基于相轨迹凹凸性的电力系统暂态稳定性识别

随着基于GPS的功角测量技术在电力系统中的广泛应用，在线识别系统不稳定成为可能，其对于暂态稳定紧急控制具有重要意义。该文研究了一种更快的在线暂态不稳定识别方法。在严格证明了一个猜想正确性的基础上，提出了一种改进的不稳定性识别方法，该方法仅使用了观测数据，而不受运行时刻网络的结构、系统参数和模型影响。证明过程中，模型计及了阻尼参数的影响，从而保证了证明过程更加合理。文中根据系统轨迹的凹凸性定义，还提出了一种新的判据指标Dk，用来识别系统的不稳定。仿真结果显示了该识别原理的正确性，以及能够更快地更有效地识别出系统不稳定。由于该方法的可靠性和要求很少的计算量，能够实际应用于失步保护设计中。

Power System Transient Stability Detection Theory Based on Characteristic Concave or Convex of Trajectory

With the application of APMU (angle &; Phase Measurement Unit) based on GPS (Global Position system) in power system, online system transient instability detection becomes feasible. It is of great significance to transient stability emergent control that out-of-step condition is as soon as possible detected. This paper is concerned with faster transient instability detection for online application. A supposition is strictly proved, and an improved instability detection method is presented, which is independent of the network structure, system parameters and model because of using observation data. During the process of proof, damp coefficient is considered in system model to keep it more reasonable. According to the geometric characteristics of system trajectory, a new index Dk is defined and used to identify system transient instability. The simulation results show that the detection theory of transient instability is correct, and the improved index is more effective than the pre-used method. Since the index is reliable and requires less computational time, it can be applied to the design of out-of-step relaying.