Simulation Research Of Temperature Control With Vapor-compression Refrigeration Technology In Dry-type Rectifier Transformer

Subway traction substation is the power source of subway power supply system,it is great significant to ensure safety and stable operation of metro vehicles.Rectifier transformer is one of the most important equipment in subway traction substation.Good working efficiency of rectifier transformer is an important factor for regular work of traction substation.Therefore,it is a practical significant to study the dry-type rectifier transformer with vapor-compression refrigeration cycle technology and its temperature control method to prevent overheating in subway traction substation of the former Soviet Union region.Firstly,dry-type rectifier transformer's temperature control technology in metro traction substation is described in thesis,this is the basic principle of vapor-compression cycle(Vapor-Compression Cycle,VCC)technology,the fundamental structure,mathematical model,module and control block of VCC system are studied,and the function of refrigerant is analyzed.Secondly,the module structures of VCC including system inner and outer loops are expounded,the control strategy of inner and outer loops controller in VCC system is discussed.The basic structure of Proportional Integral(PI)for outer loop and Model Predictive Controller(MPC)for inner loop are confirmed;then the concept of preventing overheating by temperature control in dry-type rectifier transformer and realizing of control method to prevent overheating are studied,the parameters of temperature control in dry-type rectifier transformer are designed.Finally,the rationality of VCC model and the validity of preventing overheating control method are verified by simulation research.The complexity of system control is reduced by improving inner and outer loops structure of VCC;the overheating of dry-type rectifier transformer is effectively ensured by control method of preventing overheating;freon R134 A is selected,this allows to eliminate the problems with the danger of the ecological environment.