Control method of air conditioner compressor

Abstract

The invention discloses a control method of an air conditioner compressor, which meets the following conditional expressions: an air conditioner panel sends a compressor request signal: an air conditioner starting request exists; the evaporator temperature is not less than 1 DEG C; and controlling the rotating speed of the compressor: taking a minimum value of the rotating speed of the compressor between the rotating speed corresponding to the cold-warm gear and the rotating speed corresponding to the temperature of the evaporator, and performing frequency avoiding processing on the value after the value of the rotating speed is determined. According to the electric vehicle air conditioner compressor control method, the rotating speed of the compressor is regulated and controlled in a partitioned mode through the evaporator temperature, the air conditioner operation stability is improved, and the whole vehicle comfort is improved.

Description

Technical Field

[0001] The invention relates to the field of automobile air conditioning, and in particular to a control method for an air conditioning compressor. Background Art

[0002] The existing method of controlling the speed of the electric compressor of the automobile air conditioner is generally to set the compressor to work at a fixed speed, stop the compressor when the temperature in the car reaches the lower limit of the temperature drop, and start the compressor when the temperature is too high. This control method makes the temperature drop in the car slow. If the fixed speed is set too high, it will generate a lot of noise, which will affect the service life of the compressor and the comfort in the car. If the compressor is started only when the temperature is high, it will also cause the overall temperature in the car to fluctuate greatly, affecting the riding comfort and consuming more energy. Summary of the invention

[0003] The object of the present invention is to provide a control method for an air-conditioning compressor to solve the problems raised in the above background technology.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: a control method for an air-conditioning compressor, wherein the air-conditioning panel sends a compressor request signal when the following condition is satisfied:

[0005] There is a request to turn on the air conditioner;

[0006] Evaporator temperature ≥1℃;

[0007] It also includes the control of the compressor speed: the compressor speed takes the smaller value between the speed corresponding to the cooling and heating gears and the speed corresponding to the evaporator temperature, and after the speed value is determined, the value is frequency-avoided.

[0008] Preferably, the evaporator rising temperature is T, when T≥12°C, the compressor speed is 3400rpm, when 12°C>T≥8°C, the compressor speed takes the maximum value Smax, when 8°C>T≥2°C, the compressor speed takes 1000+(Smax-1000) / 6rpm, when 2°C>T≥1°C, the compressor speed takes 1000rpm.

[0009] Preferably, the maximum compressor speed Smax is related to the air volume. When the air volume gear is at gear 1, Smax is 2000rpm, when the air volume gear is at gear 2, Smax is 2800rpm, when the air volume gear is at gear 3, Smax is 3400rpm, and when the air volume gear is at gear 4, Smax is 3400rpm.

[0010] Preferably, when the cooling and heating gear is gear 1, the compressor speed is 3400 rpm, when it is gear 2, the compressor speed is 3000 rpm, when it is gear 3, the compressor speed is 1800 rpm, and when it is gear 4-6, the compressor speed is 1000 rpm.

[0011] Preferably, the hysteresis interval of the compressor speed reduction and speed increase is eliminated, and the dwell time after the speed changes is constrained to a minimum of 4s.

[0012] Preferably, it also includes a correction strategy for the evaporator target temperature: when the refrigeration gear is at gear 1, the evaporator temperature T is 9°C, when the refrigeration gear is at gear 2, the evaporator temperature T is 7°C, and when the refrigeration gear is at gear 3, the evaporator temperature T is 5°C.

[0013] Preferably, it also includes a correction strategy for the evaporator target temperature: when the refrigeration gear is at gear 1, the evaporator temperature T is 9°C, when the refrigeration gear is at gear 2, the evaporator temperature T is 7°C, and when the refrigeration gear is at gear 3, the evaporator temperature T is 5°C.

[0014] Preferably, the evaporator temperature protection interval is 1°C-5°C. When the evaporator temperature drops below 1°C during the operation of the air conditioner, the air conditioner stops working. After stopping working, the evaporator temperature rises to 5°C before it is allowed to work.

[0015] Preferably, the compressor speed value also needs to refer to the allowable power of the air conditioner, and the minimum value is taken as the compressor speed by combining the speed corresponding to the cooling and heating gears, the speed corresponding to the evaporator temperature, and the speed corresponding to the power.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention provides a method for controlling an electric vehicle air-conditioning compressor, which regulates the compressor speed in different intervals by evaporator temperature, thereby improving the operating stability of the air-conditioning and the comfort of the whole vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall conceptual framework of the present invention. DETAILED DESCRIPTION

[0019] 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.

[0020] This embodiment provides a method for controlling an air-conditioning compressor. When the following conditions are met, the air-conditioning panel sends a compressor request (A / C) signal:

[0021] a. There is a request to turn on the air conditioner

[0022] b. Evaporator temperature ≥ 1°C (the evaporator temperature protection range is 1°C-5°C. When the air conditioner is working, the evaporator temperature drops to

[0023] When the temperature is below 1℃, the air conditioner stops working. After stopping working, the evaporator temperature will rise to 5℃ before it is allowed to work) The ice cream user adjusts the air conditioner temperature through the cold and warm knob. The cold and warm knob has 6 gears, 1-3 for cooling, and 4-6 for heating.

[0024] The compressor speed is related to the following points:

[0025] 1. The compressor speed takes the smaller value between the speed corresponding to the cooling and heating gears and the speed corresponding to the evaporator temperature. The specific compressor speed and evaporator temperature corresponding values ​​are shown in Table 1 below:

[0026] Table 1: Evaporator temperature corresponding to compressor speed switching table

[0027] Evaporator temperature rise T / ℃ Compressor speed / rpm(TBD) T≥12℃ 3400 12℃>T≥8℃ Smax 8℃>T≥2℃ 1000+(Smax-1000) / 6 2℃>T≥1℃ 1000 1℃>T 0

[0028] Smax is not subjected to frequency avoidance processing during the calculation process. Frequency avoidance processing is only performed on the last executed compressor speed. See point 6, compressor speed limit.

[0029] Note 1: The hysteresis interval of compressor speed reduction and speed increase is cancelled, and the dwell time after the speed change is constrained to a minimum of 4 seconds. (Whether it is speed increase or speed decrease, as long as the compressor speed changes, the dwell time must be 4 seconds)

[0030] Note 2: Since the compressor speed is not allowed to operate in a large range, the step-by-step speed control algorithm is cancelled.

[0031] 2. Smax is related to the air volume and is defined in the air volume and speed correspondence table as shown in Table 2:

[0032] Table 2: Air volume gear corresponding to compressor speed switching table

[0033] Air volume level Compressor speed Smax / rpm 0 0 1 2000 2 2800 3 3400 4 3400

[0034] 3. The compressor speed is also related to the cooling and heating gears. The specific correspondence between the speed and gear is as shown in Table 3:

[0035] Table 3: Compressor speed table corresponding to cooling and heating gears

[0036] Cool and warm gear Compressor speed / rpm(TBD) 1 3400 2 3000 3 1800 4-6 1000

[0037] Combined with the compressor speed corresponding to the evaporator temperature, the compressor speed corresponding to the cooling and heating gears, and the allowable power of the air conditioner, during the operation of the air conditioner, the compressor speed is adjusted as follows: Figure 1 The algorithm is obtained;

[0038] During the operation of the compressor, when the evaporator temperature T≤1℃, the compressor is turned off and the evaporator temperature is detected at the same time. When the evaporator temperature T≥5℃ is detected, the compressor is restored to work and the speed is obtained according to the above algorithm. If the VCU detects that the compressor working conditions are not met during the operation of EAC, the air conditioner is turned off.

[0039] When the air conditioner is working, the VCU controls the fan operation synchronously in combination with the working condition of the air conditioner. When the air conditioner start-up conditions are met and the VCU enables the air conditioner, the VCU receives the medium voltage switch disconnect signal (normally open) and turns on the low-speed fan. During the operation of the air conditioner, the VCU receives the medium voltage switch closing signal (hard line high level) and turns on the high-speed fan. When the air conditioner turns on the fan at a low speed, the high-speed fan is turned on in combination with the fan control strategy if the high-speed fan start-up conditions are met.

[0040] 2. Evaporator target temperature correction

[0041] In order to achieve different evaporator target temperatures at different temperature levels, the larger the refrigeration level, the lower the evaporator temperature. When calculating the compressor temperature, the difference between the evaporator temperature and the target temperature is used instead of the absolute value to replace it in the formula for calculating the compressor speed. In this way, we can get different control target values. The set values ​​of the target temperature are as shown in Table 4:

[0042] Table 4: Correspondence between cooling and heating gears and evaporator temperature control range

[0043]

[0044] 3. Compressor speed limit

[0045] Since the compressor speed will cause resonance within a certain range, resulting in great vibration and noise, the list of available compressor speeds verified by actual vehicles is as follows. When outputting the compressor speed, the closest speed is selected for output. The specific speed requirements are shown in Table 5 below.

[0046] Table 5: Specified compressor speed table

[0047]

[0048]

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for controlling an air-conditioning compressor, characterized in that: The air conditioning panel sends a compressor request signal when the following conditions are met: There is a request to turn on the air conditioner; Evaporator temperature ≥1℃; It also includes the control of the compressor speed: the compressor speed takes the smaller value between the speed corresponding to the cooling and heating gears and the speed corresponding to the evaporator temperature, and after the speed value is determined, the value is frequency-avoided.

2. The control method of an air-conditioning compressor according to claim 1, characterized in that: The evaporator rise temperature is T. When T≥12℃, the compressor speed is 3400rpm. When 12℃>T≥8℃, the compressor speed takes the maximum value Smax. When 8℃>T≥2℃, the compressor speed takes 1000+(Smax-1000) / 6rpm. When 2℃>T≥1℃, the compressor speed takes 1000rpm.

3. The control method of an air-conditioning compressor according to claim 2, characterized in that: The maximum compressor speed Smax is related to the air volume. When the air volume gear is in gear 1, Smax is 2000rpm, when the air volume gear is in gear 2, Smax is 2800rpm, when the air volume gear is in gear 3, Smax is 3400rpm, and when the air volume gear is in gear 4, Smax is 3400rpm.

4. The control method of an air-conditioning compressor according to claim 3, characterized in that: When the cooling and heating gear is at gear 1, the compressor speed is 3400rpm; when it is gear 2, the compressor speed is 3000rpm; when it is gear 3, the compressor speed is 1800rpm; when it is gear 4-6, the compressor speed is 1000rpm.

5. The control method of an air-conditioning compressor according to claim 4, characterized in that: The hysteresis interval of compressor speed reduction and speed increase is cancelled, and the dwell time after the speed change is constrained to a minimum of 4s.

6. The control method of an air-conditioning compressor according to claim 4, characterized in that: It also includes a correction strategy for the evaporator target temperature: when the refrigeration gear is in gear 1, the evaporator temperature T is 9°C, when the refrigeration gear is in gear 2, the evaporator temperature T is 7°C, and when the refrigeration gear is in gear 3, the evaporator temperature T is 5°C.

7. The control method of an air-conditioning compressor according to claim 1, characterized in that: The compressor speed value also needs to refer to the allowable power of the air conditioner. Combined with the speed corresponding to the cooling and heating gears, the speed corresponding to the evaporator temperature, and the speed corresponding to the power, the minimum value is taken as the compressor speed.

8. The control method of an air-conditioning compressor according to claim 7, characterized in that: When the air conditioner is working, the VCU controls the fan operation synchronously in combination with the working condition of the air conditioner. When the air conditioner start-up conditions are met and the VCU enables the air conditioner, the VCU receives the medium voltage switch disconnect signal and turns on the low-speed fan. During the air conditioner operation, the VCU receives the medium voltage switch closing signal and turns on the high-speed fan. When the air conditioner turns on the fan at a low speed, the high-speed fan is turned on in combination with the fan control strategy if the high-speed fan start-up conditions are met.

9. The control method of an air-conditioning compressor according to claim 1, characterized in that: The evaporator temperature protection range is 1℃-5℃. When the evaporator temperature drops below 1℃ during air conditioning operation, the air conditioner stops working. After stopping working, the evaporator temperature will rise to 5℃ before it is allowed to work.

10. The control method of an air-conditioning compressor according to claim 1, characterized in that: Set the frequency avoidance speed. When taking the compressor speed value, select the closest frequency avoidance speed for output.

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