New energy automobile charging device and charging method
By using charging devices of rotary transformers, three-phase inverters and triangular motors in new energy vehicles and controlling the inverter switch tubes by using magnetic flux angles, the problem of inability to compatible with low-voltage charging piles in the prior art is solved, and the effect of reducing costs and improving charging safety is achieved.
Patent Information
- Application Number
- CN202311804159.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-25
- Publication Date
- 2025-06-27
AI Technical Summary
Existing new energy vehicles cannot be compatible with charging piles mainly based on 500V or 750V, and require an additional boost system to increase hardware cost and complexity.
The charging device adopts a rotary transformer, a three-phase inverter and a triangular motor, and the windings of the three-phase motor are connected in series and parallel, and the inverter switch tube is controlled by the magnetic flux angle to achieve boost charging.
It reduces space and costs, is compatible with charging stations with lower voltage, reduces torque during charging, and improves charging safety and experience.
Smart Images
Figure CN120207137A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field, and particularly to a charging device and a charging method for new energy vehicles. Background Art
[0002] In order to improve the charging experience of new energy vehicles and shorten the charging time, currently, 800V high-voltage models cannot be compatible with charging piles mainly based on 500V or 750V. To charge an 800V high-voltage model, an additional boost system is required to use a 500V or 750V low-voltage charging pile.
[0003] Currently, there are mainly the following two technical solutions to use a low-voltage charging pile.
[0004] The first one: An additional DCDC device is added to achieve boost fast charging from the low-voltage charging pile end to the battery end. However, this solution will bring additional hardware costs, increase the complexity of the high-voltage and low-voltage wiring harness layout of the whole vehicle, and the limited space poses a great challenge to the integration of the whole vehicle.
[0005] The second one: Reuse the existing electric drive system structure and utilize the energy storage characteristics of the three-phase windings of the motor to achieve a boost strategy. Different forms of motor windings vary greatly when reusing the electric drive system structure to complete the boost charging function. Among them, the Y-type motor winding is more common, but the driving energy of the Y-type motor is lower and the power density is lower. Summary of the Invention
[0006] In view of this, this application provides a charging device and a charging method for new energy vehicles, which can use a low-voltage charging pile to charge a high-voltage power battery pack and reuse the delta motor winding to complete the boost.
[0007] This application provides a charging device for new energy vehicles, including: a resolver, a three-phase inverter, a three-phase motor, and a controller; the three-phase motor includes three-phase windings of U, V, and W, and the three-phase windings are delta-connected; the three-phase windings are respectively connected to the midpoints of the three-phase bridge arms of the three-phase inverter;
[0008] The resolver is used to measure the resolver angle of the three-phase motor;
[0009] The controller is used to obtain the flux linkage angle from the resolver angle. When charging the power battery pack, the first-phase winding and the second-phase winding of the three-phase motor are connected in series and then connected in parallel with the third-phase winding, and the second-phase bridge arm switch tube and the third-phase bridge arm switch tube of the inverter are controlled according to the comparison results of the current of the second phase and the current of the third phase of the three-phase motor respectively based on the magnetic circuit angle.
[0010] A possible implementation manner is that the first-phase winding is the W-phase winding, the second-phase winding is the U-phase winding, and the third-phase winding is the V-phase winding;
[0011] When the flux linkage angle is within the range of 0 to 120 degrees, if the flux linkage is in the same direction as the current in phase U, the controller controls the switching tubes of the phase U bridge arm of the three-phase inverter to perform switching actions, and the switching tubes of the phase V bridge arm of the three-phase inverter are turned off; if the flux linkage is in the same direction as the current in phase V, the controller controls the switching tubes of the phase V of the three-phase inverter to perform switching actions, and the switching tubes of the phase U of the three-phase inverter are turned off; if the flux linkage is in the same direction as the synthesis center line of the current vectors of phases U and V, the current commands of phases U and V are evenly divided with the same magnitude, and the drive signals of the switching tubes of phases U and V of the three-phase inverter are phase-shifted by 180 degrees.
[0012] A possible implementation method is that when the flux linkage is not in the same direction as the current in phase U, nor in the same direction as the current in phase V, nor in the same direction as the synthesis center line of the current vectors of phases U and V, the distribution of the current in phase U and the current in phase V is controlled as follows:
[0013] θ is the included angle between the flux linkage angle and phase U, and θ is greater than 0 and less than 120 degrees.
[0014] A possible implementation method is that when the flux linkage angle is within the range of 120 degrees to 180 degrees, the switching tubes of the bridge arm of the phase where the flux linkage is closest are selected in phases U and V to perform switching actions, and the switching tubes of the other bridge arm are turned off.
[0015] A possible implementation method is that the first-phase winding is the W-phase winding, the second-phase winding is the U-phase winding, and the third-phase winding is the V-phase winding;
[0016] When the flux linkage angle is within the range of 180 to 270 degrees, if the flux linkage is in the opposite direction to the current in U, the controller controls the switching tubes of the phase U bridge arm of the three-phase inverter to perform switching actions, and the switching tubes of the phase V of the three-phase inverter are turned off; if the flux linkage is in the opposite direction to the current in V, the controller controls the switching tubes of the phase V bridge arm of the three-phase inverter to perform switching actions, and the switching tubes of the phase U of the three-phase inverter are turned off; if the flux linkage is in the same direction as the synthesis center line of the current vectors of phases U and V, the current commands of phases U and V are evenly divided with the same magnitude, and the drive signals of the switching tubes of phases U and V of the three-phase inverter are phase-shifted by 180 degrees.
[0017] A possible implementation method is that when the flux linkage angle is within the range of 270 degrees to 360 degrees, the switching tubes of the bridge arm of the phase where the flux linkage is closest are selected in phases U and V to perform switching actions, and the switching tubes of the other bridge arm are turned off.
[0018] A possible implementation method is that when the flux linkage is not in the opposite direction to the current in phase U, nor in the opposite direction to the current in phase V, nor in the opposite direction to the synthesis center line of the current vectors of phases U and V, the distribution of the current in phase U and the current in phase V is controlled as follows:
[0019] θ is the angle between the magnetic flux angle and phase U, where θ is greater than 180 and less than 270 degrees.
[0020] This application also provides a charging method for a new energy vehicle. The new energy vehicle includes: a resolver, a three-phase inverter, and a three-phase motor; the three-phase motor includes three-phase windings U, V, and W, and the three-phase windings are connected in a delta configuration; the three-phase windings are respectively connected to the midpoints of the three-phase bridge arms of the three-phase inverter.
[0021] The method includes:
[0022] Obtaining the magnetic flux angle from the resolver angle;
[0023] When charging the power battery pack, the first-phase winding and the second-phase winding of the three-phase motor are connected in series and then connected in parallel with the third-phase winding, and the switching tubes of the second-phase bridge arm and the third-phase bridge arm of the inverter are controlled according to the comparison results of the magnetic flux angle with the currents of the second phase and the third phase of the three-phase motor respectively.
[0024] In a possible implementation, the first-phase winding is the W-phase winding, the second-phase winding is the U-phase winding, and the third-phase winding is the V-phase winding; controlling the switching tubes of the second-phase bridge arm and the third-phase bridge arm of the inverter according to the comparison results of the magnetic flux angle with the currents of the second phase and the third phase of the three-phase motor respectively specifically includes:
[0025] When the magnetic flux angle is in the range of 0 to 120 degrees, if the magnetic flux is in the same direction as the current of phase U, the controller controls the switching tube of the U-phase bridge arm of the three-phase inverter to perform switching actions, and the switching tube of the V-phase bridge arm of the three-phase inverter is turned off; if the magnetic flux is in the same direction as the current of phase V, the switching tube of the V-phase of the three-phase inverter is controlled to perform switching actions, and the switching tube of the U-phase of the three-phase inverter is turned off; if the magnetic flux is in the same direction as the synthesis center line of the current vectors of phases U and V, the current commands of phases U and V are equally divided into two equal magnitudes, and the driving signals of the switching tubes of phases U and V of the three-phase inverter are phase-shifted by 180 degrees.
[0026] In a possible implementation, controlling the switching tubes of the second-phase bridge arm and the third-phase bridge arm of the inverter according to the comparison results of the magnetic flux angle with the currents of the second phase and the third phase of the three-phase motor respectively specifically includes:
[0027] When the magnetic flux is not in the same direction as the current of phase U, nor in the same direction as the current of phase V, nor in the same direction as the synthesis center line of the current vectors of phases U and V, control the distribution of the currents of phase U and phase V as follows:
[0028]
[0029] θ is the angle between the magnetic flux angle and phase U, where θ is greater than 0 and less than 120 degrees.
[0030] A possible implementation method is to control the switching tubes of the second-phase bridge arm and the third-phase bridge arm of the inverter according to the comparison results of the magnetic circuit angle with the current of the second phase and the current of the third phase of the three-phase motor, specifically including:
[0031] When the magnetic flux angle is in the range of 120 degrees to 180 degrees, select the switching tube of the bridge arm with the closest magnetic flux in the U phase and the V phase to perform the switching action, and turn off the switching tube of the other bridge arm.
[0032] A possible implementation method is that the first-phase winding is the W-phase winding, the second-phase winding is the U-phase winding, and the third-phase winding is the V-phase winding; according to the comparison results of the magnetic circuit angle with the current of the second phase and the current of the third phase of the three-phase motor, control the switching tubes of the second-phase bridge arm and the third-phase bridge arm of the inverter, specifically including:
[0033] When the magnetic flux angle is in the range of 180 to 270 degrees, if the magnetic flux is in the reverse direction of the current of U, the controller controls the switching tube of the U-phase bridge arm of the three-phase inverter to perform the switching action, and turns off the switching tube of the V-phase of the three-phase inverter; if the magnetic flux is in the reverse direction of the current of V, the controller controls the switching tube of the V-phase bridge arm of the three-phase inverter to perform the switching action, and turns off the switching tube of the U-phase of the three-phase inverter; if the magnetic flux is in the same direction as the synthesis center line of the current vector sum of the U and V phases, equally divide the current commands of the U and V phases with the same magnitude, and control the drive signals of the switching tubes of the U and V phases of the three-phase inverter to be out of phase by 180 degrees.
[0034] A possible implementation method is to control the switching tubes of the U-phase bridge arm and the V-phase bridge arm of the inverter according to the comparison results of the magnetic circuit angle with the current of the U phase and the current of the V phase, specifically including:
[0035] When the magnetic flux angle is in the range of 270 degrees to 360 degrees, select the switching tube of the bridge arm with the closest magnetic flux in the U phase and the V phase to perform the switching action, and turn off the switching tube of the other bridge arm.
[0036] A possible implementation method is to control the switching tubes of the U-phase bridge arm and the V-phase bridge arm of the inverter according to the comparison results of the magnetic circuit angle with the current of the U phase and the current of the V phase, specifically including:
[0037] When the magnetic flux is not in the reverse direction of the current of the U phase, nor in the reverse direction of the current of the V phase, nor in the reverse direction of the synthesis center line of the current vector sum of the U and V phases, control the distribution of the U-phase current and the V-phase current as follows:
[0038]
[0039] θ is the included angle between the magnetic flux angle and the U phase, and θ is greater than 180 and less than 270 degrees.
[0040] Thus, the present application has the following beneficial effects:
[0041] The charging device for a new energy vehicle provided by the embodiment of the present application reuses the electric drive system to boost the voltage for charging the power battery pack. The first-phase winding and the second-phase winding of the three-phase motor are connected in series and then connected in parallel with the third-phase winding, and the second-phase bridge arm switch tube and the third-phase bridge arm switch tube of the inverter are controlled according to the comparison results of the currents of the second phase and the third phase of the three-phase motor with respect to the magnetic circuit angle. For example, when charging the power battery pack, the W-phase winding and the U-phase winding of the delta motor are connected in series and then connected in parallel with the V-phase winding, which can be compatible with DC charging stations with relatively low voltages. And when parking to charge the power battery pack, the switch tubes of the U-phase bridge arm and the V-phase bridge arm can be controlled according to the comparison results of the magnetic flux angle with the currents of the U phase and the V phase, so as to make the torque of the motor zero, that is, to ensure that the new energy vehicle stops stably and does not move during charging.
[0042] The charging method provided by the embodiment of the present application can give full play to the high performance and high power density of the delta motor, and reuse the electric drive system for boost charging, which can reduce the space and cost. And this technical solution can reduce the torque generated during the charging process of new energy vehicles in most cases, improve the safety of the charging process and enhance the experience. Description of the Drawings
[0043] Figure 1 It is a schematic diagram of an electric drive system of a new energy vehicle provided by the embodiment of the present application;
[0044] Figure 2 It is a schematic diagram of a charging device for a new energy vehicle provided by the embodiment of the present application;
[0045] Figure 3 It is a flowchart of a charging method for a new energy vehicle provided by the embodiment of the present application. Detailed Embodiments
[0046] To enable those skilled in the art to better understand and implement the technical solutions provided by the embodiments of the present application, the electric drive system of the new energy vehicle will be introduced first. The electric drive system includes a motor and an inverter.
[0047] See Figure 1 , which is a schematic diagram of an electric drive system of a new energy vehicle provided by the embodiment of the present application.
[0048] It should be understood that during the driving of new energy vehicles, the power battery pack (ESS) provides the energy source. In this application, the voltage of the power battery pack is taken as 800V for introduction. The direct current provided by the power battery pack is inverted into alternating current by an inverter to drive the motor. In the figure, taking the inverter including a three-phase full-bridge circuit as an example, it includes three bridge arms, namely the W, V, and U phases. Moreover, the three-phase bridge arms of the inverter are correspondingly connected to the three windings W, V, and U of the motor. The three windings W, V, and U are connected in a triangle. The power density of the triangle motor is relatively high, and the driving performance is relatively high. This triangle motor can be a permanent magnet synchronous motor.
[0049] When the vehicle stops and charges, the triangle winding can act as an inductor in the boost circuit. The switching tubes in the inverter act as the switching tubes in the boost circuit, so that the devices of the electric drive system are reused in the boost charging, saving costs.
[0050] The working principle of boost charging is introduced below in conjunction with the accompanying drawings.
[0051] The positive pole of the DC charger or charging pile is connected to the three-phase windings of the motor through the second relay K2.
[0052] The function of K2 is to realize the switching between the electric drive condition and the charging condition. When K2 is closed, it is the charging condition, and when K2 is open, it is the electric drive condition.
[0053] The positive pole of the DC charger is connected to the first end of the main relay K3 through the first relay, and the second end of K3 is connected to the positive pole of the power battery pack.
[0054] The negative pole of the DC charger is connected to the second end of the first capacitor C1 through the fifth relay K5. The second end of the inverter is connected to the second end of C1, and the first end of the inverter is connected to the first end of K3. The function of C1 is to stabilize the voltage of the charging port.
[0055] Both ends of the second capacitor C2 are respectively connected to the first end and the second end of the inverter.
[0056] The pre-charge relay K4 and the pre-charge resistor are connected in series and then connected in parallel across K3. When starting to charge, K4 can be controlled to close first and K3 to open, to avoid damaging the battery due to excessive charging current. When the battery voltage rises to the preset value, K3 can be controlled to close and K4 to open.
[0057] Since there is no neutral point in the triangle motor, but during charging, a positive high-voltage line is required to connect the charging pile and the electric drive system to form a charging loop. Therefore, in the embodiments of this application, the W-phase winding of the motor is led out and connected to the positive pole of the charging port through the vehicle high-voltage box. The controller controls the switching tubes of the U-phase bridge arm and the V-phase bridge arm of the inverter, and the upper and lower switching tubes of the W-phase bridge arm are both turned off.
[0058] When K2, K5, and K3 are all closed, the vehicle is switched to the boost charging mode, and the windings of the motor and the switching tubes of the inverter in the boost charging reuse electric drive system are completed.
[0059] Among them, the charging current flows from the charging pile to the W-phase lead wire, passes through the delta motor and controls the flow through the U and V phases, and finally reaches the power battery pack.
[0060] When the delta motor reuses the boost charging topology structure, there is a situation where the sum of the three-phase current vectors is non-zero, which will cause torque in the new energy vehicle at certain parking positions. This occurs when the angle between the direction of the current vector sum and the magnetic flux direction is not 0 degrees or 180 degrees, that is, the vehicle cannot stop in time. The generation of torque is not conducive to the temperature rise, safety, and charging experience of the electric drive system. Therefore, the technical solution provided in the embodiments of the present application can weaken the torque in most cases when reusing boost charging, enabling the new energy vehicle to charge when parked stably.
[0061] According to the torque formula of the permanent magnet synchronous motor, the methods to reduce the torque to 0 include but are not limited to the following two:
[0062] The first: The sum of the current vectors of the U and V phases is 0;
[0063] The second: The direction of the current vector sum is the same as or opposite to the magnetic flux direction;
[0064] According to the above current flow direction, it can be known that the sum of the current vectors cannot be 0. Therefore, the above second method can be used for control.
[0065] In practical applications, after the new energy vehicle stops, by reading the resolver angle of the resolver, obtaining the magnetic flux angle from the resolver angle, and appropriately adjusting the current distribution of the U and V phases, the torque can be basically 0 within the angle range covering 240 degrees.
[0066] To make the above objects, features, and advantages of the present application more obvious and understandable, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0067] See Figure 2 , this figure is a schematic diagram of a new energy vehicle charging device provided by the embodiments of the present application.
[0068] The new energy vehicle charging device provided by the embodiments of the present application includes: a resolver 100, a three-phase inverter 200, a three-phase motor 300, and a controller 400.
[0069] The three-phase motor 300 includes U, V, and W three-phase windings, and the three-phase windings are connected in a delta configuration; the three-phase windings are respectively connected to the midpoints of the three-phase bridge arms of the three-phase inverter;
[0070] Resolver 100, used to measure the rotation angle θ of a three-phase motor 300;
[0071] Controller 400, when charging the power battery pack, the first-phase winding and the second-phase winding of the three-phase motor are connected in series and then connected in parallel with the third-phase winding, and according to the comparison results of the magnetic circuit angle with the currents of the second phase and the third phase of the three-phase motor respectively, control the switching tubes of the second-phase bridge arm and the third-phase bridge arm of the inverter.
[0072] For the convenience of understanding, in the following embodiments of the present application, the example of connecting the W-phase winding and the U-phase winding in series and then connecting them in parallel with the V-phase winding is used for introduction, and according to the comparison results of the magnetic circuit angle with the currents of the U phase and the V phase respectively, control the switching tubes of the U-phase bridge arm and the V-phase bridge arm of the inverter.
[0073] It should be understood that the above is only an example of connecting the W phase and the U phase of the three-phase motor in series and then connecting them in parallel with the V phase. In addition, it can also be that the U-phase winding and the V-phase winding are connected in series and then connected in parallel with the W-phase winding, and the switching tubes of the V-phase bridge arm of the corresponding inverter are all turned off. In addition, it can also be that the W-phase winding and the V-phase winding are connected in series and then connected in parallel with the U-phase winding, and the switching tubes of the U-phase bridge arm of the corresponding inverter are all turned off. For the above two connection situations of the windings to boost the voltage for charging as an inductor, the embodiments of the present application will not be elaborated, and they also belong to the protection scope of the present application.
[0074] The following will be introduced separately when the magnetic flux angle is between 0 and 180 degrees, and when the magnetic flux angle is between 180 and 360 degrees.
[0075] First, introduce the situation when the magnetic flux angle is between 0 and 180 degrees.
[0076] Specifically, when the magnetic flux angle is within the range of 0 to 120 degrees, if the magnetic flux is in the same direction as the current of the U phase, the controller controls the switching tubes of the U-phase bridge arm of the three-phase inverter to perform switching actions, and the switching tubes of the V-phase bridge arm of the three-phase inverter are turned off; if the magnetic flux is in the same direction as the current of the V phase, control the switching tubes of the V phase of the three-phase inverter to perform switching actions, and the switching tubes of the U phase of the three-phase inverter are turned off; if the magnetic flux is in the same direction as the synthesis center line of the current vectors of the U and V phases, divide the current commands of the U and V phases equally with the same magnitude, and control the drive signals of the switching tubes of the U and V phases of the three-phase inverter to be out of phase by 180 degrees.
[0077] When the magnetic flux is not in the same direction as the current of the U phase, nor in the same direction as the current of the V phase, nor in the same direction as the synthesis center line of the current vectors of the U and V phases, control the distribution of the U-phase current and the V-phase current as follows:
[0078]
[0079] θ is the included angle between the magnetic flux angle and the U phase, and θ is greater than 0 and less than 120 degrees.
[0080] The above formula utilizes the sine theorem. Since the three windings of the triangle motor are 120 degrees apart from each other, 120 degrees is By using the above formula to control the three-phase motor, the torque can be reduced to 0.
[0081] When the flux linkage angle is in the range of 120 degrees to 180 degrees, select the switching tubes of the bridge arm with the flux linkage closest to it in the U phase and the V phase for switching operations, and turn off the switching tubes of the other bridge arm. For example, if the U phase is closest to the flux linkage, control the switching tubes of the U-phase bridge arm to operate, and turn off all the switching tubes of the V phase.
[0082] The above describes the situation where the flux linkage angle is between 0 and 180 degrees. Now, the situation where the flux linkage angle is between 180 and 360 degrees will be introduced below.
[0083] When the flux linkage angle is in the range of 180 to 270 degrees, if the flux linkage is in the reverse direction of the current in the U phase, the controller controls the switching tubes of the U-phase bridge arm of the three-phase inverter to perform switching operations, and turns off the switching tubes of the V phase of the three-phase inverter; if the flux linkage is in the reverse direction of the current in the V phase, the controller controls the switching tubes of the V-phase bridge arm of the three-phase inverter to perform switching operations, and turns off the switching tubes of the U phase of the three-phase inverter; if the flux linkage is in the same direction as the synthesis center line of the current vector sum of the U and V phases, evenly divide the current commands of the U and V phases with the same magnitude, and control the drive signals of the switching tubes of the U and V phases of the three-phase inverter to be out of phase by 180 degrees.
[0084] When the flux linkage angle is in the range of 270 degrees to 360 degrees, select the switching tubes of the bridge arm with the flux linkage closest to it in the U phase and the V phase for switching operations, and turn off the switching tubes of the other bridge arm. For example, if the U phase is closest to the flux linkage, control the switching tubes of the U-phase bridge arm to operate, and turn off all the switching tubes of the V phase.
[0085] When the flux linkage is not in the reverse direction of the current in the U phase, nor in the reverse direction of the current in the V phase, nor in the reverse direction of the synthesis center line of the current vector sum of the U and V phases, control the distribution of the U-phase current and the V-phase current as follows:
[0086]
[0087] θ is the angle between the flux linkage angle and the U phase, and θ is greater than 180 and less than 270 degrees.
[0088] The new energy vehicle charging device provided by the embodiment of the present application reuses the electric drive system to boost the voltage for charging the power battery pack. When charging the power battery pack, the W-phase winding and the U-phase winding of the triangular motor are connected in series and then connected in parallel with the V-phase winding, which can be compatible with DC charging stations with relatively low voltages. And when parking to charge the power battery pack, the switching tubes of the U-phase bridge arm and the V-phase bridge arm can be controlled according to the comparison results of the magnetic flux angle and the U-phase and V-phase currents, so as to make the torque of the motor zero, that is, to ensure that the new energy vehicle stops stably and does not move during charging.
[0089] Based on the new energy vehicle charging device provided in the above embodiments, the embodiment of the present application also provides a charging method for a new energy vehicle, which will be introduced in detail below with reference to the accompanying drawings.
[0090] See Figure 3 , which is a flowchart of a charging method for a new energy vehicle provided by the embodiment of the present application.
[0091] The charging method for a new energy vehicle provided by the embodiment of the present application, the new energy vehicle includes: a resolver, a three-phase inverter, and a three-phase motor; the three-phase motor includes U, V, and W three-phase windings, and the three-phase windings are connected in a delta connection; the three-phase windings are respectively connected to the midpoints of the three-phase bridge arms of the three-phase inverter;
[0092] The method includes:
[0093] S301: Obtain the magnetic flux angle from the resolver angle.
[0094] For example, the resolver angle of the motor can be measured by a resolver. The magnetic flux angle of the motor can be determined from the resolver angle.
[0095] S302: When charging the power battery pack, the W-phase winding and the U-phase winding are connected in series and then connected in parallel with the V-phase winding, and according to the comparison results of the magnetic circuit angle with the currents of the U-phase and the V-phase respectively, control the switching tubes of the U-phase bridge arm and the V-phase bridge arm of the inverter.
[0096] The following will be introduced separately when the magnetic flux angle is between 0 and 180 degrees, and when the magnetic flux angle is between 180 and 360 degrees.
[0097] First, introduce the situation when the magnetic flux angle is between 0 and 180 degrees.
[0098] Specifically, when the flux linkage angle is in the range of 0 to 120 degrees, if the flux linkage is in the same direction as the current in phase U, the controller controls the switching tubes of the U-phase bridge arm of the three-phase inverter to perform switching actions, and the switching tubes of the V-phase bridge arm of the three-phase inverter are turned off; if the flux linkage is in the same direction as the current in phase V, the controller controls the switching tubes of phase V of the three-phase inverter to perform switching actions, and the switching tubes of phase U of the three-phase inverter are turned off; if the flux linkage is in the same direction as the synthesis center line of the current vectors of phases U and V, the current commands of phases U and V are evenly divided with the same magnitude, and the drive signals of the switching tubes of phases U and V of the three-phase inverter are phase-shifted by 180 degrees.
[0099] When the flux linkage is not in the same direction as the current in phase U, nor in the same direction as the current in phase V, nor in the same direction as the synthesis center line of the current vectors of phases U and V, the distribution of the current in phase U and the current in phase V is controlled as follows:
[0100]
[0101] θ is the included angle between the flux linkage angle and phase U, and θ is greater than 0 and less than 120 degrees.
[0102] The above formula utilizes the sine theorem. Since the three windings of the triangular motor are 120 degrees apart from each other, therefore, 120 degrees is Controlling the three-phase motor using the above formula can achieve torque reduction to 0.
[0103] When the flux linkage angle is in the range of 120 degrees to 180 degrees, the switching tubes of the bridge arm of the phase closest to the flux linkage in phases U and V are selected to perform switching actions, and the switching tubes of the other bridge arm are turned off. For example, if phase U is closest to the flux linkage, the switching tubes of the U-phase bridge arm are controlled to act, and the switching tubes of phase V are all turned off.
[0104] The above describes the situation when the flux linkage angle is between 0 and 180 degrees. The following describes the situation when the flux linkage angle is between 180 and 360 degrees.
[0105] When the flux linkage angle is in the range of 180 to 270 degrees, if the flux linkage is in the reverse direction of the current in U, the controller controls the switching tubes of the U-phase bridge arm of the three-phase inverter to perform switching actions, and the switching tubes of phase V of the three-phase inverter are turned off; if the flux linkage is in the reverse direction of the current in V, the controller controls the switching tubes of the V-phase bridge arm of the three-phase inverter to perform switching actions, and the switching tubes of phase U of the three-phase inverter are turned off; if the flux linkage is in the same direction as the synthesis center line of the current vectors of phases U and V, the current commands of phases U and V are evenly divided with the same magnitude, and the drive signals of the switching tubes of phases U and V of the three-phase inverter are phase-shifted by 180 degrees.
[0106] When the flux linkage angle is within the range of 270 degrees to 360 degrees, the switching tubes of the bridge arm with the flux linkage closest to it are selected for switching actions in the U-phase and V-phase, and the switching tubes of the other bridge arm are turned off. For example, if the U-phase is closest to the flux linkage, the switching tubes of the U-phase bridge arm are controlled to operate, and the switching tubes of the V-phase are all turned off.
[0107] When the flux linkage is not in the reverse direction of the U-phase current, nor in the reverse direction of the V-phase current, nor in the reverse direction of the synthesis center line of the vector sum of the U- and V-phase currents, the distribution of the U-phase current and the V-phase current is controlled as follows:
[0108]
[0109] θ is the included angle between the flux linkage angle and the U-phase, and θ is greater than 180 and less than 270 degrees.
[0110] The charging method of the new energy vehicle provided by the embodiment of the present application reuses the electric drive system to boost the voltage for charging the power battery pack. When charging the power battery pack, the W-phase winding and the U-phase winding of the delta motor are connected in series and then connected in parallel with the V-phase winding, which can be compatible with DC charging stations with relatively low voltages. And when parking to charge the power battery pack, the switching tubes of the U-phase bridge arm and the V-phase bridge arm can be controlled according to the comparison results of the flux linkage angle with the U-phase and V-phase currents, so as to achieve a motor torque of 0, that is, to ensure that the new energy vehicle stops stably and does not move during charging.
[0111] The charging method provided by the embodiment of the present application can give full play to the high performance and high power density of the delta motor, and reusing the electric drive system for boost charging can reduce space and cost. And this technical solution can reduce the torque generated during the charging process of new energy vehicles in most cases, improve the safety of the charging process and enhance the experience.
[0112] Based on the charging device and charging method of a new energy vehicle provided by the above embodiments, the embodiment of the present application further provides a new energy vehicle, which includes the charging device introduced in the above embodiments.
[0113] It should be noted that the various embodiments in this specification are described in a progressive manner. The key points of each embodiment are the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other. For the systems or devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and the relevant parts can be referred to the description of the method part.
[0114] The foregoing description of the disclosed embodiments enables those skilled in the art to practice or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A charging device for a new energy vehicle, characterized in that, Comprising: A resolver, a three-phase inverter, a three-phase motor, and a controller; the three-phase motor includes U, V, and W three-phase windings, and the three-phase windings are connected in a delta connection; the three-phase windings are respectively connected to the midpoints of the three-phase bridge arms of the three-phase inverter; The resolver is used to measure the resolver angle of the three-phase motor; The controller is used to obtain the flux linkage angle from the resolver angle. When charging the power battery pack, the first-phase winding and the second-phase winding of the three-phase motor are connected in series and then connected in parallel with the third-phase winding, and according to the comparison results of the flux linkage angle with the currents of the second phase and the third phase of the three-phase motor, the switching tubes of the second-phase bridge arm and the third-phase bridge arm of the inverter are controlled.
2. The device according to claim 1, wherein The first-phase winding is the W-phase winding, the second-phase winding is the U-phase winding, and the third-phase winding is the V-phase winding; When the flux linkage angle is in the range of 0 to 120 degrees, if the flux linkage is in the same direction as the current of the U phase, the controller controls the switching tubes of the U-phase bridge arm of the three-phase inverter to perform switching actions, and the switching tubes of the V-phase bridge arm of the three-phase inverter are turned off; if the flux linkage is in the same direction as the current of the V phase, the switching tubes of the V phase of the three-phase inverter are controlled to perform switching actions, and the switching tubes of the U phase of the three-phase inverter are turned off; if the flux linkage is in the same direction as the synthesis center line of the current vectors of the U and V phases, the current commands of the U and V phases are evenly divided with the same magnitude, and the drive signals of the switching tubes of the U and V phases of the three-phase inverter are phase-shifted by 180 degrees.
3. The device according to claim 2, wherein When the magnetic flux is not in the same direction as the current in phase U, nor in the same direction as the current in phase V, nor in the same direction as the synthesis center line of the current vectors of phases U and V, the distribution of the current in phase U and the current in phase V is controlled as follows: θ is the included angle between the flux linkage angle and the U phase, and θ is greater than 0 and less than 120 degrees.
4. The device according to claim 2 or 3, characterized in that, When the flux linkage angle is in the range of 120 degrees to 180 degrees, the switching tubes of the bridge arm of the phase closest to the flux linkage in the U and V phases are selected to perform switching actions, and the switching tubes of the other bridge arm are turned off.
5. The device according to claim 1, characterized in that The first-phase winding is the W-phase winding, the second-phase winding is the U-phase winding, and the third-phase winding is the V-phase winding; When the flux linkage angle is in the range of 180 to 270 degrees, if the flux linkage is in the opposite direction to the current of the U phase, the controller controls the switching tubes of the U-phase bridge arm of the three-phase inverter to perform switching actions, and the switching tubes of the V phase of the three-phase inverter are turned off; if the flux linkage is in the opposite direction to the current of the V phase, the controller controls the switching tubes of the V-phase bridge arm of the three-phase inverter to perform switching actions, and the switching tubes of the U phase of the three-phase inverter are turned off; if the flux linkage is in the same direction as the synthesis center line of the current vectors of the U and V phases, the current commands of the U and V phases are evenly divided with the same magnitude, and the drive signals of the switching tubes of the U and V phases of the three-phase inverter are phase-shifted by 180 degrees.
6. The device according to claim 5, characterized in that, When the flux linkage angle is in the range of 270 degrees to 360 degrees, the switching tubes of the bridge arm of the phase closest to the flux linkage in the U and V phases are selected to perform switching actions, and the switching tubes of the other bridge arm are turned off.
7. The device according to claim 5 or 6, characterized in that, When the magnetic flux does not reverse with the current in phase U, nor with the current in phase V, nor with the synthetic center line of the vector sum of the currents in phases U and V, the distribution of the current in phase U and the current in phase V is controlled as follows: θ is the included angle between the flux linkage angle and the U phase, and θ is greater than 180 and less than 270 degrees.
8. A charging method for a new energy vehicle, characterized in that, The new energy vehicle includes: a resolver, a three-phase inverter, and a three-phase motor; the three-phase motor includes U, V, and W three-phase windings, and the three-phase windings are connected in a delta connection; the three-phase windings are respectively connected to the midpoints of the three-phase bridge arms of the three-phase inverter; The method includes: Obtain the flux linkage angle from the resolver angle; When charging the power battery pack, the first-phase winding and the second-phase winding of the three-phase motor are connected in series and then connected in parallel with the third-phase winding, and the second-phase bridge arm switch tube and the third-phase bridge arm switch tube of the inverter are controlled according to the comparison results of the magnetic path angle with the currents of the second phase and the third phase of the three-phase motor respectively.
9. The method according to claim 8, characterized in that The first-phase winding is the W-phase winding, the second-phase winding is the U-phase winding, and the third-phase winding is the V-phase winding; controlling the second-phase bridge arm switch tube and the third-phase bridge arm switch tube of the inverter according to the comparison results of the magnetic path angle with the currents of the second phase and the third phase of the three-phase motor respectively specifically includes: When the flux linkage angle is in the range of 0 to 120 degrees, if the flux linkage is in the same direction as the current of the U phase, the controller controls the switch tube of the U-phase bridge arm of the three-phase inverter to perform switching actions, and the switch tube of the V-phase bridge arm of the three-phase inverter is turned off; if the flux linkage is in the same direction as the current of the V phase, the switch tube of the V phase of the three-phase inverter is controlled to perform switching actions, and the switch tube of the U phase of the three-phase inverter is turned off; if the flux linkage is in the same direction as the synthesis center line of the current vectors of the U and V phases, the current commands of the U and V phases are equally divided with the same magnitude, and the drive signals of the switch tubes of the U and V phases of the three-phase inverter are phase-shifted by 180 degrees.
10. The method according to claim 9, wherein Controlling the second-phase bridge arm switch tube and the third-phase bridge arm switch tube of the inverter according to the comparison results of the magnetic path angle with the currents of the second phase and the third phase of the three-phase motor respectively specifically includes: When the magnetic flux is not in the same direction as the current of phase U, nor in the same direction as the current of phase V, nor in the same direction as the synthesis center line of the current vectors of phases U and V, the distribution of the current of phase U and the current of phase V is controlled as follows: θ is the included angle between the flux linkage angle and the U phase, and θ is greater than 0 and less than 120 degrees.
11. The method according to claim 9, characterized in that, Controlling the second-phase bridge arm switch tube and the third-phase bridge arm switch tube of the inverter according to the comparison results of the magnetic path angle with the currents of the second phase and the third phase of the three-phase motor respectively specifically includes: When the flux linkage angle is in the range of 120 degrees to 180 degrees, select the switch tube of the bridge arm of the phase with the closest flux linkage in the U phase and the V phase to perform switching actions, and the switch tube of the other bridge arm is turned off.
12. The method according to claim 8, characterized in that The first-phase winding is the W-phase winding, the second-phase winding is the U-phase winding, and the third-phase winding is the V-phase winding; controlling the second-phase bridge arm switch tube and the third-phase bridge arm switch tube of the inverter according to the comparison results of the magnetic path angle with the currents of the second phase and the third phase of the three-phase motor respectively specifically includes: When the flux linkage angle is in the range of 180 to 270 degrees, if the flux linkage is in the reverse direction of the current of the U phase, the controller controls the switch tube of the U-phase bridge arm of the three-phase inverter to perform switching actions, and the switch tube of the V phase of the three-phase inverter is turned off; if the flux linkage is in the reverse direction of the current of the V phase, the controller controls the switch tube of the V-phase bridge arm of the three-phase inverter to perform switching actions, and the switch tube of the U phase of the three-phase inverter is turned off; if the flux linkage is in the same direction as the synthesis center line of the current vectors of the U and V phases, the current commands of the U and V phases are equally divided with the same magnitude, and the drive signals of the switch tubes of the U and V phases of the three-phase inverter are phase-shifted by 180 degrees.
13. The method according to claim 12, characterized in that, Controlling the switching tubes of the U-phase bridge arm and the V-phase bridge arm of the inverter according to the comparison results of the magnetic circuit angle with the currents of the U-phase and the V-phase respectively, specifically including: When the flux angle is within the range of 270 degrees to 360 degrees, select the switching tube of the bridge arm of the phase with the closest flux in the U-phase and the V-phase to perform the switching action, and turn off the switching tubes of the other bridge arm.
14. The method according to claim 13, wherein Controlling the switching tubes of the U-phase bridge arm and the V-phase bridge arm of the inverter according to the comparison results of the magnetic circuit angle with the currents of the U-phase and the V-phase respectively, specifically including: When the magnetic flux does not reverse with the current of phase U, nor with the current of phase V, nor with the synthesis center line of the current vectors of phases U and V, the distribution of the current of phase U and the current of phase V is controlled as follows: θ is the included angle between the flux angle and the U-phase, and θ is greater than 180 and less than 270 degrees.