Robust calculation method of voltage stability margin based on voltage‐collapse‐point properties

Abstract

The progress in electricity deregulation has made electricity systems more economical while maintaining stability. Therefore, the stability of an electricity system should be evaluated more strictly than done previously. We propose a robust calculation method of voltage stability margin (VSM). The proposed method is based on the optimal‐power‐flow‐based direct method (OPF‐DM), which can calculate VSM directly when complementarity constraints related to limits for reactive‐power generation are added. However, the additional complementarity constraints may cause a convergence and local solution issues because of the numerical complexity. The proposed method calculates the appropriate VSM on the basis of several voltage‐stability properties. We implemented the proposed method on MATPOWER and evaluated it with IEEE 9‐bus, 30‐bus system, 39‐bus, 300‐bus, PEGASE 1354‐bus, and IEEJ WEST10‐O/V systems. The results indicate that the proposed method can calculate VSM robustly compared with conventional methods. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Power system stability margin prediction based on gradient lifting decision tree

“…To verify the precision of the proposed method, the proposed method in Reference [4] and Reference [5] is applied to forecast the stability margin of the target power system. The results of the forecast are shown in Figure 4.…”

“…To validate the forecast time of the proposed method, we compare the forecast time of the methods in Reference [4] and Reference [5] with the proposed method. The results of the comparison are shown in Figure 5: 5, when the gradient increases to 7 times, the prediction time of reference [4], reference [5] and this method is 0.98s, 1.12s and 0.39s. Therefore, the proposed method has the shortest prediction time.…”

“…To verify the reliability of the proposed method, we chose 10 predicted samples, and predicted them with the methods described in [4] and [5]. The relative error between the prediction and the actual operating voltage of the power system is shown in Table 2.…”

“…Comparison of prediction time by different methodsAccording to Figure5, when the gradient increases to 7 times, the prediction time of reference[4], reference[5] and this method is 0.98s, 1.12s and 0.39s. Therefore, the proposed method has the shortest prediction time.To verify the reliability of the proposed method, we chose 10 predicted samples, and predicted them with the methods described in[4] and[5]. The relative error between the prediction and the actual operating voltage of the power system is shown in Table2.…”

“…This method is to subtract the sum of acceleration and potential energy from the remaining energy to obtain the remaining energy of the system. Reference [5] gives a reliable method for calculating power system stability (VSM). After adding corresponding compensation constraints, VSM can be calculated directly.…”