火力发电厂电动给水泵采用变频调速技术，可以产生良好的经济效益。基于即能保持液力偶合器不动，又能实现变频调速的目的，提出了液力偶合器泵轮调速法，变频调速是实现液力偶合器泵轮调速的最佳方式。应用泵轮调速法可以有效实现200、300、600 MW机组电动给水泵的变频调速，达到节电20%以上的目的。

The frequency control system used in thermal power plant can produce good economic benefit. Based on the purpose of keep hydrodynamic coupling still and variable frequency speed regulation, this paper put forward pump wheel speed regulation method for hydrodynamic coupling. The result shows that the frequency control is the best way to realize this method for hydrodynamic coupling. And frequency control for motor-driven feed water pumps can be effectively implemented in 200, 300 and 600 MW unit with the utilization of this method, which can save more than 20% of electricity.