三相双Buck并网逆变器SVPWM调制研究

Study of SVPWM for three-phase dual-buck grid-connected inverter

双Buck拓扑克服了传统桥式同一桥臂直通的问题,将其用于三相并网逆变器里,可以避免死区信号的加入,带来并网电流谐波含量的增加。针对该电路拓扑文中提出了空间矢量脉宽调制结合单周期控制的方式,即在一个周期里,将三相交流母线电压均分成6个60°区间,在每个子区间内使用单周期控制。双Buck并网逆变器使用这种控制方式,开关频率一定,开关损耗较小,可靠性较高。通过Saber仿真验证了矢量控制结合单周期控制策略的正确性。最后制作了一台10k W样机,结果表明该逆变器具有良好的稳态性能,能以高功率因数向电网供电。

The dual-buck topology overcomes the straight-through problem of the traditional bridge topology in the same bridge. Using it in three-phase grid-connected inverter can avoid the increase of current harmonics caused by the dead zone. Focusing on the circuit topology, a new method combining space-vector algorithm with one-cycle control is proposed in this paper. The AC voltage of three-phase bus is divided into six regions which are all 60° in one cycle and a one-cycle control model is built for each region. The dual-buck grid-connected inverter used this control method can possesses fixed switching frequency, low switch loss and high reliability. The validities of control method have been proved by Saber. At last, a 10kW prototype is made whose result shows that the inverter possessed satisfied steady state performance and can transmit electric power under high power factor,