Research On Optimal Configuring Of Power Filter With Considering The Randomness Of Harmonic Sources

Wide-range application of nonlinear load has brought serious harmonic pollution to power grid, as well as a series of power quality problems. The power filter is one of the most effective measures to solve the problem of harmonic. In the filter configuration, harmonic current always be regard as certainty value. In fact, numbers of filed tests show that the harmonic current significant randomness. In this paper, the correlation of the harmonic current injected into each node is taken into account and the nature of the harmonic currents is described by the multi-dimensional joint probability distribution of random variables. For power flow, an improved back/forward sweep algorithm based on branch and bus layering is used. In this algorithm, the branches and buses are sorted by layers, and the branch currents and bus voltages in the same layer can be parallel computed, so as to improve the calculation efficiency greatly. The harmonic power flow, separated with fundamental power flow is solved by direct method.it solves the harmonic network equations only for once without iteration and it is simple and fast calculation. For the harmonic losses of transformer, through lots of simulation, a more accurate method between different voltage distortions is given. In this paper, pseudo-parallel genetic algorithm is first introduced to the optimization of the filter configuration which enhance the diversity of the population and prevent "premature" in the production effectively. Some improvements are also made to make the exchange with the number of adaptive changes in the population diversity and prevent the migration of the blind. Finally, an actual project is made as an example to prove the correctness of the algorithm.