DEVICE TO PROTECT CAPACITOR BANK BUILT AROUND FOUR-ARM BRIDGE CIRCUIT WITH SERIES-PARALLEL CONNECTED CAPACITORS AND INDIVIDUAL FUSES IN ARMS Russian patent published in 1995 - IPC

FIELD: electrical engineering. SUBSTANCE: each arm of bridge has series-parallel connected capacitors with individual fuses. Connected across diagonally opposite pair of junctions of bridge is current transformer responding to undalance current appearing in case of damage of capacitors. Introduced into device are: phase-sensitive reversing rectifier with signal input and switching input of reference phase, additional current transformer, additional matching gate, double-input summer, additional double-stage negative polarity comparator with independent and controlled time delay, adjustable-and-reversible shifting unit and adjustable and reversible shifting unit with disable input. Thanks to it symmetrical output characteristic of protection device is provided at any value and phase of initial unbalance current which makes unnecessary to select capacitors by rating to replace defective ones, thus increasing repairability and cutting down time taken for repair. Higher quality of characteristic increases sensitivity of device and, consequently, reliability oif operation of capacitor bank. EFFECT: enhanced repairability, cut down repair time, increased operation reliability of capacitor bank. 11 dwg