Uninterruptible power supply systems (UPS) are necessary for all applications where electronic systems have to work also in case of power failure (i.e. computer centers, hospital equipment, communication equipment etc.). Many mainframe computers are fed by UPS systems.
UPS systems conventionally consist of a synchronous generator, a fly-wheel for short-time energy storage and a battery powered motor or diesel engine.
By progress in power electronics static power converters can be realized, especially for mid-range output power (i.e. 5 - 50 kVA). In recent times there is increasing demand for UPS systems with low-distortion output voltages and sinusoidal input currents. Even at non-linear loads producing output currents with high harmonic content, sinusoidal output voltage is required. Due to this, even at unsymmetrical loads a static inverter can be better than rotating converters.
On this background the Anton Piller GmbH & Co. KG asked the IAM GmbH to design a high performance digital control together with an application specific integrated circuit (ASIC) containing the new control structure.
http://control-design.de/home_eng/Applications/UPS/ups.html
