Novel modulation equations for three-phase inverter in phase control mode

Modulation theory is widely used for power converter analysis, but it has limited number of equations and it isn´t general for all cases. To solve the two problems, the paper investigates all work states of three-phase inverter under phase control with 180-degree conduction. By analyzing the relationship of voltages and currents between the two sides of a inverter, four groups of modulation equations are derived. These equations are different from the present modulation equations. They enrich the modulation theory, and they can be used as flexible and powerful tool for the modeling and analysis of power converters. Case study validates the effectiveness the proposed modulation equations.