浅析无功补偿控制器中的功率因数和无功检测

Analysis on Power Factor and Reactive Power Measurement in Reactive Power Compensation Controller

功率因数和无功测量在无功补偿中必不可少。本文针对无功补偿控制器中的相位-时间法、S.Fryze广义无功法、交流采样移相法、DFT基波法和基于瞬时无功理论的p、q法等几种主流测量算法进行较详细分析,从补偿角度讨论了这几种测量方法的特点、自动认相的条件和它们所适用的工况。分析表明,采用基波法和p、q法的控制器适合包括电流谐波较大在内的各种工况。若电网电压畸变较小、交流采样移相法也具有同样效果。

The measurement of power factor and reactive power is indispensable in reactive power compensation.In this paper,several mainstream measurement methods in the reactive power compensation controller,such as phase-time conversion,S.Fryze generalized reactive power,AC sampling phase shift,DFT fundamental wave,pq algorithm based on instantaneous reactive power theory,are analyzed in detail.The characteristics of those measurement methods,automatic phase identification condition and applicable condition from the standard point of compensation are discussed.It is shown by the analysis that the controller adopting DFT fundamental wave and pq algorithm is suitable to various working conditions including large harmonic current.If power grid voltage distortion smaller,the AC sampling phase shift method also has the same effect.