基于风险理论和模糊推理的电力系统暂态安全风险评估

Transient security risk assessment of power system based on risk theory and fuzzy reasoning

在概率论的基础上将风险理论和模糊推理应用于电力系统暂态安全风险评估,利用特定的严重度函数将故障后系统的频率最大偏移、电压最大偏移、功角稳定裕度和故障切除时间裕度进行量化,得到量化的风险指标;将量化的频率风险指标和电压风险指标相结合,通过稳态模糊控制器计算故障的稳态指标,将量化的功角裕度指标与故障切除时间裕度指标相结合,通过暂态模糊控制器计算故障的暂态指标;通过两者的加权综合得到系统的综合暂态稳定指标。在此基础上开发了暂态安全风险评估软件,并以新英格兰39节点系统为例计算三相线路永久性接地故障各风险指标并排序,说明了该方法的有效性和合理性。

Based on probability theory, risk theory and fuzzy reasoning are applied to the transient security risk assessment of power system. Quantified risk indices are achieved by using specified severity function to quantify the maximal offsets of frequency and voltage and the margins of angle rotor stability and fault clearing time. The quantified frequency and voltage risk index are used to calculate the steady index by the steady fuzzy controller while the quantified margins of angle rotor stability and fault clearing time are used to calculate the transient index by the transient fuzzy controller. The system transient stability index is calculated by the weighted integration of steady index and transient index. Based on it, the software of transient security risk assessment is developed. Case study of risk indices calculation for a permanent three-phase grounding fault of New England 39-bus test system shows its effectiveness and rationality.