Dynamic voltage sag correction

摘要

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.