This paper presents a new genetic algorithm "Search Space Establishment-less Type High Speed Genetic Algorithm Considering Mutation Rate and Using Parallel Computer: PMSSELGA" for optimization control problems. Through the PMSSELGA, all the search space of the tuning parameters for the control are set in the range of 1000.0-0.001. And, a mutation rate is gradually to decrease with the generation from 100% to 15%. The PMSSELGA is speeded up by the parallel computation and the avoidance of repetitive calculations. It is applied to the optimum design of Multi-input power system stabilizer using Series Compensation Method in power system, which contains low-frequency oscillations, and the efficiency through the PMSSELGA is superior to conventional one.
