Frequency control method for variable frequency air conditioner

Abstract

The application provides a frequency control method of a variable frequency air conditioner, and relates to the technical field of air conditioners. A target frequency first change value is calculated through fuzzy control. If the sum of the current frequency and the target frequency first change value is in a frequency hopping range, a target frequency second change value is obtained by subtracting the current frequency from the maximum value of the frequency hopping range. A target current is calculated according to the target frequency second change value. If the target current is not higher than the maximum current allowed for compressor operation, the frequency is increased according to the target frequency second change value. If the target current is higher than the maximum current allowed for compressor operation, the target frequency second change value is reduced according to a certain rule, the reduced target frequency second change value is taken as a new target frequency first change value, and the target current is recalculated until the target current is not higher than the maximum current allowed for compressor operation. The application solves the problem of repeated frequency fluctuation in the frequency control process of the existing variable frequency air conditioner, and is suitable for frequency increasing control of air conditioners.

Description

TECHNICAL FIELD

[0001] The present application relates to the air conditioning technical field, particularly relates to a frequency control method of variable frequency air conditioner. BACKGROUND

[0002] Variable frequency air conditioner has the advantages of high efficiency, high temperature adjustment precision, low noise, wide frequency operation range, good environmental temperature adaptability and the like. However, the design of the variable frequency air conditioner is complex, the compressor and the system structure are complex, and in the whole structure system design, the system resonance points and noise points that cannot be eliminated often appear. In order to realize these advantages of the variable frequency air conditioner, the frequency control of the variable frequency air conditioner is complex, and the frequency control scheme commonly used in the industry is: fuzzy control or multi-dimensional fuzzy control. Regardless of which fuzzy control adjusts the frequency, only the temperature demand is considered, but in many working conditions, due to the current protection, frequency hopping points and other factors, the air conditioner appears the frequency fluctuation caused by the capacity, system resonance and other factors. SUMMARY

[0003] The technical problem solved by the present application is to provide a frequency control method of variable frequency air conditioner, which solves the problem of frequency fluctuation in the frequency control process of the existing variable frequency air conditioner.

[0004] The technical scheme adopted by the present application to solve the above technical problem is: a frequency control method of variable frequency air conditioner, comprising the following steps:

[0005] S1, after the air conditioner is turned on, when the frequency adjustment interval time is reached, a target frequency first change value is calculated according to the fuzzy control;

[0006] S2, if the sum of the current frequency and the target frequency first change value is in the frequency hopping segment, a target frequency second change value is calculated by the maximum value of the frequency hopping segment and the current frequency, so that the sum of the current frequency and the target frequency second change value is not in the frequency hopping segment;

[0007] S3, the target current is calculated according to the target frequency second change value, if the target current is not higher than the maximum current allowed by the compressor operation, S4 is entered, otherwise S5 is entered;

[0008] S4, the frequency is increased according to the target frequency second change value, and S1 is entered;

[0009] S5, the target frequency second change value is reduced according to a certain rule, and the reduced target frequency second change value is taken as a new target frequency first change value, and S2 is entered.

[0010] Further, the formula for calculating the target frequency second change value by the maximum value of the frequency hopping segment and the current frequency is: wherein the target frequency second change value is represented by f2, the maximum value of the frequency hopping segment is represented by fmax. Indicates the current operating frequency of the compressor. is the set coefficient.

[0011] Furthermore, the formula for calculating the target current according to the second change value of the target frequency is: ,in, represents the target current, Indicates the current operating current of the compressor. Indicates the current operating frequency of the compressor. Indicates the second change value of the target frequency, Indicates parameters, Indicates the maximum current of the compressor frequency reduction. Indicates the maximum value of the frequency-limited current.

[0012] Furthermore, reducing the second target frequency change value according to a certain rule includes reducing the second target frequency change value by one half or one third.

[0013] Beneficial effects of the present invention: The present invention provides a frequency control method for a variable frequency air conditioner, which calculates a first change value of a target frequency through existing fuzzy control. If the sum of the current frequency and the first change value of the target frequency is in a frequency hopping band, the current frequency is subtracted from the maximum value of the frequency hopping band to obtain a second change value of the target frequency. The target current is calculated according to the second change value of the target frequency. If the target current is not higher than the maximum current allowed for the operation of the compressor, the frequency is increased according to the second change value of the target frequency, so as to avoid the frequency after frequency modulation being in the frequency hopping band, thereby causing repeated frequency fluctuations. If the target current is higher than the maximum current allowed for the operation of the compressor, the second change value of the target frequency is reduced according to a certain rule, and the reduced second change value of the target frequency is used as the new first change value of the target frequency, and the target current is recalculated until the target current is no higher than the maximum current allowed for the operation of the compressor. In this way, while ensuring the safety of the compressor operation, the problem of repeated frequency fluctuations in the frequency control process of the existing variable frequency air conditioner is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention provides a flow chart of a frequency control method for a variable frequency air conditioner. DETAILED DESCRIPTION

[0015] The present invention aims to solve the problem that the frequency of the air conditioner fluctuates repeatedly due to factors such as current protection and frequency hopping point, which only considers the application temperature requirement when adjusting the frequency of the existing fuzzy control. The present invention provides a frequency control method for a variable frequency air conditioner, such as Figure 1 As shown, the following steps are included:

[0016] S1, after the air conditioner is turned on, when the frequency adjustment interval time is reached, a first change value of a target frequency is calculated according to fuzzy control; specifically, the fuzzy control belongs to the existing air conditioner frequency adjustment technology.

[0017] S2, if the sum of the current frequency and the first change value of the target frequency is in the frequency hopping segment, a second change value of the target frequency is calculated by the maximum value of the frequency hopping segment and the current frequency, so that the sum of the current frequency and the second change value of the target frequency is not in the frequency hopping segment; specifically, if the sum of the current frequency and the first change value of the target frequency is not in the frequency hopping segment, the frequency is increased by the first change value of the target frequency; the formula for calculating the second change value of the target frequency by the maximum value of the frequency hopping segment and the current frequency is: wherein the second change value of the target frequency, the maximum value of the frequency hopping segment, the current operating frequency of the compressor, is a set coefficient, for example, if the frequency hopping segment is 50Hz to 55Hz, then is 55Hz, and A is 0.1Hz, is 42Hz, then is 13.1Hz.

[0018] S3, the target current is calculated according to the second change value of the target frequency; if the target current is not higher than the maximum current allowed for the operation of the compressor, S4 is entered, otherwise S5 is entered;

[0019] Specifically, the formula for calculating the target current according to the second change value of the target frequency is: wherein, the target current, the current operating current of the compressor, the current operating frequency of the compressor, the second change value of the target frequency, the parameter, the maximum value of the compressor frequency reduction current, the maximum value of the frequency limiting current.

[0020] S4, the frequency is increased according to the second change value of the target frequency, and S1 is entered;

[0021] S5, the second change value of the target frequency is reduced according to a certain rule, and the reduced second change value of the target frequency is taken as a new first change value of the target frequency, and S2 is entered;

[0022] Specifically, the second change value of the target frequency is reduced by one half or one third, for example, if the target current calculated by 13.1Hz is higher than the maximum current allowed for the operation of the compressor, then After reducing by one half, it is 6.55 Hz, usually, take 6.6 Hz, in this way, 6.6 Hz is taken as the new , enter S2, recalculate the target current, until the target current is not higher than the maximum current allowed for compressor operation, in some cases, It will be reduced many times to meet the target current not higher than the maximum current allowed for compressor operation.

Claims

1. A frequency control method of a variable frequency air conditioner, characterized by, The method comprises the following steps: S1, after the air conditioner is started, when a frequency adjustment interval time is reached, a target frequency first change value is calculated according to fuzzy control; S2, if the sum of the current frequency and the first change value of the target frequency is in the frequency hopping range, the second change value of the target frequency is calculated by the maximum value of the frequency hopping range and the current frequency, and the formula is: wherein, the second change value of the target frequency is represented by, the maximum value of the frequency hopping range is represented by, the current operating frequency of the compressor is represented by, is a set coefficient, so that the sum of the current frequency and the second change value of the target frequency is not in the frequency hopping range; S3, calculating target current according to target frequency second change value, formula is: wherein, target current is represented by I, current running current of compressor is represented by Icur, current running frequency of compressor is represented by Fcur, target frequency second change value is represented by F2, parameter is represented by K, maximum value of compressor frequency reduction current is represented by Imin, maximum value of frequency limiting current is represented by Imax, if target current is not higher than maximum current allowed for compressor running, entering S4, otherwise entering S5; S4, the frequency is increased according to the target frequency second change value, and S1 is entered; S5, the target frequency second change value is reduced according to a certain rule, the reduced target frequency second change value is taken as a new target frequency first change value, and S2 is entered.

2. The frequency control method of a variable frequency air conditioner according to claim 1, wherein The target frequency second change value is reduced by one half or one third according to a certain rule.

Images