本文从理论上分析、讨论了传统的串级调速系统的原理,该系统无功损耗大,功率因数较低。为了克服这些缺点,开发了一种新型的三相四线双IGBT串级调速的方案,其主要特点是转子回路不仅不从电网上吸收无功功率,还会在电机低于额定转速时,向电网发出无功功率,从而提高了系统的功率因数。 This paper theoretically analyzes and discusses the principle of the traditional cascade speed regulation system. The system has large reactive power loss and low power factor. In order to overcome these shortcomings, a novel three-phase four-wire dual-IGBT cascade speed regulation scheme has been developed. Its main feature is that the rotor circuit not only does not absorb reactive power from the grid, but also when the motor is below the rated speed, Send reactive power to the grid, thereby increasing the system's power factor.