Research On Optimal Configuration Of Harmonic And Voltage Sag Monitoring Points

In recent years, power quality problem has been widely concerned. On the one hand, with the widely application of power electronic in power system, more and more harmonics injected into the power grid, on the other hand, with the increasing of complex, precision electrical equipment used in power system, the problems caused by voltage sag are gradually prominent. The accurate and effective monitoring is the premise and foundation to find and suppress these power quality problems in power grid. It is meaningful to deeply research how to rational configurate monitoring devices utilizing limited information provided by the monitors and analyze the power quality problems overall the whole network. Based on respective characteristics of these two power quality problems, monitoring points of harmonics and voltage sag are unified allocated in this paper, which could obtain the optimal configuration scheme simultaneously satisfying two problems completely observable.First of all, only considering voltage sag, this paper proposes a method of optimizing the configuration of voltage sag monitoring devices based on fuzzy control models and binary particle swarm optimization algorithm. In the method, the concept that fuzzy threshold and the observation index are proposed, and considering the bus observation ability, a fuzzy control model is established to obtain the optimization objective function. After establishment of the methetical mode, then the discrete particle swarm optimization algorithm (BPSO) is used to optimize the configuration for voltage sag. The simulation and analysis on IEEE30 bus test system showing that the proposed method dependent less on a strict threshold, can not only realize the whole network voltage sag completely observable, but also can give the sort of configuration schemes, achieving the optimal cofiguration of the monitoring devices.Based on optimal configuration of voltage sag monitoring points, the method of harmonic observability and harmonic state estimation are researched. Then the model of uniform configurating harmonic and voltage sage monitoring points is established. In the model, a observability judgment method of topological network structure with non harmonic sources is considered as constraint condition with the voltage sag monitoring point capability index as the objective function, then the unified optimal configuration is finished by discrete particle swarm algorithm. After the configuration, the results are verified by harmonic state estimation utilizing the least square method due to its advantages of simple algorithm, less priority information and good convergence ability. The simulation results and analysis on IEEE30 bus system show that the proposed method could obtain the configuration scheme simultaneously best for voltage sag harmonic monitoring points. In addition, under the consideration of the practical engineering situation, the choice of measurement points under incomplete observation condition is also researched on the IEEE30 bus system.