Charging system for vehicle, charging control method for vehicle, and vehicle

Abstract

The invention provides a vehicle charging system, a vehicle charging control method and a vehicle. The system comprises an energy conversion device, a direct current output device and a controller. Wherein the energy conversion device and the direct current output device are connected with each other, and the energy conversion device and the direct current output device are both connected to a battery of the vehicle; the energy conversion device comprises a multi-phase inverter, a multi-phase winding and a first capacitor, wire inlet ends of the multi-phase winding are correspondingly connected to multi-phase bridge arms of the multi-phase inverter respectively, and the first capacitor is connected to the multi-phase inverter in parallel; the controller is connected to the multi-phase inverter and controls multi-phase bridge arms of the multi-phase inverter to act so as to form direct current with alternating current components to charge a battery of the vehicle. When the vehicle battery is charged through direct current, the alternating current component is superposed in the direct current, so that the service life of the vehicle battery can be effectively prolonged while the charging speed of the vehicle battery is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicles, and in particular relates to a charging system for a vehicle, a charging control method for a vehicle, and a vehicle. Background Art

[0002] DC charging can directly transmit electrical energy to the vehicle's battery in the form of direct current, thereby shortening the charging time of the vehicle's battery. At present, in order to increase the charging speed of the vehicle's power battery, however, long-term use of DC current to charge the vehicle's battery will affect the battery's service life. If a portion of the periodic AC current component can be superimposed during DC charging, the charging rate can be accelerated while reducing the impact of DC charging on the battery life. However, the DC charging piles that are widely available on the market cannot generate the corresponding periodic AC current component, and adding related power electronic equipment will bring cost / volume and other issues. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a vehicle charging system, a vehicle charging control method and a vehicle, wherein when the vehicle battery is charged by direct current, an alternating current component is superimposed on the direct current to effectively improve the service life of the vehicle battery while ensuring the charging speed of the vehicle battery.

[0004] In order to solve or improve the above technical problems to a certain extent, according to one aspect of the present invention, a vehicle charging system is provided, comprising: an energy conversion device, a DC output device and a controller;

[0005] Wherein, the energy conversion device and the DC output device are connected to each other, and both the energy conversion device and the DC output device are connected to a battery of a vehicle;

[0006] The energy conversion device comprises a multi-phase inverter, a multi-phase winding and a first capacitor, the inlet terminals of the multi-phase winding are respectively connected to the multi-phase bridge arms of the multi-phase inverter, and the first capacitor is connected in parallel to the multi-phase inverter;

[0007] The controller is connected to the multi-phase inverter and controls the multi-phase bridge arms of the multi-phase inverter to generate a direct current with an alternating current component to charge the battery of the vehicle.

[0008] In some embodiments, the multi-phase inverter, the multi-phase winding, and the first capacitor of the energy conversion device are reused for an electric drive system of a vehicle.

[0009] In some embodiments, the busbar of the multiphase inverter is correspondingly connected to the busbar of the battery, and the busbar of the DC output device is connected in parallel to the busbar of the multiphase inverter and the busbar of the battery;

[0010] The controller controls the action of the switching devices of the multi-phase bridge arm, and uses the multi-phase winding and the first capacitor as energy storage devices to form the AC current component on the bus of the multi-phase inverter, which is superimposed with the DC current output from the bus of the DC output device to form a DC current with an AC component to charge the battery.

[0011] In some embodiments, the busbar of the DC output device is connected to the busbar of the multi-phase inverter;

[0012] The neutral point of the multi-phase winding is connected to one pole of the busbar of the battery, and any pole of the busbar of the multi-phase inverter is connected to the other pole of the busbar of the battery, or

[0013] The incoming line end of at least one phase of the multi-phase winding is connected to one pole of the busbar of the battery, and any pole of the busbar of the multi-phase inverter is connected to the other pole of the busbar of the battery;

[0014] The controller controls the action of the switch devices of the multi-phase bridge arm, and uses the multi-phase winding and the first capacitor as energy storage devices to convert the DC current output by the DC output device into a DC current with an AC component to charge the battery.

[0015] In some embodiments, the neutral point of the multi-phase winding is connected to one pole of the busbar of the battery, and any pole of the busbar of the multi-phase inverter is connected to the other pole of the busbar of the battery, or

[0016] The incoming line end of at least one phase of the multi-phase winding is connected to one pole of the busbar of the battery, and any pole of the busbar of the multi-phase inverter is connected to the other pole of the busbar of the battery;

[0017] The DC output device is connected in parallel to the battery;

[0018] The controller controls the action of the switching devices of the multi-phase bridge arm, and uses the multi-phase winding and the first capacitor as energy storage devices to form the AC current component on the bus of the multi-phase inverter, which is superimposed with the DC current output from the bus of the DC output device to form a DC current with an AC component to charge the battery.

[0019] In some embodiments, the energy conversion device further includes a second capacitor, one pole of the second capacitor is connected to the neutral point of the multi-phase winding or the incoming line end of at least one phase of the multi-phase winding, and the other pole of the second capacitor is connected to any pole of the busbar of the multi-phase inverter;

[0020] The busbar of the multiphase inverter is correspondingly connected to the busbar of the battery, and the busbar of the DC output device is connected in parallel to the busbar of the battery and the busbar of the multiphase inverter;

[0021] The controller controls the action of the switching devices of the multi-phase bridge arm, and uses the multi-phase winding and the second capacitor as energy storage devices to form the AC current component on the bus of the multi-phase inverter, which is superimposed with the DC current output from the bus of the DC output device to form a DC current with an AC component to charge the battery.

[0022] In some embodiments, the energy conversion device further includes a third capacitor, one pole of the third capacitor is connected to the neutral point of the multi-phase winding or the incoming line end of at least one phase of the multi-phase winding, and the other pole of the third capacitor is connected to any pole of the busbar of the multi-phase inverter;

[0023] The busbar of the multi-phase inverter is correspondingly connected to the busbar of the battery;

[0024] The busbar of the DC output device is connected in parallel to the third capacitor, or one pole of the busbar of the DC output device is connected to the third capacitor, and the other pole of the busbar of the DC output device is connected to any pole of the busbar of the multi-phase inverter;

[0025] The controller controls the action of the switch devices of the multi-phase bridge arm, and uses the multi-phase winding and the third capacitor as energy storage devices to convert the DC current output by the DC output device into a DC current with an AC component to charge the battery.

[0026] In some embodiments, during the process of charging the battery, the controller controls the multi-phase bridge arms of the multi-phase inverter to act synchronously to reduce the torque generated when current flows through the multi-phase windings.

[0027] According to an embodiment of the present invention, a vehicle charging control method is provided, which is applied to the vehicle charging system described in any one of the above embodiments, and the method includes:

[0028] During the process of charging the battery of the vehicle, the multi-phase bridge arms of the multi-phase inverter are controlled to operate so as to form a direct current with an alternating current component to charge the battery.

[0029] According to an embodiment of the present invention, a vehicle is provided, comprising the charging system for the vehicle described in any one of the above embodiments.

[0030] According to an embodiment of the present invention, a controller is provided, which includes a memory and a processor, wherein the memory stores a computer program, and when the program is executed by the processor, the steps of the vehicle charging control method described in any of the above embodiments can be implemented.

[0031] According to an embodiment of the present invention, a computer-readable storage medium is provided for storing a computer program, wherein the program, when executed by a computer or a processor, implements the steps of the vehicle charging control method described in any of the above embodiments.

[0032] Compared with the prior art, the present invention has obvious advantages and beneficial effects. By means of the above technical solution, the vehicle charging system, vehicle charging control method and vehicle of the present invention can achieve considerable technical advancement and practicality, and have wide industrial utilization value, and have at least the following advantages:

[0033] The vehicle charging system and the vehicle charging control method of the present invention, that is, the vehicle, can superimpose an AC current component on the DC charging current, thereby improving the impact of DC current charging on the service life of the battery while ensuring the charging speed. At the same time, by reusing the vehicle's electric drive system to generate an AC current component, the increase in cost and volume caused by reassembly is avoided. In addition, during the charging process, the charging current can also be boosted or stepped down, effectively improving the reuse rate of the vehicle's charging system.

[0034] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A topological diagram of a charging system for a vehicle according to a first embodiment of the present invention;

[0036] Figure 2 A topological diagram of a charging system for a vehicle according to a second embodiment of the present invention;

[0037] Figure 3 A topological diagram of a vehicle charging system according to a third embodiment of the present invention;

[0038] Figure 4 A topological diagram of a vehicle charging system according to a fourth embodiment of the present invention;

[0039] Figure 5 A topological diagram of a charging system for a vehicle according to a fifth embodiment of the present invention;

[0040] Figure 6 A schematic diagram of a current waveform of a battery charged by a charging system of a vehicle according to an embodiment of the present invention;

[0041] Figure 7 This is a schematic diagram of a current waveform when a charging system for a vehicle charges a battery according to another embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the vehicle charging system, vehicle charging control method and vehicle specific implementation methods and their effects proposed in accordance with the present invention in combination with the accompanying drawings and preferred embodiments.

[0043] References to "one embodiment" or "some embodiments" etc. described in this specification mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Thus, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways. The term "connection" includes direct connection and indirect connection, unless otherwise specified. "First", "second", "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

[0044] Figure 1-5 FIG. 1 shows a schematic diagram of the topological structure of the vehicle charging system of the present invention. Figure 1-5 As shown, the charging system of the vehicle includes an energy conversion device 1, a DC output device 2 and a controller (not shown in the figure).

[0045] The energy conversion device 1 of the vehicle includes a multi-phase inverter 10 , a multi-phase winding 20 and a first capacitor C1 .

[0046] The multi-phase incoming terminals of the multi-phase winding 20 are respectively connected to the multi-phase bridge arms of the multi-phase inverter 10. The two ends of the first capacitor C1 are respectively connected to the two poles (ie, the positive pole and the negative pole) of the busbar of the multi-phase inverter 10.

[0047] Figure 1-5 FIG. 2 shows an embodiment in which the multi-phase inverter 10 is a three-phase inverter 100 and the multi-phase winding 20 is a three-phase winding 200. Figure 1-5As shown, the three-phase inverter 100 includes three-phase bridge arms A, B, and C, wherein the A-phase bridge arm includes switch devices Q1 and Q2, the B-phase bridge arm includes switch devices Q3 and Q4, and the C-phase bridge arm includes switch devices Q5 and Q6. The three-phase winding 200 includes an A-phase winding LA, a B-phase winding LB, and a C-phase winding LC.

[0048] The incoming terminals of the windings LA, LB and LC of the three-phase winding 200 are respectively connected to the three-phase bridge arms A, B and C of the three-phase inverter 100. The first capacitor C1 of the energy conversion device 1 is connected between the busbars of the three-phase inverter 100, so that the first capacitor C1 is connected in parallel to the three-phase inverter 100.

[0049] Of course, the above Figure 1-5 What is shown are only some specific implementation methods. The multi-phase inverter 10 and the multi-phase winding 20 of the present invention are not just three-phase. The phase numbers of the multi-inverter and the winding can be configured accordingly according to actual use requirements. The present invention is not limited to the specific phase numbers of the inverter and the winding.

[0050] In one embodiment, the energy conversion device 1 of the vehicle's charging system is composed of the vehicle's electric drive system, so as to reduce the vehicle's assembly cost and body volume, and there is no need to improve the existing DC output device, which greatly reduces the configuration cost.

[0051] Specifically, the multi-phase winding 20 , the multi-phase inverter 10 and the first capacitor C1 constituting the energy conversion device 1 are all inverters, windings and capacitors used by the electric drive system of the vehicle.

[0052] like Figure 1-5 As shown, the DC output device 2 is interconnected with the energy conversion device 1, and both the energy conversion device 1 and the DC output device 2 are connected to the battery 3 of the vehicle. The controller is connected to the multi-phase inverter 10 of the energy conversion device to control the multi-phase bridge arm action of the multi-phase inverter 10 to form a DC current with an AC component to charge the battery 3 of the vehicle.

[0053] Optionally, the DC output device 2 of the present invention includes a DC charger, a vehicle AC / DC converter, an electric drive system configured in a boost or buck mode, and a wireless charging device.

[0054] In one embodiment, the bus of the multi-phase inverter 10 is correspondingly connected to the bus of the battery 3, and the bus of the DC output device 2 is connected in parallel to the bus of the multi-phase inverter 10 and the bus of the battery 3; the controller controls the action of the switching devices of the multi-phase bridge arm, and uses the multi-phase winding 20 and the first capacitor C1 as energy storage devices to form an AC current component on the bus of the multi-phase inverter 10, which is superimposed on the DC current output from the bus of the DC output device 2 to form a DC current with an AC component to charge the battery 3.

[0055] Figure 1 FIG. 1 is a schematic diagram showing a topological structure of a vehicle charging system according to an embodiment of the present invention. Figure 1 As shown, the energy conversion device 1 includes a three-phase inverter 100, a three-phase winding 200 and a first capacitor C1.

[0056] Among them, the three-phase inverter 100 includes three-phase bridge arms A, B, and C, wherein the A-phase bridge arm includes switch devices Q1 and Q2, the B-phase bridge arm includes switch devices Q3 and Q4, and the C-phase bridge arm includes switch devices Q5 and Q6. The three-phase winding 200 includes an A-phase winding LA, a B-phase winding LB, and a C-phase winding LC. The incoming ends of the windings LA, LB, and LC of the three-phase winding 200 are respectively connected to the A, B, and C three-phase bridge arms of the three-phase inverter 100. The first capacitor C1 of the energy conversion device 1 is connected between the busbars of the three-phase inverter 100 so that the first capacitor C1 is connected in parallel to the three-phase inverter 100.

[0057] The busbar of the three-phase inverter 100 is correspondingly connected to the busbar of the battery 3 of the vehicle, and the busbar of the DC output device 2 is connected in parallel to the busbar of the three-phase inverter 100 and the busbar of the battery 3 of the vehicle.

[0058] In this embodiment, during the process of charging the battery 3 of the vehicle, the DC output device 2 outputs a constant DC current, and the controller controls the upper bridge arm of one phase or two phases of the three-phase inverter 100 and the lower bridge arm of the other two phases or one phase to be turned on simultaneously for t1 time. For example, the upper bridge arm of the A-phase bridge arm and the lower bridge arm of the B-phase bridge arm and the C-phase bridge arm are turned on simultaneously for t1 time (that is, the switching devices Q1, Q4, and Q6 are controlled to be turned on simultaneously for t1 time), or the upper bridge arm of the A-phase bridge arm and the B-phase bridge arm and the lower bridge arm of the C-phase bridge arm are turned on simultaneously for t1 time (that is, the switching devices Q1, Q3, and Q6 are controlled to be turned on simultaneously for t1 time), so as to generate a current for charging the three-phase winding 200 on the bus of the three-phase inverter 100 to charge the three-phase winding 200.

[0059] After the t1 time is over, all the turned-on bridge arms are turned off. At this time, a certain amount of electric energy is stored in the three-phase winding 200. Then, the bridge arms that are not turned on during the t1 time are controlled to be turned on for the t2 time at the same time. For example, the lower bridge arm of the A-phase bridge arm and the upper bridge arms of the B-phase bridge arm and the C-phase bridge arm are turned on for the t2 time at the same time (that is, the switching devices Q2, Q3, and Q5 are controlled to be turned on for the t2 time at the same time), or the lower bridge arms of the A-phase bridge arm and the B-phase bridge arm and the upper bridge arm of the C-phase bridge arm are turned on for the t1 time at the same time (that is, the switching devices Q2, Q4, and Q5 are controlled to be turned on for the t2 time at the same time), so as to discharge the electric energy stored in the three-phase winding 200 and form a discharge current on the bus of the three-phase inverter 100.

[0060] A cycle controlled by the controller includes t1 time, t2 time and necessary dead time. By adjusting the proportion of t1 time in a cycle (i.e., duty cycle, switching frequency of bridge arm action and dead time), a periodic fluctuating current is formed on the bus of the three-phase inverter 100. The period and amplitude of the fluctuating current follow the demand instruction of the battery 3, and are superimposed with the constant DC charging current output by the DC output device 2 to form a sinusoidal DC charging current with a certain frequency and amplitude to charge the battery 3, so as to achieve the effect of reducing the attenuation of the life of the battery 3 caused by the constant DC current in the charging scenario.

[0061] In one embodiment, the busbar of the DC output device 2 is connected to the busbar of the multi-phase inverter 10; the neutral point of the multi-phase winding 20 is connected to one pole of the busbar of the battery 3, and any pole of the busbar of the multi-phase inverter 10 is connected to the other pole of the busbar of the battery 3, or at least one phase incoming line end of the multi-phase winding 20 is connected to one pole of the busbar of the battery 3, and any pole of the busbar of the multi-phase inverter 10 is connected to the other pole of the busbar of the battery 3; the controller controls the action of the switching devices of the multi-phase bridge arm, and uses the multi-phase winding 20 and the first capacitor C1 as energy storage devices, and the DC current output by the DC output device 2 is converted into a DC current with an AC component to charge the battery 3.

[0062] Figure 2 FIG. 1 is a schematic diagram showing a topological structure of a vehicle charging system according to an embodiment of the present invention. Figure 2 As shown, the energy conversion device 1 includes a three-phase inverter 100, a three-phase winding 200 and a first capacitor C1.

[0063] Among them, the three-phase inverter 100 includes three-phase bridge arms A, B, and C, wherein the A-phase bridge arm includes switch devices Q1 and Q2, the B-phase bridge arm includes switch devices Q3 and Q4, and the C-phase bridge arm includes switch devices Q5 and Q6. The three-phase winding 200 includes an A-phase winding LA, a B-phase winding LB, and a C-phase winding LC. The incoming ends of the windings LA, LB, and LC of the three-phase winding 200 are respectively connected to the A, B, and C three-phase bridge arms of the three-phase inverter 100. The first capacitor C1 of the energy conversion device 1 is connected between the busbars of the three-phase inverter 100 so that the first capacitor C1 is connected in parallel to the three-phase inverter 100.

[0064] The busbar of the DC output device 2 is correspondingly connected to the busbar of the three-phase inverter 100 , the neutral point of the three-phase winding 200 is connected to one pole of the busbar of the vehicle battery 3 , and one pole (positive pole or negative pole) of the busbar of the three-phase inverter 100 is connected to the other pole of the vehicle battery 3 .

[0065] Optionally, in this embodiment, at least one phase input end of the three-phase winding 200 may be connected to one pole of the busbar of the battery 3, and one pole (positive pole or negative pole) of the busbar of the three-phase inverter 100 may be connected to the other pole of the vehicle battery 3.

[0066] In this embodiment, the controller steps down the output voltage of the external charging device by controlling the duty cycle signal of the bridge arm. The voltage output by the bus of the three-phase inverter 100 does not remain constant in a short period of time, but fluctuates around the target voltage. A fluctuating voltage difference is generated between the output voltage and the constant voltage of the battery 3. The voltage difference generates a fluctuating current under parameters such as the internal resistance of the battery 3 and the cable impedance. The amplitude and frequency of the fluctuating current follow the DC demand of the battery 3 and are achieved by controlling the duty cycle signal. On the basis of step-down charging, a periodic AC current component is output and superimposed on the DC current output by the charging device to form a DC current with an AC component to charge the battery 3, so as to reduce the attenuation of the life of the battery 3 caused by the constant DC current in the charging scenario.

[0067] In one embodiment, the neutral point of the multi-phase winding 20 is connected to one pole of the bus of the battery 3, and any pole of the bus of the multi-phase inverter 10 is connected to the other pole of the bus of the battery 3, or at least one phase incoming line end of the multi-phase winding 20 is connected to one pole of the bus of the battery 3, and any pole of the bus of the multi-phase inverter 10 is connected to the other pole of the bus of the battery 3; the DC output device 2 is connected to the battery 3 in parallel; the controller controls the action of the switching devices of the multi-phase bridge arm, and uses the multi-phase winding 20 and the first capacitor C1 as energy storage devices to form an AC current component on the bus of the multi-phase inverter 10, which is superimposed on the DC current output from the bus of the DC output device 2 to form a DC current with an AC component to charge the battery 3.

[0068] Optionally, during the charging process of the battery 3 , the controller controls the multi-phase bridge arms of the multi-phase inverter 10 to act synchronously to reduce the torque generated when the current flows through the multi-phase winding 20 .

[0069] Figure 3 FIG. 1 is a schematic diagram showing a topological structure of a vehicle charging system according to an embodiment of the present invention. Figure 3 As shown, the energy conversion device 1 includes a three-phase inverter 100, a three-phase winding 200 and a first capacitor C1.

[0070] Among them, the three-phase inverter 100 includes three-phase bridge arms A, B, and C, wherein the A-phase bridge arm includes switch devices Q1 and Q2, the B-phase bridge arm includes switch devices Q3 and Q4, and the C-phase bridge arm includes switch devices Q5 and Q6. The three-phase winding 200 includes an A-phase winding LA, a B-phase winding LB, and a C-phase winding LC. The incoming ends of the windings LA, LB, and LC of the three-phase winding 200 are respectively connected to the A, B, and C three-phase bridge arms of the three-phase inverter 100. The first capacitor C1 of the energy conversion device 1 is connected between the busbars of the three-phase inverter 100 so that the first capacitor C1 is connected in parallel to the three-phase inverter 100.

[0071] The DC output device 2 is connected in parallel to the battery 3 , the neutral point of the three-phase winding 200 is connected to one pole of the busbar of the battery 3 , and one pole (positive or negative) of the busbar of the three-phase inverter 100 is connected to the other pole of the busbar of the battery 3 .

[0072] Optionally, in this embodiment, at least one phase incoming line end of the three-phase winding 200 may be connected to one pole of the busbar of the battery 3, and one pole (positive or negative pole) of the busbar of the three-phase inverter 100 may be connected to the other pole of the busbar of the battery 3.

[0073] In this embodiment, during the process of charging the battery 3 of the vehicle, the DC output device 2 outputs a constant DC current, and the controller controls the upper bridge arm of one phase or two phases of the three-phase inverter 100 and the lower bridge arm of the other two phases or one phase to be turned on simultaneously for t1 time. For example, the upper bridge arm of the A-phase bridge arm and the lower bridge arm of the B-phase bridge arm and the C-phase bridge arm are turned on simultaneously for t1 time (that is, the switching devices Q1, Q4, and Q6 are controlled to be turned on simultaneously for t1 time), or the upper bridge arm of the A-phase bridge arm and the B-phase bridge arm and the lower bridge arm of the C-phase bridge arm are turned on simultaneously for t1 time (that is, the switching devices Q1, Q3, and Q6 are controlled to be turned on simultaneously for t1 time), so as to generate a current for charging the first capacitor C1 on the bus of the three-phase inverter 100 to charge the first capacitor C1.

[0074] After the t1 time is over, all the turned-on bridge arms are turned off. At this time, a certain amount of electric energy is stored in the first capacitor C1. Then, the bridge arms that are not turned on during the t1 time are controlled to be turned on for the t2 time at the same time. For example, the lower bridge arm of the A-phase bridge arm and the upper bridge arms of the B-phase bridge arm and the C-phase bridge arm are turned on for the t2 time at the same time (that is, the switching devices Q2, Q3, and Q5 are controlled to be turned on for the t2 time at the same time), or the lower bridge arms of the A-phase bridge arm and the B-phase bridge arm and the upper bridge arm of the C-phase bridge arm are turned on for the t1 time at the same time (that is, the switching devices Q2, Q4, and Q5 are controlled to be turned on for the t2 time at the same time), so as to discharge the electric energy stored in the first capacitor C1 and form a discharge current on the bus of the three-phase inverter 100.

[0075] A cycle controlled by the controller includes t1 time, t2 time and necessary dead time. By adjusting the proportion of t1 time in a cycle (i.e., duty cycle, switching frequency of bridge arm action and dead time), a periodic fluctuating current is formed on the bus of the three-phase inverter 100. The period and amplitude of the fluctuating current follow the demand instruction of the battery 3, and are superimposed with the constant DC charging current output by the DC output device 2 to form a sinusoidal DC charging current with a certain frequency and amplitude to charge the battery 3, so as to achieve the effect of reducing the attenuation of the life of the battery 3 caused by the constant DC current in the charging scenario.

[0076] In one embodiment, the energy conversion device 1 also includes a second capacitor C2, one pole of the second capacitor C2 is connected to the neutral point of the multi-phase winding 20 or at least one phase input terminal of the multi-phase winding 20, and the other pole of the second capacitor C2 is connected to any pole of the bus of the multi-phase inverter 10; the bus of the multi-phase inverter 10 is correspondingly connected to the bus of the battery 3, and the bus of the DC output device 2 is connected in parallel to the bus of the battery 3 and the bus of the multi-phase inverter 10; the controller controls the action of the switching devices of the multi-phase bridge arm, and uses the multi-phase winding 20 and the second capacitor C2 as energy storage devices to form an AC current component on the bus of the multi-phase inverter 10, which is superimposed on the DC current output from the bus of the DC output device 2 to form a DC current with an AC component to charge the battery 3.

[0077] Optionally, during the charging process of the battery 3 , the controller controls the multi-phase bridge arms of the multi-phase inverter 10 to act synchronously to reduce the torque generated when the current flows through the multi-phase winding 20 .

[0078] Figure 4 FIG. 1 is a schematic diagram showing a topological structure of a vehicle charging system according to an embodiment of the present invention. Figure 4 As shown, the energy conversion device 1 includes a three-phase inverter 100, a three-phase winding 200, a first capacitor C1 and a second capacitor C2.

[0079] Among them, the three-phase inverter 100 includes three-phase bridge arms A, B, and C, wherein the A-phase bridge arm includes switching devices Q1 and Q2, the B-phase bridge arm includes switching devices Q3 and Q4, and the C-phase bridge arm includes switching devices Q5 and Q6. The three-phase winding 200 includes an A-phase winding LA, a B-phase winding LB, and a C-phase winding LC. The incoming wire ends of the windings LA, LB, and LC of the three-phase winding 200 are respectively connected to the A, B, and C three-phase bridge arms of the three-phase inverter 100. The first capacitor C1 of the energy conversion device 1 is connected between the busbars of the three-phase inverter 100 so that the first capacitor C1 is connected in parallel to the three-phase inverter 100. The two ends of the second capacitor C2 are respectively connected to the neutral point of the three-phase winding 200 and one pole (positive or negative) of the busbar of the three-phase inverter 100.

[0080] Optionally, in this embodiment, one end of the second capacitor C2 may be connected to at least one phase input terminal of the three-phase winding 200 , and the other end of the second capacitor C2 may be connected to one pole (positive pole or negative pole) of the busbar of the three-phase inverter 100 .

[0081] The busbars of the three-phase winding 200 are correspondingly connected to the busbars of the vehicle battery 3 , and the busbars of the DC output device 2 are connected in parallel to the busbars of the battery 3 and the busbars of the three-phase inverter 100 .

[0082] In this embodiment, during the process of charging the battery 3 of the vehicle, the DC output device 2 outputs a constant DC current, and the controller controls the upper bridge arm of one phase or two phases of the three-phase inverter 100 and the lower bridge arm of the other two phases or one phase to be turned on simultaneously for t1 time. For example, the upper bridge arm of the A-phase bridge arm and the lower bridge arm of the B-phase bridge arm and the C-phase bridge arm are turned on simultaneously for t1 time (that is, the switching devices Q1, Q4, and Q6 are controlled to be turned on simultaneously for t1 time), or the upper bridge arm of the A-phase bridge arm and the B-phase bridge arm and the lower bridge arm of the C-phase bridge arm are turned on simultaneously for t1 time (that is, the switching devices Q1, Q3, and Q6 are controlled to be turned on simultaneously for t1 time), so as to generate a current for charging the second capacitor C2 on the bus of the three-phase inverter 100 to charge the second capacitor C2.

[0083] After the t1 time is over, all the turned-on bridge arms are turned off. At this time, a certain amount of electric energy is stored in the second capacitor C2. Then, the bridge arms that are not turned on during the t1 time are controlled to be turned on for the t2 time at the same time. For example, the lower bridge arm of the A-phase bridge arm and the upper bridge arms of the B-phase bridge arm and the C-phase bridge arm are turned on for the t2 time at the same time (that is, the switching devices Q2, Q3, and Q5 are controlled to be turned on for the t2 time at the same time), or the lower bridge arms of the A-phase bridge arm and the B-phase bridge arm and the upper bridge arm of the C-phase bridge arm are turned on for the t1 time at the same time (that is, the switching devices Q2, Q4, and Q5 are controlled to be turned on for the t2 time at the same time), so as to discharge the electric energy stored in the second capacitor C2 and form a discharge current on the bus of the three-phase inverter 100.

[0084] A cycle controlled by the controller includes t1 time, t2 time and necessary dead time. By adjusting the proportion of t1 time in a cycle (i.e., duty cycle, switching frequency of bridge arm action and dead time), a periodic fluctuating current is formed on the bus of the three-phase inverter 100. The period and amplitude of the fluctuating current follow the demand instruction of the battery 3, and are superimposed with the constant DC charging current output by the DC output device 2 to form a sinusoidal DC charging current with a certain frequency and amplitude to charge the battery 3, so as to achieve the effect of reducing the attenuation of the life of the battery 3 caused by the constant DC current in the charging scenario.

[0085] Alternatively, if Figure 4As shown, the second capacitor C2 is connected to the three-phase winding 200 through the first switch K1 in a switchable manner, and the controller is connected to the first switch K1. When charging the battery 3 of the vehicle, the controller controls the first switch K1 to close. When the vehicle is driving, the controller controls the first switch K1 to open, so that the reused electric drive system can normally output the torque required for the vehicle to drive.

[0086] In one embodiment, the energy conversion device 1 further includes a third capacitor C3, one pole of the third capacitor C3 is connected to the neutral point of the multi-phase winding 20 or at least one phase incoming line terminal of the multi-phase winding 20, and the other pole of the third capacitor C3 is connected to any pole of the bus of the multi-phase inverter 10; the bus of the multi-phase inverter 10 is correspondingly connected to the bus of the battery 3; the bus of the DC output device 2 is connected in parallel to the third capacitor C3, or one pole of the bus of the DC output device 2 is connected to the third capacitor C3, and the other pole of the bus of the DC output device 2 is connected to any pole of the bus of the multi-phase inverter 10; the controller controls the action of the switching device of the multi-phase bridge arm, and uses the multi-phase winding 20 and the third capacitor C3 as an energy storage device to convert the DC current output by the DC output device 2 into a DC current with an AC component to charge the battery 3.

[0087] Figure 5 FIG. 1 is a schematic diagram showing a topological structure of a vehicle charging system according to an embodiment of the present invention. Figure 5 As shown, the energy conversion device 1 includes a three-phase inverter 100, a three-phase winding 200, a first capacitor C1 and a second capacitor C2.

[0088] Among them, the three-phase inverter 100 includes three-phase bridge arms A, B, and C, wherein the A-phase bridge arm includes switching devices Q1 and Q2, the B-phase bridge arm includes switching devices Q3 and Q4, and the C-phase bridge arm includes switching devices Q5 and Q6. The three-phase winding 200 includes an A-phase winding LA, a B-phase winding LB, and a C-phase winding LC. The incoming ends of the windings LA, LB, and LC of the three-phase winding 200 are respectively connected to the A, B, and C three-phase bridge arms of the three-phase inverter 100. The first capacitor C1 of the energy conversion device 1 is connected between the busbars of the three-phase inverter 100 so that the first capacitor C1 is connected in parallel to the three-phase inverter 100. The two ends of the third capacitor C3 are respectively connected to the neutral point of the three-phase winding 200 and one pole (positive or negative) of the busbar of the three-phase inverter 100.

[0089] Optionally, in this embodiment, one end of the third capacitor C3 may be connected to at least one phase input terminal of the three-phase winding 200 , and the other end of the third capacitor C3 may be connected to one pole (positive pole or negative pole) of the busbar of the three-phase inverter 100 .

[0090] The busbars of the three-phase winding 200 are correspondingly connected to the busbars of the vehicle battery 3 , and the busbars of the DC output device 2 are connected in parallel to the second capacitor C2 .

[0091] Optionally, in this embodiment, one pole of the busbar of the DC output device 2 may be connected to the third capacitor C3 , and the other pole of the busbar of the DC output device 2 may be connected to one pole (positive pole or negative pole) of the three-phase inverter 100 .

[0092] In this embodiment, the controller boosts the output voltage of the external charging device by controlling the duty cycle signal of the bridge arm. The voltage output by the bus of the three-phase inverter 100 does not remain constant in a short period of time, but fluctuates around the target voltage. A fluctuating voltage difference is generated between the output voltage and the constant voltage of the battery 3. The voltage difference generates a fluctuating current under parameters such as the internal resistance of the battery 3 and the cable impedance. The amplitude and frequency of the fluctuating current follow the DC demand of the battery 3 and are achieved by controlling the duty cycle signal. On the basis of boost charging, a periodic AC current component is output and superimposed on the DC current output by the charging device to form a DC current with an AC component to charge the battery 3, so as to reduce the attenuation of the life of the battery 3 caused by the constant DC current in the charging scenario.

[0093] Alternatively, if Figure 5 As shown, the second capacitor C2 is connected to the three-phase winding 200 through the second switch K2 in a switchable manner, and the controller is connected to the second switch K2. When charging the battery 3 of the vehicle, the controller controls the second switch K2 to close. When the vehicle is driving, the controller controls the second switch K2 to open, so that the reused electric drive system can normally output the torque required for the vehicle to drive.

[0094] In any of the above embodiments, the waveform of the DC current with AC component can be as follows: Figure 6 The continuous sinusoidal current shown can also be Figure 7 The current shown has a sinusoidal envelope with a pulsed nature.

[0095] According to another embodiment of the present invention, a vehicle charging control method is provided. The control method is applied to a vehicle charging system of any of the above embodiments. The method includes:

[0096] During the process of charging the battery of the vehicle, the multi-phase bridge arms of the multi-phase inverter are controlled to operate so as to form a direct current with an alternating current component to charge the battery.

[0097] In the method, the charge and discharge data includes at least one of a charge and discharge message, a voltage level of an external device detected by a voltage detection device, and a charge and discharge capability of the battery.

[0098] In multiple embodiments of the charging system for the above-mentioned vehicle, a method in which a controller controls the operation of a multi-phase inverter to ultimately form a DC current with an AC component to charge the battery pack of the vehicle is specifically described, which will not be repeated here.

[0099] According to another embodiment of the present invention, a vehicle is provided, which includes the vehicle charging system described in any one of the above embodiments.

[0100] According to another embodiment of the present invention, a controller is provided, which includes a memory and a processor, wherein the memory stores a computer program, and when the program is executed by the processor, the steps of the vehicle charging control method in any of the above-mentioned embodiments can be implemented.

[0101] According to another embodiment of the present invention, a readable storage medium is provided for storing a computer program, wherein the program, when executed by a computer or a processor, implements the steps of the vehicle charging control method in any of the above-mentioned embodiments.

[0102] The vehicle charging system and the vehicle charging control method of the present invention, that is, the vehicle, can superimpose an AC current component on the DC charging current, thereby improving the impact of DC current charging on the service life of the battery while ensuring the charging speed. At the same time, by reusing the vehicle's electric drive system to generate an AC current component, the increase in cost and volume caused by reassembly is avoided. In addition, during the charging process, the charging current can also be boosted or stepped down, effectively improving the reuse rate of the vehicle's charging system.

[0103] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A vehicle charging system, characterized in that: include: Energy conversion device, DC output device and controller; Wherein, the energy conversion device and the DC output device are connected to each other, and both the energy conversion device and the DC output device are connected to a battery of a vehicle; The energy conversion device comprises a multi-phase inverter, a multi-phase winding and a first capacitor, the inlet terminals of the multi-phase winding are respectively connected to the multi-phase bridge arms of the multi-phase inverter, and the first capacitor is connected in parallel to the multi-phase inverter; The controller is connected to the multi-phase inverter and controls the multi-phase bridge arms of the multi-phase inverter to generate a direct current with an alternating current component to charge the battery of the vehicle.

2. The vehicle charging system according to claim 1, characterized in that: The multi-phase inverter, the multi-phase winding and the first capacitor of the energy conversion device are reused as the electric drive system of the vehicle.

3. The vehicle charging system according to claim 1, characterized in that: The busbar of the multiphase inverter is correspondingly connected to the busbar of the battery, and the busbar of the DC output device is connected in parallel to the busbar of the multiphase inverter and the busbar of the battery; The controller controls the action of the switching devices of the multi-phase bridge arm, and uses the multi-phase winding and the first capacitor as energy storage devices to form the AC current component on the bus of the multi-phase inverter, which is superimposed with the DC current output from the bus of the DC output device to form a DC current with an AC component to charge the battery.

4. The vehicle charging system according to claim 1, characterized in that: The busbar of the DC output device is connected to the busbar of the multi-phase inverter; The neutral point of the multi-phase winding is connected to one pole of the busbar of the battery, and any pole of the busbar of the multi-phase inverter is connected to the other pole of the busbar of the battery, or The incoming line end of at least one phase of the multi-phase winding is connected to one pole of the busbar of the battery, and any pole of the busbar of the multi-phase inverter is connected to the other pole of the busbar of the battery; The controller controls the action of the switch devices of the multi-phase bridge arm, and uses the multi-phase winding and the first capacitor as energy storage devices to convert the DC current output by the DC output device into a DC current with an AC component to charge the battery.

5. The vehicle charging system according to claim 1, characterized in that: The neutral point of the multi-phase winding is connected to one pole of the busbar of the battery, and any pole of the busbar of the multi-phase inverter is connected to the other pole of the busbar of the battery, or The incoming line end of at least one phase of the multi-phase winding is connected to one pole of the busbar of the battery, and any pole of the busbar of the multi-phase inverter is connected to the other pole of the busbar of the battery; The DC output device is connected in parallel to the battery; The controller controls the action of the switching devices of the multi-phase bridge arm, and uses the multi-phase winding and the first capacitor as energy storage devices to form the AC current component on the bus of the multi-phase inverter, which is superimposed with the DC current output from the bus of the DC output device to form a DC current with an AC component to charge the battery.

6. The vehicle charging system according to claim 1, characterized in that: The energy conversion device further includes a second capacitor, one pole of the second capacitor is connected to the neutral point of the multi-phase winding or the incoming line end of at least one phase of the multi-phase winding, and the other pole of the second capacitor is connected to any pole of the busbar of the multi-phase inverter; The busbar of the multiphase inverter is correspondingly connected to the busbar of the battery, and the busbar of the DC output device is connected in parallel to the busbar of the battery and the busbar of the multiphase inverter; The controller controls the action of the switching devices of the multi-phase bridge arm, and uses the multi-phase winding and the second capacitor as energy storage devices to form the AC current component on the bus of the multi-phase inverter, which is superimposed with the DC current output from the bus of the DC output device to form a DC current with an AC component to charge the battery.

7. The vehicle charging system according to claim 1, characterized in that: The energy conversion device further includes a third capacitor, one electrode of the third capacitor is connected to the neutral point of the multi-phase winding or the incoming line end of at least one phase of the multi-phase winding, and the other electrode of the third capacitor is connected to any electrode of the busbar of the multi-phase inverter; The busbar of the multi-phase inverter is correspondingly connected to the busbar of the battery; The busbar of the DC output device is connected in parallel to the third capacitor, or one pole of the busbar of the DC output device is connected to the third capacitor, and the other pole of the busbar of the DC output device is connected to any pole of the busbar of the multi-phase inverter; The controller controls the action of the switch devices of the multi-phase bridge arm, and uses the multi-phase winding and the third capacitor as energy storage devices to convert the DC current output by the DC output device into a DC current with an AC component to charge the battery.

8. The vehicle charging system according to claim 5 or 6, characterized in that: During the process of charging the battery, the controller controls the multi-phase bridge arms of the multi-phase inverter to act synchronously to reduce the torque generated when the current flows through the multi-phase winding.

9. A vehicle charging control method, characterized in that: The charging system for a vehicle according to any one of claims 1 to 8, the method comprising: During the process of charging the battery of the vehicle, the multi-phase bridge arms of the multi-phase inverter are controlled to operate so as to form a direct current with an alternating current component to charge the battery.

10. A vehicle, characterized in that: A charging system for a vehicle comprising any one of claims 1-8.

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