Study On High Power AC Constant Current Power Supply

The AC loss in the superconducting magnet is one of the important indexes tomeasure the performance of superconducting magnet. If it is too large, it will not onlyincrease the burden on the cooling system, and also cause instability in superconductingmagnet, which is directly related to the efficiency and economic viability of hightemperature superconducting magnet. According to the need of AC loss measurement, ahigh power AC constant current power supply and its control system for superconductingmagnet are designed and developed.On the basis of the research on the analysis of the current existing constant-currentsource for measuring the AC loss of superconducting magnets, according to therequirements, such as voltage and current index, of the AC losses measurement systemof superconducting magnets, this paper is designed and developed themain circuit structure and control system of the power. Main circuit topology uses theAC/DC/AC circuit structure, including the front three-phase voltage rectifier and thesingle-phase inverter, which is used of maintaining the DC link voltage stability andcontrolling the output sinusoidal current to be constant; The control system is based on theanalysis of circuit principle and mathematical model, makes use of the voltage and currentdual loop control and output current single loop feedback control strategy and is designedand realized on the DSP digital controller, focusing on the design ofthe communication and the protection system of power supply, including remotecommunications and local communications, hardware protection and software protection.According to the design scheme of the system, a simulation model of the entire powersupply is established, on the basis of the simulation analysis, we designed and optimizedthe circuit parameters, completed the development of power system and made theexperimental test. The simulation and experimental results show that the designed high-power AC current source achieves the desired effect, and output the20-200Acontrollable sinusoidal AC current.In this paper, the high power AC constant current power supply system provides agood experimental platform for measuring the loss of high-temperature superconductingand is great significant of carrying out research and application of superconductingmagnet technology.