端口能量及其在风电系统暂态稳定分析中的应用

大规模风电接入后,研究计及风电的能量函数法有助于提高稳定评估的计算速度,并为稳定控制提供灵敏度信息。在结构保留能量函数的启发下,提出端口能量的概念,证明了采用端口能量的系统总能量是系统的能量函数;证明了端口能量的能量聚集效应;分析了采用端口能量计算对象系统的暂态能量给暂态稳定评估带来误差的原因;基于端口能量,提出了包含风电的暂态稳定能量函数分析方法。不同场景下的临界切除时间对比分析验证了所提能量函数法的有效性。在精度方面,各个场景下所提能量函数法比时域仿真法保守0~0.02s,在速度方面,所提能量函数法比基于时域仿真的二分法和逐步法快3~26倍。

Port Energy and Its Application to Transient Stability Analysis of Power Systems with Wind Generation

With large-scale wind power connected to the grid, researches on the energy function method incorporated with wind power generation will help improve the computation speed of stability assessment and provide sensitivity information to stability control. Inspired by structure preserving energy function, the concept of port energy is proposed. It is proved that the total energy is an energy function with part of the transient energy calculated by port energy. The energy aggregation effect of port energy is also proved. The causes leading to errors in transient stability assessment are also analyzed when port energy is used. An energy function method is proposed for wind power generation systems based on port energy. The effectiveness of the method is validated by a comparison of critical clear times in different scenarios. In terms of computation accuracy, the proposed method is 0~0.02 s more conservative than numerical simulation, while in terms of computation speed, the proposed method is 3~26 times faster than the bisection method or the step by step method based on numerical simulation. This work is jointly supported by National High Technology Research and Development Program of China (863 Program) (No. 2012AA050201) and National Natural Science Foundation of China (No. 51190103).