CN-121977262-A - Self-adaptive variable frequency control method of air conditioner electric control system at extreme temperature

CN121977262ACN 121977262 ACN121977262 ACN 121977262ACN-121977262-A

Abstract

The invention provides a self-adaptive variable frequency control method of an air conditioner electric control system at extreme temperature, which is characterized in that a temperature domain-load-frequency three-variable coupling model is constructed by collecting data such as ambient temperature, running load and current voltage, a compressor starting torque and frequency speed increasing strategy is optimized for a low-temperature section of-25 ℃ to-10 ℃, PWM duty ratio and bus voltage matching rules are adjusted for a high-temperature section of 45 ℃ to 60 ℃, and meanwhile overcurrent and overvoltage protection thresholds are dynamically adjusted in a linkage mode, so that grading protection logic is designed. The method solves the problems of low energy efficiency, difficult starting and stiff protection of the traditional algorithm under the extreme temperature, realizes the adjustment precision of variable frequency within wide temperature range of +/-0.5 Hz, improves the energy efficiency by more than or equal to 8 percent, remarkably reduces the operation failure rate, and is suitable for an air conditioner electric control system under the extreme climate condition.

Inventors

REN XIAOLIN
XIE JINWEN
WANG XIAOMING
XU ZHILIANG
LUO CHUNYONG
HUANG QIANYING

Assignees

中山长虹电器有限公司

Dates

Publication Date: 20260505
Application Date: 20251231

Claims (6)

1. The self-adaptive variable frequency control method of the air conditioner electric control system at the extreme temperature is characterized by comprising the following steps of: (1) Collecting and preprocessing real-time operation load data of the environment temperature, the operation current of the compressor, the bus voltage and the air conditioner; (2) Constructing a temperature domain-load-frequency three-variable coupling model, dividing temperature domain partitions and load grades, and establishing a frequency reference library; (3) Dynamically adjusting variable frequency parameters (starting torque, PWM duty ratio, bus voltage and frequency adjustment step length) aiming at different temperature zone partitions; (4) Dynamically adjusting an overcurrent and overvoltage protection threshold value in linkage with the ambient temperature, and designing a hierarchical protection logic; (5) On-line correction of parameters based on the operational feedback data, closed loop optimization is achieved.
2. The adaptive variable frequency control method of the air conditioner electric control system under the extreme temperature as set forth in claim 1, wherein in the step (1), the ambient temperature acquisition range is-25 ℃ to 60 ℃, the acquisition frequency is 10 times/second, the precision is +/-0.3 ℃, the current and voltage acquisition frequency is 50 times/second, the load data are quantized to 0-100% of load values, and the data preprocessing adopts a moving average filtering algorithm, and is particularly used for removing noise in acquired data and eliminating abnormal fluctuation data of instantaneous current peaks.
3. The adaptive variable frequency control method of an air conditioner electric control system at an extreme temperature according to claim 2, wherein in the step (2), the temperature zone comprises a low temperature section (-25 ℃ to-10 ℃), a normal section (-10 ℃ to 45 ℃) and a high temperature section (45 ℃ to 60 ℃), the load level comprises a low load (0% -30%), a medium load (31% -70%) and a high load (71% -100%), the frequency reference library presets corresponding variable frequency reference values according to the combined scene of the different temperature zone sections and the load level, and an online correction interface is reserved for subsequent parameter optimization.
4. The method for adaptively controlling the frequency conversion of an air conditioner electric control system at an extreme temperature according to claim 1, wherein in the step (3), the frequency conversion parameters are adjusted to be optimized for the orientation of the different temperature zones, specifically comprising: (a) The starting torque is maximally increased by 20 percent at the low temperature section (-25 ℃ to-10 ℃), the starting frequency is accelerated and slowed down by 30 percent, and the frequency adjustment step length is less than or equal to 0.5Hz so as to improve the low temperature starting success rate; (b) The upper limit of the PWM duty ratio is adjusted by 5% -15% in the high-temperature section (45 ℃ -60 ℃), the bus voltage adjustment range is 280-320V, and the highest operating frequency is adjusted by 10% -15% in comparison with the conventional section, so that the high-temperature operating loss and the overcurrent risk are reduced.
5. The adaptive variable frequency control method of an air conditioner electric control system under extreme temperatures as set forth in claim 4, wherein in the step (4), the dynamic protection threshold is adjusted and precisely linked with the ambient temperature, specifically, the overcurrent protection threshold is adjusted by 8% -10% when the high temperature section is raised by 5 ℃, the overvoltage protection threshold is adjusted by 5% -8% when the low temperature section is lowered by 5 ℃, and the grading protection logic comprises early warning fine adjustment and emergency shutdown two-stage response, wherein the protection response time is less than or equal to 50 mu s, and the safety risk of devices under the extreme temperatures can be rapidly dealt with.
6. The adaptive variable frequency control method of an air conditioner electric control system at an extreme temperature according to claim 1, wherein the parameters corrected online through a PID algorithm in the step (5) comprise frequency reference values and parameter adjustment coefficients in a coupling model, the operation feedback data comprise air conditioner operation energy efficiency values, current and voltage fluctuation data and compressor start and stop times, closed loop optimization is realized through real-time acquisition and analysis of the data, finally, variable frequency adjustment precision in a wide temperature range reaches +/-0.5 Hz, and energy efficiency at the extreme temperature is improved by more than or equal to 8% compared with that of the traditional algorithm.

Description

Self-adaptive variable frequency control method of air conditioner electric control system at extreme temperature Technical Field The invention belongs to the technical field of air conditioner variable frequency control, and particularly relates to a self-adaptive variable frequency control algorithm of an air conditioner electric control system at extreme temperature. Background The variable frequency control algorithm of the air conditioner electric control system is a core technology for determining the running energy efficiency and stability of the air conditioner, however, the prior art has obvious defects in an extreme temperature environment (less than-10 ℃ or more than 45 ℃), and is difficult to meet the use requirement of a wide temperature range: 1. The energy efficiency is low due to the fact that the traditional frequency conversion algorithm adopts fixed compressor starting parameters, PWM modulation strategies and bus voltage matching rules, and cannot adapt to device characteristics and operation load changes at extreme temperatures. The low temperature causes failure in starting or takes too long time due to insufficient starting torque, and the high temperature causes energy efficiency attenuation due to overlarge switching loss and increased overcurrent risk, so that the energy efficiency is reduced by more than 15% compared with the energy efficiency at the conventional temperature. 2. The protection mechanism is stiff to cause operation faults, namely the overcurrent and overvoltage protection threshold values of the traditional algorithm are fixed values, and the influence of extreme temperature on the tolerance capability of the device is not considered. The device has the advantages that the current resistance of the device is reduced at high temperature, the overcurrent damage is easy to be caused by the fixed overcurrent threshold, the insulation performance of the device is changed at low temperature, the protection is easy to be triggered by mistake by the fixed overvoltage threshold, and the air conditioner is frequently stopped. 3. The temperature range is disjoint from the load adaptation, that is, the traditional algorithm does not establish the linkage relation of 'environmental temperature range-operation load-variable frequency', and only adjusts the frequency according to a single load parameter, so that the frequency adjustment accuracy is low at the extreme temperature, the fluctuation is more than +/-1.5 Hz, and the energy efficiency waste and the operation instability are further aggravated. In the prior art, although the frequency conversion algorithm optimization aiming at the conventional temperature range is carried out, a coupling control scheme capable of simultaneously adapting to the wide temperature range from-25 ℃ to 60 ℃ and combining energy efficiency improvement and dynamic protection does not exist. Therefore, the invention provides a self-adaptive variable frequency control algorithm of an air conditioner electric control system at extreme temperature, which solves the technical pain point. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a self-adaptive variable frequency control method of an air conditioner electric control system at extreme temperature, which is suitable for wide-temperature-range environments ranging from minus 25 ℃ to 60 ℃, and improves the energy efficiency and the operation reliability of the air conditioner in the wide-temperature range by the linkage of 'temperature-load-frequency' coupling regulation and control and dynamic protection threshold values. The invention is realized by the following technical scheme that the self-adaptive variable frequency control method of the air conditioner electric control system at extreme temperature comprises the following steps: (1) Collecting and preprocessing real-time operation load data of the environment temperature, the operation current of the compressor, the bus voltage and the air conditioner; (2) Constructing a temperature domain-load-frequency three-variable coupling model, dividing temperature domain partitions and load grades, and establishing a frequency reference library; (3) Dynamically adjusting variable frequency parameters (starting torque, PWM duty ratio, bus voltage and frequency adjustment step length) aiming at different temperature zone partitions; (4) Dynamically adjusting an overcurrent and overvoltage protection threshold value in linkage with the ambient temperature, and designing a hierarchical protection logic; (5) On-line correction of parameters based on the operational feedback data, closed loop optimization is achieved. As a preferred implementation manner, the ambient temperature acquisition range in the step (1) is-25 ℃ to 60 ℃, the acquisition frequency is 10 times/second, the precision is +/-0.3 ℃, the current and voltage acquisition frequency is 50 times/second, the load data is quantized to 0-100%