PC-based real-time control system for power-electronic test benches with high I/O requirements

The control of power-electronic laboratory test benches for academic use and for industrial research and development demands a real-time control system with high flexibility and reliability at low cost. Personal computers are an ideal basis for this kind of real-time control systems because of their high processing power at very low cost and their expandability by additional interface cards. An additional field-programmable gate array is necessary to assure the real-time ability by defining the equidistant hard real-time task including the measurement routines, the control calculations and the switching signals output. The presented control system is optimized for the use in a Modular Multilevel Converter test bench, designed as a five-level converter with a high number of inputs and outputs.