Harmonic suppression of grid-connected distributed generation based on novel Hybrid power filter

Distributed generation (DG) is a hot spot nowadays, at the same time the harmonic pollution can´t be ignored when DG is connected with the power grid through power converters. First discuss several harmonic suppression methods have been adopted in practice, such as increasing the number of converter pulse, using pulse width modulation (PWM) converter, passive power filter (PPF), active power filter (APF) and so on, among these methods, hybrid type combining PPF and APF is the most economical and effective method, so a hybrid filter constructed of a shunt active filter and distributed passive filters is presented and the parameters of the passive filter are discussed. Genetic algorithm (GA) is an important method of multi-objective optimization. So using GA optimizes the PPF parameters, namely R, L, C, from three respects of the cost, the DG penetration power and the total harmonic distortion (THD), optimization results make the PPF cost is the most economical, the DG penetration power is the largest and the THD is the smallest. At last, simulation shows that PPF compensates a majority of harmonic current, APF compensates a few harmonic current and prevents series/parallel resonance, at the same time, the level of APF power is very small because of avoiding to fundamental voltage.