Multi-year multi-case optimal VAR planning

An integrated methodology for long-term VAr planning is presented that results in determining the timing (year), the location, and the amount of VAr compensation. The system security and investment and operating economics are taken into account. The proposed methodology is an integration of the Newton-OPF with the generalized Benders decomposition (GBD). The total problem is decomposed into two levels: master and slave. The master level deals with the investment decision of installing discretized new VAr devices. The slave level deals with operating the existing controllers, in conjunction with the new devices solved in the master level, to maintain system feasibility and to reduce MW losses. The overall solution methodology contains numerous extensions to the basic theory. Tests performed on actual Taiwan power system data have been encouraging. Sample results are presented