Generator over excitation capability and excitation system limiters

Sometimes, power system events have shown the need for generators to operate in the overexcited region to support stable operation. Operation up to, and transiently beyond, the overexcited limits from the capability curve is sometimes required. The two main issues in the paper are the generator capability in this region and the design of OEL (overexcitation limiters) in the excitation system that take full advantage of the capability allowed in the design and standards.