Over Modulation Strategy of Power Converters: A Review

With the increasingly prominent global energy problem, renewable energy technology has gradually become the focus of attention. The development and utilization of the pulse width modulation (PWM) converter is the key link of renewable energy technology. Moreover, overmodulation operation is one of the most important issues for PWM converters. Overmodulation strategy can effectively improve output fundamental voltage and current, shorten the system dynamic response time, and expand steady-state operating region. Although it has been sparsely discussed in the literature, the systematic investigation has not been published yet. In order to fill this gap, the research status, existing problems, and development trend of overmodulation strategy for the PWM converters are comprehensively presented in this paper. The major problems regarding the overmodulation strategy are highlighted such as the harmonic current problem, overmodulation strategy complexity, and the smooth transfer between the linear and overmodulation region. The typical overmodulation strategies along with their advantages and disadvantages are compared and discussed. Finally, a list of more than 100 relevant technical papers is also appended for a quick reference.