Electric compressor starting optimization method and system
By optimizing the open-loop and closed-loop acceleration times of the electric compressor and avoiding the vehicle resonance range, the problem of NVH performance and starting performance being difficult to balance in existing technologies has been solved, resulting in improved NVH performance and increased starting success rate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHERY AUTOMOBILE CO LTD
- Filing Date
- 2025-07-04
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies cannot simultaneously improve NVH performance and ensure starting performance when optimizing the start-up of electric compressors, and may lead to increased compressor starting capacity and costs.
By obtaining the target stable speed of the electric compressor, the open-loop and closed-loop acceleration times are determined, and the compressor is controlled to operate in open-loop and closed-loop mode according to the preset acceleration rate, avoiding the vehicle resonance range and optimizing the start-up strategy to reduce NVH peaks.
It improves the NVH performance and start-up success rate of the electric compressor, reduces start-up energy consumption and abnormal noise, adapts to different vehicle models and operating conditions, and avoids the complexity and cost increase of whole vehicle matching and adjustment.
Smart Images
Figure CN122014581A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of automatic air conditioning compressor control technology, and in particular to an optimized method and system for starting an electric compressor. Background Technology
[0002] The performance of a vehicle's thermal management system is directly related to the driving comfort and functionality of the passenger compartment. As a core component of the thermal management system, the electric compressor has a significant impact on the subjective experience of the passenger compartment. By optimizing the compressor's start-up strategy, the subjective NVH experience and the start-up capability of the air conditioning system can be improved.
[0003] The current method for optimizing the NVH performance during compressor startup is to match the dynamic balance of the compressor motor rotor with the vehicle to optimize the overall NVH performance.
[0004] The starting performance of a compressor is related to the dynamic balance of the compressor motor rotor. When the current method is used to optimize the NVH performance of the vehicle and the dynamic balance of the compressor motor rotor is adjusted, the starting performance of the compressor cannot be guaranteed. Summary of the Invention
[0005] This invention provides a method and system for optimizing the start-up of an electric compressor, which improves the compressor's NVH performance while ensuring its start-up performance.
[0006] The technical solution of the present invention is as follows: In a first aspect, a method for optimizing the start-up of an electric compressor is provided, the method comprising: When the compressor starts, the target stable speed of the electric compressor is obtained; The closed-loop acceleration time of the compressor is determined based on the target stable speed, the preset acceleration rate, and the open-loop running time. The compressor is controlled to run in an open loop for a set duration according to a preset speed-up rate; where the preset speed-up rate is the speed-up rate at which the compressor's NVH performance is optimal during startup. Then, the compressor is started by controlling the closed-loop operation of the compressor according to the preset acceleration rate and the determined closed-loop acceleration time.
[0007] Optionally, the open-loop running time is less than the time it takes for the electric compressor to start up and for the vehicle and compressor to resonate when the compressor is started at a preset acceleration rate.
[0008] Alternatively, the closed-loop acceleration time is equal to the target stable speed divided by the preset acceleration rate, minus the open-loop running time.
[0009] Optionally, during the compressor's open-loop and closed-loop operation phases, the compressor's frequency can be controlled to be half the frequency during normal operation.
[0010] Optionally, the compressor open-loop runtime and acceleration rate for each vehicle model can be determined and marked using configuration words; When controlling the compressor to start, the corresponding compressor open-loop running time and acceleration rate are determined according to the vehicle's configuration information. The compressor is started and controlled based on the determined compressor open-loop running time and acceleration rate.
[0011] Optionally, the target stable speed of the electric compressor can be determined based on the operating mode of the air conditioner.
[0012] Secondly, an electric compressor start-up optimization system is provided, comprising: The data acquisition unit is used to acquire the target stable speed of the electric compressor when the compressor starts. The closed-loop speed-up time determination unit is used to determine the closed-loop speed-up time of the compressor based on the target stable speed, the preset speed-up rate, and the open-loop running time. The control unit is used to control the compressor to run in an open loop for a set open loop duration at a preset acceleration rate, and then control the compressor to run in a closed loop for a set closed loop acceleration duration at a preset acceleration rate to start the electric compressor; wherein, the preset acceleration rate is determined based on the speed range and resonance duration of the vehicle and compressor when the electric compressor starts.
[0013] Thirdly, a control device is provided, the control device including one or more processors and one or more memories, the one or more memories storing at least one piece of program code, the at least one piece of program code being loaded and executed by the one or more processors to implement the electric compressor start-up optimization method described in any of the above implementations.
[0014] Fourthly, a computer-readable storage medium is provided, wherein at least one piece of program code is stored therein, the at least one piece of program code being loaded and executed by a processor to implement an electric compressor start-up optimization method as described in any of the above implementations.
[0015] Fifthly, a computer program product is provided, the computer program product including computer program code stored in a computer-readable storage medium, a processor of a control device reading the computer program code from the computer-readable storage medium, the processor executing the computer program code, causing the control device to execute an electric compressor start-up optimization method as described in any of the above implementations.
[0016] The beneficial effects of this invention are at least as follows: This invention predetermines the optimal acceleration rate and open-loop running time for compressor startup when NVH performance is at its best. When controlling compressor startup, the closed-loop acceleration time is determined based on the target stable speed, the preset acceleration rate, and the open-loop running time. The electric compressor is started by first controlling it to run at the preset acceleration rate for the set open-loop running time, and then controlling it to run at the preset acceleration rate for the determined closed-loop acceleration time. This reduces the NVH peaks generated during the open-loop / closed-loop switching, improving NVH performance. Since the matching between the compressor and the vehicle remains unchanged, only the open-loop and closed-loop NVH peaks of the compressor are weakened, without affecting the compressor's startup performance. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a control flowchart of an electric compressor start-up optimization method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the startup strategy of an electric compressor startup optimization method provided in an embodiment of the present invention; Figure 3 This is a comparative schematic diagram of the electric compressor switching frequency strategy provided in the embodiments of the present invention; Figure 4 The resonant speed range of the vehicle and the compressor during compressor startup is provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of the noise during compressor startup provided in an embodiment of the present invention; Figure 6 This is a schematic diagram comparing open-loop and closed-loop control strategies provided in an embodiment of the present invention. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.
[0020] Before providing a detailed explanation of the embodiments of the present invention, the application scenarios and system architecture involved in the embodiments of the present invention will be introduced first.
[0021] First, the system architecture involved in the embodiments of the present invention will be introduced.
[0022] The system includes a temperature sensor, an electric compressor, and a central control panel; Temperature sensor, used to obtain ambient temperature.
[0023] The central control unit receives the compressor start command and, upon receiving the command, determines the target stable speed of the compressor based on the ambient temperature. Based on the target stable speed, the preset acceleration rate, and the open-loop running time, it determines the closed-loop acceleration time of the compressor. It then controls the compressor to run in open loop for the preset acceleration rate for the set open-loop running time, and subsequently controls the compressor to run in closed loop for the preset acceleration rate for the determined closed-loop acceleration time, thus starting the electric compressor.
[0024] Those skilled in the art should understand that the above system architecture is merely an example, and other existing or future components or modules that are applicable to this application should also be included within the scope of protection of this application, and are hereby incorporated by reference.
[0025] Finally, the application scenarios involved in the embodiments of this disclosure are introduced.
[0026] In summer, electric vehicles often lack an engine or the engine is not running. The NVH (noise, vibration, and harshness) performance of the electric compressor during air conditioning startup directly impacts passenger comfort. Furthermore, the high load on the air conditioning system in hot summer conditions demands high compressor startup capability, frequently resulting in abnormal noises during startup and compressor failure leading to ineffective cooling. Optimizing the compressor startup strategy can improve the NVH experience in the passenger cabin and the air conditioning's startup capability.
[0027] Currently, the market's solution for improving NVH (Noise, Vibration, and Harshness) during air conditioning compressor startup is to adjust the dynamic balance of the compressor motor rotor to match the dynamic balance of the entire vehicle in order to meet the vehicle's NVH improvement goals.
[0028] The solutions to improve the compressor's starting capability are: increasing the compressor's starting current, adjusting the compressor's rotor dynamic balance, and increasing the compressor motor's torque.
[0029] Adjusting the dynamic balance of the compressor motor rotor will cause two related problems: First, the compressor motor and the vehicle that needs improvement may achieve the improvement of starting NVH, but other models that are matched with it will experience a deterioration in starting NVH, requiring retesting; second, the starting capability will change, requiring retesting.
[0030] Starting capability can be improved by increasing the compressor's starting current, adjusting the compressor's rotor dynamic balance, and increasing the compressor motor torque. Several related issues arise: First, regardless of the current increase, compressor rotor dynamic balance adjustment, or motor capacity enhancement, all methods will increase the compressor's power consumption during startup. Second, the improved starting capability from compressor rotor dynamic balance adjustments and compressor capacity enhancement may lead to NVH (noise, vibration, and harshness) issues during compressor startup, requiring vehicle-wide NVH testing. Finally, improved compressor starting capability may increase the unit cost of the compressor.
[0031] It is known that the current method for optimizing the NVH performance of the whole vehicle by adjusting the dynamic balance of the compressor motor rotor cannot guarantee the starting performance of the compressor.
[0032] Based on the above system architecture and application scenarios, this invention proposes an optimized starting method for electric compressors. To make the objectives, technical solutions, and advantages of this invention clearer, the embodiments of this invention will be further described in detail below with reference to the accompanying drawings.
[0033] This invention provides an optimized starting method for an electric compressor, such as... Figures 1-6 As shown, the method includes: When the compressor starts, the target stable speed of the electric compressor is obtained; The closed-loop acceleration time of the compressor is determined based on the target stable speed, the preset acceleration rate, and the open-loop running time. The compressor is controlled to run in an open loop for a set duration according to a preset speed-up rate; where the preset speed-up rate is the speed-up rate at which the compressor's NVH performance is optimal during startup. Then, the compressor is started by controlling the closed-loop operation of the compressor according to the preset acceleration rate and the determined closed-loop acceleration time.
[0034] in, Figure 2 The target speed is the target stable speed, which is the speed at which the compressor runs normally after startup.
[0035] The acceleration rate and open-loop running time are determined based on the vehicle's resonant frequency range. The preset acceleration rate is the acceleration rate at which the NVH performance is optimal when the compressor starts. The open-loop running time is less than the time it takes for the electric compressor to start and for the vehicle and compressor to resonate when the compressor starts at the preset acceleration rate. The closed-loop acceleration time is equal to the target stable speed divided by the preset acceleration rate minus the open-loop running time. By adjusting the open and closed loop times of the compressor startup, the NVH peak generated by the compressor during the open-loop and closed-loop switching is reduced, thereby improving the NVH performance when the compressor starts.
[0036] Furthermore, this embodiment of the invention also specifies that, during the open-loop and closed-loop operation phases of the compressor, the compressor frequency is controlled at half the frequency during normal operation. This increases the compressor's starting torque, improves the controller's efficiency, and reduces the compressor's starting energy consumption; after the compressor completes startup, the compressor's switching frequency is switched back to the normal frequency.
[0037] Preferably, the compressor is considered to have completed startup when the compressor speed reaches the target stable speed.
[0038] When the air conditioner start command is obtained in this embodiment of the invention, it is when the compressor starts. The target stable speed of the electric compressor is determined according to the air conditioner operation mode specified in the air conditioner start command.
[0039] Specifically, the target stable speed of the compressor is determined based on the air conditioner operation model and the compressor's performance indicators.
[0040] Considering that different vehicle models and compressors have different resonance ranges, the open-loop running time and acceleration rate of the compressor for each vehicle model are calibrated in advance. The open-loop running time and acceleration rate of the compressor for each vehicle model are determined and marked by configuration words, as shown in Table 1. When controlling the compressor to start, the open-loop running time and acceleration rate of the compressor are determined according to the vehicle's configuration information.
[0041] Table 1
[0042] Among them, the preset acceleration rate of the compressor for each vehicle model is the acceleration rate at which the NVH performance is optimal when the compressor of that vehicle model starts.
[0043] The preset open-loop running time of the compressor for each vehicle model is less than the time from start-up of the electric compressor to resonance between the vehicle and the compressor when the compressor is started at the preset acceleration rate.
[0044] The process of determining the resonance range of the entire vehicle is as follows: (1) Determine the rigid body mode of the compressor, wherein the compressor is required to be installed on a rigid support, the excitation point and the response point are close, and the first-order mode of the compressor bench is required to be greater than 350Hz; (2) If there is a compressor bracket, confirm the rigid body mode of the compressor bracket. The mode needs to be greater than 350Hz. If there is no compressor bracket, the compressor is directly fixed to the engine or other vehicle fixing points.
[0045] (3) By controlling the closed-loop start of the compressor at various test speeds, the NVH of the whole vehicle is tested to determine the NVH performance of the compressor when starting at each test speed and the resonance range of the compressor when starting at each test speed.
[0046] The optimal test acceleration rate for NVH performance was selected as the preset acceleration rate for compressor startup. The time it took for the compressor speed to reach the resonance range when the compressor was started at the test acceleration rate was determined. Different open-loop running times were selected, and each open-loop running time was less than the time it took for the compressor speed to reach the resonance range when the compressor was started at the test acceleration rate.
[0047] Determine the open-loop runtime for each type of experiment and the corresponding closed-loop ramp-up time.
[0048] For each test open-loop running duration, the compressor is controlled to run in open loop at the optimal test ramp rate for that test open-loop running duration. Then, the electric compressor is started in closed loop at the optimal test ramp rate for the determined closed-loop ramp duration.
[0049] Determine the NVH performance of the electric compressor during startup for each test open-loop running length; select the test open-loop running length with the best NVH performance as the preset open-loop running length for electric compressor startup.
[0050] When testing the NVH of the whole vehicle, the speed range of resonance between the whole vehicle and the compressor is identified by the noise change part and energy concentration part (red area) in the test spectrum, that is, the resonance range of the compressor.
[0051] Preferably, when calibrating the acceleration rate, the compressor is started with test acceleration rates of 500 rpm / s, 1000 rpm / s, 2000 rpm / s and 2500 rpm / s respectively. After testing, the NVH performance is optimal when the test acceleration rate is 2500 rpm / s. Therefore, 2500 rpm / s is set as the preset acceleration rate for compressor startup.
[0052] NVH performance can be characterized by vibration and noise.
[0053] like Figure 3 As shown, t1 is a segment of the response period at 10 K, t3 is a segment of the response period at 20 K, t2 is the work phase in the response period at 10 K, and t4 is the work phase in the response period at 20 K; the rectangle represents ineffective work. Through simple calculation: the efficiency at 10 K is t2 / t1 = 45%; the efficiency at 20 K is t4 / t3 = 40%.
[0054] This invention provides an electric compressor startup optimization method that improves the smoothness of open-loop and closed-loop switching and reduces compressor noise peaks by adjusting the open-loop and closed-loop times of the compressor during startup. Furthermore, by using an appropriate acceleration rate to avoid resonance ranges in different vehicle models, resonance noise is reduced, thereby improving the NVH experience for passengers.
[0055] Since the matching between the compressor and the vehicle has not changed, only the peak values of the compressor's open-loop and closed-loop NVH have been weakened, which will not have an adverse effect on the starting NVH of other models; and since the hardware of the compressor has not been adjusted, the starting capability of the compressor will not be affected.
[0056] By reducing the switching frequency of the controller during startup, i.e. the compressor frequency, the starting torque and efficiency of the compressor are increased. After the compressor has finished starting, the switching frequency of the compressor is switched back to the normal frequency.
[0057] Since this does not involve an increase in compressor current, it will not lead to an increase in compressor energy consumption, and there are no hardware changes to the compressor, so there is no need to re-perform NVH vehicle testing. It is important to note that after the compressor has finished starting, it needs to be switched back to its normal operating frequency; this is because a low switching frequency at high speeds can cause electromagnetic noise, and higher power is required at high speeds, which a low switching frequency cannot meet.
[0058] Since compressors need to be used in various vehicle models and under various operating conditions, optimizing the compressor starting strategy is a high-fault-tolerant, highly adaptable, and high-performance strategy to adapt to complex and ever-changing environments. It can be adjusted according to different vehicle models and different environments, so that the electric compressor starting optimization method provided in this embodiment of the invention can be well compatible with different vehicle models and different operating conditions. Not only is the compressor starting NVH significantly improved, but the compressor starting success rate and robustness are also significantly improved, which can meet the starting requirements of existing intelligent vehicle compressors.
[0059] The following are system embodiments of the present invention. For details not described in detail in the system embodiments, please refer to the above method embodiments. This invention provides an electric compressor start-up optimization system, the device comprising: The data acquisition unit is used to acquire the target stable speed of the electric compressor when the compressor starts. The closed-loop speed-up time determination unit is used to determine the closed-loop speed-up time of the compressor based on the target stable speed, the preset speed-up rate, and the open-loop running time. The control unit is used to control the compressor to run in an open loop for a set open loop duration at a preset acceleration rate, and then control the compressor to run in a closed loop for a set closed loop acceleration duration at a preset acceleration rate to start the electric compressor; wherein, the preset acceleration rate is determined based on the speed range and resonance duration of the vehicle and compressor when the electric compressor starts.
[0060] It should be noted that the electric compressor start-up optimization system provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the equipment can be divided into different functional modules to complete all or part of the functions described above. In addition, the electric compressor start-up optimization system and the electric compressor start-up optimization method embodiment provided in the above embodiments belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be repeated here.
[0061] An embodiment of the present invention provides a control device, the control device including one or more processors and one or more memories, the one or more memories storing at least one piece of program code, the at least one piece of program code being loaded and executed by the one or more processors to implement an electric compressor start-up optimization method as described in any of the above implementations.
[0062] The present invention provides a computer-readable storage medium storing at least one piece of program code, which is loaded and executed by a processor to implement an electric compressor start-up optimization method as described in any of the above implementations.
[0063] This invention provides a computer program product, which includes computer program code stored in a computer-readable storage medium. A processor of a control device reads the computer program code from the computer-readable storage medium and executes the computer program code, causing the control device to perform an electric compressor start-up optimization method as described in any of the above implementations.
[0064] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware, or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.
[0065] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for optimizing the start-up of an electric compressor, characterized in that, The method includes: When the compressor starts, the target stable speed of the electric compressor is obtained; The closed-loop acceleration time of the compressor is determined based on the target stable speed, the preset acceleration rate, and the open-loop running time. The compressor is controlled to run in an open loop for a set duration according to a preset speed-up rate; where the preset speed-up rate is the speed-up rate at which the compressor's NVH performance is optimal during startup. Then, the compressor is started by controlling the closed-loop operation of the compressor according to the preset acceleration rate and the determined closed-loop acceleration time.
2. The electric compressor start-up optimization method as described in claim 1, characterized in that, The open-loop running time is less than the time it takes for the electric compressor to start and for the vehicle and compressor to resonate when the compressor is started at the preset acceleration rate.
3. The electric compressor start-up optimization method as described in claim 1, characterized in that, The closed-loop acceleration time is equal to the target stable speed divided by the preset acceleration rate, minus the open-loop running time.
4. The electric compressor start-up optimization method as described in claim 1, characterized in that, During the open-loop and closed-loop operation phases of the compressor, the compressor frequency is controlled at half the frequency during normal operation.
5. The electric compressor start-up optimization method as described in claim 1, characterized in that, Determine the compressor open-loop runtime and acceleration rate for each vehicle model, and mark them using configuration words; When controlling the compressor to start, the corresponding compressor open-loop running time and acceleration rate are determined according to the vehicle's configuration information. The compressor is started and controlled based on the determined compressor open-loop running time and acceleration rate.
6. The electric compressor start-up optimization method as described in claim 1, characterized in that, Determine the target stable speed of the electric compressor based on the air conditioner's operating mode.
7. An electric compressor start-up optimization system, characterized in that, The device includes: The data acquisition unit is used to acquire the target stable speed of the electric compressor when the compressor starts. The closed-loop speed-up time determination unit is used to determine the closed-loop speed-up time of the compressor based on the target stable speed, the preset speed-up rate, and the open-loop running time. The control unit is used to control the compressor to run in an open loop for a set open loop duration at a preset acceleration rate, and then control the compressor to run in a closed loop for a set closed loop acceleration duration at a preset acceleration rate to start the electric compressor; wherein, the preset acceleration rate is determined based on the speed range and resonance duration of the vehicle and compressor when the electric compressor starts.
8. A control device, characterized in that, The control device includes one or more processors and one or more memories, wherein at least one program code is stored in the one or more memories, and the at least one program code is loaded and executed by the one or more processors to implement the electric compressor start-up optimization method according to any one of claims 1-6.
9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one piece of program code, which is loaded and executed by a processor to implement the electric compressor start-up optimization method according to any one of claims 1-6.
10. A computer program product, characterized in that, The computer program product includes computer program code stored in a computer-readable storage medium. The processor of the control device reads the computer program code from the computer-readable storage medium and executes the computer program code, causing the control device to perform an electric compressor start-up optimization method according to any one of claims 1-6.