Unbalanced Modelling of STATCOM and SVC in Hybrid Load Flow Method

Modern power distribution systems are installed with a number of distributed power generation. Increased integration of distributed power generation makes the distribution system vulnerable to unbalanced operating conditions. This would then require the support of Flexible AC Transmission System (FACTS) devices for a smooth operation of the distribution system. Unbalanced power system operation requires an unbalanced load flow analysis in order to assess true system feasibility. This paper presents an innovative unbalance load flow analysis method with the presence of unbalanced operation of SVCs (Static Var Compensators) and STATCOMs (STATic synchronous COMpensators). Unlike the existing methods, the proposed method applies reduced steps in the calculation, and the parameter limits of FACTS devices are dynamically determined in an iterative process. Case studies demonstrate its improved convergence characteristics, reduced computing demand and the robustness of the solution.