A central air-conditioning control method based on self-tuning discrete pid algorithm

Abstract

The invention discloses a central air conditioner control method based on a self-tuning discrete PID algorithm. A timer is adopted for sampling the temperature of a coil pipe, the temperature of a room, the rotating speed of an EC motor and opening information of a proportional electromagnetic valve in a timed mode, filtering processing is carried out, and valid sampling values are obtained; the working state of a system is judged through changes of sampling information; then, according to a self-tuning coefficient table, a proportionality coefficient, an integral coefficient, a differential coefficient, the control weight of the EC motor and the control weight of the proportional electromagnetic valve, needing to be adjusted, are obtained through table look-up; a temperature deviation, an integral value and a differential value are worked out, and the rotating speed of the EC motor and the opening angle of the proportional electromagnetic valve are worked out through the coefficients obtained through table look-up; finally, the EC motor and the proportional electromagnetic valve are driven to reach required values. The EC motor and the proportional electromagnetic valve are controlled through the self-tuning discrete PID algorithm, namely the cooling capacity and air volume of an air conditioner system are controlled, the room can reach a set target temperature rapidly, and the system can keep running in the cooling capacity consumption and supplementation stabilization state.

Description

technical field [0001] The invention belongs to the field of central air-conditioning controllers, and in particular relates to a central air-conditioning control method based on a self-tuning discrete PID algorithm. Background technique [0002] At present, the motors used by most central air-conditioning controllers are three-speed tap motors, PG motors or BLDC motors, and the water valves are two-wire or three-wire solenoid valves. The control algorithms used include ON-OFF, PI adjustment control, etc. [0003] The air conditioner adopting the ON-OFF control method has the disadvantages of large room temperature fluctuations and low comfort. The control method is as follows: figure 1 shown. In this control mode, when the room temperature Tr drops to Ts-ΔT, the water valve will close, and when Tr rises, it will rise to Ts+ΔT, then the water valve will open. Due to the inertia of temperature, this At that time, the room temperature Tr will rise a little, and then it will ...

AI Technical Summary

Problems solved by technology

[0004] There are also many problems with the controller using PI regulation control. The system adaptability is not high. It has a better control effect in a certain occasion, but it will have a large over-control behavior when it is replaced in other occasions, and even in some extreme situations. Oscillation will occur in the case, and the PI parameters need to be adjusted, which is not universal

In addition, when PI is used to adjust the variable flow and variable air volume at the same time, there will be a mismatch, resulting in large fluctuations in the indoor temperature

Images