Controller Research Of VRV Central Air-Conditioning

With the development of economic and technological rapidly and the improvement ofliving standards in recent years, air-conditioning equipments has been used more widely byall walks of life. The requirements for comfort are also higher. However, the problem ofenergy shortage is growing recently. As an energy-hungry, the research for air-conditioningenergy-saving technologies should be paid attention for us.This paper analyzes the control technology development status and the workingprinciple of VRV central air-conditioning. The air-conditioning system has somecharacteristics that are parameters tuning difficult, slow time-varying, nonlinear,uncertainty. Fuzzy adaptive controller is less demanding on the model and has strongadaptability to uncertainties. It solves the contradiction between stability and veracity incontrol system. This paper uses fuzzy adaptive to control superheat degree at the outlet ofthe evaporator up to the ideal setting by opening of electronic expansion valve. It achievesa reasonable distribution of refrigerant and improves the energy efficiency of airconditioningThe mathematical model of the controlled plant is established by experiment platform.The fuzzy adaptive method is used to control above model. To build the control system andsimulation are all by using the Simulink in the MATLAB. In addition, compare to thecontrol effects of the three options that traditional PID controller, fuzzy controller andfuzzy adaptive controller under different conditions to verify the control effect to themethod further. Analysis of the experimental data and obtain the maximum overshoot, risetime, settling time and steady state error of the system and verifies the superiority of thesuperheat controller based on fuzzy adaptive.The analysis of experimental data shows fuzzy adaptive controller that designed canrealize the optimal control of superheat. The controller can still get satisfactory controleffect when the controlled plant changed under varieties of operating conditions. It makemaximum overshoot of the system is less than 5%, steady state error of the system is less than 1%. It improves the energy efficiency of air conditioning and verifies the feasibilityand the superiority of the superheat controller based on fuzzy adaptive. It has someengineering reference value.