Simulation Study on Iron-core Loss and Temperature Distribution of Saturable Reactor for ±1 100 kV UHVDC Converter Valves

Abstract

In order to analyze the core loss and temperature distribution of the saturable reactors, firstly, we established a simulation model of saturable reactor in ANSYS Maxwell software based on the finite element analysis, which can reduce the calculation time and ensure the calculation accuracy. Then, the instantaneous power waveform and power density distribution of the normal operating saturation reactor at the rectifier valve side were simulated by importing the instantaneous current data of 5 000 A under full load condition into the model. Finally, taking the density distribution of core loss as the load of temperature field analysis, we established an electromagnetic thermal coupling simulation model of the saturable reactors in ANSYS Workbench software and simulated the law of temperature distribution of core loss. The simulation results show that the core loss near the air gap and at both ends is higher than that in the middle, and the left side is higher than the right. The temperature of the core at both terminals is higher than that at the middle, and the temperature of core near the winding side is higher. The hottest point of the core near the terminal is 107℃. Thus, the epoxy resin close to both ends of core is weak. The research results can provide references for the insulation life aging evaluation of local weak points in epoxy resin and the thermal design of saturable reactors.