Influence of Ultra-High-Voltage hybrid reactive power compensation on interruption performance of circuit breakers under different faults

For extremely large ultra-high-voltage (UHV) power transmission and distribution lines with typical project using hybrid reactive power compensation (HRPC), single-phase earth fault (1LG), three-phase ground fault (3LG), phase-to-phase fault (2LS), and two-phase grounding fault (2LG) often occurs. Circuit breaker is one of the most critical equipment of UHV transmission system. And the interruption performance is crucial to circuit breakers' breaking capability. In this study, formal expressions of the indicators for the interruption performance of the circuit breaker are deduced in case of different faults based on the equivalent-valued parameter circuit based on the structure a UHV demonstration project. The simulations are used to validate the accuracy of formal expressions. Then, the influence of such factors as the location of the fault and the degree of HRPC on the interruption performance of the 1LG, 2LG, 3LG, and 2LS is analyzed. Finally, the interruption performance of circuit breakers under different faults are compared. A quantitative evaluation of the influence of changes in the relevant indicators on the interruption performance of circuit breakers can provide a technical basis for choosing the appropriate design of the circuit breaker in light of the application as well as equipment development and assessment.(c) 2017 Elsevier Inc. All rights reserved.