Study On Passive Optimization Based On The Adaptive Genetic Algorithm And Fuzzy Set In The Hybrid Active Power Filter

In the modern society, the harm from harmonic makes people increasingly concerned about power quality. Because the pollution of harmonic becomes more and more seriously and the need to improve power quality become more and more strongly, so it is more severe for us to improve the problem. In the factories of our country, it is almost usual for them to use the PPF to manage filter in order to improve power quality. The shortcomings of the PPF(passive power filter) and APF(active power filter) in managing the pollution of harmonic make the HAPF (hybrid active power filter) used in the actual application broadly. As a result, it has a new application prospect for the PPF which can be used to the HAPF by optimizing its parameters and studying its optimal algorithms.In the paper, taking the harmonic management and reactive power compensation in one steel plant of 35kV distribution network in 110kV substation in shizuishan for example, it is proposed to use a HSHIAPF(High-capacity shunt Hybrid Injection Type Active power Filter) in the plant to improve the situation of the harmonic in the power quality. The basic structure and principle are discussed and then the conclusion is given that the structure of HSHIAPF is more suitable for harmonic management in the distribution network of industrial enterprises with its well filter, reducing capacity of the APF and very large capacity reactive power. The capacity of the APF in the structure is focused on discussion by computing in the paper. And the relations among the capacity of the APF, harmonic sources and the PPF is analyzed which nicely plays a foreshadowing role for the necessity of the PFF parameters optimization in the continuation.In the structure of HAPF, it can reduce the capacity of the APF to optimal the parameters of the PPF, so it is necessary to study the methods of optimization based on the calculating the sensitivity of the PPF parameters and then the optimization model of the PPF is built up in the paper.The approach combined the Refined Genetic algorithm and fuzzy set to optimal parameters of the PPF is suggested, the former reproved the initialization genetic operator, got the corresponding fitness function with a normalization method and a sub domain searching method to process the objective function and the fitness function, and obtained a lot of best individuals which is the target of optimization algorithm by using the adaptive crossover rate and mutation probability. And then, the further optimal parameters are got by further optimizing using the later method with gradient based on the results got by the Genetic algorithm to help designer to find the better parameters and at last, they are used into the structure of the HSHIAPF to find the finally results.Based on the results had got above, the effective of the frequency fluctuation to the passive power filter. Then, the parameters of PPF in the HAPF after optimization used into the structure of the HSHIAPF are verified by simulink in the MATLAB. By comparing the filter results of the PPF optimized by the adaptive genetic algorithm and the fuzzy set method, it can be given that the later method has the better efficient,and the best parameters after optimization are got by simulation. Then, the conclusion is that: the several parameters after optimization are effective to reduce more the capacity of the APF and have better filter effect than before, so the whole system has better harmonic management effect and the power quality of the system is raised further. And the dynamic characteristics are discussed by simulation to verify the stability of the system.At the last, The summery and prospect are raised at the end of the paper which summarizes the importance of the optimization to the PPF in the harmonic management which is an important step to improve power quality and the next plan is provided.