Circuit disconnection (English name: Circuit-Breaker, Circuit Breaker) refersSwitch device.The circuit breaker can be used to allocate power, and the asynchronous motor is not frequently activated, and the power lines and motors are implemented. When they have serious overload or short circuit and underwriting failure, they can automatically cut off the circuit. The function is equivalent to the fuse -type switchCombination with over -the -heated relays.
Circuit breaker parameter
The basic working performance of the high -voltage circuit breaker is usually used to characterize the following parameters: 1. The rated voltage (nominal voltage) It is a parameter of the insulation strength of the section of the circuit breaker.In order to meet the requirements of the work of the power system, the circuit breaker also stipulates the maximum working voltage corresponding to the rated voltage at all levels.For 3-220KV at all levels, its maximum working voltage is about 15%higher than the rated voltage; for 330kV or above, the maximum working voltage is about 10%higher than the rated voltage.Under the maximum working voltage of circuit breakers, it should be able to work and reliable for a long time.2. The rated current is the parameter of the signs of the signs through long -term current capacity, that is, the circuit breaker allows the maximum current to pass continuously for a long time.3. The rated open -cut current is a parameter for the disconnection of the cutter.Under the rated voltage, the circuit breaker can ensure the maximum current of reliable and open breaking, which is called the rated turnover current. The unit is expressed by Qianan numbers with the valid value of the short -circuit current cycle of the intervention of the section of the circuit breaker.When a cutter works in a grid below its rated voltage, its open break current can increase.However, the mechanical strength of the arc is restricted, and the turnover current has a maximum value, which is called the extreme opening of the interrupt current.
The role of the circuit breaker
First, in the power grid, the main role of the circuit breaker has two aspects 1. Control effect.That is, according to the operational needs, invest or remove some electric equipment or lines.2. Protection.That is, when the power equipment or line fails, the circuit breaker is used through relay protection and automatic devices, and the fault part is quickly removed from the grid to ensure the normal operation of the non -fault part of the power grid.Second, the role of high -voltage circuit breakers 1. Insemble and disconnect the air load and load current in the high -voltage circuit under normal circumstances.2. When the system fails, it can cooperate with the protection device and the automatic device to quickly cut off the fault current to prevent the accident from expanding, thereby ensuring the safe operation of the system.In fact, the cutter is a kind of switch. The difference between it and other ordinary switches is mainly: (1) the high voltage level is high; (2) the arc extinguishing medium and method, there is vacuum, less oil, more oil, and hexarin sulfur sulfur sulfur sulfurWait; (3) Strong arc extinguishing ability and good effect.
Circuit breaker model
At present, my countrys circuit breaker model is generally composed of text symbols and numbers according to the national technical standards.1. Model representative significance ① —— Product letter code, use the following letters: S -less oil breakfire; D -multi -oil circuit breaker; K -air circuit breaker; L -hexal fluoride sulfur circuit breaker; Z -vacuum circuit breakerQ — Qi -producing circuit breaker; C -magnetic blower.② —— The location code of the device; n -indoor, W — outdoor.③ -Design series number; use numbers 1, 2, 3 ... indicate.④ -Rated voltage, KV.⑤ — Other supplementary work characteristics signs, G -improvement type, F -division operation.⑥ -rated current, A.⑦ -the rated turnover current, KA.⑧ — Special environment code.
Router work principle
The circuit breaker is generally composed of the contact system, the arc extinguishing system, the operating mechanism, the deedr, the shell, etc.When a short circuit, the magnetic field generated by large currents (generally 10 to 12 times) overcome the reaction spring, the deedr pulls the operation of the operating mechanism, and the switch is switched instantly.During the overload, the current becomes larger, the heat is intensified, and the dual metal piece deformation to a certain extent to promote the movement of the mechanism (the larger the current, the shorter the action time).For electronic types, each phase current is collected by the intestinal sensor. Compared with the set value, when the current is abnormal, the microprocessor sends a signal, so that the electronic deedr drives the operation of the operating mechanism.The role of the circuit breaker is to cut off and connect the load circuit, as well as cutting off the fault circuit to prevent the accident from expanding and ensure safe operation.The high-voltage circuit breaker should be cut off 1500V, and the current is an arc with a current of 1500-2000A. These arcs can be extended to 2m and continue to burn without extinguishing.Therefore, arc extinguishing is a problem that high -decaying circuit breakers must solve.

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