Common direct current bus structure motor simulator modulation unit and application thereof

The invention provides a common DC bus structure motor simulator modulation unit and application thereof, and the modulation unit comprises a common-mode voltage calculation module which is used for calculating the common-mode voltage outputted by a motor controller and a motor simulator in real time; the direct-current component tracking module is used for tracking the direct-current component of the zero-sequence circulating current existing in the motor twin trawling test platform; the zero-sequence component calculation module is used for tracking a low-frequency component of the zero-sequence circulating current and generating a zero-sequence component changing in real time based on the direct-current component and the low-frequency component; and the modulation algorithm generation module is used for injecting the zero-sequence component which changes in real time into a modulation wave generated by a sine pulse width modulation algorithm to obtain an actual switching signal for controlling each branch