Alternating current charging and discharging system of vehicle and vehicle comprising alternating current charging and discharging system

Abstract

The invention provides an alternating current charging and discharging system of a vehicle and the vehicle comprising the alternating current charging and discharging system. The alternating current charging and discharging system comprises two groups of multiphase inverters and two groups of multiphase windings, wherein the buses of the two groups of multi-phase inverters are connected with each other, the two groups of multi-phase windings are respectively connected to the corresponding multi-phase inverters, and the two groups of multi-phase windings are connected with each other; the alternating-current power grid is connected to at least one of the two groups of multi-phase windings; and the mutually connected windings of corresponding phases in the two groups of multi-phase windings are located in different pole pairs of the motor. When the electric drive system of the multiplex vehicle is used for electric energy conversion, the mutual inductance value between the windings can be effectively reduced, the motor inductance is used as the grid-connected inductance to the maximum extent, and then ripples generated by the mutual inductance of the windings are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicles, and in particular relates to an AC charging and discharging system of a vehicle and a vehicle comprising the same. Background Art

[0002] At present, electric vehicles need to rely on OBC (On-Board Charger), non-on-board converters and other devices to realize the power conversion between DC on-board batteries and AC power grids, and the use scenarios are limited. Based on this, it is proposed to reuse the electric drive system to convert the corresponding power, which can reduce the cost and volume of related devices. However, it has the safety risks of switching between motor drive and grid connection, motor rotation during grid connection charging and discharging, resulting in unexpected movement of the vehicle, and ripple caused by mutual inductance between motor windings. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an AC charging and discharging system for a vehicle and a vehicle including the same, so that when the electric drive system of the reused vehicle is used for electric energy conversion, the mutual inductance between windings can be effectively reduced, the motor inductance can be maximized as the grid inductance, and the ripple generated by the mutual inductance of the windings can be reduced.

[0004] In order to solve or improve the above technical problems to a certain extent, according to one aspect of the present invention, an AC charging and discharging system for a vehicle is provided, comprising: two sets of multi-phase inverters and two sets of multi-phase windings of a multiplexing electric drive system;

[0005] The busbars of the two groups of multi-phase inverters are connected to each other, the two groups of multi-phase windings are respectively connected to the corresponding multi-phase inverters, and the two groups of multi-phase windings are connected to each other;

[0006] The AC power grid is connected to at least one of the two groups of multi-phase windings;

[0007] The windings of corresponding phases connected to each other in the two groups of multi-phase windings are located at different pole pairs of the motor.

[0008] In some embodiments, the first ends of the two groups of multi-phase windings are respectively connected to the midpoints of the multi-phase bridge arms of the two groups of multi-phase inverters, and the second ends of the two groups of multi-phase windings are connected to each other, and the AC power grid can be connected to the second ends of the two groups of multi-phase windings in an on-off manner at the same time.

[0009] In some embodiments, non-same-name ends of corresponding phase windings of two groups of the multi-phase windings are connected to each other.

[0010] In some embodiments, in the AC charging and discharging mode, the AC power grid is connected to the second ends of the two groups of multi-phase windings, and the bridge arm switching devices of the corresponding phases of the two groups of multi-phase inverters are synchronously turned on or off;

[0011] In the driving mode, the AC power grid is disconnected from the second ends of the two groups of the multi-phase windings.

[0012] In some embodiments, the first ends of the two groups of multi-phase windings are respectively connected to the midpoints of the multi-phase bridge arms of the two groups of multi-phase inverters, and the second ends of the two groups of multi-phase windings are connected, and the AC power grid can be simultaneously connected to the first end of one of the two groups of multi-phase windings in an on-off manner.

[0013] In some embodiments, the second ends of the two groups of multi-phase windings are interconnected through a conversion device. In the AC charge and discharge mode, the conversion device opens the neutral point of the multi-phase winding and connects the corresponding phase windings of the two groups of multi-phase windings to each other.

[0014] In some embodiments, in the driving mode, the conversion device connects the neutral points of the two groups of the multi-phase windings to each other.

[0015] In some embodiments, in the AC charging and discharging mode, the conversion device connects the same-named ends of corresponding phases of the two groups of multi-phase windings to each other.

[0016] In some embodiments, the conversion device includes a plurality of switches, and the plurality of switches are respectively arranged between windings of corresponding phases of two groups of the multi-phase windings and between adjacent phases of each group of the multi-phase windings.

[0017] According to an embodiment of the present invention, a vehicle is provided, comprising the battery heating system for the vehicle described in any one of the above embodiments.

[0018] Compared with the prior art, the present invention has obvious advantages and beneficial effects. By means of the above technical solution, the AC charging and discharging system of the vehicle of the present invention and the vehicle including the same can achieve considerable technical advancement and practicality, and have wide industrial utilization value, and at least have the following advantages:

[0019] The AC charging and discharging system of the vehicle of the present invention and the vehicle including the same, by reusing the electric drive system of the vehicle, does not need to add new inverters and windings in the vehicle, effectively reduces the equipment cost and volume, and improves the integration of the AC charging and discharging system of the vehicle. Placing the windings of the corresponding phases connected to each other in the two sets of multi-phase windings in different motor pole pairs can greatly reduce the coupling coefficient (mutual inductance) between the two interconnected windings, so as to maximize the use of the motor inductance as the grid inductance, and at the same time can reduce the ripple of the grid current caused by voltage fluctuations. By changing the arrangement of the two sets of multi-phase windings, the grid current can flow through the non-same-name ends of the two sets of multi-phase windings at the same time during charging and discharging, and under the action of the grid current, opposite electromagnetic torques will be generated on the corresponding phase windings. The opposite electromagnetic torques generated by the corresponding phase windings are superimposed and offset each other, so that the motor does not output torque, effectively avoiding the situation where the vehicle moves due to the output torque of the motor during the charging and discharging process.

[0020] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the topological structure of an AC charging and discharging system for a vehicle according to an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of the topological structure of an AC charging and discharging system for a vehicle according to another embodiment of the present invention;

[0023] Figure 3 for Figure 2 A schematic diagram of the topological structure of the AC charging and discharging system of the vehicle shown is in the grid-connected mode;

[0024] Figure 4 for Figure 2 A schematic diagram of the topological structure of the AC charging and discharging system of the vehicle shown is in driving mode;

[0025] Figure 5 for Figure 1 A schematic diagram of the grid-connected inductance of the corresponding phase winding of the AC charging and discharging system of the vehicle shown;

[0026] Figure 6 for Figure 3 A schematic diagram of the grid-connected inductance of the corresponding phase winding of the AC charging and discharging system of the vehicle is shown. DETAILED DESCRIPTION

[0027] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the AC charging and discharging system for a vehicle and the specific implementation methods and effects of the vehicle including the same proposed by the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0028] Figure 1 and Figure 2 FIG. 2 shows a schematic diagram of the topological structure of the AC charging and discharging system of a vehicle of the present invention. Figure 1 and Figure 2 As shown, the AC charging and discharging system of the vehicle reuses two sets of multi-phase inverters 10, 20 of the vehicle's electric drive system and two sets of multi-phase windings 30, 40 of the motor, without adding new inverters and windings to the vehicle, effectively reducing equipment cost and volume and improving the integration of the vehicle's AC charging and discharging system.

[0029] Among them, the busbars of the two groups of multi-phase inverters 10 and 20 are interconnected, and the busbars of the two groups of multi-phase inverters 10 and 20 are both connected to the battery of the vehicle (not shown in the figure), the two groups of multi-phase windings 30 and 40 are respectively connected to the two groups of multi-phase inverters 10 and 20, and the two groups of multi-phase windings 30 and 40 are connected to each other, the AC power grid 50 is connected to at least one of the two groups of multi-phase windings 30 and 40, and the windings of the corresponding phases that are interconnected in the two groups of multi-phase windings 30 and 40 are in different pole pairs of the motor.

[0030] It is known that each phase winding of the motor will generate N and S magnetic poles, and the number of N and S magnetic poles contained in each phase of the motor is the number of pole pairs. The present invention places the windings of the corresponding phases connected to each other in the two sets of multi-phase windings 30 and 40 in different pole pairs of the motor, which can greatly reduce the coupling coefficient (mutual inductance) between the two interconnected windings, so as to maximize the use of the motor inductance as the grid-connected inductance, and at the same time can reduce the ripple of the grid-connected current caused by voltage fluctuations.

[0031] In one embodiment, if Figure 1 As shown, the busbars of the two groups of multi-phase inverters 10 and 20 are interconnected, and the busbars of the two groups of multi-phase inverters 10 and 20 are both connected to the busbars of the vehicle battery. The first ends of the two groups of multi-phase windings 30 and 40 are respectively connected to the midpoints of the multi-phase bridge arms of the two groups of multi-phase inverters 10 and 20, and the second ends of the two groups of multi-phase windings 30 and 40 are interconnected so that the corresponding phase windings of the two groups of multi-phase windings 30 and 40 are connected. The AC power grid 50 can be connected to the second ends of the two groups of multi-phase windings 30 and 40 in an on-off manner at the same time.

[0032] The AC charging and discharging system of the vehicle of the present invention can switch between a grid-connected mode and a driving mode, wherein the grid-connected mode is to reuse the vehicle's electric drive system as an AC isolation inverter to convert the AC power transmitted by the AC power grid 50 into DC power to charge the vehicle's battery, or to convert the DC power stored in the vehicle's battery into AC power and transmit it to the AC power grid 50; the driving mode is to provide electrical energy to the vehicle's battery so that the motor of the electric drive system generates torque, so that the vehicle can be driven to move by the torque generated by the motor.

[0033] When the AC charging and discharging system of the vehicle is in the grid-connected mode (i.e., the charging and discharging mode), the AC power grid 50 is connected to the second ends of the two sets of multi-phase windings 30 and 40. When the AC charging and discharging system of the vehicle is in the driving mode, the AC power grid 50 is disconnected from the second ends of the two sets of multi-phase windings 30 and 40, so that the multi-phase inverter and multi-phase winding of the multiplexed electric drive system can realize the driving function to provide the vehicle with the kinetic energy required for normal operation.

[0034] In this embodiment, the non-same-named ends of the corresponding phase windings of the two groups of multi-phase windings 30 and 40 are connected to each other. In the process of winding, the end that is first wound is the head end, and the end of the last winding is the tail end. If the two windings are wound in the same direction, the head ends of the two windings are the same-named ends, the tail ends of the two windings are also the same-named ends, and the head end of one winding and the tail end of the other winding in the two windings are non-same-named ends. If the two windings are wound in different directions, the head end of one winding and the tail end of the other winding are the same-named ends, the head ends of the two windings are non-same-named ends, and the tail ends of the two windings are also non-same-named ends.

[0035] In this embodiment, if Figure 1 As shown, the non-same-named ends of the corresponding phase windings of the two sets of multi-phase windings 30 and 40 are connected to each other. In the grid-connected mode, the grid-connected current output by the AC power grid 50 will simultaneously flow into the non-same-named ends of the corresponding phase windings of the two sets of multi-phase windings 30 and 40. At this time, under the action of the grid-connected current, opposite electromagnetic torques will be generated on the corresponding phase windings. The opposite electromagnetic torques generated by the corresponding phase windings are superimposed and offset each other, so that the motor does not output torque, effectively avoiding the situation where the vehicle moves due to the motor output torque during the charging and discharging process.

[0036] like Figure 1 As shown, in the driving mode, the driving current output by the vehicle battery can flow into the same-named ends of the corresponding phase windings of the two sets of multi-phase windings 30 and 40 at the same time, thereby generating the same electromagnetic torque in the multi-phase windings. After the same electromagnetic torque generated by the corresponding phases is superimposed, the motor can output the torque required for vehicle driving, thereby driving the vehicle to move.

[0037] In this embodiment, in the grid-connected mode, the bridge arm switching devices of the corresponding phases of the two groups of multi-phase inverters 10 and 20 are synchronously turned on or off to ensure that the currents of the corresponding phase windings of the two groups of multi-phase windings 30 and 40 are the same in real time, completely eliminating the torque generated by the motor during the charging and discharging process, and avoiding the NVH problem of the vehicle caused by the low-order pulse torque brought about by the multiplexing electric drive system to realize AC charging and discharging.

[0038] In a specific embodiment, Figure 1 As shown, the AC charging and discharging system of the vehicle includes a first three-phase inverter 100 , a second three-phase inverter 200 , a first three-phase winding 300 , and a second three-phase winding 400 .

[0039] The busbars of the first three-phase inverter 100 and the second three-phase inverter 200 are connected to each other, and the busbars of the first three-phase inverter 100 and the second three-phase inverter 200 are both connected to the battery of the vehicle. The first three-phase inverter 100 includes bridge arm switching devices Q1-Q6, wherein Q1 and Q2 constitute the A-phase bridge arm, Q3 and Q4 constitute the B-phase bridge arm, and Q5 and Q6 constitute the C-phase bridge arm. The first three-phase inverter 100 also includes a capacitor C1, and the two ends of the capacitor C1 are correspondingly connected to the busbars of the first three-phase inverter 100. The second three-phase inverter 200 includes bridge arm switching devices Q7-Q12, wherein Q7 and Q8 constitute the A-phase bridge arm, Q9 and Q10 constitute the B-phase bridge arm, and Q11 and Q12 constitute the C-phase bridge arm.

[0040] The first three-phase winding 300 includes an A-phase winding, a B-phase winding and a C-phase winding, wherein the A-phase winding includes a head end A1 and a tail end X1, the B-phase winding includes a head end B1 and a tail end Y1, and the C-phase winding includes a head end C1 and a tail end Z1. The second three-phase winding 400 includes an A-phase winding, a B-phase winding and a C-phase winding, wherein the A-phase winding includes a head end A2 and a tail end X2, the B-phase winding includes a head end B2 and a tail end Y2, and the C-phase winding includes a head end C2 and a tail end Z2.

[0041] The first three-phase winding 300 is respectively connected to the midpoints of the three bridge arms of the first three-phase inverter 100. Specifically, the tail end X1 of the A-phase winding is connected to the midpoint of the A-phase bridge arm, the tail end Y1 of the B-phase winding is connected to the midpoint of the B-phase bridge arm, and the tail end Z1 of the C-phase winding is connected to the midpoint of the C-phase bridge arm.

[0042] The second three-phase winding 400 is respectively connected to the midpoints of the three bridge arms of the second three-phase inverter 200. Specifically, the head end A2 of the A-phase winding is connected to the midpoint of the A-phase bridge arm, the head end B2 of the B-phase winding is connected to the midpoint of the B-phase bridge arm, and the head end C2 of the C-phase winding is connected to the midpoint of the C-phase bridge arm.

[0043] The first three-phase winding 300 is connected to the corresponding phase windings of the second three-phase winding 400. Specifically, the head end A1 of the A-phase winding of the first three-phase winding 300 is connected to the tail end X2 of the A-phase bridge arm of the second three-phase winding 400, the head end B1 of the B-phase winding of the first three-phase winding 300 is connected to the tail end Y2 of the B-phase winding of the second three-phase winding 400, and the head end C1 of the C-phase winding of the first three-phase winding 300 is connected to the tail end Z2 of the C-phase winding of the second three-phase winding 400.

[0044] In this embodiment, the head end of the first three-phase winding 300 and the head end of the second three-phase winding 400 are the same-named ends, and the tail end of the first three-phase winding 300 and the tail end of the second three-phase winding 400 are the same-named ends. In this embodiment, the head end of the first three-phase winding 300 is correspondingly connected to the tail end of the second three-phase winding 400, that is, the first three-phase winding 300 and the second three-phase winding 400 are connected at non-same-named ends.

[0045] In this embodiment, taking the A-phase winding connected with two sets of three-phase windings as an example, the equivalent circuit of the connected A-phase windings is as follows: Figure 5 As shown, Figure 5 As shown in the figure, two mutually coupled A-phase windings are connected in reverse parallel, and the equivalent inductance calculation formula is as follows:

[0046]

[0047] In the above formula, L1 and L2 are the inductances of the two A-phase windings, M 12 is the mutual inductance between the two A-phase windings. From the above formula, we can know that the mutual inductance M of the two A-phase windings 12 In this embodiment, the windings of the corresponding phases of the two sets of three-phase windings are in different pole pairs, so that the mutual inductance between the corresponding phase windings can be reduced, the winding inductance can be maximized as the grid-connected inductance, and the ripple of the grid-connected current caused by voltage fluctuation can be reduced.

[0048] In this embodiment, the AC power grid 50 is a three-phase power grid, and the three-phase power grid includes three phases L1, L2 and L3, and the three-phase power grid is respectively and simultaneously connected to the first group of three-phase windings 300 and the second group of three-phase windings 400. Specifically, the L1 phase of the three-phase power grid is simultaneously connected to the A-phase winding of the first group of three-phase windings 300 and the second group of three-phase windings 400, the L2 phase of the three-phase power grid is simultaneously connected to the B-phase winding of the first group of three-phase windings 300 and the second group of three-phase windings 400, and the L3 phase of the three-phase power grid is simultaneously connected to the C-phase winding of the first group of three-phase windings 300 and the second group of three-phase windings 400.

[0049] In this embodiment, when the AC charging and discharging system of the vehicle is in the grid-connected mode, the three-phase grid is connected to the first three-phase winding 300 and the second three-phase winding 400. Figure 1 As shown, the current of the three-phase power grid flows through the head end of the first three-phase winding 300 and the tail end of the second three-phase winding 400 at the same time, so that the corresponding phase windings of the first three-phase winding 300 and the second three-phase winding 400 respectively generate opposite electromagnetic torques. After the opposite electromagnetic torques are superimposed, no torque is generated on the motor.

[0050] When the AC charging and discharging system of the vehicle is in the driving mode, the three-phase grid is disconnected from the first three-phase winding 300 and the second three-phase winding 400. Figure 1 As shown, the current of the vehicle battery flows through the tail end of the first group of three-phase windings 300 and the tail end of the second group of three-phase windings 400, so that the corresponding phase windings of the first group of three-phase windings 300 and the second group of three-phase windings 400 respectively generate the same electromagnetic torque, and the same electromagnetic torque is superimposed and the motor generates a torque to drive the vehicle to move.

[0051] In one embodiment, if Figure 2 As shown, the busbars of the two groups of multi-phase inverters 10 and 20 are connected to each other, and the busbars of the two groups of multi-phase inverters 10 and 20 are connected to the busbars of the vehicle battery (not shown in the figure). The first ends of the two groups of multi-phase windings 30 and 40 are respectively connected to the midpoints of the multi-phase bridge arms of the corresponding two groups of multi-phase inverters 10 and 20, and the second ends of the two groups of multi-phase windings 30 and 40 are connected. The AC power grid 50 can be connected to the first end of one of the two groups of multi-phase windings 30 and 40 in a switchable manner at the same time.

[0052] When the AC charging and discharging system of the vehicle is in the grid-connected mode (i.e., the charging and discharging mode), the AC power grid 50 is connected to the second ends of the two sets of multi-phase windings 30 and 40. When the AC charging and discharging system of the vehicle is in the driving mode, the AC power grid 50 is disconnected from the second ends of the two sets of multi-phase windings 30 and 40, so that the multi-phase inverter and multi-phase winding of the multiplexed electric drive system can realize the driving function to provide the vehicle with the kinetic energy required for normal operation.

[0053] In this embodiment, the second ends of the two groups of multi-phase windings 30 and 40 are connected to each other through a conversion device 60. In the grid-connected mode, Figure 3 As shown, the switching device 60 opens the neutral point of the multi-phase winding and connects the corresponding phase windings of the two sets of multi-phase windings 30 and 40 to each other. Figure 4 As shown, the switching device 60 connects the neutral points of the two groups of multi-phase windings 30, 40 to each other.

[0054] Optionally, the conversion device 60 includes multiple switches, which are respectively arranged between the windings of corresponding phases of the two groups of multi-phase windings 30 and 40, and between adjacent phases of the two groups of multi-phase windings 30 and 40, so that the connection mode between the two groups of multi-phase windings 30 and 40 can be switched by controlling the opening and closing of the multiple switches.

[0055] In a specific embodiment, if Figure 2 As shown, both groups of multi-phase windings 30 and 40 are three-phase windings, and the conversion device 60 includes a first switch K1 to a seventh switch K7. The first switch K1, the fourth switch K4 and the sixth switch K6 are arranged between the corresponding phase windings of the first group of three-phase windings 300 and the second group of three-phase windings 400, the second switch K2 and the fifth switch K5 are arranged between each adjacent two windings of the first group of three-phase windings 300, and the third switch K3 and the seventh switch K7 are arranged between each adjacent two windings of the second group of three-phase windings 400.

[0056] When the AC charging and discharging system of the vehicle is in the grid-connected mode, the second switch K2, the third switch K3, the fifth switch K5 and the seventh switch K7 are disconnected, and the first switch K1, the fourth switch K4 and the sixth switch K6 are closed, so that the corresponding phase windings of the first three-phase winding 300 and the second three-phase winding 400 are connected to each other. When the AC charging and discharging system of the vehicle is in the driving mode, the first switch K1 and the sixth switch K6 are disconnected, and the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5 and the seventh switch K7 are closed, so that the neutral points of the first three-phase winding 300 and the second three-phase winding 400 are connected to each other.

[0057] In this embodiment, when the AC charging and discharging system of the vehicle is in the grid-connected mode, the same-named ends of the corresponding phase windings of the two sets of multi-phase windings 30 and 40 are connected to each other. In the process of winding, the end that is first wound is the head end, and the end of the last winding is the tail end. If the two windings are wound in the same direction, the head ends of the two windings are the same-named ends, and the tail ends of the two windings are also the same-named ends, and the head end of one winding and the tail end of the other winding in the two windings are non-same-named ends. If the two windings are wound in different directions, one of the windings and the head end and the tail end of the other winding are the same-named ends, the head ends of the two windings are non-same-named ends, and the tail ends of the two windings are also non-same-named ends.

[0058] In this embodiment, if Figure 3As shown, when the AC charging and discharging system of the vehicle is in the grid-connected mode, the AC grid 50 is between a group of multi-phase windings and an adjacent group of multi-phase inverters. At this time, the group of multi-phase inverters closer to the AC grid 50 does not work, and the grid-connected current of the AC grid 50 will flow through the non-same-name ends of the two groups of multi-phase windings 30 and 40 at the same time. At this time, under the action of the grid-connected current, opposite electromagnetic torques will be generated on the corresponding phase windings. The opposite electromagnetic torques generated by the corresponding phase windings are superimposed and offset each other, so that the motor does not output torque, effectively avoiding the situation where the vehicle moves due to the output torque of the motor during the charging and discharging process.

[0059] like Figure 4 As shown, in the driving mode, the driving current output by the vehicle battery can flow into the same-named ends of the corresponding phase windings of the two sets of multi-phase windings 30 and 40 at the same time, thereby generating the same electromagnetic torque in the corresponding phase windings of the two sets of multi-phase windings 30 and 40. After the same electromagnetic torque generated by the corresponding phase windings is superimposed, the motor can output the torque required for vehicle driving, thereby driving the vehicle to move.

[0060] In a specific embodiment, Figure 2 As shown, the AC charging and discharging system of the vehicle includes a first three-phase inverter 100 , a second three-phase inverter 200 , a first three-phase winding 300 , a second three-phase winding 400 and a conversion device 60 .

[0061] The busbars of the first three-phase inverter 100 and the second three-phase inverter 200 are connected to each other, and the busbars of the first three-phase inverter 100 and the second three-phase inverter 200 are both connected to the battery of the vehicle. The first three-phase inverter 100 includes bridge arm switching devices Q1-Q6, wherein Q1 and Q2 constitute the A-phase bridge arm, Q3 and Q4 constitute the B-phase bridge arm, and Q5 and Q6 constitute the C-phase bridge arm. The first three-phase inverter 100 also includes a capacitor C1, and the two ends of the capacitor C1 are correspondingly connected to the busbars of the first three-phase inverter 100. The second three-phase inverter 200 includes bridge arm switching devices Q7-Q12, wherein Q7 and Q8 constitute the A-phase bridge arm, Q9 and Q10 constitute the B-phase bridge arm, and Q11 and Q12 constitute the C-phase bridge arm.

[0062] The first three-phase winding 300 includes an A-phase winding, a B-phase winding and a C-phase winding, wherein the A-phase winding includes a head end A1 and a tail end X1, the B-phase winding includes a head end B1 and a tail end Y1, and the C-phase winding includes a head end C1 and a tail end Z1. The second three-phase winding 400 includes an A-phase winding, a B-phase winding and a C-phase winding, wherein the A-phase winding includes a head end A2 and a tail end X2, the B-phase winding includes a head end B2 and a tail end Y2, and the C-phase winding includes a head end C2 and a tail end Z2.

[0063] The conversion device 60 includes a first switch K1 to a seventh switch K7, wherein the first switch K1 is arranged between the A-phase winding of the first three-phase winding 300 and the second three-phase winding 400, the fourth switch K4 is arranged between the B-phase winding of the first three-phase winding 300 and the second three-phase winding 400, the sixth switch K6 is arranged between the C-phase winding of the first three-phase winding 300 and the second three-phase winding 400, the second switch K2 is arranged between the A-phase winding and the B-phase winding of the first three-phase winding 300, the fifth switch K5 is arranged between the B-phase winding and the C-phase winding of the first three-phase winding 300, the third switch K3 is arranged between the A-phase winding and the B-phase winding of the second three-phase winding 400, and the seventh switch K7 is arranged between the B-phase winding and the C-phase winding of the second three-phase winding 400.

[0064] The first three-phase winding 300 is respectively connected to the midpoints of the three bridge arms of the first three-phase inverter 100. Specifically, the tail end X1 of the A-phase winding is connected to the midpoint of the A-phase bridge arm, the tail end Y1 of the B-phase winding is connected to the midpoint of the B-phase bridge arm, and the tail end Z1 of the C-phase winding is connected to the midpoint of the C-phase bridge arm.

[0065] The second three-phase winding 400 is respectively connected to the midpoints of the three bridge arms of the second three-phase inverter 200. Specifically, the tail end X2 of the A-phase winding is connected to the midpoint of the A-phase bridge arm, the tail end Y2 of the B-phase winding is connected to the midpoint of the B-phase bridge arm, and the tail end Z2 of the C-phase winding is connected to the midpoint of the C-phase bridge arm.

[0066] When the AC charging and discharging system of the vehicle is in the grid-connected mode, the second switch K2, the third switch K3, the fifth switch K5 and the seventh switch K7 are disconnected, and the first switch K1, the fourth switch K4 and the sixth switch K6 are closed, so that the first end A1 of the A-phase winding of the first three-phase winding 300 is connected to the first end A2 of the A-phase bridge arm of the second three-phase winding 400, the first end B1 of the B-phase winding of the first three-phase winding 300 is connected to the first end B2 of the B-phase winding of the second three-phase winding 400, and the first end C1 of the C-phase winding of the first three-phase winding 300 is connected to the first end C2 of the C-phase winding of the second three-phase winding 400, as shown in FIG. Figure 3 shown.

[0067] When the AC charging and discharging system of the vehicle is in the driving mode, the first switch K1 and the sixth switch K6 are disconnected, and the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5 and the seventh switch K7 are closed, so that the neutral points of the first three-phase winding 300 and the second three-phase winding 400 are connected to each other. Figure 4 shown.

[0068] In this embodiment, the head end of the first three-phase winding 300 and the head end of the second three-phase winding 400 are the same end, and the tail end of the first three-phase winding 300 and the tail end of the second three-phase winding 400 are the same end. In this embodiment, the head end of the first three-phase winding 300 is correspondingly connected to the head end of the second three-phase winding 400, that is, the first three-phase winding 300 and the second three-phase winding 400 are connected at the same end.

[0069] In this embodiment, taking the A-phase winding connected with two sets of three-phase windings as an example, the equivalent circuit of the connected A-phase windings is as follows: Figure 6 As shown, two mutually coupled A-phase windings are connected in series in the same direction, and the equivalent inductance calculation formula is as follows:

[0070] L eq =L1+L2-2*M 12

[0071] In the above formula, L1 and L2 are the inductances of the two A-phase windings, M 12 is the mutual inductance between the two A-phase windings. From the above formula, we can know that the mutual inductance M of the two A-phase windings 12 In this embodiment, the windings of the corresponding phases of the two sets of three-phase windings are in different pole pairs, so that the mutual inductance between the corresponding phase windings can be reduced, the winding inductance can be maximized as the grid-connected inductance, and the ripple of the grid-connected current caused by voltage fluctuation can be reduced.

[0072] In this embodiment, the AC power grid 50 is a three-phase power grid, and the three-phase power grid includes three phases L1, L2 and L3, and the three-phase power grid is respectively and simultaneously connected to the first group of three-phase windings 300 and the second group of three-phase windings 400. Specifically, the L1 phase of the three-phase power grid is simultaneously connected to the A-phase winding of the first group of three-phase windings 300 and the second group of three-phase windings 400, the L2 phase of the three-phase power grid is simultaneously connected to the B-phase winding of the first group of three-phase windings 300 and the second group of three-phase windings 400, and the L3 phase of the three-phase power grid is simultaneously connected to the C-phase winding of the first group of three-phase windings 300 and the second group of three-phase windings 400.

[0073] In this embodiment, when the AC charging and discharging system of the vehicle is in the grid-connected mode, the three-phase grid is connected to the first three-phase winding 300 and the second three-phase winding 400. Figure 3 As shown, the current of the three-phase power grid flows through the tail end of the first three-phase winding 300 and the head end of the second three-phase winding 400 at the same time, so that the corresponding phase windings of the first three-phase winding 300 and the second three-phase winding 400 respectively generate opposite electromagnetic torques. After the opposite electromagnetic torques are superimposed, no torque is generated on the motor.

[0074] When the AC charging and discharging system of the vehicle is in the driving mode, the three-phase grid is disconnected from the first three-phase winding 300 and the second three-phase winding 400. Figure 4 As shown, the current of the vehicle battery flows through the tail end of the first group of three-phase windings 300 and the tail end of the second group of three-phase windings 400 at the same time, so that the corresponding phase windings of the first group of three-phase windings 300 and the second group of three-phase windings 400 respectively generate the same electromagnetic torque, and the same electromagnetic torque is superimposed and the motor generates a torque to drive the vehicle to move.

[0075] According to another embodiment of the present invention, a vehicle is provided, comprising the AC charging and discharging system for the vehicle described in any one of the above embodiments.

[0076] The AC charging and discharging system of the vehicle of the present invention and the vehicle including the same, by reusing the electric drive system of the vehicle, does not need to add new inverters and windings in the vehicle, effectively reduces the equipment cost and volume, and improves the integration of the AC charging and discharging system of the vehicle. Placing the windings of the corresponding phases connected to each other in the two sets of multi-phase windings in different motor pole pairs can greatly reduce the coupling coefficient (mutual inductance) between the two interconnected windings, so as to maximize the use of the motor inductance as the grid inductance, and at the same time can reduce the ripple of the grid current caused by voltage fluctuations. By changing the arrangement of the two sets of multi-phase windings, the grid current can flow through the non-same-name ends of the two sets of multi-phase windings at the same time during charging and discharging, and under the action of the grid current, opposite electromagnetic torques will be generated on the corresponding phase windings. The opposite electromagnetic torques generated by the corresponding phase windings are superimposed and offset each other, so that the motor does not output torque, effectively avoiding the situation where the vehicle moves due to the output torque of the motor during the charging and discharging process.

[0077] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. An AC charging and discharging system for a vehicle, characterized in that: include: Multiplexing two sets of multi-phase inverters and two sets of multi-phase windings of the electric drive system; The busbars of the two groups of multi-phase inverters are connected to each other, the two groups of multi-phase windings are respectively connected to the corresponding multi-phase inverters, and the two groups of multi-phase windings are connected to each other; The AC power grid is connected to at least one of the two groups of multi-phase windings; The windings of corresponding phases connected to each other in the two groups of multi-phase windings are located at different pole pairs of the motor.

2. The AC charging and discharging system for a vehicle according to claim 1, characterized in that: The first ends of the two groups of multi-phase windings are respectively connected to the midpoints of the multi-phase bridge arms of the two groups of multi-phase inverters, and the second ends of the two groups of multi-phase windings are connected to each other, and the AC power grid can be connected to the second ends of the two groups of multi-phase windings in an on-off manner at the same time.

3. The AC charging and discharging system for a vehicle according to claim 2, characterized in that: The non-same-name ends of the corresponding phase windings of the two groups of multi-phase windings are connected to each other.

4. The AC charging and discharging system for a vehicle according to claim 2 or 3, characterized in that: In the AC charging and discharging mode, the AC power grid is connected to the second ends of the two groups of multi-phase windings, and the bridge arm switching devices of the corresponding phases of the two groups of multi-phase inverters are synchronously turned on or off; In the driving mode, the AC power grid is disconnected from the second ends of the two groups of the multi-phase windings.

5. The AC charging and discharging system for a vehicle according to claim 1, characterized in that: The first ends of the two groups of multi-phase windings are respectively connected to the midpoints of the multi-phase bridge arms of the two groups of multi-phase inverters, and the second ends of the two groups of multi-phase windings are connected, and the AC power grid can be connected to the first end of one of the two groups of multi-phase windings in an on-off manner at the same time.

6. The AC charging and discharging system for a vehicle according to claim 5, characterized in that: The second ends of the two groups of multi-phase windings are connected to each other through a conversion device. In the AC charge and discharge mode, the conversion device opens the neutral point of the multi-phase windings and connects the corresponding phase windings of the two groups of multi-phase windings to each other.

7. The AC charging and discharging system for a vehicle according to claim 5, characterized in that: In the driving mode, the conversion device connects the neutral points of the two groups of multi-phase windings to each other.

8. The AC charging and discharging system for a vehicle according to claim 6, characterized in that: In the AC charging and discharging mode, the conversion device connects the same-named ends of the corresponding phases of the two groups of multi-phase windings to each other.

9. The AC charging and discharging system for a vehicle according to any one of claims 6 to 8, characterized in that: The conversion device comprises a plurality of switches, and the plurality of switches are respectively arranged between the windings of corresponding phases of the two groups of the multi-phase windings and between adjacent phases of each group of the multi-phase windings.

10. A vehicle, characterized in that: A battery heating system for a vehicle comprising any one of claims 1-9.

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