Self-tuning-parameter fuzzy PID control in fresh air system

A fresh air system with solar collectors and LHTS (Latent Heat Thermal Storage) was presented in this paper. It can not only keep indoor air good quality, but also supply part of heat for rooms. In addition, it has an advantage of energy-efficient and will not cause extra air-conditioning load when the system is used in conjunction with air-conditioning system. For the nonlinearity and hysteresis of the system, it is difficult to found precise mathematical model. Consequently, fuzzy logic control algorithm can be used to realize the fresh air temperature control in the system. In consideration of the PID controllers´ good performance to minimize the steady state error of the system, a self-tuning-parameter fuzzy PID controller was designed in this paper. Result from experiments shows that the self-tuning-parameter fuzzy PID controller has superior control performance in fresh air temperature control system compared to a conventional PID controller.