双三电平交-直-交变频系统研究

Study on Dual-PWM Three-Level AC-DC-AC Inverter System

双PWM变频调速系统采用交-直-交拓扑结构,通过可控整流,实现网侧电流接近正弦波,网侧功率因数近似为1,具有较快的动态响应,双向传输电能等诸多优点,实现了节能调速。针对NPC型三电平拓扑给出了一种参考电压分解的三电平SVPWM算法,简化为两电平SVPWM算法,比传统的三电平SVPWM算法易于实现,仿真验证了该算法的有效性。通过改变小矢量作用时间法来控制中点电压的平衡,直流侧中点电位的偏差很好的控制在±1范围之内。

Dual PWM frequency control system uses the AC - DC - AC topology, through the controlled rectifier to achieve network side of the current close to sinusoidal, the net power factor close to 1, with fast dynamic response, power transmission, and many two- way advantages, to achieve energy-saving speed. For type three-level NPC topology gives a reference voltage three-level SVPWM decomposition algorithm, which simplifies the two-level SVPWM algorithm, than the traditional three-level SVPWM algorithm is easy to achieve, simulation results show the effectiveness of the algorithm. By changing the role of small-time method to control the vector point voltage balance, the deviation of the DC side of the midpoint potential well within the scope of control.