Static UPS Technology
Power Systems & Controls specializes in static (solid-state) uninterruptible power supply systems. A static uninterruptible power supply consists of a battery to provide continuous electrical power, a rectifier to charge the batteries and provide input power to the inverter, an inverter to provide power to the load during operation, a static switch to transfer load automatically, a manual maintenance bypass switch, isolation transformers, and filters (as needed) to provide additional isolation and disturbance attenuation.
A static UPS supports the critical load when utility power fails by utilizing batteries to bridge the gap. Battery power is a group of electo-chemical cells connected to supply a nominal direct current (DC) voltage to the inverter when required. The number of cells connected in series determines the nominal voltage rating of the battery and the amount of backup time available. The charger is the converter section of the UPS system, which charges the batteries and supplies DC to the inverter.
When the rectifier/charger and battery are connected and start to regulate the voltage supplied to the load, the system is known as a floating battery system. The load is the inverter, which converts the DC power to AC power composed of a sine wave free from harmonic distortion. The bridge circuit in modern PWM technology normally uses insulated gate bipolar transistors (IBGT) for power switching. However, silicon controlled rectifiers (SCR) are still widely used for their effective yet cheaper solution.
PS&C Static UPS Systems:
There are two types of static UPS systems available today. There is Line Interactive and On-line (Double Conversion). Each offer unique benefits; however, the on-line UPS systems will provide greater overall protection due to its more advanced design. Static UPS systems offer many advantages, including: high efficiency, small footprint, low cost, quiet operation, system protections, and rapid response to transient load changes.