Analysis, Measurement, and Compensation of the System Time Delay in a Three-Phase Voltage Source Rectifier

The system time delay, which can be several times greater than the switching period, is typically neglected during the design of a three-phase voltage source rectifier system. As a result, the system time delay can cause different types of deteriorations, including a surge in the ac current, an overshoot in the dc-link voltage, and a decrease in system stability. This study first develops a dc model and linear model to form the basis of the analysis of the relationships between the system time delay and deteriorations. A novel method is then proposed to provide an accurate measurement of the system time delay to improve the efficiency of compensation methods. Based on the analysis and measurement results, two new compensation methods are subsequently proposed to effectively mitigate these deteriorations. The efficiency of the measurement and compensation methods is finally demonstrated via simulations and experiments.