Optimal Capacitor Allocation in Sub-Transmission Networks to Mitigate Overloading Considering Harmonic Resonance

In conventional electricity grids, although power plants can support the active power of loads, transmission and sub-transmission networks deal with overloading situations in the transformers caused by reactive power of loads. Hence, local reactive power compensation of loads by capacitor allocation is an important solution. In this paper, the genetic algorithm (GA) is employed for the optimal capacitor allocation then the transformer tap changing is used to regulate the voltage profile in the buses. The tap regulation can eliminate the over-voltage, which is produced by capacitors installation. Eventually, harmonic analysis is applied to prevent harmonic resonance in capacitor banks. For validating the efficiency of the proposed method, it is examined in the typical transmission and subtransmission networks. The simulations are done in DIgSILENT software using DIgSILENT Programming Language (DPL) that is interfaced with MATLAB software.