Optimal design of passive filters considering the effect of Steinmetz circuit resonance under unbalanced and non-sinusoidal conditions

In order to reduce the voltage unbalancing, the delta reactances connected to the single-phase load, known as the Steinmetz circuit, are utilised. In this study, the design of passive filters in presence of the Steinmetz circuit is presented to balance the unbalanced networks including single-phase load. Voltage distortion and resonance phenomenon are very serious problems in power systems. Some methods have been proposed to provide the solution to this problem, among which passive filters are used as the most economical and efficient way to reduce harmonics. In this research, in addition to a brief review of the passive filters and their common types, the objective functions of the issue are discussed. The optimised functions for this issue are total harmonic distortion,voltage deviation value, total filters cost, frequency response and the critical bus power factor of the network. To solve the problem of the suggested multi-objective optimisation, NSGA-II is presented, and finally, the best solution is proposed with the normalised method from among the Pareto front. To verify the effectiveness of the proposed method, two networks of 13-buses industrial test network and modified 33-buses IEEE network are evaluated. These networks are included non-linear loads and Steinmetz circuit.