ISOLATION PARALLEL CONTROL APPARATUS FOR UNINTERRUPTIBLE POWER SUPPLY WHICH USING OF COMMON BATTERY

An isolation parallel control apparatus for a UPS(Uninterruptible Power Supply) using a common battery is provided to cut down a cost by reducing the number of battery cells. A commercial power input unit(1) inputs AC power to a UPS. A converter unit(2) is positioned at a front end of the commercial power input unit and converts AC into DC. An inverter unit(3) is connected to the converter unit in series and converts DC into AC. Loads(13) of various devices are connected to the inverter unit in series. A battery control unit(4) is connected to front ends of the converter unit and the inverter unit in parallel and uses an IGBT(Insulated Gate Bipolar Transistor) in stead of an SCR(Silicon Controlled Rectifier) to control a battery(10). The battery is connected to the battery control unit. A charge current detection unit(8) and a charge voltage detection unit(9) are connected between the battery control unit and the battery in parallel. A control gain addition unit(7) multiplies charge current detected through the charge current detection unit by a control gain. A proportional-integral controlling unit(6) minimizes an error range by comparing a difference between data by the control gain addition unit and data by the charge voltage detection unit.