核反应堆棒控电源电路仿真与优化

Simulation and optimization of rod control power circuit in nuclear power plants

棒控电源是核电站反应堆燃料棒的驱动机构的电源,核电站内的棒控电源柜通常与驱动机构相距较远,通过电缆相连接。为了提高设备的集成度,棒控电源柜中多个直流斩波模块共用一个整流模块,这种设计大大增加了直流母线的长度。直流母线和电缆的分布电感和分布电容,会产生电压过冲、增加开关损耗、产生高频振荡,并对电源控制产生巨大干扰。通过对电源电路的分析,计算直流母线的分布电感和电缆的分布电容,建立棒控电源系统PSIM仿真模型,得到了与样机测试波形近似的仿真结果。然后提出了减小直流母线分布电感的优化方法,经理论推导和仿真验证,可有效改善高频振荡和电压过冲等问题,显著提高电路性能指标。

[Background]The rod control power supply is the power supply for the driving mechanism of fuel rods in nuclear power plants(NPP).In the actual nuclear power plants,the rod control cabinet is usually far away from the driving mechanism and needs to be connected by a cable.In order to improve the integration of the equipment,many DC chopper modules in the bar control power supply cabinet share a rectifier module,but this design greatly increases the length of DC bus.The distributed inductance and distributed capacitance of the DC bus and cables will cause voltage overshoot,increase switching losses,and generate high-frequency oscillation,and cause great interference to power supply control.[Purpose]This study aims to improve the performance of rod control power supply by circuit simulation and experimental verification.[Methods]Based on the analysis of the power circuit,the distributed inductance of the DC bus and the distributed capacitance of the cable were calculated.Power simulation(PSIM)model of the rod-controlled power system was established,and the simulation results were compared with the prototype test waveforms.Then,an optimization method to reduce the distributed inductance of the DC bus was proposed.[Results and Conclusions]After theoretical derivation and simulation verification,it can effectively improve the problems of high-frequency oscillation and voltage overshoot,and significantly improve the circuit performance indicators.