Improving the protective performance of the Gas turbine and HRSG trip from hydraulic damper closing in power plant

After using low frequency switching circuit technique [2] to solved the problem of accumulated heat transfer in solenoid coil of the solenoid valve controlling hydraulic damper. This paper presents an improvement of switching circuit performance by adding the voltage supply comparator for more reliable of power supply to the solenoid coil and still save the energy loss in solenoid coil of the solenoid valve and completely protect the gas turbine trip from hydraulic damper closing failure and heat recovery steam generator (HRSG) trip.