Automatic power factor correction based on alienation technique

In modern digital protection and control systems, an alienation technique has recently become the workhorse of quantitative research and analysis. In this paper, an alienation technique is developed for calculations of original power factor on-line, active and compensation reactive powers and determination of the required number of capacitor banks to get the desired power factor. Alienation coefficients are calculated between phase voltage and current signals of power supply. These calculations are performed within one-cycle. Thus, the algorithm is well suited for implementation in a digital reactive power control scheme. This scheme is able accurately to identify the required capacitor rating to get the desired power factor under different loading levels. It does not need any extra equipment as it depends only on the voltage and linecurrent measurements which are mostly available at the relay location. Alternative transient program (ATP) and MATLAB programs are used to implement the proposed technique.