first boost energy storage circuit and a first boost energy discharge circuit;

[0026] The first boost energy storage circuit includes the second relay closed in the first switch switching module, and the second power tube turned on in the motor control module;

[0027] The first boost energy dissipation circuit includes the second relay that is closed in the first switch module and the fifth power tube that is turned on in the motor control module.

[0028] Furthermore, the first step-down discharge circuit includes a first step-down energy storage circuit and a first step-down energy discharge circuit;

[0029] The first step-down energy storage circuit includes the second relay closed in the first switch switching module, and the fifth power tube turned on in the motor control module;

[0030] The first voltage reduction and energy dissipation circuit includes the second relay that is closed in the first switch switching module and the second power tube that is turned on in the motor control module.

[0031] Furthermore, the vehicle charging and discharging system also includes a second switch switching module;

[0032] The second switch switching module is arranged in the motor control module;

[0033] When the power supply module is connected to the battery pack through the first switch switching module, the motor control module and the second switch switching module, a second direct charging circuit can be formed;

[0034] When the power supply module is connected to the battery pack through the first switch switching module, the delta-connected motor winding, the motor control module and the second switch switching module, a second boost charging circuit can be formed;

[0035] When the battery pack is connected to the power supply module through the second switch switching module, the motor control module, the delta-connected motor winding and the first switch switching module, a second step-down discharge circuit can be formed.

[0036] Further, the second switch switching module includes a third relay, a fourth relay, a fifth relay and a sixth relay;

[0037] A first end of the third relay is connected to a common end of the first power tube and the fourth power tube, and a second end of the third relay is connected to a second end of the first winding;

[0038] The first end of the fourth relay is connected to the common end of the first power tube and the fourth power tube, and the second end of the fourth relay is connected to the common end of the third power tube and the sixth power tube;

[0039] The first end of the fifth relay is connected to the common end of the third power tube and the sixth power tube, and the second end of the fifth relay is connected to the second end of the second winding;

[0040] The first end of the sixth relay is connected to the common end of the third power tube and the sixth power tube, and the second end of the sixth relay is connected to the common end of the fifth power tube and the second power tube.

[0041] Further, the second switch switching module includes a third single-pole double-throw switch and a fourth single-pole double-throw switch;

[0042] The first end of the third single-pole double-throw switch is connected to the common end of the first power tube and the fourth power tube, the second end of the third single-pole double-throw switch is connected to the common end of the third power tube and the sixth power tube, and the third end of the third single-pole double-throw switch is connected to the second end of the first winding;

[0043] The first end of the fourth single-pole double-throw switch is connected to the common end of the third power tube and the sixth power tube, the second end of the fourth single-pole double-throw switch is connected to the common end of the fifth power tube and the second power tube, and the third end of the fourth single-pole double-throw switch is connected to the second end of the second winding.

[0044] Compared with the prior art, the utility model has the following advantages:

[0045] The vehicle charging and discharging system described in the utility model connects the power supply module to the battery pack to form a direct charging circuit through the first switch switching module and the motor control module, and can realize the high-voltage direct charging function when the power supply module is a high-voltage charging pile. The power supply module is connected to the battery pack to form a boost charging circuit through the first switch switching module, the angle-connected motor winding and the motor control module, and can realize the boost charging function when the power supply module is a low-voltage charging pile. The battery pack is connected to the power supply module to form a step-down discharge circuit through the motor control module, the angle-connected motor winding and the first switch switching module, and can realize the step-down discharge function when the power supply module is a battery pack of other vehicles or a DC load. Therefore, the vehicle charging and discharging system of the utility model does not need to additionally set up a boost and buck circuit, and has the advantages of simple structure, small size and low cost.

[0046] In addition, by setting the winding connection method of the corner-connected three-phase motor, setting the motor control module including the first power tube, the second power tube, the third power tube, the fourth power tube, the fifth power tube, the sixth power tube and the second capacitor, setting the first switch switching module including the first relay and the second relay arranged in parallel, and by specifically setting the connection method, it is possible to achieve zero torque control of the motor without leading out the neutral point of the motor and the rotor at any angle, thereby having the advantages of small charging ripple current and no risk of unexpected movement of the vehicle.

[0047] In addition, by providing a second switch switching module, the power tube load of the motor control module in the charge and discharge circuit is uniform, the heat is small, and the service life of the power tube is improved. Further, by providing the second switch switching module including a third single-pole double-throw switch and a fourth single-pole double-throw switch, the circuit structure can be simplified and the volume cost can be saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0049] Figure 1 A schematic diagram of the structure of a vehicle charging and discharging system provided by an embodiment of the utility model;

[0050] Figure 2 A schematic diagram of the circuit structure of a vehicle charging and discharging system provided by an embodiment of the utility model;

[0051] Figure 3 A schematic diagram of the circuit structure of a first direct charging circuit provided in an embodiment of the utility model;

[0052] Figure 4 A schematic diagram of the circuit structure of a first boost energy storage circuit provided in an embodiment of the utility model;

[0053] Figure 5 A schematic diagram of the circuit structure of a first boost and energy dissipation circuit provided in an embodiment of the utility model;

[0054] Figure 6 A schematic diagram of the current direction and magnetic field coupling in a winding provided by an embodiment of the utility model;

[0055] Figure 7 A schematic diagram of the circuit structure of a first voltage-reducing energy storage circuit provided in an embodiment of the utility model;

[0056] Figure 8 A schematic diagram of the circuit structure of a first pressure reduction and energy dissipation circuit provided in an embodiment of the utility model;

[0057] Fig. 9 A schematic diagram of the circuit structure of a second vehicle charging and discharging system provided by an embodiment of the utility model;

[0058] Fig.10 A schematic diagram of the circuit structure of a second direct charging circuit provided in an embodiment of the utility model;

[0059] Fig.11 A schematic diagram of the circuit structure of a second boost energy storage circuit provided in an embodiment of the utility model;

[0060] Fig.12 A schematic diagram of the circuit structure of a second boost and energy dissipation circuit provided in an embodiment of the utility model;

[0061] Fig.13 A schematic diagram of the circuit structure of a second voltage-reducing energy storage circuit provided in an embodiment of the utility model;

[0062] Fig.14 A schematic diagram of the circuit structure of a second pressure reduction and energy dissipation circuit provided in an embodiment of the utility model;

[0063] Fig.15 A schematic diagram of the circuit structure of a third vehicle charging and discharging system provided by an embodiment of the utility model;

[0064] Fig.16 A schematic diagram of the circuit structure of another second direct charging circuit provided by an embodiment of the utility model;

[0065] Fig.17 A schematic diagram of the circuit structure of another second boost energy storage circuit provided in an embodiment of the utility model;

[0066] Fig.18 A schematic diagram of the circuit structure of another second boost energy dissipation circuit provided in an embodiment of the utility model;

[0067] Fig.19 A schematic diagram of the circuit structure of another second voltage-reducing energy storage circuit provided in an embodiment of the utility model;

[0068] Fig. 20 A schematic diagram of the circuit structure of another second voltage reduction and energy dissipation circuit provided in an embodiment of the utility model.

[0069] Description of reference numerals:

[0070] 1. Power supply module; 2. First switch switching module; 3. Corner-connected motor winding; 4. Motor control module; 5. Battery pack. DETAILED DESCRIPTION

[0071] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0072] In the description of the present invention, it should be noted that if there are terms such as "upper", "lower", "inner", "outer" and the like indicating orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, if there are terms such as "first" and "second", they are also used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0073] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installation", "connection", "connection" and "connector" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in combination with specific circumstances.

[0074] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0075] Embodiment 1

[0076] This embodiment relates to a vehicle charging and discharging system, the overall structure of which is as follows: Figure 1 As shown, the vehicle charging and discharging system includes a power supply module 1 , a motor control module 4 , a first switch switching module 2 and a delta-connected motor winding 3 .

[0077] Among them, the positive pole of the power supply module 1 can be connected to the positive pole of the battery pack 5 in the vehicle through the first switch switching module 2, the delta motor winding 3 and the motor control module 4 in sequence, and the negative pole of the power supply module 1 can be connected to the negative pole of the battery pack 5.

[0078] In addition, when the power supply module 1 is connected to the battery pack 5 through the first switch switching module 2 and the motor control module 4, a first direct charging circuit can be formed, and when the power supply module 1 is connected to the battery pack 5 through the first switch switching module 2, the delta-connected motor winding 3 and the motor control module 4, a first boost charging circuit can be formed. When the battery pack 5 is connected to the power supply module 1 through the motor control module 4, the delta-connected motor winding 3 and the first switch switching module 2, a first step-down discharge circuit can be formed.

[0079] At this time, as set above, the power supply module 1 is connected to the battery pack 5 through the first switch switching module 2 and the motor control module 4 to form a direct charging circuit. This embodiment can realize the high-voltage direct charging function when the power supply module 1 is a high-voltage charging pile. The power supply module 1 is connected to the battery pack 5 through the first switch switching module 2, the angle-connected motor winding 3 and the motor control module 4 to form a boost charging circuit. This embodiment can realize the boost charging function when the power supply module 1 is a low-voltage charging pile. And the battery pack 5 is connected to the power supply module 1 through the motor control module 4, the angle-connected motor winding 3 and the first switch switching module 2 to form a step-down discharge circuit. This embodiment can also realize V2V (Vehicle to Vehicle) charging when the power supply module 1 is the power battery of other vehicles, or power the load when the power supply module 1 is other DC loads.

[0080] In this way, the vehicle charging and discharging system of this embodiment can realize high-voltage direct charging, boost charging and buck discharging, and there is no need to add additional boost and buck circuits. The structure is simple and has cost advantages.

[0081] Based on the above overall introduction, specifically, as a preferred implementation form, Figure 2 As shown, the motor control module of this embodiment includes a first power tube Q 1 , the second power tube Q 2 、The third power tube Q 3 、The fourth power tube Q 4 、The fifth power tube Q 5 And the sixth power tube Q 6 and a second capacitor C2.

[0082] Among them, the first power tube Q 1 With the fourth power tube Q 4 The first control branch formed in series, the third power tube Q 3 With the sixth power tube Q 6 The second control branch formed in series, the fifth power tube Q 5 With the second power tube Q 2 The third control branch formed in series is connected in parallel. The second capacitor C2 is arranged in parallel between the battery pack BT1 and the first control branch, and the first power tube Q 1 、The third power tube Q 3 And the fifth power tube Q 5 Connect to the positive terminal of the battery pack BT1.

[0083] As a preferred embodiment, Figure 2 As shown, the above-mentioned delta-connected motor winding specifically includes a first winding, a second winding and a third winding.

[0084] Among them, the first end of the first winding is the current inflow end, the second end of the first winding is connected to the first end of the second winding, the second end of the second winding is connected to the first end of the third winding, and the second end of the third winding is the current outflow end.

[0085] In addition, the second end of the first winding is connected to the first power tube Q 1 With the fourth power tube Q 4 The common end of the second winding is connected to the third power tube Q 3 With the sixth power tube Q 6 The common end of the third winding is connected to the fifth power tube Q 5 With the second power tube Q 2 The public end of the

[0086] This embodiment, as a preferred implementation form, continues as follows Figure 2 As shown, the first switch switching module specifically includes a first relay S1 and a second relay S2.

[0087] The first end of the first relay S1 is connected to the second end of the third winding, the second end of the first relay S1 is connected to the first end of the second relay S2, the first end of the second relay S2 is connected to the first end of the first winding, and the second end of the first relay S1 is connected to the positive pole of the power supply module.

[0088] In this embodiment, it should be noted that: Figure 2 The charging pile shown is a power supply module, the motor controller is a motor module, and the motor is a delta-connected motor winding. The first winding is the winding between the motor U phase and the motor W phase, which can also be called the UW winding, the second winding is the winding between the motor U phase and the motor V phase, which can also be called the UV winding, and the third winding is the winding between the motor V phase and the motor W phase, which can also be called the VW winding. In addition, the first end of the first relay S1 can also be connected to the second end of any of the three windings in the delta-connected motor winding, that is, it can be connected to Figure 2 Any one of the three phases UVW of the motor shown in is connected.

[0089] At this time, the setting method of the above-mentioned motor control module, motor winding and switch switching module of this embodiment, as well as the connection method therebetween, does not require the motor neutral point to be led out and the charging ripple current is small, and the magnetic fields of the three-phase windings cancel each other out, which can ensure the zero torque output of the motor and solve the problem of zero torque control of the motor caused by the random current rotor position, and will not cause the risk of unexpected movement of the vehicle.

[0090] As a possible implementation form, continue as Figure 3 As shown, the first direct charging circuit of this embodiment includes a first relay S1 and a second relay S2 closed in the first switch switching module, and a fifth power tube Q turned on in the motor control module.5 .

[0091] When the charging pile voltage is higher than the battery pack voltage, the first relay S1 and the second relay S2 are closed, and the fifth power tube Q 5 It should be noted that if the power tube Q 1 -Q 6 If it is an IGBT (Insulated Gate Bipolar Transistor), the power tube Q is turned off. 1 -Q 6 , if the power tube Q 1 -Q 6 If it is a SiC MOSFET (Metal Oxide Semiconductor Field Effect Transistor), the first power tube Q is turned off. 1 , the second power tube Q 2 、The third power tube Q 3 、The fourth power tube Q 4 And the sixth power tube Q 6 , turn on the fifth power tube Q 5 .

[0092] It can be understood that through the first direct charging circuit, the charging pile can directly charge the battery pack through the power tube in the motor control module. The charging path at this time is: charging pile positive electrode → second relay S2 → first relay S1 → fifth power tube Q 5 →Battery pack BT1→Charging pile negative pole. 1 -Q 6 When it is IGBT, the current flows through the fifth power tube Q 5 The anti-parallel diode, when the power tube Q 1 -Q 6 When it is SiC MOSFET, the current flows through the fifth power tube Q 5 .

[0093] It should be noted that when the first end of the first relay S1 is connected to the second end of the other windings in the delta-connected motor winding, for example Figure 3 When the V phase of the motor winding shown in FIG. is connected, the direct charging circuit includes a third power tube Q connected to the V phase. 3 When the first relay S1 is connected Figure 3 When the U phase of the motor winding shown in FIG. is connected, the direct charging circuit includes a first power tube Q connected to the U phase. 1 .

[0094] As a possible implementation form, continue as Figure 4 and Figure 5 As shown, the first boost charging circuit of this embodiment includes a first boost energy storage circuit and a first boost energy discharge circuit.

[0095] The first boost energy storage circuit includes a second relay S2 closed in the first switch switching module and a second power tube Q turned on in the motor control module. 2 The first boost energy dissipation circuit includes a second relay S2 closed in the first switch switching module and a fifth power tube Q turned on in the motor control module. 5 .

[0096] In this embodiment, when the charging pile voltage is lower than the battery pack voltage, the angle-connected motor winding and the motor control module can be used to boost the voltage and charge the battery pack. It should be noted that when the vehicle is parked and charged, the direction of the rotor magnetic field is random within the electrical angle of 0° to 360°. In this embodiment, the motor uses an angle connection method. During boost charging, the magnetic fields of the three-phase windings are offset to ensure zero torque output of the motor, which is not affected by the random position of the rotor, and there is no risk of demagnetization of the rotor magnet. Among them, the current direction in the three-phase winding of the motor is coupled with the magnetic field as shown in Figure 6 shown.

[0097] In the first boost energy storage circuit, Figure 4 As shown, the current path is as follows: positive pole of charging pile → second relay S2 → motor winding UW → motor winding UV → motor winding VW → second power tube Q 2 →The negative pole of the charging pile, where the second power tube Q 2 In the first boost energy storage circuit, the charging pile is connected in series with the motor winding, the current in the winding inductance increases, and an induced magnetic field is formed to realize inductive energy storage, thereby performing charging energy storage.

[0098] In the first boost and energy release circuit, Figure 5 As shown, the current path is as follows: positive pole of charging pile → second relay S2 → motor winding UW → motor winding UV → motor winding VW → fifth power tube Q 5 →Battery pack BT1→Charging pile negative pole, where the fifth power tube Q 5 In the first boost energy dissipation circuit, due to the current holding characteristics of the inductor, as the three-phase winding current of the motor flows to the battery pack, the winding inductor generates an induced voltage due to the change of current. At the same time, since the winding is connected in series with the charging pile, the voltage input to the battery pack is the voltage generated by the winding inductor and the charging pile voltage superimposed. After the charging voltage is raised, the fifth power tube Q 5 Then charge the battery pack BT1. It should be noted that if the power tube Q 1 -Q 6 If it is IGBT, the power tube Q is turned off. 1 -Q6 , if the power tube Q 1 -Q 6 For SiC MOSFET, turn off the first power tube Q 1 , the second power tube Q 2 、The third power tube Q 3 、The fourth power tube Q 4 And the sixth power tube Q 6 , turn on the fifth power tube Q 5 .

[0099] It is understandable that in practical applications, the power tube Q can be controlled by PWM (Pulse Width Modulation). 1 -Q 6 The opening or closing of the first boost charging circuit can continuously switch the first boost energy storage circuit and the first boost energy discharge circuit alternately, so as to realize the voltage boosting to charge the battery when the charging pile voltage is lower than the battery pack voltage. The frequency and duty cycle of PWM are set according to the voltage of the charging pile, the battery pack voltage, the ripple current requirements and the capability range of the power device.

[0100] At the same time, as a feasible implementation form, such as Figure 7 and Figure 8 As shown, the first step-down discharge circuit of this embodiment includes a first step-down energy storage circuit and a first step-down energy discharge circuit.

[0101] The first step-down energy storage circuit includes a second relay S2 closed in the first switch switching module and a fifth power tube Q turned on in the motor control module. 5 The first voltage reduction and energy dissipation circuit includes a second relay S2 closed in the first switch switching module and a second power tube Q turned on in the motor control module. 2 .

[0102] In this embodiment, the power supply module may be a power battery pack of other vehicles, such as Figure 3 and Fig.10 BT2 shown in the figure may also be other DC loads. Moreover, in the first step-down discharge circuit, the energy stored in the battery pack BT1 can be charged to BT2 after stepping down through the BUCK circuit composed of the motor control module and the delta-connected motor winding, thereby realizing V2V charging.

[0103] In the first step-down energy storage circuit, if Figure 7 As shown, the current path is as follows: BT1 positive electrode → fifth power tube Q 5 →Motor winding VW→Motor winding UV→Motor winding UW→Second relay S2→BT2 positive pole→BT1 negative pole, where the fifth power tube Q 5In the first step-down energy storage circuit, the battery pack BT1 is connected in series with the motor winding, and the fifth power tube Q 5 It is turned on to control the current in the motor winding inductance to rise, and the energy of the battery pack BT1 flows to the motor winding, forming an induced magnetic field to realize inductive energy storage.

[0104] In the first pressure reduction and energy release circuit, Figure 8 As shown, the current path is as follows: motor winding VW→motor winding UV→motor winding UW→second relay S2→BT2 positive pole→BT2 negative pole→second power tube Q 2 →Motor winding VW. It should be noted that in the first voltage reduction and energy dissipation circuit, if the power tube Q 1 -Q 6 If it is IGBT, the power tube Q is turned off. 1 -Q 6 , group through the second power tube Q 2 The anti-parallel diode is connected to the power tube Q 1 -Q 6 For SiC MOSFET, turn off the first power tube Q 1 、The third power tube Q 3 、The fourth power tube Q 4 、The fifth power tube Q 5 And the sixth power tube Q 6 , turn on the second power tube Q 2 At this time, due to the current holding characteristics of the inductor, the current in the three-phase winding of the motor flows to the low-voltage battery pack BT2, the motor winding inductance generates an induced voltage due to the change in current, and the current in the motor winding inductance gradually decreases.

[0105] It is understandable that in practical applications, similar to the above description, the power tube Q can be controlled by PWM. 1 -Q 6 The opening and closing of the first step-down discharge circuit can continuously switch the first step-down energy storage circuit and the first step-down energy release circuit alternately, thereby reducing the voltage to charge the battery pack BT2 when the voltage of the battery pack BT1 is higher than that of the battery pack BT2.

[0106] As a preferred embodiment, Figure 3 As shown, the vehicle charging and discharging system of this embodiment further includes a filter module, and the power supply module is connected through the filter module and the switch switching module.

[0107] At this time, the filtering module may include a first capacitor C1 and a first inductor L1 to filter out ripples during the charging process.

[0108] In addition, as a further preferred embodiment, Figure 3As shown, the vehicle charging and discharging system of this embodiment further includes a discharging module. The power supply module is connected to the filter module through the discharging module, and the discharging module is used to reduce the voltage of the first capacitor and the second capacitor.

[0109] In specific implementation, the discharge module of this embodiment may include a first resistor R1 and a seventh power tube Q7, wherein the first resistor R1 is used as a discharge resistor, and the seventh power tube Q7 may be a MOSFET. When the boost charging or buck discharging is completed, the voltage of the capacitor C1 in the filter module may be reduced to below the safe voltage within a specified time through the discharge module. If the specified discharge time is long, only the first resistor R1 may be used for discharge.

[0110] In addition, according to actual needs, the discharge module can also be used to release the electric energy stored in the second capacitor C2 in the motor control module when needed. Specifically, by closing the first relay S1 and the second relay S2, the discharge module can reduce the voltage of the second capacitor C2 to below the safe voltage within a specified time.

[0111] As a preferred implementation form, the vehicle charging and discharging system of this embodiment further includes a second switch switching module. The second switch switching module is arranged in the motor control module, wherein when the power supply module is connected to the battery pack through the first switch switching module, the motor control module and the second switch switching module, a second direct charging circuit can be formed, when the power supply module is connected to the battery pack through the first switch switching module, the delta-connected motor winding, the motor control module and the second switch switching module, a second boost charging circuit can be formed, and when the battery pack is connected to the power supply module through the second switch switching module, the motor control module, the delta-connected motor winding and the first switch switching module, a second step-down discharge circuit can be formed.

[0112] Specific implementation four, as a preferred implementation form, as Fig. 9 As shown, the second switch switching module includes a third relay S3, a fourth relay S4, a fifth relay S5 and a sixth relay S6.

[0113] The first end of the third relay S3 is connected to the first power tube Q 1 With the fourth power tube Q 4 The common end of the third relay S3 is connected to the second end of the first winding. The first end of the fourth relay S4 is connected to the first power tube Q 1 With the fourth power tube Q 4 The common end of the fourth relay S4 is connected to the third power tube Q 3 With the sixth power tube Q 6 The public end of the

[0114] The first end of the fifth relay S5 is connected to the third power tube Q3 With the sixth power tube Q 6 The common end of the fifth relay S5 is connected to the second end of the second winding. The first end of the sixth relay S6 is connected to the third power tube Q 3 With the sixth power tube Q 6 The common end of the sixth relay S6 is connected to the fifth power tube Q 5 With the second power tube Q 2 The public end of the

[0115] It can be understood that, in this embodiment, by providing the second switch switching module, the power tube load of the motor control module in the charge and discharge loop is uniform, the heat generation is small, and it is beneficial to increase the service life of the power tube.

[0116] As a feasible implementation form, Fig.10 As shown, the second direct charging circuit of this embodiment includes a first relay S1 and a second relay S2 closed in the first switch switching module, a fourth relay S4 and a sixth relay S6 closed in the second switch switching module, and a first power tube Q turned on in the motor control module. 1 、The third power tube Q 3 And the fifth power tube Q 5 .

[0117] When the charging pile voltage is higher than the battery pack voltage, the first relay S1, the second relay S2, the fourth relay S4 and the sixth relay S6 are closed, and the first power tube Q 1 、The third power tube Q 3 And the fifth power tube Q 5 The charging pile can directly charge the battery pack through the power tube in the motor control module. The charging path at this time is: the positive electrode of the charging pile → the second relay S2 → the first relay S1 → the fifth power tube Q 5 →Battery pack BT1→Charging pile negative pole, charging pile positive pole→Second relay S2→First relay S1→Sixth relay S6→Third power tube Q 3 →Battery pack BT1→Charging pile negative electrode, and, charging pile positive electrode→Second relay S2→First relay S1→Sixth relay S6→Fourth relay S4→First power tube Q 1 →Battery pack BT1→negative pole of charging pile.

[0118] It should be noted that if the power tube Q 1 -Q 6 If it is IGBT, the power tube Q is turned off. 1 -Q 6 , if the power tube Q 1 -Q 6 If it is SiCMOSFET, the second power tube Q is turned off.2 、The fourth power tube Q 4 And the sixth power tube Q 6 , turn on the first power tube Q 1 、The third power tube Q 3 And the fifth power tube Q 5 In the above second direct charging circuit, when the power tubes Q1-Q6 are IGBTs, the current flows through the first Q 1 、The third power tube Q 3 And the fifth power tube Q 5 The anti-parallel diode, when the power tube Q 1 -Q 6 When it is SiC MOSFET, the current flows through the first power tube Q 1 、The third power tube Q 3 And the fifth power tube Q 5 .

[0119] As a feasible implementation form, Fig.11 and Fig.12 As shown, the second boost charging circuit of this embodiment includes a second boost energy storage circuit and a second boost energy discharge circuit.

[0120] The second boost energy storage circuit includes a second relay S2 closed in the first switch switching module, a fourth relay S4 and a sixth relay S6 closed in the second switch switching module, and a second power tube Q turned on in the motor control module. 2 、The fourth power tube Q 4 And the sixth power tube Q 6 The second boost energy dissipation circuit includes the second relay S2 closed in the first switch switching module, the fourth relay S4 and the sixth relay S6 closed in the second switch switching module, and the first power tube Q turned on in the motor control module. 1 、The third power tube Q 3 And the fifth power tube Q 5 .

[0121] In the second boost energy storage circuit, if Fig.11 As shown, the current path is as follows: positive pole of charging pile → second relay S2 → motor winding UW → motor winding UV → motor winding VW → Q 2 → negative pole of charging pile, positive pole of charging pile → second relay S2 → motor winding UW → motor winding UV → motor winding VW → sixth relay S6 → sixth power tube Q 6 → negative pole of charging pile, and positive pole of charging pile → second relay S2 → motor winding UW → motor winding UV → motor winding VW six relays S6 → fourth relay S4 → fourth power tube Q 4→The negative pole of the charging pile. At this time, similar to the aforementioned boost energy storage circuit, the motor winding current increases to charge and store energy.

[0122] In the second boost and energy release circuit, if Fig.12 As shown, the current path is as follows: positive pole of charging pile → second relay S2 → motor winding UW → motor winding UV → motor winding VW → fifth power tube Q 5 →Battery pack BT1→Charging pile negative pole, charging pile positive pole→Second relay S2→Motor winding UW→Motor winding UV→Motor winding VW→Sixth relay S6→Third power tube Q 3 →Battery pack BT1→Charging pile negative pole, and charging pile positive pole→Second relay S2→Motor winding UW→Motor winding UV→Motor winding VW→Sixth relay S6→Fourth relay S4→First power tube Q 1 →Battery pack BT1→Charging pile negative pole. At this time, similar to the aforementioned boost energy dissipation circuit, the motor winding current decreases, the voltage increases, and the first power tube Q 1 、The third power tube Q 3 And the fifth power tube Q 5 Then charge the battery pack BT1.

[0123] It should be noted that if the power tube Q 1 -Q 6 If it is IGBT, the power tube Q is turned off. 1 -Q 6 , if the power tube Q 1 -Q 6 If it is SiCMOSFET, the second power tube Q is turned off. 2 、The fourth power tube Q 4 And the sixth power tube Q 6 , turn on the first Q of the power tube 1 , power tube third Q 3 And the fifth power tube Q 5 .

[0124] As a feasible implementation form, Fig.13 and Fig.14 As shown, the second step-down charging circuit of this embodiment includes a second step-down energy storage circuit and a second step-down energy discharge circuit.

[0125] The second step-down energy storage circuit includes a second relay S2 closed in the first switch switching module, a fourth relay S4 and a sixth relay S6 closed in the second switch switching module, and a first power tube Q turned on in the motor control module. 1 、The third power tube Q 3 And the fifth power tube Q 5The second boost energy dissipation circuit includes the second relay S2 closed in the first switch switching module, the fourth relay S4 and the sixth relay S6 closed in the second switch switching module, and the second power tube Q turned on in the motor control module. 2 、The fourth power tube Q 4 And the sixth power tube Q 6 .

[0126] In the second step-down energy storage circuit, if Fig.13 As shown, the current path is as follows: BT1 positive electrode → fifth power tube Q 5 →Motor winding VW→Motor winding UV→Motor winding UW→Second relay S2→BT2 positive pole→BT1 negative pole, BT1 positive pole→Third power tube Q 3 →Sixth relay S6→motor winding VW→motor winding UV→motor winding UW→second relay S2→BT2 positive→BT1 negative, and BT1 positive→Q 1 → fourth relay S4 → sixth relay S6 → motor winding VW → motor winding UV → motor winding UW → second relay S2 → BT2 positive pole → BT1 negative pole. In this second step-down energy storage loop, similar to the aforementioned step-down energy storage loop, the energy of battery BT1 flows to the motor winding, and the winding current increases.

[0127] In the second pressure reduction and energy dissipation circuit, if Fig.14 As shown, the current path is as follows: motor winding VW→motor winding UV→motor winding UW→second relay S2→BT2 positive pole→BT2 negative pole→second power tube Q 2 →Motor winding VW, motor winding VW→motor winding UV→motor winding UW→second relay S2→BT2 positive pole→BT2 negative pole→sixth power tube Q 6 →sixth relay S6→motor winding VW, and motor winding VW→motor winding UV→motor winding UW→second relay S2→BT2 positive pole→BT2 negative pole→Q 4 → fourth relay S4 → sixth relay S6 → motor winding VW. It should be noted that in the second voltage reduction and energy dissipation circuit, if the power tube Q 1 -Q 6 If it is IGBT, the power tube Q is turned off. 1 -Q 6 , group through the second power tube Q 2 、The fourth power tube Q 4 And the sixth power tube Q 6 The anti-parallel diode is connected to the power tube Q 1 -Q 6 If it is SiC MOSFET, the first power tube Q is turned off. 1 、The third power tube Q 3And the fifth power tube Q 5 , turn on the second power tube Q 2 、The fourth power tube Q 4 And the sixth power tube Q 6 At this time, similar to the aforementioned voltage reduction and energy dissipation circuit, the motor winding current gradually decreases.

[0128] As a preferred embodiment, Fig.15 As shown, the second switch switching module of this embodiment includes a third single-pole double-throw switch S3 and a fourth single-pole double-throw switch S4.

[0129] The first end of the third single-pole double-throw switch S3 is connected to the first power tube Q 1 With the fourth power tube Q 4 The common end of the third single-pole double-throw switch S3 is connected to the third power tube Q 3 With the sixth power tube Q 6 The third end of the third single-pole double-throw switch S3 is connected to the second end of the first winding. The first end of the fourth single-pole double-throw switch S4 is connected to the third power tube Q 3 With the sixth power tube Q 6 The common end of the fourth single-pole double-throw switch S4 is connected to the fifth power tube Q 5 With the second power tube Q 2 The common end of the fourth single-pole double-throw switch S4 is connected to the second end of the second winding.

[0130] It should be noted that the first end of the third single-pole double-throw switch S3 is the moving end of the third single-pole double-throw switch S3, and the first end and the third end of the third single-pole double-throw switch S3 are the fixed ends of the third single-pole double-throw switch S3. The first end of the fourth single-pole double-throw switch S4 is the moving end of the fourth single-pole double-throw switch S4, and the first end and the third end of the fourth single-pole double-throw switch S4 are the fixed ends of the fourth single-pole double-throw switch S4.

[0131] Moreover, it can be understood that by providing the second switch switching module including a third single-pole double-throw switch and a fourth single-pole double-throw switch, the circuit structure can be simplified and the volume cost can be saved.

[0132] It should be noted that the closing of the single-pole double-throw switch hereinafter refers to the closing of the first end and the second end of the single-pole double-throw switch.

[0133] In this embodiment, as a feasible implementation form, Fig.16 As shown, the second direct charging circuit includes a first relay S1 and a second relay S2 closed in the first switch switching module, a third single-pole double-throw switch S3 and a fourth single-pole double-throw switch S4 closed in the second switch switching module, and a first power tube Q turned on in the motor control module. 1 、The third power tube Q3 And the fifth power tube Q 5 .

[0134] When the charging pile voltage is higher than the battery pack voltage, the first relay S1 and the second relay S2 are closed, the third single-pole double-throw switch S3 and the fourth single-pole double-throw switch S4 are closed, and the first power tube Q 1 、The third power tube Q 3 And the fifth power tube Q 5 The charging pile can directly charge the battery pack through the power tube in the motor control module. The charging path at this time is: the positive electrode of the charging pile → the second relay S2 → the first relay S1 → the fifth power tube Q 5 →Battery pack BT1→Charging pile negative pole, charging pile positive pole→Second relay S2→First relay S1→Fourth single-pole double-throw switch S4→Third power tube Q 3 →Battery pack BT1→Charging pile negative pole, and charging pile positive pole→Second relay S2→First relay S1→Fourth single-pole double-throw switch S4→Third single-pole double-throw switch S3→First power tube Q 1 →Battery pack BT1→negative pole of charging pile.

[0135] It should be noted that if the power tube Q 1 -Q 6 If it is IGBT, the power tube Q is turned off. 1 -Q 6 , if the power tube Q 1 -Q 6 If it is SiCMOSFET, the second power tube Q is turned off. 2 、The fourth power tube Q 4 And the sixth power tube Q 6 , turn on the first power tube Q 1 、The third power tube Q 3 And the fifth power tube Q 5 In the above second direct charging circuit, when the power tubes Q1-Q6 are IGBTs, the current flows through the first power tube Q 1 、The third power tube Q 3 And the fifth power tube Q 5 The anti-parallel diode, when the power tube Q 1 -Q 6 When it is SiC MOSFET, the current flows through the first power tube Q 1 、The third power tube Q 3 And the fifth power tube Q 5 .

[0136] As a feasible implementation form, Fig.17 and Fig.18As shown, the second boost charging circuit of this embodiment includes a second boost energy storage circuit and a second boost energy discharge circuit.

[0137] The second boost energy storage circuit includes a second relay S2 closed in the first switch switching module, a third single-pole double-throw switch S3 and a fourth single-pole double-throw switch S4 closed in the second switch switching module, and a second power tube Q turned on in the motor control module. 2 、The fourth power tube Q 4 And the sixth power tube Q 6 The second boost energy dissipation circuit includes the second relay S2 closed in the first switch switching module, the third single-pole double-throw switch S3 and the fourth single-pole double-throw switch S4 closed in the second switch switching module, and the first power tube Q turned on in the motor control module. 1 、The third power tube Q 3 And the fifth power tube Q 5 .

[0138] In the second boost energy storage circuit, if Fig.17 As shown, the current path is as follows: positive pole of charging pile → second relay S2 → motor winding UW → motor winding UV → motor winding VW → second power tube Q 2 → negative pole of charging pile, positive pole of charging pile → second relay S2 → motor winding UW → motor winding UV → motor winding VW → fourth single-pole double-throw switch S4 → sixth power tube Q 6 → negative pole of charging pile, and positive pole of charging pile → second relay S2 → motor winding UW → motor winding UV → motor winding VW six relays S6 → fourth single-pole double-throw switch S4 → fourth single-pole double-throw switch S4 → fourth power tube Q 4 →The negative pole of the charging pile. Similar to the aforementioned boost energy storage circuit, the motor winding current increases to charge and store energy.

[0139] In the second boost and energy release circuit, if Fig.18 As shown, the current path is as follows: positive pole of charging pile → second relay S2 → motor winding UW → motor winding UV → motor winding VW → fifth power tube Q 5 →Battery pack BT1→Charging pile negative pole, charging pile positive pole→Second relay S2→Motor winding UW→Motor winding UV→Motor winding VW→Fourth single-pole double-throw switch S4→Third power tube Q 3 →Battery pack BT1→Charging pile negative pole, and charging pile positive pole→Second relay S2→Motor winding UW→Motor winding UV→Motor winding VW→Fourth single-pole double-throw switch S4→Third single-pole double-throw switch S3→First power tube Q 1 →Battery pack BT1→Charging pile negative pole. At this time, similar to the aforementioned boost energy dissipation circuit, the motor winding current decreases, the voltage increases, and the first power tube Q1 、The third power tube Q 3 And the fifth power tube Q 5 Then charge the battery pack BT1.

[0140] It should be noted that if the power tube Q 1 -Q 6 If it is IGBT, the power tube Q is turned off. 1 -Q 6 , if the power tube Q 1 -Q 6 If it is SiCMOSFET, the second power tube Q is turned off. 2 、The fourth power tube Q 4 And the sixth power tube Q 6 , turn on the first power tube Q 1 、The third power tube Q 3 And the fifth power tube Q 5 .

[0141] As a feasible implementation form, the second step-down charging circuit of this embodiment includes a second step-down energy storage circuit and a second step-down energy discharge circuit.

[0142] The second step-down energy storage circuit includes a second relay S2 closed in the first switch switching module, a third single-pole double-throw switch S3 and a fourth single-pole double-throw switch S4 closed in the second switch switching module, and a first power tube Q turned on in the motor control module. 1 、The third power tube Q 3 And the fifth power tube Q 5 The second boost energy dissipation circuit includes the second relay S2 closed in the first switch switching module, the third single-pole double-throw switch S3 and the fourth single-pole double-throw switch S4 closed in the second switch switching module, and the second power tube Q turned on in the motor control module. 2 、The fourth power tube Q 4 And the sixth power tube Q 6 .

[0143] In the second step-down energy storage circuit, if Fig.19 As shown, the current path is as follows: BT1 positive electrode → fifth power tube Q 5 →Motor winding VW→Motor winding UV→Motor winding UW→Second relay S2→BT2 positive pole→BT1 negative pole, BT1 positive pole→Third power tube Q 3 →The fourth single-pole double-throw switch S4→motor winding VW→motor winding UV→motor winding UW→the second relay S2→BT2 positive pole→BT1 negative pole, and BT1 positive pole→the first power tube Q 1→ third single-pole double-throw switch S3 → fourth single-pole double-throw switch S4 → motor winding VW → motor winding UV → motor winding UW → second relay S2 → BT2 positive pole → BT1 negative pole. In this second step-down energy storage circuit, similar to the aforementioned step-down energy storage circuit, the energy of battery BT1 flows to the motor winding, the winding current rises, and inductive energy storage is realized.

[0144] In the second pressure reduction and energy dissipation circuit, if Fig. 20 As shown, the current path is as follows: motor winding VW→motor winding UV→motor winding UW→second relay S2→BT2 positive pole→BT2 negative pole→second power tube Q 2 →Motor winding VW, motor winding VW→motor winding UV→motor winding UW→second relay S2→BT2 positive pole→BT2 negative pole→sixth power tube Q 6 →The fourth single-pole double-throw switch S4→motor winding VW, and motor winding VW→motor winding UV→motor winding UW→the second relay S2→BT2 positive pole→BT2 negative pole→the fourth power tube Q 4 → third single-pole double-throw switch S3 → fourth single-pole double-throw switch S4 → motor winding VW. It should be noted that in the second voltage reduction and energy dissipation circuit, if the power tube Q 1 -Q 6 If it is IGBT, the power tube Q is turned off. 1 -Q 6 , through the second power tube Q 2 、The fourth power tube Q 4 And the sixth power tube Q 6 The anti-parallel diode is connected to the power tube Q 1 -Q 6 If it is SiC MOSFET, the first power tube Q is turned off. 1 、The third power tube Q 3 And the fifth power tube Q 5 , turn on the second power tube Q 2 、The fourth power tube Q 4 And the sixth power tube Q 6 At this time, similar to the aforementioned step-down energy dissipation circuit, the motor winding inductance generates an induced voltage due to the change in current, and the current in the motor winding gradually decreases.

[0145] The vehicle charging and discharging system of this embodiment adopts the above structure, and does not need to set up additional boost and buck circuits. It has a simple structure and cost advantages. It can achieve zero torque control of the motor at any angle without leading out the neutral point of the motor. It also has the advantages of small charging ripple current and no risk of unexpected vehicle movement. In addition, the vehicle charging and discharging system of this embodiment, by setting up the second switch switching module, makes the power tube load uniform and generates less heat, which is conducive to improving the service life of the power tube. At the same time, by making the second switch switching module composed of the third single-pole double-throw switch and the fourth single-pole double-throw switch, it can also simplify the circuit structure, save volume cost, and have good practicality.

[0146] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A vehicle charging and discharging system, characterized in that: It includes a power supply module, a motor control module, a first switch switching module and a delta-connected motor winding; The positive electrode of the power supply module can be connected to the positive electrode of the battery pack in the vehicle through the first switch switching module, the delta motor winding and the motor control module in sequence; The negative electrode of the power supply module can be connected to the negative electrode of the battery pack; When the power supply module is connected to the battery pack through the first switch switching module and the motor control module, a first direct charging loop can be formed; When the power supply module is connected to the battery pack through the first switch switching module, the delta-connected motor winding and the motor control module, a first boost charging loop can be formed; When the battery pack is connected to the power supply module through the motor control module, the delta-connected motor winding and the first switch switching module, a first step-down discharge circuit can be formed.

2. The vehicle charging and discharging system according to claim 1, characterized in that: The motor control module includes a first power tube, a second power tube, a third power tube, a fourth power tube, a fifth power tube, a sixth power tube and a second capacitor; A first control branch formed by the first power tube and the fourth power tube connected in series, a second control branch formed by the third power tube and the sixth power tube connected in series, and a third control branch formed by the fifth power tube and the second power tube connected in series are connected in parallel; The second capacitor is arranged in parallel between the battery pack and the first control branch; The first power tube, the third power tube and the fifth power tube are connected to the positive electrode of the battery pack.

3. The vehicle charging and discharging system according to claim 2, characterized in that: The delta-connected motor winding comprises a first winding, a second winding and a third winding; The first end of the first winding is a current inflow end, the second end of the first winding is connected to the first end of the second winding, the second end of the second winding is connected to the first end of the third winding, and the second end of the third winding is a current outflow end; The second end of the first winding is connected to the common end of the first power tube and the fourth power tube; The second end of the second winding is connected to the common end of the third power tube and the sixth power tube; The second end of the third winding is connected to a common end of the fifth power tube and the second power tube.

4. The vehicle charging and discharging system according to claim 3, characterized in that: The first switch switching module includes a first relay and a second relay; The first end of the first relay is connected to the second end of the third winding, and the second end of the first relay is connected to the first end of the second relay; A first end of the second relay is connected to a first end of the first winding, and a second end of the first relay is connected to a positive electrode of the power supply module.

5. The vehicle charging and discharging system according to claim 4, characterized in that: The first direct charging loop includes the first relay and the second relay that are closed in the first switch switching module, and the fifth power tube that is turned on in the motor control module.

6. The vehicle charging and discharging system according to claim 4, characterized in that: The first boost charging circuit includes a first boost energy storage circuit and a first boost energy discharge circuit; The first boost energy storage circuit includes the second relay closed in the first switch switching module, and the second power tube turned on in the motor control module; The first boost energy dissipation circuit includes the second relay that is closed in the first switch module and the fifth power tube that is turned on in the motor control module.

7. The vehicle charging and discharging system according to claim 4, characterized in that: The first step-down discharge circuit includes a first step-down energy storage circuit and a first step-down energy discharge circuit; The first step-down energy storage circuit includes the second relay closed in the first switch switching module, and the fifth power tube turned on in the motor control module; The first voltage reduction and energy dissipation circuit includes the second relay that is closed in the first switch switching module and the second power tube that is turned on in the motor control module.

8. The vehicle charging and discharging system according to any one of claims 4 to 7, characterized in that: Also includes a second switch switching module; The second switch switching module is arranged in the motor control module; When the power supply module is connected to the battery pack through the first switch switching module, the motor control module and the second switch switching module, a second direct charging circuit can be formed; When the power supply module is connected to the battery pack through the first switch switching module, the delta-connected motor winding, the motor control module and the second switch switching module, a second boost charging circuit can be formed; When the battery pack is connected to the power supply module through the second switch switching module, the motor control module, the delta-connected motor winding and the first switch switching module, a second step-down discharge circuit can be formed.

9. The vehicle charging and discharging system according to claim 8, characterized in that: The second switch switching module includes a third relay, a fourth relay, a fifth relay and a sixth relay; A first end of the third relay is connected to a common end of the first power tube and the fourth power tube, and a second end of the third relay is connected to a second end of the first winding; The first end of the fourth relay is connected to the common end of the first power tube and the fourth power tube, and the second end of the fourth relay is connected to the common end of the third power tube and the sixth power tube; The first end of the fifth relay is connected to the common end of the third power tube and the sixth power tube, and the second end of the fifth relay is connected to the second end of the second winding; The first end of the sixth relay is connected to the common end of the third power tube and the sixth power tube, and the second end of the sixth relay is connected to the common end of the fifth power tube and the second power tube.

10. The vehicle charging and discharging system according to claim 8, characterized in that: The second switch switching module includes a third single-pole double-throw switch and a fourth single-pole double-throw switch; The first end of the third single-pole double-throw switch is connected to the common end of the first power tube and the fourth power tube, the second end of the third single-pole double-throw switch is connected to the common end of the third power tube and the sixth power tube, and the third end of the third single-pole double-throw switch is connected to the second end of the first winding; The first end of the fourth single-pole double-throw switch is connected to the common end of the third power tube and the sixth power tube, the second end of the fourth single-pole double-throw switch is connected to the common end of the fifth power tube and the second power tube, and the third end of the fourth single-pole double-throw switch is connected to the second end of the second winding.

Images