Research On Stochastic Harmonics Power Flow With Considering The Randomness Of Harmonics Generated By Distributed Generators

More and more Distributed Generators are accessing to power system because of theirspecial advantages. But the harmonics Distributed Generator injected into the distributionnetwork it connected with will influence the quality of electric energy, and then bringhidden troubles to the safe operation of power system. Meanwhile, the stochasticfluctuations of harmonics generated by Distributed Generators also lead to the randomvariation of harmonics distribution. How to evaluate the Stochastic Harmonics Power Flowof Distributed Power System reasonably is an important subject in studying the operation,planning and design of Distributed Power System.This paper studied the method of Stochastic Harmonics Power Flow with consideringthe randomness of harmonics generated by Distributed Generators based on analyzing thecharacteristics of harmonics generated by Distributed Generators. The algorithm ofStochastic Harmonics Power Flow was realized by C++programming after the harmonicequations linearization and using the theories of cumulants and Gram-Charlier eapansions.The simulation example of this paper is a0.4kV Benchmark microgrid connected withDistributed Generators. The simulation calculated the randomness indexes (such asexpectation, variance and the CP95%, etc.) that can measure the randomness of harmonicvoltage amplitude and the total harmonic distortion factor (%) of voltage, and then usedthose indexes to analyze the randomness of harmonics in power system. Example analysisindicated the effectiveness of Stochastic Harmonics Power Flow algorithm andcorresponding C++programming. And the randomness indexes from Stochastic HarmonicsPower Flow can provide references to power system operators and equipment designers.