不同稳态工况对同步调相机单相短路后暂态温升的影响

Influence of Different Steady State Conditions on Transient Temperature Rise of Synchronous Condenser After Single-phase Short-circuit

同步调相机可在系统故障时为特高压直流换流站提供暂态无功支持,以保持系统电压稳定,防止直流换相失败,但调相机的高无功输出也会导致其温升增加,运行能力受限。系统故障前同步调相机的初始工况是影响其暂态温升和运行能力的一个重要因素,为研究系统低电压时调相机暂态温升与初始工况之间的关系,该文将调相机的电磁场、温度场与电网模型耦合,计算调相机不同稳态工况下的定转子损耗和温度分布;以线路单相短路故障引起的系统低电压为例,研究调相机初始工况对暂态温升的影响。在考虑各结构件最大容许温度的条件下,揭示调相机单相短路持续时间随初始工况的变化规律。研究结果为提升调相机在系统低电压下的暂态运行能力提供技术支持。

The synchronous condenser(SC)can provide transient reactive power support for the ultra-high voltage direct current(UHVDC)converter station in system fault,keep voltage stability and prevent commutation failure.However,high reactive power output leads to the temperature rise of the SC and limits its transient operation ability.The initial condition before the fault has an important impact on the transient temperature rise and operation ability of the SC.In order to study the relationship between the transient temperature rise and the initial condition,the electromagnetic field and temperature field of the SC are coupled with the grid model,and the stator and rotor losses and temperature of the SC under different steady-state operating conditions are calculated.Taking the single-phase short-circuit fault as an example,the influence of the initial condition of the SC on the transient temperature rise is studied.The variation law of single-phase short-circuit duration of the SC with initial condition is revealed based on the maximum withstand temperature of each component.The research provides the technical support for improving the transient operation ability of the SC under low system voltage.