Uninterruptible power supply multiloop control employing digital predictive voltage and current regulators

A digital control technique for the inverter stage of uninterruptible power supplies (UPSs) is described, which is based on voltage and current predic tive regulators. Its aim is to achieve a deadbeat dynamic response for the controlled variables (output voltage and inverter current). The controller maintains the advantageous conventional multiloop structure and is capable of guaranteeing a high-quality dynamic performance. Moreover, its design is extremely simple and requires only a reasonably accurate knowledge of the output filter parameters. Finally, the only sensed variables are the output voltage and the converter output current. The validity of the proposed str ategy is demonstrated by means of simulation and experimental results refer ring to a single-phase UPS laboratory prototype (I kVA).