Starting control strategy and system for electric compressor

Abstract

The invention discloses a starting control strategy and system for an electric compressor. The starting control strategy comprises the steps that the rotating speed of the compressor is increased to a first switching rotating speed through open-loop control; increasing the rotating speed of the compressor from the first switching rotating speed to a second switching rotating speed through closed-loop control; the rotating speed of the compressor is increased to the target rotating speed from the second switching rotating speed through open-loop control; wherein the time required by the whole starting process is within a preset time range. According to the method, the compressor is ensured to reach the target rotating speed within the set time, meanwhile, through the open loop-closed loop-open loop multi-stage control strategy, impact and vibration generated by rotating speed changes of the compressor are weakened, and the noise vibration performance in the starting process is controlled within an acceptable range.

Description

Technical Field

[0001] The present application relates to the technical field of electric compressors, and more specifically, to a startup control strategy and system for an electric compressor. Background Art

[0002] As the trend of automobile electrification intensifies, the thermal management system has an increasingly greater impact on the NVH (noise, vibration and harshness) performance of the vehicle. As one of the main noise sources in the thermal management system, the electric compressor has become the focus of NVH research.

[0003] In the prior art, the startup control strategy of the compressor is to increase the speed to the target speed at a certain rate based on the initial speed. Such a strategy results in a large startup impact of the compressor and a large vibration and noise when the compressor is started. Summary of the invention

[0004] The present application provides a startup control strategy and system for an electric compressor, which ensures that the compressor reaches the target speed within a specified time, while reducing the impact and vibration caused by the change in compressor speed through a multi-stage control strategy of open-loop-closed-loop-open-loop, and controlling the noise and vibration performance during the startup process within an acceptable range.

[0005] The present application provides a startup control strategy for an electric compressor, including:

[0006] increasing the speed of the compressor to a first switching speed through open-loop control;

[0007] increasing the speed of the compressor from a first switching speed to a second switching speed through closed-loop control;

[0008] increasing the speed of the compressor from the second switching speed to the target speed through open-loop control;

[0009] The time required for the entire startup process is within a preset time range.

[0010] Preferably, in the process of increasing the speed of the compressor from the second switching speed to the target speed, the second acceleration of the speed is determined according to the response speed of the actual vehicle to the target speed.

[0011] Preferably, in the process of increasing the speed of the compressor to the first switching speed, the first acceleration of the speed and the current of the compressor are determined in combination with the first switching speed, the second switching speed and a preset time range.

[0012] Preferably, the startup control strategy of the electric compressor also includes:

[0013] Analyze whether the noise and vibration performance during the startup process is qualified;

[0014] If it is unqualified, adjust the startup process parameters until the noise and vibration performance of the startup process is qualified.

[0015] Preferably, the starting process parameters include the first switching speed and / or the second switching speed.

[0016] The present application also provides a startup control system for an electric compressor, comprising a first open-loop control module, a closed-loop control module and a second open-loop control module;

[0017] The first open-loop control module is used to increase the speed of the compressor to a first switching speed through open-loop control;

[0018] The closed-loop control module is used to increase the speed of the compressor from a first switching speed to a second switching speed through closed-loop control;

[0019] The second open-loop control module is used to increase the speed of the compressor from the second switching speed to the target speed through open-loop control; wherein the time required for the entire startup process is within a preset time range.

[0020] Preferably, the second open-loop control module is used to determine the second acceleration of the speed according to the response speed of the actual vehicle to the target speed during the process of increasing the speed of the compressor from the second switching speed to the target speed.

[0021] Preferably, the first open-loop control module is used to determine the first acceleration of the speed and the current of the compressor in combination with the first switching speed, the second switching speed and a preset time range during the process of increasing the speed of the compressor to the first switching speed.

[0022] Preferably, the startup control system of the electric compressor further includes an analysis module and an adjustment module;

[0023] The analysis module is used to analyze whether the noise and vibration performance during the startup process is qualified;

[0024] The adjustment module is used to adjust the startup process parameters if the noise and vibration performance is unqualified until the noise and vibration performance of the startup process is qualified.

[0025] Preferably, the starting process parameters include the first switching speed and / or the second switching speed.

[0026] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0028] Figure 1A flow chart of the startup control strategy of the electric compressor provided in this application;

[0029] Figure 2 and Figure 3 The vibration spectrum diagram and speed curve of the compressor during the startup process corresponding to startup procedure 1 and startup procedure 2 respectively;

[0030] Figure 4 This is a structural diagram of the start-up control system of the electric compressor provided in this application. DETAILED DESCRIPTION

[0031] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0032] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0033] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0034] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0035] The present application provides a startup control strategy and system for an electric compressor, which ensures that the compressor reaches the target speed within a specified time, while reducing the impact and vibration caused by the change in compressor speed through a multi-stage control strategy of open-loop-closed-loop-open-loop, and controlling the noise and vibration performance during the startup process within an acceptable range.

[0036] In the startup control strategy for the electric compressor provided in the present application, the time required for the entire startup process is within a preset time range t.

[0037] like Figure 1 As shown, the startup control strategy includes:

[0038] S110: Raise the speed of the compressor to a first switching speed V1 through open-loop control.

[0039] S120: Increase the speed of the compressor from the first switching speed V1 to the second switching speed V2 through closed-loop control.

[0040] S130: Increase the speed of the compressor from the second switching speed V2 to the target speed V3 through open-loop control.

[0041] Based on the above, as an embodiment, in S120, closed-loop control is implemented through PID (proportional-integral-differential) control. The execution current is calculated in each cycle through the actual speed and actual current of the compressor collected. The step size of the feedback control loop process reaches the millisecond level, thereby improving the control accuracy.

[0042] As an embodiment, in the present application, the parameters of the PID control are determined, thereby determining the second time t2 required to increase the speed of the compressor from the first switching speed V1 to the second switching speed V2.

[0043] As an embodiment, in S130, during the process of increasing the speed of the compressor from the second switching speed V2 to the target speed V3, the second acceleration a2 of the speed is determined according to the response speed of the actual vehicle to the target speed V3.

[0044] Specifically, a2 = V3 / t0

[0045] Among them, t0 is the response time, which is a fixed value determined by the vehicle manufacturer.

[0046] Thus, when the second switching rotation speed and the target rotation speed are determined, the third time t3 required for the rotation speed of the compressor to increase from the second switching rotation speed V2 to the target rotation speed V3 is determined.

[0047] As an embodiment, in S110, in the process of increasing the speed of the compressor to the first switching speed V1, the first acceleration a1 of the speed and the current I1 of the compressor are determined in combination with the first switching speed V1, the second switching speed V2 and the preset time range t. Specifically, it can be seen from the above that in the process of formulating the startup strategy, after the first switching speed V1 and the second switching speed V2 are determined, the second time t2 and the third time t3 can be determined. On this basis, the first time t1 required to increase the speed of the compressor to the first switching speed V1 can be obtained in combination with the preset time range t, and on this basis, the first acceleration a1 and the current I1 of the compressor can be calculated.

[0048] Preferably, the startup control strategy of the electric compressor also includes:

[0049] S140: Analyze whether the noise and vibration performance during the startup process is qualified. If so, end the process; otherwise, execute S150.

[0050] S150: Adjust the startup process parameters until the noise and vibration performance of the startup process is qualified.

[0051] As an embodiment, the starting process parameters include the first switching speed V1 and / or the second switching speed V2. After adjusting the first switching speed V1 and / or the second switching speed V2, the first time t1, the second time t2, and the third time t3 will be adjusted accordingly, thereby changing the noise and vibration performance of the starting process.

[0052] Table 1 shows an example of two sets of start-up process control parameters (start-up procedure 1, start-up procedure 2) for an electric compressor. Figure 2 and Figure 3 The vibration spectrum and speed curve of the compressor during the startup process corresponding to startup procedure 1 and startup procedure 2 respectively.

[0053] Table 1 Start-up control parameters of electric compressor

[0054]

[0055] Figure 2 The following speed curve shows the influence of the start control parameters of start procedure 1 on the start process. The speed curve starts at 0 and ends at the first turning point, which is an open-loop control process. In this process, the speed continues to rise under the influence of the first acceleration and open-loop current, reaching the first switching speed of 120RPM. Then it enters the closed-loop feedback control process, and after reaching the second switching speed of 750RPM, it increases the speed according to the second acceleration to reach the target speed.

[0056] like Figure 2 As shown, during the entire startup process of startup procedure 1, the vibration energy corresponding to the first switching speed point and the second switching speed point is relatively large, and is the main contribution to the startup impact.

[0057] Based on startup procedure 1, startup procedure 2 weakens the first acceleration and reduces the first switching speed and the second switching speed, thereby reducing the first acceleration of the speed change, reducing the vibration impact of the compressor, and optimizing the vibration impact energy of the startup process.

[0058] Based on the above, the present application also provides a startup control system for an electric compressor. Figure 4 As shown, the startup control system includes a first open-loop control module 410 , a closed-loop control module 420 and a second open-loop control module 430 .

[0059] The first open-loop control module 410 is used to increase the speed of the compressor to a first switching speed through open-loop control.

[0060] The closed-loop control module 420 is used to increase the speed of the compressor from the first switching speed to the second switching speed through closed-loop control.

[0061] The second open-loop control module 430 is used to increase the speed of the compressor from the second switching speed to the target speed through open-loop control.

[0062] Preferably, the second open-loop control module 420 is used to determine the second acceleration of the speed according to the response speed of the actual vehicle to the target speed during the process of increasing the speed of the compressor from the second switching speed to the target speed.

[0063] Preferably, the first open-loop control module 410 is used to determine the first acceleration of the speed and the current of the compressor in combination with the first switching speed, the second switching speed and a preset time range during the process of increasing the speed of the compressor to the first switching speed.

[0064] Preferably, the start-up control system of the electric compressor further includes an analysis module 440 and an adjustment module 450 .

[0065] The analysis module 440 is used to analyze whether the noise and vibration performance during the startup process is qualified.

[0066] The adjustment module 450 is used to adjust the startup process parameters if the noise and vibration performance is unqualified, until the noise and vibration performance of the startup process is qualified.

[0067] Preferably, the starting process parameters include the first switching speed and / or the second switching speed.

[0068] In the startup control of the electric compressor of the present application, the compressor is adapted to different vehicles by adjusting the multi-stage control parameters of open-loop-closed-loop-open-loop, thereby achieving the purpose of controlling the noise and vibration performance of the compressor when starting.

[0069] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A startup control strategy for an electric compressor, characterized in that: include: increasing the speed of the compressor to a first switching speed through open-loop control; increasing the speed of the compressor from the first switching speed to the second switching speed through closed-loop control; increasing the speed of the compressor from the second switching speed to the target speed through open-loop control; The time required for the entire startup process is within a preset time range.

2. The startup control strategy of the electric compressor according to claim 1, characterized in that: In the process of increasing the speed of the compressor from the second switching speed to the target speed, the second acceleration of the speed is determined according to the response speed of the actual vehicle to the target speed.

3. The startup control strategy of the electric compressor according to claim 2, characterized in that: In the process of increasing the speed of the compressor to the first switching speed, the first acceleration of the speed and the current of the compressor are determined in combination with the first switching speed, the second switching speed and the preset time range.

4. The startup control strategy of the electric compressor according to claim 1, characterized in that: Also includes: Analyze whether the noise and vibration performance during the startup process is qualified; If it is unqualified, adjust the startup process parameters until the noise and vibration performance of the startup process is qualified.

5. The startup control strategy of the electric compressor according to claim 4, characterized in that: The startup process parameters include the first switching speed and / or the second switching speed.

6. A startup control system for an electric compressor, characterized in that: It includes a first open-loop control module, a closed-loop control module and a second open-loop control module; The first open-loop control module is used to increase the speed of the compressor to a first switching speed through open-loop control; The closed-loop control module is used to increase the speed of the compressor from the first switching speed to the second switching speed through closed-loop control; The second open-loop control module is used to increase the speed of the compressor from the second switching speed to the target speed through open-loop control; wherein the time required for the entire startup process is within a preset time range.

7. The startup control system of the electric compressor according to claim 6, characterized in that: The second open-loop control module is used to determine the second acceleration of the speed according to the response speed of the actual vehicle to the target speed during the process of increasing the speed of the compressor from the second switching speed to the target speed.

8. The start-up control system of the electric compressor according to claim 7, characterized in that: The first open-loop control module is used to determine the first acceleration of the speed and the current of the compressor in combination with the first switching speed, the second switching speed and the preset time range during the process of increasing the speed of the compressor to the first switching speed.

9. The startup control system of the electric compressor according to claim 6, characterized in that: It also includes an analysis module and an adjustment module; The analysis module is used to analyze whether the noise and vibration performance of the startup process is qualified; The adjustment module is used to adjust the startup process parameters if the noise and vibration performance is unqualified, until the noise and vibration performance of the startup process is qualified.

10. The start-up control system of the electric compressor according to claim 9, characterized in that: The startup process parameters include the first switching speed and / or the second switching speed.

Images