Compensation of Multisampling-Induced Dead Band Effects on Switching-Mode Power Inverters

To reduce the control delay existed in the digital control of dc-ac power inverters, control strategies based on multisampling technology become attractive. Thereby, a high-bandwidth design and higher stability margin can be achieved. However, the increased sampling frequency leads to an undesired phenomenon referred to as vertical crossing that modulation signal crosses with the carrier signal vertically. PWM wave will not flip and a dead band will be introduced when vertical crossings occur. Such phenomena negatively affect the system operation. Hence, this paper presents a control algorithm for eliminating the multisampling-induced vertical crossings. The proposed method is evaluated with a single-phase dc-ac inverter and the effectiveness is validated through the experiment.