Research and application of high voltage frequency conversion based on cascaded multilevel in synchronous motor speed regulation

With the development of industy,synchronous motor has been widely used in the occasions needing large-capacity such as air pressure presses,ball mills because its high power factor,stable rotation speed,simple design while low speed and other advantages.First of all,the principle and advantages of the high voltage frequency conversion based on cascaded multilevel are described.Secondly,the frequency conversion starting of the large capacity synchronous motor is analyzed.It researches the control of excitation system while synchronous motor is in steady-state.