非变频压缩机培养箱温湿度控制算法改进

Improvement of Temperature and Humidity Control Algorithm for Non-inverter Compressor Incubator

在压缩机非变频,且有从关闭到开启冷却时间限制的培养箱情景中,传统定点开关结合PID的控制算法往往达不到预期的控制精度。针对该情况,在先控温再控湿的策略下,设计一种对压缩机表现进行线性估计的算法。算法在压缩机间断工作时,线性量化上一个升降温周期内的降温斜率和升温斜率,以此估计本周期降温时间及降温点,以满足压缩机冷却时间要求并减小温度振幅,最终实现对温湿度的稳定控制。通过搭建实物进行测试,结果表明,在温度存在采集扰动的情况下,该算法的温度控制偏差相比传统定点控制算法,由±1℃缩减到±0.5℃,湿度控制偏差也达到±5%RH的水平。

In the case where the compressor is not frequency-converted and has a cooling time requirement from the on state to the off state,the control algorithm of traditional fixed-point control combined with PID often fails to achieve the expected control accuracy. In view of this situation,this paper introduces an algorithm by linearly estimating the performance of the compressor under the strategy of controlling temperature first and then controlling humidity. When the compressor is working intermittently,the algorithm linearly quantifies the cooling slope and heating slope in the previous heating and cooling cycle,then these data are used to calculate the cooling time and cooling point in this cycle. In that way,the cooling time and cooling point can meet the closing time requirements of the compressor and reduce the temperature amplitude. According to the physical test set up in this paper,compared with the traditional fixed-point control algorithm,the temperature control deviation of the designed algorithm is reduced to ±0.5℃from ±1℃,and the humidity control deviation has reached a level of ±5%RH in the case of temperature disturbance.