Electric drive noise reduction method, electric drive system and new energy vehicle

Abstract

The invention provides an electric drive noise reduction method, an electric drive system and a new energy vehicle. The electric drive noise reduction method comprises the steps that electric drive operation condition information is acquired; on the basis of the operation condition information, reverse compensation harmonic current corresponding to gear meshing excitation vibration of the current reduction gearbox is obtained through an open-loop algorithm or a closed-loop algorithm; and injecting the reverse compensation harmonic current into the motor driving current of the electric drive to counteract or weaken the meshing excitation vibration. According to the configuration, on the basis of the operation condition information of the electric drive, the reverse compensation harmonic current corresponding to the gear meshing excitation vibration of the current reduction gearbox can be obtained through an open-loop algorithm or a closed-loop algorithm; therefore, the reverse compensation harmonic current is compensated into the motor driving current, the gear meshing excitation vibration of the reduction gearbox can be reduced, the noise is controlled at a noise source, and the mechanical noise of the reduction gearbox is effectively and actively controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to an electric drive noise reduction method, an electric drive system and a new energy vehicle. Background Art

[0002] Currently, new energy vehicles have increasingly higher requirements for the noise of electric drive products. The mainstream solution usually reduces the electromagnetic noise of the motor or the mechanical noise of the reduction gearbox by optimizing the mechanical structure. Although there are also methods to suppress electromagnetic noise, there is no mature and reliable control solution for mechanical noise. Summary of the invention

[0003] The purpose of the present invention is to provide an electric drive noise reduction method, an electric drive system and a new energy vehicle to solve the problem that the existing electric drive system lacks control over mechanical noise.

[0004] In order to solve the above technical problems, the present invention provides a noise reduction method for electric drive, which comprises: obtaining operating status information of the electric drive; Based on the operating status information, a reverse compensation harmonic current corresponding to the gear meshing excitation vibration of the current reduction box is obtained through an open-loop algorithm or a closed-loop algorithm; The reverse compensation harmonic current is injected into the motor drive current of the electric drive to offset or weaken the meshing excitation vibration.

[0005] Optionally, the operating status information of the electric drive includes real-time torque information and real-time speed information of the motor of the electric drive; and the open-loop algorithm includes: Based on the real-time torque information and the real-time speed information, the reverse compensation harmonic current is obtained by looking up a preset amplitude phase table.

[0006] Optionally, the amplitude phase table is obtained through online calibration during the research and development or production stage of the electric drive.

[0007] Optionally, the operating status information of the electric drive includes vibration information of the electric drive and angle information of the rotor of the motor; and the closed-loop algorithm includes: Based on the vibration information and the angle information, obtaining amplitude information and phase information of meshing excitation vibration; The reverse compensation harmonic current is calculated based on the amplitude information and phase information of the meshing excitation vibration.

[0008] Optionally, based on the vibration information and the angle information, the amplitude information and the phase information are obtained by discrete Fourier transform and order calculation.

[0009] Optionally, the vibration information is collected based on a vibration sensor disposed on an integrated housing of the electric drive.

[0010] Optionally, the step of injecting the reverse compensation harmonic current into the motor drive current of the electric drive to offset or weaken the meshing excitation vibration includes: Obtaining required torque of the motor and angle information of the rotor of the motor; Based on the required torque and the angle information, an expected driving current is obtained; The reverse compensation harmonic current is combined with the expected driving current to obtain an actual driving current, and the motor is driven with the actual driving current.

[0011] In order to solve the above technical problems, the present invention also provides an electric drive system, which includes: an electric drive and a vibration control unit; the electric drive includes at least a motor, a motor controller and a reduction box; the vibration control unit is configured to obtain the amplitude information and phase information of the reverse compensation harmonic current according to the noise reduction method of the electric drive as described above, and send the amplitude information and phase information of the reverse compensation harmonic current to the motor controller; the motor controller compensates the actual drive current according to the amplitude information and phase information of the reverse compensation harmonic current.

[0012] Optionally, the electric drive system also includes a vibration sensor; the vibration sensor is used to obtain vibration information of the reduction box; the vibration sensor is communicatively connected to the vibration control unit, and is used to send the vibration information to the vibration control unit.

[0013] In order to solve the above technical problems, the present invention also provides a new energy vehicle, which includes the electric drive system as described above.

[0014] In summary, in the electric drive noise reduction method, electric drive system and new energy vehicle provided by the present invention, the electric drive noise reduction method includes: obtaining the operating status information of the electric drive; based on the operating status information, obtaining the reverse compensation harmonic current corresponding to the gear meshing excitation vibration of the current reduction box through an open-loop algorithm or a closed-loop algorithm; injecting the reverse compensation harmonic current into the motor drive current of the electric drive to offset or weaken the meshing excitation vibration.

[0015] With such configuration, based on the operating status information of the electric drive, the reverse compensation harmonic current corresponding to the gear meshing excitation vibration of the current reduction gearbox can be obtained through an open-loop algorithm or a closed-loop algorithm; and then the reverse compensation harmonic current is compensated into the motor drive current, which can reduce the gear meshing excitation vibration of the reduction gearbox, achieve noise control at the noise source, and effectively and actively control the mechanical noise of the reduction gearbox. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Those skilled in the art will appreciate that the drawings are provided for a better understanding of the present invention, but do not constitute any limitation on the scope of the present invention.

[0017] Figure 1 Schematic diagram of a module of an electric drive system according to an embodiment of the present invention.

[0018] Figure 2 It is a schematic structural diagram of a reduction gearbox with a parallel shaft structure according to an embodiment of the present invention.

[0019] Figure 3 It is a schematic structural diagram of a reduction gearbox with a planetary gear structure according to an embodiment of the present invention.

[0020] Figure 4 It is a schematic diagram of meshing excitation force compensation according to an embodiment of the present invention.

[0021] Figure 5 4 is a flow chart of a noise reduction method for electric drive according to an embodiment of the present invention.

[0022] Figure 6 It is a flow chart of electric drive noise reduction control based on an open-loop algorithm according to an embodiment of the present invention.

[0023] Figure 7 It is a flow chart of electric drive noise reduction control based on a closed-loop algorithm according to an embodiment of the present invention.

[0024] In the attached drawings: 1-electric drive; 10-integrated housing; 11-motor; 111-rotor; 112-motor shaft; 113-stator; 12-motor controller; 13-reduction gearbox; 131-first-stage driving gear; 132-first-stage driven gear; 133-second-stage driving gear; 134-second-stage driven gear; 135-sun gear; 136-large planetary gear; 137-small planetary gear; 138-ring gear; 2-vibration control unit; 3-vibration sensor. DETAILED DESCRIPTION

[0025] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0026] As used in the present invention, the singular forms "a", "an", "one" and "the" include plural objects, the term "or" is usually used to include the meaning of "and / or", the term "several" is usually used to include the meaning of "at least one", and the term "at least two" is usually used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features, "one end" and "the other end" as well as "proximal end" and "distal end" generally refer to two corresponding parts, which include not only endpoints. In addition, as used in the present invention, "installed", "connected", "connected", and one element "set" on another element should be understood in a broad sense, usually only indicating that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the connection, coupling, cooperation or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any orientation such as inside, outside, above, below or one side of another element, unless the content clearly indicates otherwise. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used relative to the exemplary embodiments as shown in the figures, with the upward or upper direction toward the top of the corresponding figure, and the downward or lower direction toward the bottom of the corresponding figure.

[0027] The purpose of the present invention is to provide an electric drive noise reduction method, an electric drive system and a new energy vehicle to solve the problem that the existing electric drive system lacks control over mechanical noise. The following is a description with reference to the accompanying drawings.

[0028] Please refer to Figure 1 , this embodiment provides an electric drive 1, which is a three-in-one electric drive, that is, it integrates a motor 11, a motor controller 12 and a reduction box 13, and the three preferably have an integrated housing 10. It should be noted that the electric drive 1 referred to in this embodiment is not limited to being a three-in-one electric drive, and it can also be a multi-functional multi-in-one electric drive, which is not limited in this embodiment. For example, the electric drive 1 may also include at least one of the functional modules such as a charger, DCDC, VCU, BMS, TMS and PDU.

[0029] Please refer to Figure 2 and Figure 3Optionally, the motor 11 includes a rotor 111, a motor shaft 112 and a stator 113, the reduction box 13 includes a plurality of gears meshing with each other, the motor shaft 112 is connected to a gear in the reduction box 13, and power transmission is achieved through gear meshing transmission.

[0030] The inventors have found that due to the mechanical structure of the gears, the mutual meshing of the teeth is not smoothly excited, and the gear meshing excitation force will produce certain periodic fluctuations, such as Figure 4 The gear meshing excitation vibration is an important source of mechanical noise of the reduction gearbox 13. Since the torque, speed, angle of the rotor 111 and other parameters of the motor 11 are all changing in real time, and the reduction gearboxes 13 with different structures contain different gear matching forms, these changing parameters will cause the amplitude and phase of the meshing excitation vibration to change, which brings difficulties to the control of the meshing excitation vibration.

[0031] To achieve active control of meshing excitation vibration, please refer to Figure 5 , an embodiment of the present invention provides a noise reduction method for electric drive, which includes: Step S1: obtaining the operating status information of the electric drive 1; Step S2: Based on the operating status information, a reverse compensation harmonic current corresponding to the gear meshing excitation vibration of the current reduction box 13 is obtained through an open-loop algorithm or a closed-loop algorithm; Step S3: injecting the reverse compensation harmonic current into the motor drive current of the electric drive 1 to offset or weaken the meshing excitation vibration.

[0032] The operating status information of the electric drive 1 in step S1 can be obtained according to the subsequent different algorithm requirements for reverse compensation harmonic current. The operating status information of the electric drive 1 mainly includes the operating status information of the motor 11 and the operating status information of the reducer 13. In the open-loop algorithm, it is not necessary to obtain the feedback information after the motor 11 is driven, but in the closed-loop algorithm, it is necessary to obtain the feedback information after the motor 11 is driven, and return the feedback information to the calculation of the reverse compensation harmonic current, thereby forming a closed loop. Those skilled in the art can select the operating status information of the electric drive 1 that needs to be obtained according to the specific algorithm.

[0033] In step S2, meshing excitation vibration refers to the vibration caused by gear meshing excitation in the reducer 13. The reverse compensation harmonic current corresponds to the meshing excitation vibration. For details, please refer to Figure 4, where curve B is the excitation force generated by the corresponding reverse compensation harmonic current. Ideally, the excitation force generated by the corresponding reverse compensation harmonic current is preferably the same as the gear meshing excitation force in amplitude and opposite in phase. In this way, after the reverse compensation harmonic current is injected into the driving current of the motor 11 in step S3, the excitation force generated by the reverse compensation harmonic current and the gear meshing excitation force can be exactly offset, so that the synthesized excitation force ( Figure 4 Curve C) in the figure is smoother, thus reducing the structural vibration and noise caused by gear meshing excitation.

[0034] With such configuration, based on the operating status information of the electric drive 1, a reverse compensation harmonic current corresponding to the gear meshing excitation vibration of the current reduction gear 13 can be obtained through an open-loop algorithm or a closed-loop algorithm; and then the reverse compensation harmonic current is compensated into the motor drive current, which can reduce the gear meshing excitation vibration of the reduction gear 13, achieve noise control at the noise source, and effectively and actively control the mechanical noise of the reduction gear 13.

[0035] Several different algorithms for obtaining the reverse compensation harmonic current in step S2 are described below.

[0036] In one embodiment, an open-loop algorithm can be used to obtain the reverse compensation harmonic current. For the overall control process, please refer to Figure 6 The operating status information of the electric drive 1 includes the real-time torque information and real-time speed information of the motor 11 of the electric drive 1. The open-loop algorithm includes: Step S21: Based on the real-time torque information and the real-time speed information, the reverse compensation harmonic current is obtained by looking up a preset amplitude phase table.

[0037] Optionally, the amplitude-phase table is obtained by online calibration during the R&D or production stage of the electric drive 1. After the electric drive 1 is finalized during the R&D or production stage, the specifications and structure of its reducer 13 are determined. Under certain torque and speed conditions, the amplitude and phase of the meshing excitation vibration generated by the gears in the reducer 13 can also be basically determined. Therefore, the relationship between the torque and speed and the amplitude and phase of the meshing excitation vibration can be obtained through online calibration, and the amplitude-phase table can be obtained. In this way, in subsequent practical applications, as long as the current real-time torque information and real-time speed information are known, the amplitude and phase of the current actual meshing excitation vibration can be found out by looking up the amplitude-phase table. At this time, according to the amplitude and phase of the meshing excitation vibration, the amplitude and phase of the reverse compensation harmonic current can be set to offset the meshing excitation vibration.

[0038] In another embodiment, a closed-loop algorithm can be used to obtain the reverse compensation harmonic current. For the overall control process, please refer to Figure 7The operating status information of the electric drive 1 includes vibration information of the electric drive 1 and angle information of the rotor 111 of the motor 11. The closed-loop algorithm includes: Step S22: obtaining amplitude information and phase information of meshing excitation vibration based on the vibration information and the angle information; Step S23: Calculate the reverse compensation harmonic current according to the amplitude information and phase information of the meshing excitation vibration.

[0039] In the open-loop algorithm of step S21, only the torque and speed of the motor 11 are obtained, and the effect of the reverse compensation harmonic current after the actual injection into the drive is not monitored. In some scenarios, for example, after the gears in the reduction box 13 have a certain wear, the actual meshing excitation vibration of the reduction box 13 will deviate from the amplitude phase table originally calibrated, which leads to a deterioration in the noise control effect. By adopting a closed-loop algorithm, the effect of the reverse compensation harmonic current after the actual injection into the drive can be obtained by obtaining the vibration information of the electric drive 1, and the reverse compensation harmonic current can be closed-loop adjusted based on the vibration information, thereby further ensuring the effect of noise control.

[0040] Optionally, the vibration information is collected based on a vibration sensor 3 arranged on the integrated housing 10 of the electric drive 1. The integrated housing 10 can be an integral housing formed in one piece, or a combined housing formed by a plurality of sub-housings. The various parts of the integrated housing 10 corresponding to the motors 11, 12 and the reducer 13 (other functional modules are also included in the case of an all-in-one electric drive) are physically fixedly connected or integrally formed with each other, so the vibrations between the various parts can be transmitted to each other. The vibration sensor 3 is arranged in the part of the integrated housing 10 corresponding to any one of the motor 11, the motor controller 12 and the reducer 13, and can collect vibration information from the reducer 13.

[0041] By analyzing the vibration information and the angle signal of the rotor 111, the amplitude and phase of the gear meshing excitation vibration of the current reduction box 13 can be known, so that step S23 can set the amplitude and phase of the reverse compensation harmonic current according to the amplitude and phase of the meshing excitation vibration to offset the meshing excitation vibration.

[0042] Optionally, based on the vibration information and the angle information, the amplitude information and the phase information are obtained by discrete Fourier transform and order calculation.

[0043] It can be understood that by performing discrete Fourier transform on the vibration information and the angle information of the rotor 111, N characteristic quantities of different orders can be obtained, and then by order calculation, the amplitude information and phase information of the meshing excitation vibration of the gears at different specific positions in the reduction box 13 can be obtained. The specific principles of order calculation and Fourier transform can be referred to the prior art, and will not be elaborated in the present invention.

[0044] The study found that there is a certain correspondence between the characteristic quantities of N different orders and the meshing of gears at different specific positions in the reduction box 13. When the gears at a certain position are meshing, a vibration of a specific order will be generated. Therefore, according to the correspondence between the order and the mechanical characteristics of the gear, the amplitude information and phase information of the gear meshing excitation vibration at a specific position can be further clarified, so that the reverse compensation harmonic current corresponding to the gear meshing excitation vibration at that position can be set more specifically.

[0045] The following is further explained through two examples.

[0046] Please refer to Figure 2 , which shows an example of a reduction gear 13 with a parallel shaft structure, wherein the reduction gear 13 includes a two-stage gear set, specifically including a primary driving gear 131, a primary driven gear 132, a secondary driving gear 133 and a secondary driven gear 134, the rotor 111, the motor shaft 112 and the primary driving gear 131 are coaxially connected, the primary driving gear 131 is meshed with the primary driven gear 132, the primary driven gear 132 is coaxially connected with the secondary driving gear 133, the secondary driving gear 133 is meshed with the secondary driven gear 134, and the rotating shaft of the secondary driven gear 134 is the output shaft of the reduction gear 13.

[0047] For the reduction box 13 of the two-stage gear set, there are two gear meshing parts, namely the primary meshing N1 between the primary driving gear 131 and the primary driven gear 132, and the secondary meshing N2 between the secondary driving gear 133 and the secondary driven gear 134. Both gear meshing parts may generate meshing excitation vibration, and the amplitude information and phase information of the meshing excitation vibration are likely to be different. Through discrete Fourier transform and order calculation, the amplitude information and phase information of the meshing excitation vibration corresponding to each of the two gear meshing parts can be distinguished.

[0048] Furthermore, a reverse compensating harmonic current including two component signals is set according to the amplitude information and phase information of the meshing excitation vibration corresponding to each of the two gear meshing parts, so that the rotor 111 forms two partial compensating excitation forces when being driven, one of which is transmitted to the primary driving gear 131 and acts on the primary meshing N1 of the primary driven gear 132, and the other is transmitted to the secondary driving gear 133 and acts on the secondary meshing N2 of the secondary driven gear 134, thereby suppressing different gear meshing excitation vibrations respectively.

[0049] Please refer to Figure 3 , which shows an example of a planetary gear structure reduction box 13, the reduction box 13 includes a two-stage gear set, specifically including a sun gear 135, a large planetary gear 136, a small planetary gear 137 and a ring gear 138, the rotor 111, the motor shaft 112 and the sun gear 135 are coaxially connected, the sun gear 135 is meshed with the large planetary gear 136, the large planetary gear 136 is coaxially connected with the small planetary gear 137, and the small planetary gear 137 is meshed with the ring gear 138. It can be understood that the reduction box 13 also has two gear meshing parts, namely the primary meshing N1 between the sun gear 135 and the large planetary gear 136, and the secondary meshing N2 between the small planetary gear 137 and the ring gear 138.

[0050] The principle and method of the graded compensation of the reverse compensation harmonic current for the reduction box 13 of the planetary gear structure Figure 7 The reduction gearbox 13 of the parallel shaft structure shown is similar and will not be described again here.

[0051] Please refer to Figure 2 and Figure 3 Optionally, step S3 of injecting the reverse compensation harmonic current into the motor drive current of the electric drive 1 to offset or weaken the meshing excitation vibration includes: Step S31: obtaining the required torque of the motor 11 and the angle information of the rotor 111 of the motor 11; Step S32: obtaining an expected driving current based on the required torque and the angle information; Step S33: combining the reverse compensation harmonic current with the expected driving current to obtain an actual driving current, and driving the motor 11 with the actual driving current.

[0052] To implement the above noise reduction method, please refer to Figure 1An embodiment of the present invention further provides an electric drive system, which includes: an electric drive 1 and a vibration control unit 2; the electric drive 1 includes at least a motor 11, a motor controller 12 and a reduction box 13; the vibration control unit 2 is configured to obtain the amplitude information and phase information of the reverse compensation harmonic current according to the noise reduction method of the electric drive as described above, and send the amplitude information and phase information of the reverse compensation harmonic current to the motor controller 12; the motor controller 12 compensates the actual drive current according to the amplitude information and phase information of the reverse compensation harmonic current.

[0053] Step S2 may be implemented by the vibration control unit 2 , and step S3 may be implemented by the vibration control unit 2 and the motor controller 12 .

[0054] Furthermore, the electric drive system also includes a vibration sensor 3; the vibration sensor 3 is used to obtain the vibration information of the reduction box 13; the vibration sensor 3 is connected to the vibration control unit 2 for communication, and is used to send the vibration information to the vibration control unit 2. Thus, the vibration control unit 2 can execute a closed-loop algorithm based on the vibration information, as described above, which will not be repeated here. In one embodiment, the vibration sensor 3 can be arranged in the integrated housing 10. Of course, in other embodiments, the vibration sensor 3 can also be directly arranged on the reduction box 13, and the present invention is not limited to this.

[0055] The electric drive noise reduction method provided in this embodiment is preferably executed repeatedly periodically, and the repetition period can be selected to be 0.01s~3600s. Optionally, in some embodiments, the electric drive noise reduction method provided in this embodiment can be configured as an executable program, which can be written in the vibration control unit 2, for example. Further, the vibration control unit 2 can be an independent module or a virtual program module integrated in the vehicle control system of the new energy vehicle, and the present invention is not limited to this.

[0056] Based on the electric drive fault diagnosis method and electric drive system described above, an embodiment of the present invention further provides a new energy vehicle, which includes the electric drive system described above. The new energy vehicle can be a pure electric vehicle or a hybrid vehicle, which is not limited in this embodiment. The structure and principle of other components of the new energy vehicle can refer to the prior art, which will not be described in detail in this embodiment.

[0057] In summary, in the electric drive noise reduction method, electric drive system and new energy vehicle provided by the present invention, the electric drive noise reduction method includes: obtaining the operating status information of the electric drive; based on the operating status information, obtaining the reverse compensation harmonic current corresponding to the gear meshing excitation vibration of the current reduction box through an open-loop algorithm or a closed-loop algorithm; injecting the reverse compensation harmonic current into the motor drive current of the electric drive to offset or weaken the meshing excitation vibration. With such a configuration, based on the operating status information of the electric drive, the reverse compensation harmonic current corresponding to the gear meshing excitation vibration of the current reduction box can be obtained through an open-loop algorithm or a closed-loop algorithm; and then the reverse compensation harmonic current is compensated into the motor drive current, which can reduce the gear meshing excitation vibration of the reduction box, realize noise control at the noise source, and effectively actively control the mechanical noise of the reduction box.

[0058] It should be noted that the above embodiments can be combined with each other. The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the protection scope of the present invention.

Claims

1. A noise reduction method for electric drive, characterized in that: include: Obtaining the operating status information of the electric drive; Based on the operating status information, a reverse compensation harmonic current corresponding to the gear meshing excitation vibration of the current reduction box is obtained through an open-loop algorithm or a closed-loop algorithm; The reverse compensation harmonic current is injected into the motor drive current of the electric drive to offset or weaken the meshing excitation vibration.

2. The noise reduction method of electric drive according to claim 1, characterized in that: The operating status information of the electric drive includes real-time torque information and real-time speed information of the motor of the electric drive; the open-loop algorithm includes: Based on the real-time torque information and the real-time speed information, the reverse compensation harmonic current is obtained by looking up a preset amplitude phase table.

3. The noise reduction method of electric drive according to claim 2, characterized in that: The amplitude phase table is obtained through online calibration during the research and development or production stage of the electric drive.

4. The noise reduction method of electric drive according to claim 1, characterized in that: The operating status information of the electric drive includes vibration information of the electric drive and angle information of the rotor of the motor; the closed-loop algorithm includes: Based on the vibration information and the angle information, obtaining amplitude information and phase information of meshing excitation vibration; The reverse compensation harmonic current is calculated based on the amplitude information and phase information of the meshing excitation vibration.

5. The noise reduction method of electric drive according to claim 4, characterized in that: Based on the vibration information and the angle information, the amplitude information and the phase information are obtained through discrete Fourier transform and order calculation.

6. The noise reduction method of electric drive according to claim 4, characterized in that: The vibration information is collected based on a vibration sensor arranged on the integrated housing of the electric drive.

7. The noise reduction method of electric drive according to claim 1, characterized in that: The step of injecting the reverse compensation harmonic current into the motor drive current of the electric drive to offset or weaken the meshing excitation vibration includes: Obtaining required torque of the motor and angle information of the rotor of the motor; Based on the required torque and the angle information, an expected driving current is obtained; The reverse compensation harmonic current is combined with the expected driving current to obtain an actual driving current, and the motor is driven with the actual driving current.

8. An electric drive system, characterized in that: include: An electric drive and a vibration control unit; the electric drive comprises at least a motor, a motor controller and a reduction box; the vibration control unit is configured to obtain the amplitude information and phase information of the reverse compensation harmonic current according to the noise reduction method of the electric drive according to any one of claims 1 to 7, and send the amplitude information and phase information of the reverse compensation harmonic current to the motor controller; The motor controller compensates the actual driving current according to the amplitude information and phase information of the reverse compensation harmonic current.

9. The electric drive system according to claim 8, characterized in that: The electric drive system also includes a vibration sensor; the vibration sensor is used to obtain vibration information of the reduction box; the vibration sensor is communicatively connected to the vibration control unit, and is used to send the vibration information to the vibration control unit.

10. A new energy vehicle, characterized in that: Comprising the electric drive system according to claim 8 or 9.

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