基于圆形度指标的电能质量综合评估方法

Comprehensive evaluation method of power quality based on circular degree indicators

就电能质量问题分别建立了数学模型或物理模型，以方便对电能质量问题进行研究。在叙述了实际电量与理想电量贴近度分析的理论基础上，引入了傅立叶级数法对贴近度进行数学描述，解释了αβ两相合成曲线的实际意义。提出了用圆形度量化稳态电能质量指标的方法，通过绘出单独的电能质量问题对应的αβ两相合成曲线，计算其圆形度可验证该理论的合理性。对实测数据进行分析，分别计算圆形度、谐波总畸变率，绘出αβ两相合成曲线，进行傅里叶分析，通过一致性分析判断合理性。

Mathematical model and physical model are established for power quality problems in order to explore power quality issues conveniently. On the theoretical basis of the analysis posted on the closeness degree between actual electricity and ideal electricity, Fourier analysis method is introduced to describe closeness mathematically and practical significance of αβ two-phase synthetic curve is explained. Circular degree is presented to quantify steady power quality indicators. To verify the rationality of the theory, corresponding αβ two-phase synthetic curve of various power quality problems can be curved and circular degree can be calculated. On calculating circular degree, total harmonic distortion, plotting αβ two-phase synthetic curve, building fast Fourier transformation based on actual measured waveforms, consistency can be judged.