การประมาณสถานะระบบกำลังแบบค่าช่วงโดยอิงการผ่อนปรนเชิงเส้นและการแพร่กระจายเงื่อนไขบังคับ

Abstract

This research proposes an approach for improving the interval value state estimation technique of power system by using McCormick linear relaxation together with interval constraint propagation. The measurement data of the power system is assumed to be within bounded tolerance. The proposed method gives the values of state variables as the consistent interval numbers. The method has been tested on the IEEE 14, 30, 57 and 118 bus system and compared with the results from the global optimal value estimation method. The tests are based on the same measurement data and network structure of the power system. This study analyzes the test results by comparing the mean error of the estimated state variables and the computation time. From the numerical experimental results, it is found that small average errors are obtained by the improved method. The graphs of the results of the improved method is very similar to those obtained by the global optimization based estimation method. However, the proposed method uses much less computation time.