An over-modulation scheme of SVPWM used in multi-level inverters

作者：Liu, He; Jiang, Jian Guo; Qiao, Shu Tong

来源：Electric Machines and Control, 2016, 20(1): 7-13.

DOI：10.15938/j.emc.2016.01.002

• Inverter
• Multilevels
• Over modulation
• Simplified two-level
• SVPWM

In order to improve voltage output capability of the multi-level inverter, an over-modulation scheme was studied, which is an extension of SVPWM for multi-level voltage source inverters. The over-modulation scheme based on two-level simplification algorithm, according to the modulation index mi(0≤mi≤1), the algorithm is divided into three modulation modes. They are line-modulation(0≤mi<0.907), Over-modulation I (0.907≤mi<mmax2), and over-modulationII(mmax2≤mi<1). In mode I, the compensation factor λwas introduced to compensate the volt-second lossless in over modulation region. In mode II, switch angle αhwas calculated by a simplified wethod called 'volt-freq'quickly. In each mode, the over-modulation scheme does not need to store data and complex calculation, and it is easy to expand to n-level inverters and applicate the DSP. Simulation and experimental results that provided by a five level NPC/H topology inverter, verify that the over-modulation scheme is fundamental voltage line-gain, low harmonic content and easy to implement.

• 出版日期2016
• 单位上海交通大学