面向系统功角稳定性提升的变速抽水蓄能机组故障穿越性能优化

Fault Ride-through Performance Optimization of Variable-speed Pumped Storage Units for Enhancing Power Angle Stability of Power Systems

含定、变速机组的大容量抽水蓄能电站经弱交流通道送出场景下,定速机组存在功角失稳风险,为此,通过优化变速机组故障穿越性能提出了系统功角稳定性提升方法。首先,建立了抽水蓄能电站送出系统的动态模型,推导了变速机组输出功率对系统减速面积的灵敏度,明确了变速机组故障穿越特性对系统功角稳定的影响;然后,在确保故障期间变速机组转子无超速风险的前提下,提出了变速机组故障穿越电流限值和电压阈值的整定方法,以降低故障期间变速机组有功、无功功率恢复速度,提升系统功角稳定性;最后,采用基于中国河北省丰宁抽水蓄能电站的仿真算例验证了文中方法的有效性。

In the scenario of large-capacity pumped storage power plant (PSPP) with fixed-speed pumped storage units (FSPSUs) and variable-speed pumped storage units (VSPSUs) transmitting through weak AC lines, there is a risk of power angle instability for the FSPSUs. Therefore, a method for improving system power angle stability is proposed by optimizing the fault ride-through (FRT) performance of VSPSUs. First, the dynamic model of the power transmission system of the PSPP is established, the sensitivity of the output power of VSPSUs to the system deceleration area is derived, and the impact of the FRT performance of VSPSUs on the system power angle stability is clarified. Then, on the premise of ensuring that there is no risk of rotor overspeed of the VSPSUs during the fault period, a setting method for the FRT current limit and voltage threshold of the VSPSUs is proposed to reduce the recovery speed of active and reactive power of the VSPSUs during the fault period, and improve the system power angle stability. Finally, a simulation case based on the Fengning PSPP in Hebei Province, China, is used to verify the effectiveness of the proposed method.