抽蓄机组“背靠背”起动过程电气暂态特性研究

Research on electrical transient characteristics of pumped storage unit during“back to back”starting process

“背靠背”起动是抽水蓄能机组泵水方向的重要起动方式。基于白莲河抽水蓄能电站实际参数和MATLAB/Simulink平台,以拖动机转速变化作为输入参数建立了仿真数学模型,该模型考虑了发电机的起动转速、励磁电流的影响,用以探究“背靠背”起动过程中阻尼绕组的影响。仿真计算结果表明:①发电机起动转速增幅不宜超过正常起动发电机起动转速的13%,发电机外加励磁电流不应低于0.6倍空载励磁电流;②适当减小发电机起动转速、增大励磁电流有利于提高机组起动的成功率;③电机阻尼绕组在起动过程中会消耗掉一部分的母线电流并产生对电动机转速上升有阻碍作用的电磁力矩。

“Back to back”starting is an important starting mode of pumped storage units in pumping direction.Based on the actual parameters of the Bailianhe Pumped Storage Power Station and MATLAB/Simulink platform,this paper establishes a simulation mathematical model with the speed change of the tractor as the input parameter.This model considers the effects of the starting speed and the excitation current of the generator to explore the influence of the damper winding during the back-to-back starting process.The simulation results show that the increase of starting speed of generator should not exceed 13%of the normal starting speed,and the external excitation current of the generator should not be less than 0.6 times of the no-load excitation current.Properly reducing the starting speed and increasing the excitation current are conducive to improving the starting power of the unit.The damping winding of the motor will consume a part of the bus current during the starting process and generate the electromagnetic torque that hinders the rise of engine speed.