Fast space vector pulse width modulation algorithm for neutral point clamped H-bridge five-level inverter

While the conventional multi-level space vector pulse width modulation (SVPWM) algorithm has a large amount of calculation, a fast SVPWM algorithm suit for neutral point clamped H-bridge inverter was proposed. The essential reason that the conventional 5-level algorithm is of great complexity was analyzed firstly. A novel sector dividing scheme was derived by analyzing the 5-level space vector diagram. The 5-level space vector diagram is equivalent to the combination of 4 2-level space vector diagrams for the scheme. In contrast with the traditional 5-level SVPWM algorithm, in the new algorithm the two-level SVPWM method was used to complete the operation, and calculations for locating the reference vector and getting the duty ratios of the basic vectors dramatically decreased. Finally, a prototype of the three-phase neutral point clamped H-bridge 5-level inverter was built. Experimental results indicate that the output voltages from the new algorithm are identical with the conventional one, while calculation time of the new algorithm is just 55.27% of the conventional one. © 2022 Editorial Department of Electric Machines and Control. All rights reserved.