Inverter module

The inverter module is a DC/AC converter that provides clean 3-phase AC power to a variety of loads. . Figure 1 depicts the power converter topology used to implement the inverter module. As shown, this component consists of an input capacitor, a 3-phase fully controlled bridge converter, an output LC filter, and the control algorithms. The LC filter, illustrated in Figure 2, is used to filter the switching frequency component harmonics from the output in order to provide clean ac power to its loads.

The overall control of the inverter module contains a voltage control loop and a synchronous current regulator (SCR).  A diagram of the voltage control loop is shown in Figure 3.  The voltage control loop drives the error in the output voltage to zero by generating a current command through the use of a PI regulator with decoupling and feed-forward control.  The voltage control loop takes as inputs the desired output voltage and the desired output frequency.  A synchronous current regulator shown in Figure 4, uses the current command from the voltage control loop and actively regulates the fundamental component of the current so the command is exactly achieved.  A hysteretic/delta modulator regulates the current in the output filter inductors to the SCR commanded value.  It generates the switching commands for the power semiconductors.