Identification method of model parameters for air conditioning indoor temperature time-delay characteristics based on relay feedback control

 Analyses the main factors leading to indoor temperature delay response characteristics in the process of supply air rate regulation based on the control principle of VAV air conditioning system, and studies the description and modeling method for delay response characteristics of indoor temperature versus system regulation variables in the dynamic regulation process of VAV air conditioning system. Analyses the relationship between relay feedback control technology and the transfer function of indoor temperature delay first order inertia plus time-delay link of VAV air conditioning system, and proposes an identification method for delay response characteristic model of indoor temperature based on hysteretic relay feedback control. Through the closed loop response test, studies the dynamic response characteristics of indoor temperature to the opening of terminal air valve and supply fan speed in the process of supply air rate regulation. According to the experimental results, completes the parameter identification of the transfer function model of the indoor temperature delay first order inertia plus time-delay link, and verifies the effectiveness and practicability of the method by comparing with the open-loop response test results. The results show that this method can realize the parameter identification of the first order inertia plus time-delay link transfer function model of indoor temperature versus terminal air valve opening and supply fan speed without a priori knowledge of the controlled object. With the increase of hysteretic coefficient, the calculated results are convergent, which meets the requirements of on-line application.