Application Research On Frequency Conversion Technology Based Improved Air-conditioning Control System Of YZ25

With the development of China's economy and the continuous expansion of the railway, the train is the first choice of traveling by more and more travelers. In addition to the high-speed railway which is rapid developing, the capacity of the ordinary passenger train also occupies a large proportion. However, there are still a lot of problems in the air conditioning system of the ordinary passenger train such as temperature fluctuations, air dry, insufficient oxygen and so on. All these problems caused a lot of discomfort, such as head stuffy, feel cold and tongue scorched, which affect traveling experience greatly. Aiming at the large demands of the ordinary passenger trains and the problems of its air conditioning system, this thesis completes the improve design of the air conditioning control system of YZ25 passenger train based on frequency conversion technology.The YZ25 passenger train is as the research object, to improve the design of its air conditioning control system for make a further contribution to passenger comfort. The main contents of this thesis are as follows:(1) For the comfort of passenger train's air conditioning, the optimum setting temperature of air conditioning is calculated by using the indirect PMV method, which has taken the factors of human body thermal comfort into account from the root.(2) It provides convenient and efficient to the design and simulation of the air conditioning control system of passenger train by establishing the temperature environment model of passenger train compartment.(3)Based on the analysis of the operation principle and control method of the air conditioning of YZ25 passenger train, the compressor, the fan and the fresh air door are selected as three main objects to improve. Then the fuzzy controller of air conditioning is designed, and the simulation analysis of the controller is carried out by MATLAB 11, which has confirmed the validity and reliability of the control algorithm.(4)S7-200 is chosen as the control core and ET070 touch screen is chosen as the man-machine interface. The interface of the passenger train air conditioning control system is designed through the configuration software. The control of passenger train air conditioning is completed by the connection of S7-200 PLC, touch screen, each sensor and air conditioner actuators. Based on the recalculation of the optimum temperature setting of the passenger train air conditioning, the thermal comfort of the human body is incorporated into the air conditioning control target.In this thesis, a compartment temperature environment model is established, and a fuzzy controller of air conditioning is designed by adopting frequency conversion technology, and then, the validity and reliability of the algorithm is proved through the analysis and comparison. In the last, using PLC as the control core, touch screen as man-machine interface, the hardware and software design of the control system of passenger train air conditioning is completed in this thesis, which is practical significance to improve the comfort of air conditioning of passenger trains.