3-Phase Overmodulation PLECS 1.5 Online Help 3-Phase Overmodulation Purpose Extend the linear range of the modulation index for three-phase converters. Library Extras/Modulators Description For three-phase signals, this block extends the linear range of the modulation index from [-1 1] to [-1.154 1.154] by adding a zero-sequence offset. This block may be used for the control of three-phase converters without neutral point connection such as the 2-Level IGBT Converter. The figures below illustrates the working principle of the 3-Phase Overmodulation block in conjunction with the Symmetrical PWM. Dialog Box