CN102538150A - Method for controlling multiple air conditioners through variable-parameter intelligent PID linkage - Google Patents

Abstract

The invention discloses a method for variable parameter intelligent PID linkage control of multiple air conditioners. Weighted average calculation is performed according to the detection data of each sensor in each area to obtain the temperature and humidity errors in each area. The PID parameters proposed by the invention The deviation relationship with the set value adjusts the PID parameters in real time, so as to jointly adjust the operating parameters of the air conditioning system around the area, so that the output variable and deviation can achieve the best combination, and ensure that the system working condition is closest to the set value. Eliminate the occurrence of cold and hot opposite working conditions caused by local load fluctuations in traditional large-space air-conditioning systems, and meet the requirements of high-precision constant temperature and humidity in large spaces.

Description

A method for variable parameter intelligent PID linkage control of multiple air conditioners

technical field

The invention belongs to the technical field of automation control, and in particular relates to a control method for variable parameter intelligent PID linkage control of multiple air conditioners, especially a control method for high energy saving, high stability, constant temperature and humidity, and high precision for large-space factory buildings .

Background technique

Traditional large spaces generally use an air-conditioning system. When the local load fluctuates greatly, the air-conditioning system cannot adjust to the local load change, resulting in local air parameters that do not meet the process requirements, and even some areas may be cooling down, while the adjacent The area may need to be heated due to the influence of cold air next to it or the difference in equipment load distribution, resulting in an opposing working condition. Moreover, the control of the current air-conditioning system is generally based on conventional PID control. When the feedback value of the controlled variable is too large in this control method, it will cause too much input of the control amount, resulting in system overshoot or even divergence. Therefore, in the control In a dynamic and long-delay system, conventional PID regulation has certain disadvantages. In some spaces, such as the packing workshop of a cigarette factory, the load distribution changes with time and space, and there is a certain delay in reflecting the change of local load at the air measuring point, which belongs to a dynamic and long-delay system. If according to the conventional PID Adjustment will make the indoor temperature and humidity unable to meet the production requirements, resulting in production loss.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the prior art, to provide a method for variable parameter intelligent PID linkage control of multiple air conditioners, to eliminate the occurrence of cold and hot opposite working conditions caused by local load fluctuations in traditional large space air conditioning systems, and to meet the High-precision constant temperature and humidity requirements in large spaces.

The object of the present invention is achieved through the following technical solutions.

A method for variable-parameter intelligent PID linkage control of multiple air conditioners, characterized in that it includes a deviation relational expression between PID parameters and set values, and the PID parameters can be adjusted in real time according to changes in air-conditioning conditions, so that the output variable and the deviation To achieve the best combination, to ensure that the system operating conditions are closest to the set value.

For air conditioning load fluctuations in local areas, the variable parameter PID control method can be used to jointly adjust the operating parameters of the air conditioning system around the area, so that when the air jet flows to the area, it can offset the load fluctuations and effectively eliminate the opposite working conditions.

Detailed ways

The present invention will be described in further detail below in conjunction with the drawings and examples, but the drawings and examples are not intended to limit the technical solution of the present invention.

Example 1

The air conditioning of a building with a large space consists of multiple independent air conditioning systems, each of which is only responsible for a certain area, and each air conditioning system can be adjusted individually. Place temperature and humidity sensors in the area responsible for each air-conditioning system, and the PLC controller will perform weighted average calculations based on the detection data of each sensor in the area to obtain regional temperature and humidity errors. For local load fluctuations, adjust through variable parameters PID The operating parameters of the air conditioning system around this area make the air jet flow to this area to offset the load fluctuation and effectively eliminate the opposite working conditions. Through the linkage control of multiple air-conditioning systems, the air supply parameters of different air-conditioning systems are adjusted to make the temperature and humidity of the building space meet the process precision requirements.

Figure 1 is a schematic diagram of variable parameter PID adjustment:

Among them, T is the sampling period, and T must be small enough to ensure a certain accuracy of the system; e(k) is the deviation value of the kth sampling; e(k-1) is the (k-1)th sampling The deviation value at time; k is the sampling sequence number; u(k) is the output of the kth sampling regulator.

The variable parameter PID adjustment solution that the present invention adopts is:

K _p , T _i and T _d can be adjusted in real time according to the change of the working condition of the air conditioning system, so as to achieve the best combination of output variable and deviation, and ensure that the working condition of the system is closest to the set value. The deviation relationship between PID parameters and the set value is:

Among them, K _p0 , K _i0 , K _d0 are the initial proportional coefficient, integral coefficient and differential coefficient; e is the deviation; K _p1 , K _i1 , K _i2 , K _d1 are undetermined coefficients, which are determined by the system structure. According to the formula (1) ~ (3) to determine the PID parameters.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned specific implementation, those of ordinary skill in the art can make Various similar representations and such transformations all fall within the protection scope of the present invention.

Claims (2)

1. A method for variable-parameter intelligent PID linkage control of multiple air conditioners, characterized in that: the deviation relational expression between PID parameters and set values is included, and the PID parameters are adjusted in real time according to changes in air-conditioning conditions, so that the output variable and The deviation achieves the best combination to ensure that the system working condition is closest to the set value. 2. The control method according to claim 1, characterized in that: for the air conditioning load fluctuation in a local area, the operating parameters of the air conditioning system around the area are adjusted through the variable parameter PID control method, so that when the air jet flows to the area, the Load fluctuations can effectively eliminate opposing working conditions.

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