H桥级联变频器在笼型异步电机上的应用

中高压变频器在工业变频领域应用广泛。H桥级联多电平变频器具有模块化特点,可利用低压器件实现电压和功率的扩展。为此,介绍了一种3级H桥级联变频器拖动笼型异步电机的主回路结构,载波移相正弦波脉宽调制,功率单元直流电压均衡控制,以及基于电压电流混合磁链观测器的无速度传感器矢量控制等核心控制技术。MATLAB仿真结果验证了该变频器采用所提出的控制技术控制笼型异步电机,具有良好的起动和运行性能,为中高压大功率传动应用领域提供了技术保障。

Application of H-Bridge Cascaded Converter to Squirrel Cage Asynchronous Motor

Medium and high voltage frequency converters has wide applications in the field of industrial frequency conversion. H bridge cascaded multilevel frequency converter has the characteristics of modularization and can realize the expansion of voltage and power by using low voltage devices. The main circuit structure of a three stage H bridge cascaded converter driving squirrel cage asynchronous motor is introduced. Then, the key control technologies, such as the carrier phase shifting sine wave pulse width modulation (PWM), the DC voltage equalization control of power unit, and speed sensorless vector control based on the voltage and current hybrid flux observer are introduced. The MATLAB simulation results show that the converter has good start up and operation performance by using the proposed control technologies to control squirrel cage asynchronous motor. It provides technical support for medium and high voltage and high power transmission applications.