New reliable inverter with intelligent power module

A new reliable three-phase inverter using three intelligent power modules is proposed, of which the performances are improved in size and reliability. The intelligent power module has its own DSP(ARM Cortex M) which can monitor the operation at each pole of the inverter, protecting the faults, and transfers the important data between the main controller and the module. One of the receiving data is the switching function or variance of the two IGRTs in each leg of the inverter. The DSP in each module receives switching functions and generates the PWM switching signal for IGBTs. Optical CAN communications method is used for the noise-free data transfer, which improves the reliability of the inverter operation. In this paper, the structure and functions of the intelligent power module are explained and the feasibility of the 100 kVA three-phase inverter with the power module is verified experimentally.