Abstarct: Cooling water pumps (CWP) in the power plant usually work at the constant speed and pump cold water into the condenser. In the cooling section of power plant, seawater is used as a fluid for cooling. In this system, seawater is pumped into the condenser and then hot water returns to the sea. Due to the tidal sea level, the amount of pumped water will change. Hence, these variationswill effect on the condenser pressure and also Heat rate of the turbine cycle. The cycle efficiency is affected by Heat rate; therefore, the turbine cycle efficiency will bechange. By using a variable frequency drive (VFD) in order to maintain the flow rate of the cooling water pumps, the pumpspower consumption will be reduce(compared with the pumps working at the constant speed) . In this thesis,atheoretical methodis presentedto optimize the condenser consumptionby using the variable frequency drive (VFD) in the power plantcooling section. By utilizing the VFD, we can control the speed of the CWP. Close scrutiny of the results reveals that the amount of the power consumption of the CWP, in the case of using variable frequency drives to control theirspeed,is approximately half of that without using drive. However,using thevariable frequency drive (VFD) will increase the heat rate. The proposed method canevaluate the possibility of using the VFD in the CWP. In the simulation section, we assumed that the heat load (Q) is constant at first. Then, we consider it as a variable (LDC curve)