The performance of high voltage circuit breakers

High voltage circuit breaker performance
(1) Rated voltage (nominal voltage): it is characterized by the parameters of the circuit breaker dielectric strength, which is the standard voltage circuit breaker

long-term work. In order to meet the requirements of the power system work, but also provides a circuit breaker with rated voltage levels corresponding to the maximum

operating voltage. In 3 -

220KV levels, the maximum operating voltage than the rated voltage of about 15% higher; pair of 330KV and above the maximum operating voltage than the rated voltage of

about 10% higher. Maximum operating voltage of the circuit breaker should be long-term work reliably.
(2) Rated current: it is characterized by long-term current capability through the circuit breaker parameters, namely the circuit breaker to allow the maximum current

through continuous long-term.
(3) Rated breaking current: it is the ability to characterize the circuit breaker parameters. At rated voltage, the circuit breaker can guarantee reliable breaking the

maximum current, known as the rated breaking current, the unit circuit breaker contact separation instantaneous short-circuit current kA rms periodic component count

Representation. When the circuit breaker, below its rated voltage grid work, the breaking current can be increased. But by the interrupter mechanical strength

limitations, there is a maximum breaking current, called the ultimate breaking current.
(4) Dynamic current: it is characterized by short-time current capability through the circuit breaker parameters, reflecting breaker short-circuit current withstand

capacity of electric power effect. State of the circuit breaker in the closing moments or closing, the maximum allowed by the current peak is called stable electric

current, and

Called by the current limit. Through dynamic current circuit breaker, it is not the role of electric power due to damage.
(5) closing current: is the characterization of the circuit breaker closing current capability parameters. Because the circuit breaker is turned on, the circuit may

Yufu short-circuit fault, the circuit breaker closing time large short circuit current. Thus, on the one hand because of short circuit current electric power weakened

aggregate

Brake operating force, on the other hand because the contact has not occurred prior to contacting the breakdown and arc welding of the contacts may thus cause damage

to the circuit breaker. Closing the circuit breaker can be reliably maximum peak current, known as the rated making current. Rated making current and dynamic stability

Constant current is numerically equal, both are equal to the rated breaking current of 2.55 times.
(6) thermal stability and thermal stability current current duration: Executive steady current through the circuit breaker is characterized by short-time current

capability parameters, but it reflects the breaker short-circuit current withstand capability of thermal effects. Is the thermal current circuit breaker in the closed

state, in a certain

The duration, the maximum allowed current through periodic component rms, when the breaker is not due to short-term heat damage. National standards:
circuit breakers

rated thermal current equal to the rated breaking current. Rated thermal current duration of 2S,

Require more than 2S is recommended 4S.
(7) closing time and opening time: This is the characterization of the circuit breaker operating performance parameters. Various types of circuit breaker, closing at

different times, but require rapid action. Closing time is measured from the circuit breaker operating mechanism closing coil connected to the main contacts touch this

Time to trip the Circuit breaker trip time includes the time and the inherent extinction time in two parts. Inherent opening time is the time from tripping coil

actuator connected to the contact separation time. Extinction is the time from contact separation to each phase arc is extinguished this time. The

So, also called full opening time opening time.
(8) Operation cycle: This is characterized by the circuit breaker operating performance indicators. Short-circuit overhead line faults are mostly temporary, short-

circuit current is cut off, the fault that is rapidly disappearing. Therefore, in order to improve power supply reliability and system stability, the circuit breaker

should be able to

Withstand more than once or twice closing, breaking, or immediately after closing the action breaking ability. Such multiple times at intervals of, co-operation called

operating cycle.