Study On Power Quality Simulation And Test System And Comprehensive Evaluation Method

With the rapid development of national economic and industry technology, power quality is more and more required by customers. Establishing an entire simulation and testing system has significant meaning to the simulation, analysis, evaluation, study and management of power quality problems. Power quality is a synthesis of several indexes, in competitive electricity market, a logical comprehensive evaluation on power quality is an essential prerequisite to establish a fair electricity market.An entire simulation and test system on power quality is mainly researched in this paper, and the detection models of every separate technology index are established, the simulation validates the correctness and rationality of analysis disposal method. Integrated weight method is applied in comprehensive evaluation, and test results show the feasibility of the method.The preprocessing technology of analog signal is introduced firstly. According to the measurement principle of flicker meter recommended by IEC, the simulation model of flicker meter is built. After theoretical analyzing the gain of the flicker meter and leading it into the simulation, the simulation error is decreased in great extension. The statistic sequencing method is employed to handle the instantaneous flicker sensation and the short term flicker sensation indicator is obtained by programming. The sub-harmonics are extracted by comb filtering in this paper, and the simulation of this algorithm is built. The simulation results certificate the validity of the comb filtering. Then, the simulation model of three-phase unbalanced circuit is built and the degree of three-phase unbalanced ness can be calculated correctly.On the basis of analysis to the present comprehensive evaluation methods, an integrated weight method is put forward to evaluate the power quality comprehensively in this paper. In this method, G1 algorithm is used to determine the subjective weights, information entropy algorithm is used to determine the objective weights, and above two weights are synthesize to constitute comprehensive weights.At last, an simulation model with electric arc furnace load is built, and the power quality is evaluated in this model. The weight of every index is obtained and then comprehensive evaluation is processed. The results verified the feasibility and practicability of this method proposed in this paper.