Study Of Optimal PMU Placement Based On Power Grid Vulnerability And Economy

With the continuous development of modern power system, the operation state of power system and the power system structure itself have become increasingly complex, modern scheduling system needs to install the PMU through the grid to accurately and comprehensively grasp the actual situation of power grid to prevent failures, which lead to serious consequences. However, the whole grid installation of PMUs is unrealistic and not economic.Traditional PMU placement can meet the observability requirements under normal circumstances, but it does not include grid topology changes which may lead to unobservability of the grid. The PMU placement considering N-1 situation could meet the observation requirements under N-1 failures, but more PMUs should be needed compared to the traditional PMU placement, which means the much more cost.How to solve the problems above has become a new research direction of PMU placement. Thus, in this paper propose a new method of PMU placement to balance the contradiction between N-1 failures and economy in the aspect of grid vulnerability and economy.First of all, identify vulnerable areas of the grid by using generalized tellegen's theorem. First, calculate the sensitivity, then, form vulnerability index for the assessment of bus and branch in the grid. A few examples included the networks of IEEE14 and IEEE30 are set to get the vulnerability sorts of bus and branch, which provides the analysis basis of PMU placement.Then an example of the network of IEEE39 is set to compare the algorithms of PMU placement. The result shows that by using the regression-based spanning tree algorithm without zero-injection buses, we could get the result with more programs and less PMUs compared to other graph algorithms. Through the placement result calculated by the algorithm above under normal circumstances and N-1 failures, it is clear that solving OPP problems with consideration of observability under N-1 failures and economy is very meaningful.Based on the vulnerability sorts, the PMU placement results under normal circumstances and N-1 failures, economic index, robustness analysis, new method of PMU placement is given. Use the improved procedure of the rapid decomposition for the state estimation to test the result of PMU placement. Use the networks of IEEE14 and IEEE30 as examples to prove that the new method of PMU placement is reasonable and feasible.