An FPGA-Based Fault-Tolerant Method for Reliable Current Commutation of Direct Matrix Converter

Reliable current commutation, which is essential for the safe operation of a direct matrix converter, can be implemented with a field-programmable gate array (FPGA) to benefit from its parallelism and pipelining. However, the gating signals that are received in the FPGA from a digital controller (DSP or dSPACE) cannot strictly complement with each other, making this process more challenging. To immune their side effects, this paper analyzes state transitions of the defective input gating signals and contributes a fault-tolerant method for the reliable current commutation. Specifically, a practical and concise coding rule is first proposed to uniquely identify the states of input gating signals. The proper commutation moment can then be determined by recording and comparing the nearest two states. Based on these efforts, a robust current commutation based on an FPGA is subsequently achieved even with defective input gating signals. Effectiveness of the proposed method is finally proved in a 5 kW direct matrix converter platform.