粗糙集与证据理论结合的电网运行优质性综合评价

Evaluation of power quality performance based on rough set and evidence theory

电力系统运行的核心目标之一是提供优质电能,电力系统运行的优质性指标主要通过电能质量好坏来体现。为了能够客观、有效地评价电网运行优质性水平,提出一种粗糙集与证据理论结合的电网运行优质性综合评价方法。应用粗糙集理论建立决策强度和决策扩充规则,利用决策表获取证据理论的基本概率赋值,使概率赋值结果更具有客观性。再应用证据理论的融合规则将电压偏差、电压波动、三相不平衡、谐波畸变等优质性指标进行融合,得到各观测点电能质量的优劣状况,实现电网优质性综合评价。算例表明,该方法得到的优质性综合评价结果更客观合理,证明了方法的正确性和优越性。

One of the core objectives of power system operation is to provide high-quality energy, the quality indicators of power system operation are mainly reflected by power quality. In order to assess the power quality objectively and effectively, a comprehensive evaluation method of high-quality network operation based on rough set and evidence theory is proposed. The method applies rough set theory to define the decision-making strength and expansion rules and uses the decision-making table to obtain the basic probability assignment of evidence theory, which make the result of probability assignment more objective. And then by applying the fusion rules of evidence theory to integrate the various indicators of power quality, the pros and cons of ordering from each power quality evaluations can be obtained to achieve a comprehensive evaluation of power quality. The examples show that the results of power quality evaluation are more objective and rational by using this method. So it can prove the correctness and superiority of this method.