Converse-solution PWM (Pulse-Width Modulation) inverter and control method

[0002] The development of new energy makes the application of inverter more and more extensive. Among them, in the new energy power generation system with three-phase inverter as the power interface unit, there are many inverter control methods. The traditional inverter The control methods mainly include SPWM and SVPWM. These methods are modulated according to the three-phase phase voltage as the modulation wave. At this time, the three-phase phase voltage output by the system can only be balanced when the load and the middle point of the DC side voltage are clear. In the actual application system, because it is difficult to find and connect the midpoint of the three-phase phase voltage output by the inverter system and the midpoint of the DC side voltage of the inverter, it is difficult to find the real phase voltage output by the system. Once the load is unbalanced or the DC There is an error in finding the midpoint of the side voltage. Even if an advanced control strategy is used to adjust the system, because of the coupling between the three-phase voltages, the obtained three-phase voltage is still unbalanced, so the line voltage is also unbalanced. Balanced, that is, it cannot guarantee that the line voltage output by the three-phase inverter is the expected sinusoidal waveform. In practice, although the load is connected to the phase voltage on the surface, it is actually a line voltage in essence, no matter what the characteristics of the load are. Yes, as long as the line voltage is a sinusoidal waveform, it can meet the requirements