Neutral point clamp type multilevel inverter single phase topology circuit

The practical control method of the multi-level inverter has two methods: the series multi-level method and the practical control method of the inverter, and the harmonic PwM control method (SHPWM) and the space vector control method can also be used. The SHPWM control method uses a continuous distribution of N amplitudes, and a carrier triangular wave having the same frequency and the same amplitude is compared with a common sinusoidal modulated wave, and a driving pulse is generated where the sine wave is larger than the triangular wave, according to the phase of the carrier triangular wave. Different can be divided into several situations. It will not be described in detail here, because the dynamic response of the electric vehicle to the motor has high requirements. Therefore, electric vehicles that use three-phase asynchronous motors as power are generally suitable for space vector control. This method can also improve the utilization of battery voltage. It also enables multi-level inverters to output multiple SPWM levels, so when using current tracking control. It can greatly reduce the number of switching and reduce the harmonics of the output current. Improve tracking performance. Series multilevel inverters. It is suitable for high-power electric vehicle drive system, which can reduce the danger caused by multiple batteries connected in series, can reduce the voltage stress of the switching device and reduce electromagnetic radiation interference. This series stacking does not require a superimposed transformer or reactor. Reduced size, weight and cost. The waveform of the output voltage of the series multilevel inverter is good. The control flexibility is good, the control precision is high, and the neutral point voltage fluctuation is small. In order to maintain the balance of the power of each battery pack, it is ensured that the discharge time of the battery is consistent during operation, and the battery can be flexibly charged by the bypass mode, and the torque of the regenerative braking can also be controlled.