Patent ID: 7920392

Claim:
A dynamic voltage sag correction device comprising: an input terminal adapted to receive a first operating signal, wherein the first operating signal has a line-to-neutral voltage; an output terminal in electrical communication with the input terminal and through which the first operating signal is provided to a load: a regulator module comprising a rectifying device adapted to rectify a line-to-line input signal, wherein the line-to-line input signal is obtained from a second operating signal having the line-to-neutral voltage and a third operating signal having the line-to-neutral voltage; a storage unit adapted to store energy corresponding to the rectified line-to-line input signal; and an inverter switching device adapted to use the stored energy to generate a correction signal during at least a portion of a voltage sag; an injection transformer in electrical communication with the regulator module and adapted to reduce a voltage of the correction signal, wherein a primary winding of the injection transformer is connected across an output of the inverter switching device and a second input terminal adapted to receive the second operating signal, wherein the second operating signal has the line-to-neutral voltage; and a bypass switch in electrical communication with the input terminal and the output terminal, wherein the bypass switch is in a closed position during a normal operating condition such that the injection transformer is bypassed, and further wherein the bypass switch is in an open position during at least a portion of the voltage sag such that the injection transformer is energized.