A COTS-based dependable excitation system design for 500 MW-class thermal power plants

This paper deals with an experience of the design and implementation of a dependable excitation system for large thermal power plants. Dependability enhancement in the design is mainly achieved by adopting hardware redundancy techniques. A pool, which is a set of component modules, is constructed by gathering commercial-off-the-self (COTS) products in market. Then, the authors derive a finite parameter space of possible values of the reliability for every functional block of the system. The parameter space is determined by the possible types of the configuration of each block. With a given constraint that is unique to the excitation system, they try to find a good configuration for the excitation system from the given COTS component pool. The chosen configuration from the above analysis is implemented as a real digital excitation system which is now in commercial operation at several power plants in Korea.