Negative-phase-sequence reduction with adjacent static reactive-power compensators

Abstract

Static reactive power (VAr) compensators (SVCs) can be used to reduce negative phase sequence (NPS) voltages by balancing, for example, phase-to-phase-connected loads. In such cases, they are effective until their controlled elements, usually thyristor-controlled reactors, reach their operating limits. Once this happens, NPS currents flow in the system and produce NPS voltages. If several load balancing SVCs are located in close electrical proximity, adjacent load balancing SVCs are able to absorb some of this uncompensated NPS current, reducing the overall NPS voltage profile. The mutual support thus provided should be considered when designing the ranges of such load balancing SVCs. The paper describes how to quantify the mutual support in a system with multiple load balancing SVCs.