초록 ▼

A power circuit breaker controller and its method of use. Surge voltages associated with the closing of a high voltage circuit breaker for a polyphase alternating current line are lowered substantially by our invention. Although several lines and phases are involved, each is considered and operated

A power circuit breaker controller and its method of use. Surge voltages associated with the closing of a high voltage circuit breaker for a polyphase alternating current line are lowered substantially by our invention. Although several lines and phases are involved, each is considered and operated independently of the other. All lines have preinserted closing resistors, to reduce the surge voltages, that are preinserted in parallel across the main contacts of each phase one step prior to the main contact closing. Between the resistor switch closings certain staggering takes place. For example, if 3 phases are involved the resistor closings are staggered by about 60 or more electrical degrees. Further, there is circuitry to insure that the polarity of the bus side phase-to-ground voltage is of the same polarity as the trapped charges on the corresponding phases on the line side of the breaker when the resistor switch contacts are engaged. When the voltage across the main contacts is zero after the resistor is inserted, circuitry provides that the main contacts be directly engaged and the resistors be shortened out.

대표청구항 ▼

A programable method for limiting the voltages surges on a high voltage alternating current power line upon closure of a main contact switch which is connected in parallel with a single normally preinsertable resistor comprising the steps of: first continuously monitoring the polarity of the bus vol

A programable method for limiting the voltages surges on a high voltage alternating current power line upon closure of a main contact switch which is connected in parallel with a single normally preinsertable resistor comprising the steps of: first continuously monitoring the polarity of the bus voltage and trapped line charge voltage on both sides of said main switch at the time said switch is opened; second comparing the monitored polarities against each other and when of equal polarity, operatively inserting said resistor into the power line before closure of said main switch; and then predetermining the time of closure of said main switch when the voltage difference between its bus and line sides will be near zero and then effectively by-passing the inserted preinserted single resistor by closure of the main contact switch.