计及集中式和分布式新能源的电力系统连锁故障模拟

Cascading Failure Simulation for Power System with Utility-scale and Distributed Renewable Energy

在评估高比例新能源电力系统的大停电风险时,现有连锁故障模型对新能源动态特性的刻画仍有待改进。为此,提出一种计及集中式(场站型)和分布式新能源的连锁故障动态模型,通过求解含新能源电力系统的动态方程,模拟输电线路、常规机组、集中式新能源和分布式新能源等元件的保护逻辑,更全面地分析源-网-荷之间的故障交互动态。其中,为刻画新能源在连锁故障中对系统安稳运行的影响,采用美国西部电力协调委员会的新能源通用模型建立集中式新能源的动态方程,并采用节点净负荷水平模拟分布式新能源与主网的交互;为刻画新能源的耐扰动能力,对集中式新能源的电压保护、频率保护和分布式新能源的反孤岛保护,建立动作模拟逻辑。采用IEEE 39节点系统的仿真结果表明:所提模型可以有效地描述不同新能源渗透率下连锁故障中的源-网-荷的耦合作用。该模型可以同时刻画集中式和分布式新能源对电网安全风险的影响,在新型电力系统建设中具有良好应用场景。

When assessing the blackout risk of power system with high penetration of renewable energy,the existing cascading failure models need to be improved for capturing the dynamics of renewable generation.In this paper,a dynamic model of cascading failure considering the utility-scale and distributed renewable energy is proposed.With the solution of dynamic equations for power system,the relaying logics are simulated for system components such as transmission lines,conventional generators,and renewable generations.The failure interactions among sources,networks,and loads are analyzed comprehensively.In the proposed model,to discuss the impact of renewable energy on the system dynamics,the dynamic equations for the utility-scale renewables are constructed with the second-generation generic model of Western Electricity Coordinating Council,and the interactions among distributed renewables and the transmission system are captured through the net load level at buses.Besides,to analyze the tolerance of renewables for disturbances,the simulation logic is constructed for the voltage relays and frequency relays of utility-scale renewables and the anti-islanding relay of distributed renewables.The simulation results on the IEEE 39-bus system show that the proposed model can effectively describe the coupling in cascading failures among sources,networks,and loads under different penetration levels of renewable energy.This proposed model can quantify the impact of utility-scale and distributed renewable energy on security risk of power grid,and has good prospects in the construction of new power systems.