Electric Vehicle Charging Control Method, Motor Controller and Electric Vehicle Charging Circuit

Abstract

The present application provides an electric vehicle charging control method, a motor controller and an electric vehicle charging circuit. Among them, the positive pole of the DC charging port of the electric vehicle is connected to the connection point corresponding to at least one phase of the motor winding in the electric vehicle and the corresponding phase of the AC side of the motor controller through at least one switching switch. Furthermore, the motor winding without a center tap can be reused, and combined with the motor controller to achieve the charging of the electric vehicle with a high-voltage platform. Moreover, before the electric vehicle enters the charging state, the rotor position angle of the motor in the electric vehicle is adjusted to a preset angle range; after the electric vehicle enters the charging state, the main circuit of the motor controller is controlled to act, so that each winding in the motor flows through the corresponding current according to a preset current distribution system; and the preset angle range is the angle range in which the torque of the motor is less than a preset threshold under the preset current distribution system, thereby ensuring that the torque of the motor during the charging state will not cause the vehicle to move forward.

Description

Technical Field

[0001] This application relates to the technical field of electric vehicles, and particularly to an electric vehicle charging control method, a motor controller, and an electric vehicle charging circuit. Background Art

[0002] Currently, the voltage platform of electric vehicle power batteries is changing from 400V to 800V. Under the original vehicle architecture, the DC fast charging port is directly connected to the power battery. Therefore, the original 400V DC fast charging pile cannot realize the charging function for electric vehicles with an 800V voltage platform, which limits the usage range of electric vehicles with an 800V high-voltage platform. Summary of the Invention

[0003] In view of this, this application provides an electric vehicle charging control method, a motor controller, and an electric vehicle charging circuit to reuse the motor windings without a center tap to achieve charging for electric vehicles with a high-voltage platform.

[0004] To achieve the above object, this application provides the following technical solutions:

[0005] The first aspect of this application provides an electric vehicle charging control method, including:

[0006] Before the electric vehicle enters the charging state, adjust the rotor position angle of the motor in the electric vehicle to a preset angle range;

[0007] After the electric vehicle enters the charging state, control the main circuit of the motor controller in the electric vehicle to act, so that each winding in the motor flows through the corresponding current according to a preset current distribution system;

[0008] Wherein, the preset angle range is an angle range in which the torque of the motor is less than a preset threshold under the preset current distribution system.

[0009] Optionally, adjusting the rotor position angle of the motor in the electric vehicle to a preset angle range includes:

[0010] Obtain the rotor position angle;

[0011] Determine the rotor position angle command value; the rotor position angle command value is in the same direction or the opposite direction as the current vector of the motor under the preset current distribution system;

[0012] Adjust the rotor position angle with the rotor position angle command value as a reference.

[0013] Optionally, after adjusting the rotor position angle with the rotor position angle command value as a reference, it further includes:

[0014] Obtain the rotor position angle again;

[0015] Determine whether the current value of the rotor position angle is within the preset angle range; the preset angle range includes the rotor position angle command value;

[0016] If so, complete the adjustment of the rotor position angle.

[0017] Optionally, obtaining the rotor position angle includes:

[0018] Detect the motor position signal output by the position sensor in the motor;

[0019] Verify the authenticity of the motor position signal;

[0020] After the authenticity of the motor position signal passes the verification, determine the rotor position angle based on it.

[0021] Optionally, determining the rotor position angle command value includes:

[0022] Determine the angle difference between the rotor position angle and the current vector in the same direction, and the angle difference between the rotor position angle and the current vector in the opposite direction;

[0023] When the angle difference between the rotor position angle and the current vector in the same direction is smaller, determine the rotor position angle command value as the angle in the same direction as the current vector;

[0024] When the angle difference between the rotor position angle and the current vector in the opposite direction is smaller, determine the rotor position angle command value as the angle in the opposite direction as the current vector.

[0025] Optionally, adjusting the rotor position angle with reference to the rotor position angle command value includes:

[0026] Compare the rotor position angle command value and the rotor position angle through the position loop to obtain a torque command;

[0027] According to the torque command, determine the current vector command through the motor torque ammeter;

[0028] Control the current vector command and the current vector through the current loop to obtain a three-phase voltage command;

[0029] Control the main circuit to operate in the inverter mode according to the three-phase voltage command to change the rotor position angle.

[0030] Optionally, the rotor position angle command value is the central value within the preset angle range.

[0031] Optionally, after determining whether the current value of the rotor position angle is within the preset angle range, it further includes:

[0032] If the current value of the rotor position angle is not within the preset angle range, the electric vehicle is prohibited from entering the charging state, and information is reported to the vehicle controller.

[0033] Optionally, for the DC charging port of the electric vehicle, its positive pole is connected to the connection point of at least one phase of the motor winding in the electric vehicle and the corresponding phase on the AC side of the motor controller through at least one switching switch; when the electric vehicle enters the charging state, it includes:

[0034] The switching switch is controlled to close;

[0035] The main circuit receives the electric energy of the DC charging port through each winding in the motor;

[0036] The main circuit charges the power battery of the electric vehicle.

[0037] Optionally, for the DC charging port of the electric vehicle, its positive pole is connected to the connection point of at least one phase of the motor winding in the electric vehicle and the corresponding phase on the AC side of the motor controller through at least one switching switch; controlling the operation of the main circuit of the motor controller includes:

[0038] Controlling the arm connected to the switching switch in the main circuit to turn off;

[0039] Controlling at least one other phase arm in the main circuit to operate in an interleaved parallel boost mode.

[0040] Optionally, before adjusting the rotor position angle of the motor in the electric vehicle to the preset angle range, it further includes:

[0041] Receiving a charging instruction sent by the vehicle controller.

[0042] The second aspect of the present application provides a motor controller, including: a main circuit and a controller;

[0043] The DC side of the main circuit, as the DC side of the motor controller, is used to connect the power battery of the electric vehicle; and the DC side of the main circuit and the DC charging port of the electric vehicle share the negative pole;

[0044] The AC side of the main circuit, as the AC side of the motor controller, is used to connect each winding of the motor of the electric vehicle;

[0045] At least one phase of the AC side of the main circuit is connected to the positive pole of the DC charging port through a corresponding switching switch;

[0046] The main circuit is controlled by the controller, and the controller is used to execute the electric vehicle charging control method according to any one of the above first aspects.

[0047] Optionally, the main circuit includes: a three-phase full-bridge inverter and a DC capacitor connected between the positive and negative poles of its DC side.

[0048] A third aspect of the present application provides an electric vehicle charging circuit, which is characterized by including: at least one switching switch, the motor of the electric vehicle, and the motor controller according to any one of the above second aspects;

[0049] The DC side of the motor controller is used to connect to the power battery of the electric vehicle; the DC side of the motor controller and the DC charging port of the electric vehicle share the same negative pole;

[0050] The AC side of the motor controller is used to connect to each winding of the motor; and at least one phase of the AC side of the motor controller is connected to the positive pole of the DC charging port through a corresponding switching switch.

[0051] Optionally, the number of the switching switches is one;

[0052] Any one phase of the AC side of the motor controller is connected to the positive pole of the DC charging port through the switching switch.

[0053] Optionally, it further includes: a pre-charge circuit arranged between the DC side of the motor controller and the power battery.

[0054] The electric vehicle charging control method provided by the present application first adjusts the rotor position angle of the motor in the electric vehicle to a preset angle range before the electric vehicle enters the charging state; then, after the electric vehicle enters the charging state, it controls the main circuit of the motor controller to act so that each winding in the motor respectively passes through corresponding currents according to a preset current distribution system; moreover, the preset angle range is an angle range in which the torque of the motor is less than a preset threshold under the preset current distribution system. Therefore, even when the vector sum of the currents in each winding of the motor is not zero during the charging process, it can ensure that the torque of the motor during the charging state will not cause the vehicle to move forward. Furthermore, the motor windings without a center tap can be reused, and combined with the above control of the motor controller, the charging of the electric vehicle with a high-voltage platform can be realized. Description of the Drawings

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the provided drawings.

[0056] Figure 1aSchematic diagram of the structure of the electric vehicle charging circuit provided by the embodiment of the present application;

[0057] Figure 1b Schematic diagram of the current path of the electric vehicle charging circuit provided by the embodiment of the present application in the charging state;

[0058] Figure 2 、 Figure 3a and Figure 3b Three current vector diagrams of the motor in the charging state provided by the embodiment of the present application respectively;

[0059] Figure 4 Current vector and flux linkage vector diagram of the motor in the charging state provided by the embodiment of the present application;

[0060] Figure 5 、 Figure 6 and Figure 7 Three flowcharts of the electric vehicle charging control method provided by the embodiment of the present application respectively;

[0061] Figure 8 Control block diagram of the rotor position angle provided by the embodiment of the present application. Detailed implementation manners

[0062] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0063] In the present application, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0064] The present application provides an electric vehicle charging control method to reuse the motor winding without a center tap to achieve the charging of electric vehicles on a high-voltage platform.

[0065] As Figure 1aAs shown, the DC charging port 30 of the electric vehicle shares the negative electrode with the motor controller 101, and the positive electrode of the DC charging port 30 is connected to the connection point between at least one phase of the motor winding in the electric vehicle and the corresponding phase on the AC side of the motor controller 101 through at least one switching switch 103; Figure 1a Taking a switching switch 103 connected to phase A on the AC side of the motor controller 101 as an example for display. In actual application, switching switches connected to the positive electrode of the DC charging port 30 can also be respectively arranged on any two or three phases on the AC side of the motor controller 101. No specific limitation is made here. As long as when charging the power battery 20 of the electric vehicle, one or two switching switches are closed.

[0066] Taking Figure 1a the shown situation as an example for explanation. When the electric vehicle is working normally, the switching switch 103 is in the off state, and the power battery 20 drives the motor 102 to rotate through the motor controller 101; at this time, alternating current flows through each winding in the motor 102, and the motor controller 101 is in the driving state. Its working mode and control method can refer to the prior art and will not be elaborated here. When the electric vehicle needs to be charged, the switching switch 103 is in the closed state, and all the switching tubes in the bridge arm connected to the A-phase winding LA in the motor controller 101 are kept off; the external electric energy received by the DC charging port 30, after passing through the A-phase winding LA in the motor 102, then passes through the B-phase winding LB and the C-phase winding LC and the corresponding phase bridge arm in the motor controller 101 to form an interleaved parallel BOOST boost circuit, and then boosts and charges the power battery 20. Its current path is as shown by the arrow in Figure 1b . At this time, direct current flows through each winding in the motor 102, and the motor controller 101 is in the charging state and is controlled according to the control method of the interleaved parallel boost circuit. Specifically, according to the voltage command signal sent by the vehicle controller, the input voltage of the DC charging port 30 is boosted to the charging voltage required by the power battery 20; among them, the input voltage of the DC charging port 30 can be up to about 450V at most, and the charging voltage required by the power battery 20 can be about 800V.

[0067] It should be noted that the above structure can boost the external 400V charging electric energy to the required voltage and then charge the power battery 20. However, during the charging process, since the vector sum of the currents in the three-phase windings (i.e., LA, LB, and LC) is not zero, a large motor torque may be generated, which may then push the vehicle forward and cause a safety hazard. Although the vehicle can be parked by the cooperation of the braking system, such a solution requires the cooperation of the brakes, has high requirements for the vehicle system, and there are still relatively large safety hazards in the braking and parking itself, and the motor torque caused by charging is not eliminated at the source.

[0068] Therefore, this embodiment provides an electric vehicle charging control method. Considering the actual application of electric vehicles, when they are in the charging state, the vector diagram of the three-phase current in the motor is as follows Figure 2 shown, where is the A-phase current vector, is the B-phase current vector, is the C-phase current vector. From Figure 1b it can be seen that since the three-phase currents in the charging state are all direct currents, the magnitudes of the three-phase currents satisfy i a = i b + i c . Therefore, the synthesized three-phase current vector is the shown in the figure. This synthesized vector is also the current vector of the motor, and its direction is related to the magnitude distribution of the B-phase and C-phase currents. If the B-phase and C-phase currents are evenly distributed, i.e., i b = i c , then the direction of the current vector is opposite to the positive direction of the A-phase, and its magnitude is 1.5 times that of . The current vector angle θi = 180°, as Figure 2 shown. If in the extreme case where the magnitude of the B-phase current is equal to that of the A-phase current and the C-phase current is zero, then the synthesized current vector has the direction as Figure 3a shown, and the corresponding current vector angle θi = 210°. If in another extreme case, the magnitude of the C-phase current is equal to that of the A-phase current and the B-phase current is zero, then the synthesized current vector has the direction as Figure 3b shown, and the corresponding current vector angle θi = 150°.

[0069] In addition, since the torque of the permanent magnet synchronous motor is the cross product of the current vector and the flux linkage vector , and the direction of the flux linkage vector is related to the rotor position angle θr of the motor, as Figure 4 shown. When the current vector and the flux linkage vector are in the same or opposite directions, their cross product result is zero, and the corresponding motor torque during charging is zero. When the current vector and the flux linkage vector are orthogonal, the motor torque during charging is the largest. Therefore, the electric vehicle charging control method provided by this embodiment, as Figure 5 shown, specifically includes: step S101 executed before the electric vehicle enters the charging state, and step S102 executed after the electric vehicle enters the charging state.

[0070] S101. Adjust the rotor position angle of the motor in the electric vehicle to a preset angle range.

[0071] The preset angle range is the angle range that makes the torque of the motor less than the preset threshold under the preset current distribution system. Specifically, under the preset current distribution system, the motor can reach the preset current vector to obtain the corresponding current vector angle θi; there are two preset angle ranges for the rotor position angle θr, one is the first range including the current vector angle θi, and the other is the second range including θi - 180°. Preferably, the first range has θi as the central value, and the second range has θi - 180° as the central value; if the rotor position angle θr is adjusted to the first range, the corresponding flux linkage vector will be closer to 0° in direction to the current vector ; and if the rotor position angle θr is adjusted to the second range, the corresponding flux linkage vector will be closer to 180° in direction to the current vector .

[0072] S102. Control the main circuit of the motor controller to act so that each winding in the motor flows through the corresponding current according to the preset current distribution system.

[0073] Through step S101, the position of the vehicle can be adjusted before charging, so as to control the rotor position angle θr of the motor; and through step S102, the currents of each winding in the motor during charging can be synthesized into a preset current vector so that the flux linkage vector is as close as possible to 0° or 180° in direction to the preset current vector , making the cross product result of the current vector and the flux linkage vector less than the preset threshold, such as close to zero, to reduce the motor torque.

[0074] For the electric vehicle charging control method provided in this embodiment, before starting charging, the rotor position angle of the motor is adjusted through the control of the motor controller, so that the rotor position angle is within a suitable range before entering the charging state. In this way, after entering the charging process, according to the preset charging current distribution scheme, no additional control adjustment is required, and the motor torque can be made close to zero. Even when the sum of the current vectors of each winding in the motor is not zero during the charging process, it can be ensured that the torque of the motor in the charging state will not cause the vehicle to move forward, improving safety. Therefore, when this method is applied to Figure 1a the circuit structure shown, the motor windings without a center tap can be reused, and combined with the above control process of the motor controller, the charging of the electric vehicle on the high-voltage platform can be realized.

[0075] Based on the previous embodiment, in the electric vehicle charging control method, in step S101, the rotor position angle of the motor in the electric vehicle is adjusted to a preset angle range, specifically as follows Figure 6 shown in

[0076] S201. Obtain the rotor position angle.

[0077] This step S201 may specifically include:

[0078] (1). Detect the motor position signal output by the position sensor in the motor.

[0079] (2). Verify the authenticity of the motor position signal.

[0080] (3). After the authenticity of the motor position signal passes the verification, determine the rotor position angle according to it.

[0081] After step S201 is completed, step S202 can be executed.

[0082] S202. Determine the command value of the rotor position angle.

[0083] The command value of the rotor position angle is in the same direction or the opposite direction as the current vector of the motor under the preset current distribution system; when the command value of the rotor position angle is in the same direction as the current vector of the motor under the preset current distribution system, the preset angle range is the above-mentioned first range; when the command value of the rotor position angle is in the opposite direction as the current vector of the motor under the preset current distribution system, the preset angle range is the above-mentioned second range. Preferably, the command value of the rotor position angle is the central value within the preset angle range, that is, the first range is centered on θi, and the second range is centered on θi - 180°. The upper and lower limit values of the preset angle range only need to ensure that the torque of the motor during charging will not cause the vehicle to move forward, and no specific limitations are made here. It depends on the specific application environment and is within the protection scope of this application.

[0084] The execution of this step S202 can be determined according to the relationship between the rotor position angle θr and the current vector angle θi under the preset current distribution system, that is: if the rotor position angle θr is closer to the current vector angle θi, then select the first range where the magnetic flux vector is close to the same direction as the current vector ; if the rotor position angle θr is closer to θi - 180°, then select the second range where the magnetic flux vector is close to the opposite direction as the current vector ; this can make the execution process of step S203 shorter and faster, and the moving distance of the vehicle is the shortest.

[0085] At this time, this step S202 may specifically include:

[0086] (1) Determine the angle difference between the rotor position angle and the current vector in the same direction, and the angle difference between the rotor position angle and the current vector in the opposite direction.

[0087] (2) When the angle difference between the rotor position angle and the current vector in the same direction is smaller, determine the rotor position angle command value as the angle in the same direction as the current vector.

[0088] (3) When the angle difference between the rotor position angle and the current vector in the opposite direction is smaller, determine the rotor position angle command value as the angle in the opposite direction as the current vector.

[0089] In practical applications, any range can also be specified as the execution target of this step S202, not limited to the above method. As long as the motor torque can be reduced, it is within the protection scope of this application.

[0090] After step S202 is completed, step S203 can be executed.

[0091] S203: Adjust the rotor position angle with reference to the rotor position angle command value.

[0092] This step S203 may specifically include:

[0093] (1) Compare the rotor position angle command value and the rotor position angle through the position loop to obtain the torque command.

[0094] (2) According to the torque command, determine the current vector command through the motor torque ammeter.

[0095] (3) Control the current vector command and the current vector through the current loop to obtain the three-phase voltage command.

[0096] (4) Control the main circuit to operate in the inverter mode according to the three-phase voltage command to change the rotor position angle.

[0097] Further, after step S203: Adjust the rotor position angle with reference to the rotor position angle command value, the following may also be included in this step S101 Figure 7 as shown in:

[0098] S204: Obtain the rotor position angle again.

[0099] S205: Determine whether the current value of the rotor position angle is within a preset angle range.

[0100] This preset angle range includes the rotor position angle command value.

[0101] If the current value of the rotor position angle is within the preset angle range, execute step S206. If the current value of the rotor position angle is not within the preset angle range, execute step S207.

[0102] S206. Complete the adjustment of the rotor position angle.

[0103] S207. Prohibit the electric vehicle from entering the charging state and report information to the vehicle controller.

[0104] In practical applications, when the motor controller receives the charging instruction sent by the vehicle controller, it can start to execute the zero-torque control before charging in step S101. The following introduces a preferred solution for the execution process of this step S101:

[0105] (1) Detect the motor position signal of the position sensor and verify the authenticity of the signal to obtain the motor rotor position angle θr. Judge the magnitude of the rotor position angle θr.

[0106] (2) According to the magnitude of the rotor position angle θr and the preset current control scheme, set the rotor position angle command value θr_rdf. There are various ways to set this command value, and the finally set command value needs to satisfy: θr_rdf = θi or θr_rdf = θi – 180°.

[0107] In the preferred method given above, the forward and backward movement of the vehicle during the control process can be minimized, that is: when θr < θi - 90° or θr > θi - 270°, that is, when the angle difference between the rotor position angle and the current vector is smaller in the reverse direction, set the command value θr_rdf to θi – 180°; and when θr > θi - 90° and θr < θi - 270°, that is, when the angle difference between the rotor position angle and the current vector is smaller in the same direction, set the command value θr_rdf to θi.

[0108] (3) Perform rotor position control according to the rotor position angle command value, and control the actual position angle of the rotor to track the rotor position angle command value. During the rotor position control process, the vehicle will have a small amount of forward and backward movement. There are various control methods for rotor position control, Figure 8 which is one of the control block diagrams for the rotor position angle control given above, but not limited to this.

[0109] See Figure 8 , the rotor position command value θr_rdf and the actual rotor position angle θr are compared in the position loop to output the torque command Te ref , and then the current vector command can be obtained through the motor torque ammeter The actual current of the motor stator (i.e., the above-mentioned current vector ) and the current vector command pass through the current loop control to obtain the three-phase voltage Take it as the three-phase voltage command and output it to the motor controller and the motor to realize the control of the motor position.

[0110] (4) After completing the above rotor position control, verify the actual rotor position to ensure the authenticity of the rotor position at this moment.

[0111] (5) According to the result of the rotor position verification, judge the control result. When the error between the actual rotor position angle θr and the rotor position angle command value θr_rdf is greater than or equal to the error threshold err, it indicates that the current value of the rotor position angle is not within the preset angle range, and the rotor position control fails. At this time, a large torque will be generated in the charging motor, causing unexpected acceleration of the vehicle. Therefore, entering the charging state is prohibited and information is reported to the vehicle controller. When the error between the actual rotor position angle θr and the rotor position angle command value θr_rdf is less than or equal to the error threshold err, it indicates that the current value of the rotor position angle is within the preset angle range, that is, the rotor position control is successful. At this time, the torque generated in the charging motor is small enough not to move the vehicle. The specific value of this error threshold err can be calculated inversely according to the minimum torque that can move the vehicle, the maximum charging current, and the motor parameters. No specific limitation is made here, and it can be determined according to its application environment, all within the protection scope of this application.

[0112] Entering the charging state specifically includes: the switching switch is controlled to close, the main circuit receives the electric energy of the DC charging port through each winding in the motor, and the main circuit charges the power battery of the electric vehicle. Moreover, controlling the main circuit of the motor controller in step S102 includes: controlling the arm connected to the switching switch in the main circuit to turn off; and controlling at least one other arm in the main circuit to operate in an interleaved parallel boost mode. The specific control process can refer to the previous embodiment and will not be elaborated here.

[0113] After entering the charging state control mode, the motor controller controls according to the control method of the interleaved parallel boost circuit, receives the voltage command signal of the vehicle controller, and boosts the input voltage (about 450V at most) of the DC charging port to the charging voltage (about 800V at most) required by the 800V power battery. The specific method will not be repeated either.

[0114] Another embodiment of this application also provides a motor controller, which specifically includes: a main circuit (such as Figure 1a the circuit within the dotted line box shown in 101) and a controller (not shown).

[0115] See Figure 1a , the DC side of this main circuit, as the DC side of the motor controller 101, is used to connect to the power battery 20 of the electric vehicle; and the DC side of the main circuit and the DC charging port 30 of the electric vehicle share the negative electrode.

[0116] The AC side of the main circuit, as the AC side of the motor controller 101, is used to connect the windings of the motor 102 of the electric vehicle.

[0117] Specifically, the main circuit may include Figure 1a As shown by the dashed box in 101: a three-phase full-bridge inverter, and a DC capacitor connected between the positive and negative poles of its DC side. However, it is not limited thereto, and any circuit capable of implementing the driving and charging functions described in the above embodiments is within the protection scope of this application.

[0118] At least one phase of the AC side of the main circuit is connected to the positive pole of the DC charging port 30 through a corresponding switching switch 103 ( Figure 1a One is shown as an example in).

[0119] The main circuit is controlled by a controller, and the controller is used to execute the electric vehicle charging control method described in any of the above embodiments. For the process and principle of the electric vehicle charging control method, refer to the above embodiments, and details will not be repeated here.

[0120] The motor controller provided in this embodiment can be combined with a motor winding without a center tap to achieve charging for electric vehicles on a high-voltage platform. Moreover, its controller adjusts the rotor position angle before charging to achieve torque control that is as close to zero as possible during the charging process, ensuring vehicle safety during charging and avoiding unexpected vehicle acceleration caused by torque generation during charging, greatly enhancing the safety of this solution.

[0121] Another embodiment of this application also provides an electric vehicle charging circuit, as shown in the structure within the dashed box 10 in Figure 1a Specifically, it includes: at least one switching switch 103, the motor 102 of the electric vehicle, and the motor controller 101 as described in the above embodiments; where:

[0122] The DC side of the motor controller 101 is used to connect to the power battery 20 of the electric vehicle; the DC side of the motor controller 101 and the DC charging port 30 of the electric vehicle share the negative pole.

[0123] The AC side of the motor controller 101 is used to connect to the windings of the motor 102; and at least one phase of the AC side of the motor controller 101 is connected to the positive pole of the DC charging port 30 through a corresponding switching switch 103 ( Figure 1a One is shown as an example in).

[0124] In practical applications, the number of the switching switches 103 can be one. In this case, any one phase of the AC side of the motor controller 101 is connected to the positive pole of the DC charging port 30 through the switching switch 103. Alternatively, switching switches for connecting to the positive pole of the DC charging port 30 can also be respectively arranged on any two or three phases of the AC side of the motor controller 101. No specific limitation is made here. As long as one or two switching switches are closed when the power battery 20 needs to be charged.

[0125] In addition, the electric vehicle charging circuit may further include: a pre-charge circuit arranged between the DC side of the motor controller 101 and the power battery 20. The specific implementation structure and working principle of the pre-charge circuit are the same as those of the prior art and will not be elaborated here one by one.

[0126] The electric vehicle charging circuit provided in this embodiment can realize the multiplexing boost of the motor and the motor controller without a motor with a center tap. Compared with the prior art solution using a motor with a center tap, the application scope of this embodiment is wider and the design of the motor is simpler. Moreover, by adopting the above-mentioned electric vehicle charging control method, this circuit can also solve the safety problem that there is a large motor torque during charging when applying this topology, which may cause unexpected vehicle acceleration.

[0127] For the same or similar parts among the various embodiments in this specification, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiments, since they are basically similar to the method embodiments, the description is relatively simple. For the relevant parts, reference can be made to the partial description of the method embodiments. The systems and system embodiments described above are only illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative work.

[0128] Those skilled in the art can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in this article can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0129] Regarding the above description of the disclosed embodiments, the features described in each embodiment in this specification can be replaced or combined with each other, enabling those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electric vehicle charging control method, characterized in that, it includes: Before the electric vehicle enters the charging state, adjust the rotor position angle of the motor in the electric vehicle to a preset angle range based on the rotor position angle command value; The rotor position angle command value is in the same direction or the opposite direction as the current vector of the motor under the preset current distribution system; After the electric vehicle enters the charging state, control the main circuit of the motor controller in the electric vehicle to act, so that each winding in the motor flows through the corresponding current according to the preset current distribution system; Wherein, the preset angle range is the angle range in which the torque of the motor is less than a preset threshold under the preset current distribution system; Wherein, determining the rotor position angle command value includes: Determine the difference in the angle between the rotor position angle and the current vector in the same direction, and the difference in the angle between the rotor position angle and the current vector in the opposite direction; When the difference in the angle between the rotor position angle and the current vector in the same direction is smaller, determine the rotor position angle command value as the angle in the same direction as the current vector; When the difference in the angle between the rotor position angle and the current vector in the opposite direction is smaller, determine the rotor position angle command value as the angle in the opposite direction as the current vector.

2. The electric vehicle charging control method according to claim 1, characterized in that, Adjusting the rotor position angle of the motor in the electric vehicle to a preset angle range includes: Obtain the rotor position angle; Determine the rotor position angle command value; Taking the rotor position angle command value as a reference, adjust the rotor position angle.

3. The electric vehicle charging control method according to claim 2, characterized in that, After adjusting the rotor position angle with the rotor position angle command value as a reference, it further includes: Obtain the rotor position angle again; Judge whether the current value of the rotor position angle is within the preset angle range; the preset angle range includes the rotor position angle command value; If so, complete the adjustment of the rotor position angle.

4. The electric vehicle charging control method according to claim 2, characterized in that, Obtaining the rotor position angle includes: Detect the motor position signal output by the position sensor in the motor; Verify the authenticity of the motor position signal; After the authenticity of the motor position signal passes the verification, determine the rotor position angle according to it.

5. The electric vehicle charging control method according to claim 2, characterized in that, Adjusting the rotor position angle with the rotor position angle command value as a reference includes: Compare the rotor position angle command value and the rotor position angle through a position loop to obtain a torque command; According to the torque command, determine the current vector command through a motor torque ammeter; Control the current vector command and the current vector through a current loop to obtain a three-phase voltage command; Control the main circuit to operate in an inverter mode according to the three-phase voltage command to change the rotor position angle.

6. The electric vehicle charging control method according to claim 3, characterized in that, The rotor position angle command value is the central value within the preset angle range.

7. The electric vehicle charging control method according to claim 3, characterized in that, after determining whether the current value of the rotor position angle is within the preset angle range, it further includes: if the current value of the rotor position angle is not within the preset angle range, the electric vehicle is prohibited from entering the charging state, and information is reported to the vehicle controller.

8. The electric vehicle charging control method according to any one of claims 1 to 7, characterized in that, for the DC charging port of the electric vehicle, its positive pole is connected to the connection point between at least one phase of the motor winding in the electric vehicle and the corresponding phase on the AC side of the motor controller through at least one switching switch; for the electric vehicle to enter the charging state, it includes: the switching switch is controlled to close; the main circuit receives the electric energy of the DC charging port through each winding in the motor; the main circuit charges the power battery of the electric vehicle.

9. The electric vehicle charging control method according to any one of claims 1 to 7, characterized in that, for the DC charging port of the electric vehicle, its positive pole is connected to the connection point between at least one phase of the motor winding in the electric vehicle and the corresponding phase on the AC side of the motor controller through at least one switching switch; controlling the operation of the main circuit of the motor controller includes: controlling the arm connected to the switching switch in the main circuit to turn off; controlling at least one other phase arm in the main circuit to operate in an interleaved parallel boost mode.

10. The electric vehicle charging control method according to any one of claims 1 to 7, characterized in that, before adjusting the rotor position angle of the motor in the electric vehicle to the preset angle range, it further includes: receiving a charging instruction sent by the vehicle controller.

11. A motor controller, characterized in that, it includes: a main circuit and a controller; the DC side of the main circuit, as the DC side of the motor controller, is used to connect the power battery of the electric vehicle; and the DC side of the main circuit and the DC charging port of the electric vehicle share the negative pole; the AC side of the main circuit, as the AC side of the motor controller, is used to connect each winding of the motor of the electric vehicle; at least one phase of the AC side of the main circuit is connected to the positive pole of the DC charging port through a corresponding switching switch; the main circuit is controlled by the controller, and the controller is used to execute the electric vehicle charging control method according to any one of claims 1 to 10.

12. The motor controller according to claim 11, characterized in that, the main circuit includes: a three-phase full-bridge inverter and a DC capacitor connected between the positive and negative poles of its DC side.

13. An electric vehicle charging circuit, characterized in that, it includes: at least one switching switch, the motor of the electric vehicle and the motor controller according to claim 11 or 12; the DC side of the motor controller is used to connect the power battery of the electric vehicle; the DC side of the motor controller and the DC charging port of the electric vehicle share the negative pole; The AC side of the motor controller is used to connect each winding of the motor; and at least one phase of the AC side of the motor controller is connected to the positive pole of the DC charging port through a corresponding switching switch.

14. The electric vehicle charging circuit according to claim 13, characterized in that the number of the switching switches is one; any phase of the AC side of the motor controller is connected to the positive pole of the DC charging port through the switching switch.

15. The electric vehicle charging circuit according to claim 13 or 14, characterized in that further comprising: a pre-charge circuit disposed between the DC side of the motor controller and the power battery.

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