The Research Of The Pmu's Optimal Allocation In The Wide Area Measurement System

The WAMS (Wide Area Measurement System) is mainly derived from the power system on the synchronization of both the space and the time. The Power system analysis and control is mainly on the state of measurement. By using some buses voltage and phase's angle, we can get the whole system's phase buses voltage and phase angle, And it provide the basis of the dynamic monitoring in the later period. The traditional SCADA(Supervisory Control And Data Acquisition) system can not make the power grid completely observable (the amplitude of the voltage can only be observed).And it is difficult to ensure consistency in the time, so it is hard to be controled by the Dispatchers. Therefore it can't meet the smart grid's requirements, such as observation, being controlled, and adaptive real-time analysis and decision-making.With the in-depth study and the wide range of applications in the WAMS, the economy, reliability, availability of it will be even more important, Because this article focus on the optimal allocation of PMU(Phasor Measurement Unit), the state estimation and the PMU reliability analysis ,the three aspects of economic WAMS is mainly about the economy, the reliability, and the availability.This study is divided into the following main aspects:(1) The WAMS: It is about the function block of it, and the analysis of its structure.(2) The PMU optimal allocation: Before the Optimization of the power network in a specific configuration, we need to do some pretreatment of the optimal allocation of PMU which include building mathematical models, selecting the initial value, the node admittance matrix obtained, the constraints. Finally, by the three aspects (the number of PMU, thePMU of redundancy, and Utilization of PMU), we can get the advantages and disadvantages of several algorithms (select practical algorithm for comparison), so the optimal algorithm can be drawn.(3) The WAMS's state estimation: Basing on the fully observation of the system, we can use a linear model and the weighted least squares method for the entire system state estimation. And then we can use hypothesis testing to detect whether the data is bad data based on the objective function.(4) The WAMS's reliability analysis: The entire system can be divided into the WAMS master state detection, the digital relay protection systems, the data acquisition subsystem, SDH ring network, and the ATM switches, the overall reliability is consisted by them. The detection algorithm analysis and digital relay to protect the master system reliability can through the continuous Markov state, at the same time we can get the reliability of the data acquisition subsystem by the series-parallel model method. At last we can get the simulation curve of the wide area measurement system's reliability in the different repair rates.