Development of cost-effective redundant digital excitation control

In this paper, the developed digital excitation control system was evaluated to get the strength of operating situations in the small power plant. Recently, most automatic voltage control systems for big power plants employ a quick response and stationary excitation technology. But cost of older excitation systems has been prohibitive for redundancy. And they add much complexity to the system relative to wiring and interconnection. To solve these problems, the new redundancy digital excitation control system was developed. This system ensures adequate steady-state, dynamic reactive reserves, and zero tolerance. In addition, it provides protective features for the generator such as over flux limiting and field current limiting. Finally, the performance of this digital excitation control system was verified in a gas turbine of a coal-fired plant.