Optimal capacitor placement in distribution systems feeding nonlinear loads

The nonlinear portion of electrical loads has increased significantly in recent years. Harmonic currents injected by these loads into the distribution system should be considered when solving the capacitor placement problem to obtain optimum solution and assure that this solution does not result in excessive harmonic distortion. A voltage dependent current injection load model is presented to determine voltage waveform characteristics. A genetic algorithm technique shows that optimal capacitor sizes and locations depend on the load model used at fundamental frequency and on harmonic content, especially when limits are imposed on voltage waveforms. A case study using a 32-bus test system is presented to demonstrate the applicability of the presented algorithm.