New energy automobile, battery alternating current heating system and heating control method

Abstract

The invention provides a new energy automobile, a battery alternating current heating system and a heating control method. The battery alternating current heating system comprises a power battery unit, a three-phase bridge arm unit, a bus capacitor, a first switch and a motor. The bus capacitor is connected in parallel with the three-phase bridge arm unit, one parallel end is connected to the anode of the power battery unit through the first switch, and the other end is connected to the cathode of the power battery unit; the positive electrodes of the power battery units are further connected to corresponding phase windings in the motor through corresponding second switches, and an inductance adjusting unit is arranged on at least one phase winding branch and comprises an inductor and a third switch which are connected in parallel. In other words, the inductor and the switch assembly are additionally arranged in the battery alternating current heating system, the battery end alternating current effective value and the NVH performance in the heating process are improved, and the problems existing in an existing electric automobile in the low-temperature environment are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery heating, and in particular to a new energy vehicle, a battery AC heating system and a heating control method. Background Art

[0002] At present, a new round of global technological and industrial changes is booming, and technologies in the fields of automobiles, new energy, transportation, information and communications are accelerating their integration. As an important component of new energy vehicles, power batteries provide power sources for vehicles and can store and recycle energy.

[0003] At present, new energy vehicles mainly use lithium-ion batteries, and the external characteristics of lithium batteries are easily affected by the external ambient temperature, especially in low temperature environments. For example, when the ambient temperature is below 0°C, the battery capacity and charge and discharge rate will drop significantly. Therefore, electric vehicles have problems such as reduced range and long charging time at low temperatures; at the same time, when the car is cold-started, the power battery will not be able to quickly provide sufficient power to the motor, which will also lead to problems such as low starting power and poor starting performance of the drive system, which directly affects the user's driving experience. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a new energy vehicle, a battery AC heating system and a heating control method. By adding inductance and switch components to the battery AC heating system, the effective value of the AC current at the battery end and the NVH performance during the heating process are improved, thereby solving the problems existing in electric vehicles in existing low temperature environments.

[0005] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0006] A first aspect of an embodiment of the present invention discloses a battery AC heating system, comprising: a power battery unit, a three-phase bridge arm unit, a bus capacitor, a first switch and a motor;

[0007] The bus capacitor is connected in parallel with the three-phase bridge arm unit, one end of the parallel connection is connected to the positive electrode of the power battery unit through the first switch, and the other end is connected to the negative electrode of the power battery unit;

[0008] The positive poles of the power battery units are also connected to the corresponding phase windings in the motor through corresponding second switches, and at least one phase winding branch is provided with an inductance adjustment unit, which includes an inductor and a third switch connected in parallel.

[0009] Optionally, in the above battery AC heating system, the power battery unit includes: a battery, a first resistor, a second resistor and a capacitor;

[0010] The positive electrode of the battery is connected to one end of the first resistor, the other end of the first resistor is respectively connected to one end of the second resistor and one end of the capacitor, the other end of the second resistor is connected to the other end of the capacitor, and the connection point serves as the positive electrode of the power battery unit;

[0011] The negative electrode of the battery serves as the negative electrode of the power battery unit.

[0012] Optionally, in the above battery AC heating system, each phase bridge arm in the three-phase bridge arm unit includes two switch conduction elements connected in series.

[0013] Optionally, in the above-mentioned battery AC heating system, the first switch, the second switch and the third switch are all electromagnetic relays.

[0014] Optionally, in the above-mentioned battery AC heating system, the motor is a star-connected motor, or a delta-connected motor.

[0015] A second aspect of an embodiment of the present invention discloses a new energy vehicle, comprising: a battery AC heating system as described in any one of the items disclosed in the first aspect.

[0016] A third aspect of an embodiment of the present invention discloses a heating control method, which is applied to the battery AC heating system as disclosed in any one of the first aspects, and the method includes:

[0017] When the battery AC heating system is in a battery AC heating operating state, determining a current motor electrical angle of the battery AC heating system;

[0018] According to the current motor electrical angle, the corresponding second switch state in the battery AC heating system is controlled so that the battery AC heating system generates a battery terminal heating current of required frequency and amplitude at the battery terminal.

[0019] Optionally, in the above heating control method, after controlling the corresponding second switch state in the battery AC heating system according to the current motor electrical angle so that the battery AC heating system generates a battery terminal heating current of a required frequency and amplitude at the battery terminal, the method further includes:

[0020] determining a target battery terminal heating current value of the battery AC heating system;

[0021] According to the relationship between the current battery terminal heating current value of the battery AC heating system and the target battery terminal heating current value, the corresponding third switch state in the battery AC heating system is controlled to change the inductance value in the battery AC heating system loop so that the battery terminal heating current generated at the battery terminal by the battery AC heating system reaches the target battery terminal heating current value.

[0022] Optionally, in the above-mentioned heating control method, according to the current motor electrical angle, the corresponding second switch state in the battery AC heating system is controlled so that the battery AC heating system generates a battery terminal heating current of a required frequency and amplitude at the battery terminal, including:

[0023] If the current motor angle satisfies a first control condition, the second switch on the U-phase winding branch of the battery AC heating system is controlled to be closed, and the second switch on the V-phase winding branch and the second switch on the W-phase winding branch are controlled to be opened, and the first control condition is that the current motor electrical angle is within a first preset range or a second preset range;

[0024] If the current motor electrical angle satisfies a second control condition, the second switch on the V-phase winding branch of the battery AC heating system is controlled to be closed, and the second switch on the U-phase winding branch and the second switch on the W-phase winding branch are controlled to be opened, and the second control condition is that the current motor electrical angle is within a third preset range or a fourth preset range;

[0025] If the current motor electrical angle satisfies the third control condition, the second switch on the W-phase winding branch in the battery AC heating system is controlled to be closed, and the second switch on the U-phase winding branch and the second switch on the V-phase winding branch are controlled to be disconnected, and the third control condition is that the current motor electrical angle is within the fifth preset range or the sixth preset range.

[0026] Optionally, in the above-mentioned heating control method, according to the magnitude relationship between the current battery terminal heating current value of the battery AC heating system and the target battery terminal heating current value, the corresponding third switch state in the battery AC heating system is controlled so as to change the inductance value in the battery AC heating system loop so that the battery terminal heating current generated by the battery AC heating system at the battery terminal reaches the target battery terminal heating current value, including:

[0027] Determining whether the current battery terminal heating current value is greater than the target battery terminal heating current value;

[0028] If it is determined that the current battery terminal heating current value is greater than the target battery terminal heating current value, controlling the third switch on the corresponding winding branch to be closed;

[0029] If it is determined that the current battery terminal heating current value is not greater than the target battery terminal heating current value, the third switch on the corresponding winding branch is controlled to be disconnected;

[0030] The corresponding winding branch is a winding branch in which the second switch is in a closed state.

[0031] The battery AC heating system provided based on the above-mentioned embodiment of the present invention includes: a power battery unit, a three-phase bridge arm unit, a bus capacitor, a first switch and a motor; the bus capacitor is connected in parallel with the three-phase bridge arm unit, one end of the parallel connection is connected to the positive electrode of the power battery unit through the first switch, and the other end is connected to the negative electrode of the power battery unit; the positive electrode of the power battery unit is also connected to the corresponding phase winding in the motor through the corresponding second switch, and there is at least one phase winding branch provided with an inductance adjustment unit, the inductance adjustment unit includes an inductor and a third switch connected in parallel, that is, the present application can improve the effective value of the AC current at the battery end and the NVH performance during the heating process by adding an inductor and a switch component to the battery AC heating system, thereby solving the problems existing in electric vehicles in existing low temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0033] Figure 1 A schematic diagram of the structure of a battery AC heating system provided in this application;

[0034] Figure 2 A circuit diagram of a battery AC heating system provided in an embodiment of the present application;

[0035] Figure 3 and Figure 4 Schematic diagram of two battery AC heating systems provided in embodiments of the present application;

[0036] Figure 5 and Figure 6 Flowcharts of two heating control methods provided in embodiments of the present application. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0039] First of all, it should be noted that the existing electric vehicles have reduced cruising range and long charging time in low temperature environments, and during cold start, the power battery will not be able to quickly provide sufficient power to the motor, which will also lead to low starting power of the drive system, poor starting performance and other problems that directly affect the user's driving experience. At present, they are generally solved by external heating and AC heating methods. Among them, the external heating method mainly relies on the heating equipment to provide heat to the power battery from the outside, so that the power battery can be quickly heated up to ensure the driving ability of the electric drive system. However, the inventors have found that the external heating method has a complex structure, and there is not only an additional cost burden in the implementation process of the vehicle-mounted end, but also has problems such as difficulty in layout. In addition, in extremely low temperature environments, the discharge power of the power battery is limited, which also affects the actual heating effect; while the AC heating method mainly relies on generating AC power at the battery end for self-heating, does not change the architecture of the electric drive system, is more economical, the battery heats up evenly and the motor torque is 0, but the inventors have found that the existing scheme has problems such as low effective value of charging and discharging current at the battery end, high harmonic content of motor phase current, increased rotor temperature, large vibration noise, and large bus capacitor voltage impact.

[0040] In this regard, an embodiment of the present invention provides a battery AC heating system. By adding inductance and switch components to the battery AC heating system, the effective value of the AC current at the battery end and the NVH performance during the heating process are improved, thereby solving the problems of the existing solution, such as the low effective value of the charging and discharging current at the battery end, the high harmonic content of the motor phase current, the increased rotor temperature, the large vibration noise, and the large bus capacitor voltage impact.

[0041] In addition, compared with the external heating method, the AC heating method provided in this application has a relatively simple structure. During the implementation on the vehicle side, there is almost no additional cost burden and the layout is easy. In addition, in an extremely low temperature environment, the discharge power of the power battery is almost unrestricted, and the actual heating effect is good.

[0042] See also Figure 1 and Figure 2 The battery AC heating system may include: a power battery unit 1, a three-phase bridge arm unit 7, a bus capacitor 6, a first switch 2 and a motor 8.

[0043] The bus capacitor 6 is connected in parallel with the three-phase bridge arm unit 7, one end of the parallel connection is connected to the positive electrode of the power battery unit 1 through the first switch 2, and the other end is connected to the negative electrode of the power battery unit 1;

[0044] The positive pole of the power battery unit 1 is also connected to the corresponding phase winding in the motor 8 through the corresponding second switch 4, and there is an inductance adjustment unit 5 arranged on at least one phase winding branch, and the inductance adjustment unit 5 includes an inductor 51 and a third switch 52 connected in parallel.

[0045] In practical applications, the first switch 2 is mainly used to establish and disconnect the high voltage of the motor controller.

[0046] In some embodiments, Figure 1 , Figure 2 , Figure 3 or Figure 4 As shown, the power battery unit 1 may include: a battery V l , a first resistor Rs, a second resistor Rp and a capacitor Cp.

[0047] Among them, the battery V l The positive electrode of the first resistor Rs is connected to one end of the first resistor Rs, the other end of the first resistor Rs is connected to one end of the second resistor Rp and one end of the capacitor Cp respectively, the other end of the second resistor Rp is connected to the other end of the capacitor Cp, and the connection point serves as the positive electrode of the power battery unit 1; the battery V l The negative electrode of is used as the negative electrode of the power battery unit 1.

[0048] It should be noted that Figure 1 , Figure 2 , Figure 3 or Figure 4 This is only a specific example of the power battery unit 1 in practical application, and the specific structure of the power battery unit 1 is not limited to this. No matter what structure the power battery unit 1 adopts, it is within the protection scope of this application.

[0049] In some embodiments, each phase bridge arm in the three-phase bridge arm unit 7 includes two switch conduction elements connected in series.

[0050] In practical applications, the switch conducting element may be a switch tube with a diode, that is, Figure 1 , Figure 2 , Figure 3 or Figure 4 S1, S2, S3, S4, S5 and S6 are shown; of course, they are not limited to these, and may also be other existing switch guide elements, which are not limited in the present application and are all within the protection scope of the present application.

[0051] It should be noted that, combined with Figure 1 , Figure 2 , Figure 3 or Figure 4 The three-phase bridge arm unit may include: a U-phase bridge arm, a V-phase bridge arm and a W-phase bridge arm. The U-phase bridge arm is formed by connecting the switch conducting element S1 and the switch conducting element S2 in series; the V-phase bridge arm is formed by connecting the switch conducting element S3 and the switch conducting element S4 in series; and the W-phase bridge arm is formed by connecting the switch conducting element S5 and the switch conducting element S6 in series.

[0052] In some embodiments, the first switch 2, the second switch 4 and the third switch 52 can all be electromagnetic relays; of course, this is not limited to this, and they can also be other types of existing relays or switch elements. This application does not limit them and they are all within the protection scope of this application.

[0053] In some embodiments, the specific type of motor 8 may be a star-connected motor or a delta-connected motor; of course, it is not limited thereto, and may also be other existing motors, which are not limited in this application and are within the protection scope of this application. Figure 1 and Figure 2 Only the star-connected motor is shown.

[0054] It should be noted that the first switch 2, the second switch 4 and the third switch 52 can be controlled by the motor controller in the battery AC heating system, or other controllers, such as a host computer, etc., which can control them through corresponding heating protection logic, thereby changing the inductance value of the loop in the battery AC heating system, thereby improving the battery-end AC current value and NVH (Noise, Vibration, Harshness) performance.

[0055] Under the battery AC heating condition, by controlling the on-off state of the third switch 52 in the inductance adjustment unit 5, the loop inductance value in the battery AC heating system can be changed to achieve the purpose of adjusting the battery-side AC inductance value and NVH performance in the electric drive system.

[0056] In practical applications, when the number of the inductance adjustment unit 5 is 1, it can be set on any one-phase winding branch of the battery AC heating system; when the number of the inductance adjustment unit 5 is 2, it can be set on any two-phase winding branches of the battery AC heating system; when the number of the inductance adjustment unit 5 is 3, it can be set on any three-phase winding branches of the battery AC heating system, that is, Figure 1 and Figure 2 shown.

[0057] Combination Figure 2In the battery AC heating condition, the first switch 2 can be opened, and the corresponding phase switch can be selected to close according to the electrical angle of the motor 8. For example, when the electrical angle is 0° or 180°, the second switch 4 corresponding to U can be closed, the second switch 4 corresponding to V and the second switch 4 corresponding to W can be opened. At this time, the principle of the reconstructed battery AC heating system is as follows: Figure 3 As shown, after reconstruction, the system can be transformed into a Boost / Buck system, which generates the battery-end AC heating current of the required frequency and amplitude by controlling the upper and lower switch conduction elements of the U-phase bridge arm, the upper and lower switch conduction elements of the V-phase bridge arm, and the upper and lower switch conduction elements of the W-phase bridge arm. In order to optimize the effective value of the battery-end AC heating current and the NVH performance, the inductance value of the system loop can be changed by controlling the on and off of the third switch 52 corresponding to U. Specifically, the third switch 52 corresponding to U is controlled to be closed, and the equivalent system principle block diagram can be as follows Figure 3 As shown; the third switch 52 corresponding to the control U is disconnected, and the equivalent system principle block diagram can be as follows Figure 4 shown.

[0058] It should be noted that in practice, the motor winding current command can be converted into a voltage command through closed control, and then the voltage command can be converted into a control command to control the opening and closing of each phase bridge arm; the action control of the upper and lower switch guide elements in each phase bridge arm of the three-phase bridge arm unit 7 can be referred to the prior art, and this application will not go into details one by one.

[0059] It can be understood that by adding an inductance adjustment unit 5 composed of an inductor 51 and a third switch 52 to the battery AC heating system, the inductance value in the battery AC heating system loop based on the electric drive system can be made variable, providing a variable dimension for optimizing the effective value of the AC current at the battery end and the NVH performance during the heating process.

[0060] Based on the above principles, the battery AC heating system provided in this embodiment may include: a power battery unit 1, a three-phase bridge arm unit 7, a bus capacitor 6, a first switch 2 and a motor 8; the bus capacitor 6 is connected in parallel with the three-phase bridge arm unit 7, one end of the parallel connection is connected to the positive electrode of the power battery unit 1 through the first switch 2, and the other end is connected to the negative electrode of the power battery unit 1; the positive electrode of the power battery unit 1 is also connected to the corresponding phase winding in the motor 8 through the corresponding second switch 4, and there is at least one phase winding branch provided with an inductance adjustment unit 5, the inductance adjustment unit 5 includes an inductor 51 and a third switch 52 connected in parallel, that is, the present application can improve the effective value of the AC current at the battery end and the NVH performance during the heating process by adding inductance and switch components to the battery AC heating system, and solves the problems of low effective value of charging and discharging current at the battery end, high harmonic content of motor phase current, increased rotor temperature, large vibration noise, and large bus capacitor voltage impact in the existing solution.

[0061] On the basis of the battery AC heating system provided in the above embodiments, another embodiment of the present application further provides a new energy vehicle, which includes the battery AC heating system shown in any of the above embodiments.

[0062] It should be noted that, for the relevant description of the battery AC heating system, please refer to the above corresponding embodiments, which will not be repeated here. For the new energy vehicle, please refer to the prior art, which will not be repeated in this application.

[0063] Optionally, another embodiment of the present application further provides a heating control method, which can be applied to the battery AC heating system provided in any of the above embodiments, see Figure 5 , the heating control method may include the following steps:

[0064] S101. When the battery AC heating system is in a battery AC heating operating condition, determine a current motor electrical angle of the battery AC heating system.

[0065] The current motor electrical angle may be the current electrical angle of the motor in the battery AC heating system.

[0066] In practical applications, the current electrical angle of the motor can be calculated based on the mechanical angle and pole pair number of the motor in the battery AC heating system; of course, it is not limited to this, and the current electrical angle of the motor can be determined by other existing methods. This application does not limit the determination method, and all are within the protection scope of this application.

[0067] It should be noted that when the battery AC heating system is in the battery AC heating working condition, the first switch in the battery AC heating system is in an off state.

[0068] S102. Control the corresponding second switch state in the battery AC heating system according to the current motor electrical angle, so that the battery AC heating system generates a battery terminal heating current of required frequency and amplitude at the battery terminal.

[0069] In practical applications, according to the current motor electrical angle, the corresponding second switch state in the battery AC heating system is controlled so that the battery AC heating system generates a battery terminal heating current of the required frequency and amplitude at the battery terminal. The specific process can be roughly divided into the following three cases:

[0070] Case 1: If the current motor angle meets the first control condition, the second switch on the U-phase winding branch in the battery AC heating system is controlled to be closed, and the second switch on the V-phase winding branch and the second switch on the W-phase winding branch are disconnected. The first control condition is that the current motor electrical angle is within the first preset range or the second preset range.

[0071] The first preset range may be an electrical angle of about 0°, and the second preset range may be an electrical angle of about 180°. Specifically, the upper and lower limits of the first preset range and the second preset range may be determined according to the application environment and user needs. For example, the electrical angle may be 0° or 180° alone. This application does not limit this, and all are within the protection scope of this application.

[0072] Case 2: If the current motor electrical angle meets the second control condition, the second switch on the V-phase winding branch in the battery AC heating system is controlled to be closed, and the second switch on the U-phase winding branch and the second switch on the W-phase winding branch are disconnected. The second control condition is that the current motor electrical angle is within the third preset range or the fourth preset range.

[0073] Among them, the third preset range may be an electrical angle of about 60°, and the fourth preset range may be an electrical angle of about 240°. Specifically, the specific upper and lower limits of the third preset range and the fourth preset range may be determined according to the application environment and user needs. For example, the electrical angle may be 60° or 240° alone, which is not limited in this application and is within the protection scope of this application.

[0074] Case 3: If the current motor electrical angle meets the third control condition, the second switch on the W-phase winding branch in the battery AC heating system is controlled to be closed, and the second switch on the U-phase winding branch and the second switch on the V-phase winding branch are disconnected. The third control condition is that the current motor electrical angle is within the fifth preset range or the sixth preset range.

[0075] Among them, the fifth preset range may be an electrical angle of about 120°, and the sixth preset range may be an electrical angle of about 300°. Specifically, the specific upper and lower limits of the fifth preset range and the sixth preset range may be determined according to the application environment and user needs. For example, the electrical angle may be 120° or 300° alone. This application does not limit this, and all are within the protection scope of this application.

[0076] In this embodiment, the corresponding second switch in the battery AC heating system can be controlled according to the current electrical angle of the motor, and the system can be reconstructed into a Boost / Buck system. Then, by controlling the action of each switch conduction element in the three-phase bridge arm unit in the battery AC heating system, the battery-end AC heating current of the required frequency and amplitude can be generated.

[0077] In some embodiments, after executing step S102, according to the current motor electrical angle, the corresponding second switch state in the battery AC heating system is controlled so that the battery AC heating system generates a battery terminal heating current of the required frequency and amplitude at the battery terminal, see Figure 6 , the heating control method may further include the following steps:

[0078] S201. Determine a target battery terminal heating current value of a battery AC heating system.

[0079] Among them, the target battery-end heating current value can be the value that the battery-end AC current in the battery AC heating system wants to reach; the specific value of this value can be determined according to the application environment and user needs, and this application does not limit it, and it is within the protection scope of this application.

[0080] S202. Based on the relationship between the current battery terminal heating current value and the target battery terminal heating current value of the battery AC heating system, the corresponding third switch state in the battery AC heating system is controlled to change the inductance value in the battery AC heating system loop so that the battery terminal heating current generated at the battery terminal by the battery AC heating system reaches the target battery terminal heating current value.

[0081] In practical applications, we can first determine whether the current battery terminal heating current value is greater than the target battery terminal heating current value, and then control the corresponding switch based on the determination result to change the inductance value in the battery AC heating system loop so that the battery terminal heating current generated by the battery AC heating system at the battery terminal reaches the target battery terminal heating current value.

[0082] If it is determined that the current battery terminal heating current value is greater than the target battery terminal heating current value, the third switch on the corresponding winding branch can be controlled to be closed; if it is determined that the current battery terminal heating current value is not greater than the target battery terminal heating current value, the third switch on the corresponding winding branch can be controlled to be opened. Specifically, the corresponding winding branch can be a winding branch in which the second switch is in a closed state.

[0083] It should be noted that in actual applications, the motor controller or other controllers in the battery AC heating system, such as a host computer, can execute the logic of the above heating control method to achieve battery heating.

[0084] Based on the above, the heating control method provided in this embodiment can control the corresponding third switch state in the battery AC heating system according to the relationship between the current battery terminal heating current value and the target battery terminal heating current value of the battery AC heating system, so as to change the inductance value in the battery AC heating system loop so that the battery terminal heating current generated by the battery AC heating system at the battery terminal reaches the target battery terminal heating current value, thereby improving the battery terminal AC current value and NVH performance.

[0085] In addition, based on factors such as the service life of the battery and battery drive system and the safety of charging and discharging, the corresponding software algorithm can be used to optimize and improve the battery-end heating value and NVH performance of the battery AC heating system to meet the battery heating needs of the entire vehicle.

[0086] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0087] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0088] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery AC heating system, characterized in that: include: Power battery unit, three-phase bridge arm unit, bus capacitor, first switch and motor; The bus capacitor is connected in parallel with the three-phase bridge arm unit, one end of the parallel connection is connected to the positive electrode of the power battery unit through the first switch, and the other end is connected to the negative electrode of the power battery unit; The positive poles of the power battery units are also connected to the corresponding phase windings in the motor through corresponding second switches, and at least one phase winding branch is provided with an inductance adjustment unit, which includes an inductor and a third switch connected in parallel.

2. The battery AC heating system according to claim 1, characterized in that: The power battery unit comprises: a battery, a first resistor, a second resistor and a capacitor; The positive electrode of the battery is connected to one end of the first resistor, the other end of the first resistor is respectively connected to one end of the second resistor and one end of the capacitor, the other end of the second resistor is connected to the other end of the capacitor, and the connection point serves as the positive electrode of the power battery unit; The negative electrode of the battery serves as the negative electrode of the power battery unit.

3. The battery AC heating system according to claim 1, characterized in that: Each phase bridge arm in the three-phase bridge arm unit includes two switch conducting elements connected in series.

4. The battery AC heating system according to any one of claims 1 to 3, characterized in that: The first switch, the second switch and the third switch are all electromagnetic relays.

5. The battery AC heating system according to any one of claims 1 to 3, characterized in that: The motor is a star-connected motor or a delta-connected motor.

6. A new energy vehicle, characterized in that: include: A battery AC heating system as claimed in any one of claims 1 to 5.

7. A heating control method, characterized in that: Applied to the battery AC heating system according to any one of claims 1 to 5, the method comprises: When the battery AC heating system is in a battery AC heating operating state, determining a current motor electrical angle of the battery AC heating system; According to the current motor electrical angle, the corresponding second switch state in the battery AC heating system is controlled so that the battery AC heating system generates a battery terminal heating current of required frequency and amplitude at the battery terminal.

8. The heating control method according to claim 7, characterized in that: After controlling the corresponding second switch state in the battery AC heating system according to the current motor electrical angle so that the battery AC heating system generates a battery terminal heating current of a required frequency and amplitude at the battery terminal, the method further includes: determining a target battery terminal heating current value of the battery AC heating system; According to the relationship between the current battery terminal heating current value of the battery AC heating system and the target battery terminal heating current value, the corresponding third switch state in the battery AC heating system is controlled to change the inductance value in the battery AC heating system loop so that the battery terminal heating current generated at the battery terminal by the battery AC heating system reaches the target battery terminal heating current value.

9. The heating control method according to claim 7, characterized in that: According to the current motor electrical angle, the corresponding second switch state of the battery AC heating system is controlled so that the battery AC heating system generates a battery terminal heating current of a required frequency and amplitude at the battery terminal, including: If the current motor angle satisfies a first control condition, the second switch on the U-phase winding branch of the battery AC heating system is controlled to be closed, and the second switch on the V-phase winding branch and the second switch on the W-phase winding branch are controlled to be opened, and the first control condition is that the current motor electrical angle is within a first preset range or a second preset range; If the current motor electrical angle satisfies a second control condition, the second switch on the V-phase winding branch of the battery AC heating system is controlled to be closed, and the second switch on the U-phase winding branch and the second switch on the W-phase winding branch are controlled to be opened, and the second control condition is that the current motor electrical angle is within a third preset range or a fourth preset range; If the current motor electrical angle satisfies the third control condition, the second switch on the W-phase winding branch in the battery AC heating system is controlled to be closed, and the second switch on the U-phase winding branch and the second switch on the V-phase winding branch are controlled to be disconnected, and the third control condition is that the current motor electrical angle is within the fifth preset range or the sixth preset range.

10. The heating control method according to claim 8, characterized in that: According to the magnitude relationship between the current battery terminal heating current value of the battery AC heating system and the target battery terminal heating current value, the corresponding third switch state of the battery AC heating system is controlled to change the inductance value in the battery AC heating system loop so that the battery terminal heating current generated by the battery AC heating system at the battery terminal reaches the target battery terminal heating current value, including: Determining whether the current battery terminal heating current value is greater than the target battery terminal heating current value; If it is determined that the current battery terminal heating current value is greater than the target battery terminal heating current value, controlling the third switch on the corresponding winding branch to be closed; If it is determined that the current battery terminal heating current value is not greater than the target battery terminal heating current value, the third switch on the corresponding winding branch is controlled to be disconnected; The corresponding winding branch is a winding branch in which the second switch is in a closed state.

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