Research On Complete Sets Of Commercial Refrigerators Control System Based On The Wireless Network Wifi

Commercial refrigerator mainly means the large refrigerator that to use for business, it focuses more on use function, volume and power consumption characteristics, its volume is generally much greater in terms of household refrigerators, and its shape and technic are relatively simple. Due to its larger quantities, and each used in an "individual" form, setted with fixed cooling and freezing temperature, different type of fresh food is stored in a simple mixing way in cooling or freezing room with no mark, which result in several typical problems in actual use:1) high energy consumption, and poor effect of preservation;2) compressors start and shut down frequently, which result in a short life;3) poor sanitary condition;4) be no good to scheduling management;5) poor emergency response. These deficiencies seriously affect the development of high-end refrigerator industry, the traditional multi-door refrigerators designed with network smart controllers have become the trend of future refrigerators development.This paper will introduce the wireless communication technology into the sets of commercial refrigerators intelligent controllers, aimed at improving the management of current commercial refrigerators, change the compressor drive mode of original commercial refrigerator based on fuzzy frequency control theory, and make some pre-judgments during the working time of commercial refrigerators, therefore it has a very good studying significance and application value. Main research work of this paper are as follows:(1) Principle of brushless DC motor drive control based on zero-crossing point detection are simply discussed, and commutation delay time setting method are introduced. A detailed analysis of getting fuzzy control rule table under the difference and change rate of temperature is proposed based on the fuzzy control theory. A brief overview of the refrigerator system fault diagnosis is introduced to analysis and diagnose some common problems of refrigerators.(2) According to the functional requirements of network commercial refrigerators, the overall control scheme of refrigerator controller is designed and the experimental hardware platform is built. The detail circuit principle of compressor frequency control module is elaborated, the drive principle of full bridge IGBT is studied to make sure the drive waveform well. A barcode scanning engine is used to get the information of storing food that sent to PC through serial port to WiFi module. Meanwhile, the AD detection module is used to sample the temperature of fridge room and the current and voltage of actuator of refrigerators, which not only improve the dynamic performance of the compressor, but also play a part in the motor protection.(3) In order to solve the "networking" issue of commercial refrigerators, a software implementation of the control system is given. The overall framework of control software is part into the on-site control software and PC monitoring software using TCP/IP communication protocol, the WiFi communications is acted as software as the communication link between the upper layer and the lower layer software to built the control system. The compressor zero-crossing detection and commutation control strategy, temperature fuzzy control strategy, and fault diagnosis analysis strategies are elaborated in the on-site control software. The PC software design was completed for the function of food information management, data analysis of temperature and electrical parameters and self-diagnose.(4) The experimental platform is built to accomplish the control experiments of network commercial refrigerator controllers. The experimental results show that the compressor driven by the controller runs smoothly and downtime can be shortened by about36%, food preservation effect is much better; Debugging for the remote monitoring system of network refrigerators, the results shows the remote control accuracy and convenience of the network control and management software, and the intelligent management of storing food and fault diagnosis reminding are achieved; The energy consumption before and after using fuzzy control algorithm of controller is studied for comparison, The experimental results show that: the power consumption of refrigerator compressor derived by fuzzy variable frequency controller is42.3percent smaller than compressor of ordinary refrigerator, and one commercial refrigerator can save930Yuan each year in electricity cost, and energy saving effect is obvious.