Design And Realization Of Control System Of Variable Frequency Air Conditioner

With the rapid development of economy and science and technology,human beings pay more and more attention to the life and work environment.And air conditioning is more and more widely used.At the same time,environmental protection and energy saving problems have attracted widespread attention.Variable frequency air conditioner meets the needs of the indoor temperature and comfort.And its performance in energy-saving and environmental protection has improved a lot,compared with the traditional fixed frequency air conditioner.So the inverter air conditioner has gradually become the mainstream of the air conditioner market.The technology of variable frequency air conditioner is also in rapid development.Some key techniques and improvement continuously appear like fuzzy control technology,positioning technology without position sensor,field oriented control and so on,so that the controlling of variable frequency air conditioner is easier,with performance improves,and behaves better in energy conservation and environmental protection.The embedded system,designed for the indoor and outdoor machine control system according to the architecture and the principle of operation of variable frequency air conditioner,is running in two microprocessors,CS8953 and CS6257.Firstly,the overall control structure of variable frequency air conditioner was designed.Secondly,the hardware of main control circuit boards for indoor and outdoor machine consist of power circuit,microprocessor peripheral circuit,sensor circuit,fan motor circuit,display circuit,communication circuit,inverter and power module circuit for the speed control of compressor,and control circuit of the key devices,four way valve and electronic expansion valve.Finally,the design and implementation of indoor and outdoor machine software were implemented separately for the microprocessors according to the hardware design and the air conditioning mode design.The block-based designed software,designed according to the hardware controlling methods,complete the controlling of circuits and the corresponding functions.The designed control system was applied to a variable frequency air conditioner.Tests verified the correctness and completeness of the hardware and software design.The controlling was stable,and all operating mode were realized.