Open AccessEfficiency‐optimised modulation technique of three‐level NPC inverter
Author(s) -
Li Ning,
Li Wanting,
Zhang Hui,
Yang Ping
Publication year - 2019
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2018.8845
Subject(s) - inverter , modulation index , pulse width modulation , computer science , voltage , waveform , modulation (music) , total harmonic distortion , control theory (sociology) , electronic engineering , compensation (psychology) , power (physics) , electrical engineering , engineering , physics , artificial intelligence , psychology , control (management) , quantum mechanics , acoustics , psychoanalysis
The three‐level NPC inverter has many advantages, such as the characteristics of high output power, low device stress, and low harmonic distortion of output waveform. It is widely used in the fields of high‐voltage conversion and reactive power compensation. As the most commonly used multi‐level inverter, three‐level NPC inverter has its own disadvantage which is the NP potential fluctuations. It may lead to poor output performance even damage to the devices. Therefore, the problem of NP potential fluctuation of three‐level NPC inverter has been the hotspot of its research. This paper presents an efficiency‐optimised dual modulation wave carrier‐based PWM (DMWPWM) strategy of three‐level NPC inverter. First, the basic principle of traditional DMWPWM is analysed, and the deficiency of traditional DMWPWM modulation technique is described. Then, the efficiency‐optimised DMWPWM strategy is deduced. Compared with traditional DMWPWM strategy, the new strategy inherits the advantage of traditional DMWPWM that the NP voltage balance can be maintained in any modulation index and power factor. Moreover, it can reduce the system switching loss which leads to efficiency improvement, and it is simple and easy to implement. Finally, the proposed modulation technique is verified by simulation.