초록 ▼

A low cost, small size, light weight, and highly effective system and method for providing dynamic power line voltage sag correction is provided. A dynamic voltage sag corrector includes a static bypass switch and a regulator/storage module connected together in parallel between input terminals and

A low cost, small size, light weight, and highly effective system and method for providing dynamic power line voltage sag correction is provided. A dynamic voltage sag corrector includes a static bypass switch and a regulator/storage module connected together in parallel between input terminals and output terminals. Under normal operating conditions, the static bypass switch is closed, and a normal line voltage level is provided directly from the input terminals to the output terminals via the static bypass switch. When a voltage sag condition is indicated, the static bypass switch is opened, and the regulator/storage module is controlled to provide a near normal output voltage signal to the output terminals. The regulator/storage module includes a power conversion circuit which is controlled to provide the desired output voltage signal by adding a voltage level on storage capacitors to the available input line voltage signal. The components of the dynamic voltage sag corrector are selected to provide voltage sag correction for a duration sufficient to provide correction of 90-95% of voltage sag/drop conditions which are likely to be encountered. The size, cost, and weight of the dynamic voltage sag corrector is thereby reduced. The dynamic voltage sag corrector may also provide surge condition correction, may be configured to provide extended duration voltage sag correction to a priority portion of a load, may provide support to a load even if there is a complete break in an input power line, and may be employed in single or multi-phase applications.

대표청구항 ▼

[ What is claimed is:] [1.] A dynamic voltage sag corrector, comprising:(a) input terminals;(b) output terminals;(c) a bypass switch connected between the input terminals and the output terminals and responsive to bypass switch control signals to open and close the bypass switch;(d) a power conversi

[ What is claimed is:] [1.] A dynamic voltage sag corrector, comprising:(a) input terminals;(b) output terminals;(c) a bypass switch connected between the input terminals and the output terminals and responsive to bypass switch control signals to open and close the bypass switch;(d) a power conversion and storage module connected in parallel with the bypass switch between the input terminals and the output terminals, wherein the power conversion and storage module includes a rectifier for rectifying power available at the input terminals, an energy storage device for storing the rectified power, and an inverter responsive to inverter control signals to provide an AC signal from energy stored in the energy storage device in parallel with the bypass switch; and(e) system controller means for detecting a voltage sag condition when an AC line voltage signal provided to the input terminals drops below a selected low line voltage threshold level, for providing a bypass switch control signal to the bypass switch to open the bypass switch in response to the detection of a voltage sag condition, for providing inverter control signals to the inverter to control the inverter to provide an AC output voltage signal at approximately a pre-voltage sag condition voltage level to the output terminals in response to the detection of the voltage sag condition by adding a voltage level of the storage device to a voltage level of the AC line voltage signal, for detecting a termination of the voltage sag condition when the AC line voltage signal returns to approximately a pre-voltage sag condition voltage level, for terminating the providing of inverter control signals to the inverter in response to the detected termination of the voltage sag condition, and for providing a bypass switch control signal to the bypass switch to close the bypass switch in response to the detected termination of the voltage sag condition.