The Optimal Power Flow Algorithm Considering Load Power Factor Limits

Jong-Man Cho, Kwang-Wook Kim, Hyun-Soo Jung, Jin-O Kim


Efficient reactive power operation enhances economic operation of the power system. Toprovide reliable and economic system operation, the acceptable load power factor must be analyzedaccording to the demand level of load bus. This paper presents two-bus equivalent method combinedwith stability index analysis to calculate acceptable load power factor range. The above methodbegins with searching the critical load bus with the line stability index, where the two-bus equivalentcircuit is applied to determine the acceptable load power factor limit for the critical load bus. Theacceptable range of load power factors is portrayed as bandwidths of load power factor expressedas a function of load level. After critical bus selection and load power factor calculation, an optimalpower flow considering load power factor is carried out to optimize reactive power source. A casestudy using an IEEE 26 buses system is presented to demonstrate the suggested OPF method, andresults show that system loss is reduced as well as load power factors are improved.

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