What is the working principle of the circuit breaker in 10KV, beginners, more detailed, thank you 15

10kV circuit breaker——

According to the different arc extinguishing medium, there are several kinds of oil immersion, vacuum, SF6, etc., the most common is the vacuum circuit breaker, the oil immersion circuit breaker has been gradually eliminated due to the heavy structure, and the cost of SF6 circuit breaker is too high, and it is not used much;

According to the different operating structures, it can be divided into electromagnetic switches, spring energy storage switches and permanent magnet switches. The working principle of the electromagnetic switch is very simple, like the contactor, the switch is equipped with an electromagnet inside, when the magnet is charged, the switch closes, and the opposite is disconnected; The advantage of this switch is that the action is reliable and the mechanism is simple, and the disadvantage is that the closing current is large. Spring energy storage mechanism, its principle is to use the mechanical energy generated by spring telescopic to complete the opening and closing, the advantage of this operating mechanism is that the closing current is small (only to the energy storage motor power supply), the cost is low, the disadvantage is that the structure is complex.

Permanent magnet type is an electromagnetic upgrade, the purpose is to solve the shortcomings of the electromagnetic circuit breaker closing current, the permanent magnet circuit breaker provides a capacitor that can provide a short-term closing current to solve this problem, but because of the factor of capacitor material, the cost is too high, and the application is not much. At present, spring energy storage circuit breaker is the most widely used.

By the way, to correct the mistake upstairs, the 10kV circuit breaker does not have the function of automatically cutting off the short-circuit current, which is the fundamental difference from the knife fuse switch, the knife fuse switch uses the current thermal effect of the fuse to cut off the short-circuit current, and the 10kV vacuum circuit breaker must be tripped with the help of a microcomputer protection device to realize the trip in the event of a fault.

No matter how many kV the circuit breaker is the same principle and function. In the event of a serious overload, short circuit, undervoltage or other faults, it can automatically cut off the circuit, and its function is equivalent to the combination of fuse-type switch and over/underheat relay.

Do you know what a circuit breaker is? The circuit breaker is a kind of instrument and equipment that can realize the circuit switch, which is generally suitable for installation on the switchgear and can realize the distribution of electric energy. The function of the circuit breaker is relatively simple, mainly as a current protection device.

Circuit breakers are installed in most circuits, which can effectively prevent various man-made disasters caused by circuit burnout or excessive voltage. What is the function of a circuit breaker? What does a circuit breaker make of?

Let's introduce the working principle of the circuit breaker.

1. Circuit breaker

Circuit breaker (English name: circuit-breaker, circuit breaker) refers to a switchgear that can close, carry and break the current under normal circuit conditions, and can close, carry and break the current under abnormal circuit conditions within a specified time. Circuit breakers are divided into high-voltage circuit breakers and low-voltage circuit breakers according to their scope of use, and the division of high and low voltage boundaries is relatively blurred, and generally more than 3kV is called high-voltage electrical appliances.

The circuit breaker can be used to distribute electrical energy, start the asynchronous motor infrequently, and protect the power line and motor.

When they have serious overload, short circuit, undervoltage and other faults, they can automatically cut off the circuit, and their function is equivalent to the combination of fuse-type switches and over- and under-heat relays. In addition, it is generally not necessary to change the parts after the fault current is switched off. At present, it has been widely used.

In the generation, transmission and use of electricity, power distribution is an extremely important link. The power distribution system includes transformers and various high and low voltage electrical equipment, and the low voltage circuit breaker is a kind of electrical appliances that are widely used.

Second, the working principle of the circuit breaker

The circuit breaker is generally composed of a contact system, an arc extinguishing system, an operating mechanism, a tripper, a shell, etc. When there is a short circuit, the magnetic field generated by the high current (generally 10 to 12 times) overcomes the reaction spring, the tripper pulls the operating mechanism to act, and the switch trips instantaneously. When overloaded, the current becomes larger, the heat generation intensifies, and the bimetal sheet deforms to a certain extent to push the mechanism to act (the larger the current, the shorter the action time).

If there is an electronic type, the transformer is used to collect the current of each phase, and compared with the set value, when the current is abnormal, the microprocessor sends a signal to make the electronic tripper drive the operating mechanism to act. The function of the circuit breaker is to cut off and turn on the load circuit, as well as cut off the fault circuit, to prevent the expansion of the accident and ensure safe operation. The high-voltage circuit breaker should break the arc of 1500V and the current is 1500-2000A, which can be stretched to 2m and continue to burn without extinguishing.

Therefore, arc extinguishing is a problem that must be solved by high-voltage circuit breakers.

The above is an introduction to various contents about circuit breakers, do you understand what circuit breakers are now? The main function of the circuit breaker is to cut off the load current, when the circuit is under load, the circuit breaker can directly cut it off to prevent the accident from becoming more serious. Circuit breaker is a kind of safety device, the commonly used voltage is relatively low, generally installed on the high-voltage line.

Circuit breaker, also known as automatic air switch, is a relatively common safety switch device that blocks circuits.

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With the progress of society, the working principle of low-voltage circuit breaker is a kind of switching electrical appliance that can not only turn on and break the normal load current and overload current, but also turn on the sensitive and break short-circuit current. Let's briefly introduce the working principle of low-voltage circuit breaker.

How does a low-voltage circuit breaker work?

Low-voltage circuit breakers, also known as automatic air switches, can be used to turn load circuits on and off, as well as to control motors that start infrequently. Its function is equivalent to the sum of some or all the functions of electrical appliances such as knife switch, overcurrent relay, loss of voltage relay, thermal relay and leakage protector, and is an important protective appliance in the low-voltage distribution network.

In particular, with the development and application of the digital process of power system control mode and the wide application of power system integrated automation, the requirements for system visualization, excitation automation, networking, real-time and precision are getting higher and higher, and correspondingly the low-voltage circuit breaker with wide application area, complex network structure, frequent operation and high failure rate also puts forward higher requirements, and the traditional circuit breaker can not meet the needs of modern power system integrated automation. The application of intelligent technology is an important development and application direction of Chengxin low-voltage circuit breaker.

Low-voltage circuit breakers have a variety of protection functions (overload, short circuit, undervoltage protection, etc.), adjustable action value, high breaking capacity, convenient operation, safety and other advantages, so they are widely used at present.

The application core of intelligent technology in the intelligent circuit breaker is a multi-functional trip device integrating protection, measurement and monitoring, which is mainly composed of several parts, such as microprocessor unit, signal detection and acquisition unit, switching input unit, display and keyboard unit, execution output unit, communication interface, power supply and so on.

In general, the main contacts are manually operated or electrically closed. After the main contact is closed, the free trip mechanism locks the main contact on the lead branch in the closing position. The coil of the overcurrent tripper and the thermal element of the thermal tripper are connected in series with the main circuit, and the coil of the undervoltage tripper and the power supply are connected in parallel.

When the circuit is short-circuited or seriously overloaded, the armature of the overcurrent tripper is engaged, so that the free tripping mechanism acts, and the main contact disconnects the main circuit. When the circuit is overloaded, the heat of the thermal element of the thermal tripper causes the bimetal sheet to bend and push the free release mechanism to act. When the circuit is undervoltage, the armature of the undervoltage tripper is released.

It also makes the free trip mechanism move. The shunt tripper is used for long-distance control, during normal operation, the coil is power-off, when the distance control is required, press the start button to energize the coil, and the armature drives the free tripping mechanism to act, so that the main contact is disconnected.

The vacuum circuit breaker is named because the arc extinguishing medium and the insulating medium in the contact gap after arc extinguishing are high vacuum; It has the advantages of small size, light weight, suitable for frequent operation, and no need for maintenance for arc extinguishing, and is widely used in the distribution network. Vacuum circuit breaker is an indoor power distribution device in 3 10kV, 50Hz three-phase AC system, which can be used for the protection and control of electrical equipment in industrial and mining enterprises, power plants and substations, especially suitable for the use of places requiring oil-free, less maintenance and frequent operation, and the circuit breaker can be configured in the central cabinet, double-layer cabinet and fixed cabinet as a control and protection of high-voltage electrical equipment.

The working principle of the vacuum circuit breaker is: when the dynamic and static contacts are opened under the action of the operating mechanism, the arc is generated between the contacts, and the surface of the contact volatilizes steam at high temperature, because the contact is designed to be a special shape, a magnetic field is generated when the current passes, and the arc moves rapidly along the tangential direction of the contact surface under the action of this magnetic field, and condenses part of the metal vapor on the metal cylinder (shielding cover), and the arc is extinguished when it naturally crosses zero, and the medium strength between the contacts is quickly restored.

It seems that there are three kinds of permanent magnet operating mechanisms.

Now everybody on the low-voltage circuit breaker.

This word feels a little unfamiliar, and I don't even know what it means? So what is a low-voltage circuit breaker and what is its function?

Now let's take a look: a low-voltage circuit breaker (formerly known as an automatic switch) is a kind of switching appliance that can not only turn on and off normal load current and overload current, but also turn on and off short-circuit current. In addition to playing a controlling role in the circuit, the low-voltage circuit breaker also has certain protection functions, such as overload, short circuit, undervoltage and leakage protection.

There are many classification methods of low-voltage circuit breakers, according to the use category, there are selective type (protection device parameters can be adjusted) and non-selective type (protection device parameters are not adjustable), according to the arc extinguishing medium, there are air type and vacuum type (domestic mostly air type). The capacity of the low-voltage circuit breaker is large, with a minimum of 4A and a maximum of 5000ALow-voltage circuit breakers are widely used in low-voltage power distribution systems at all levels of feedout lines, power control of various mechanical equipment and control and protection of power terminals.

With the research hotspots caused by smart grids at home and abroad, the "intelligence" and "communication" of low-voltage electrical appliances will eventually develop in the direction of smart grids, forming a low-voltage user-end industry of smart grids. The role of low-voltage circuit breaker Low-voltage circuit breaker: Low-voltage circuit breaker is also known as automatic air switch or automatic air circuit breaker, referred to as circuit breaker.

It is an electrical appliance that not only has the function of manual switching, but also can automatically carry out loss of voltage, undervoltage, overload, and short circuit protection. It can be used to distribute electric energy, start asynchronous motors infrequently, protect power lines and motors, and automatically cut off circuits when they occur serious overload or short circuit and undervoltage and other faults, and its function is equivalent to the combination of fuse switch and underheating relay. In addition, it is generally not necessary to change parts after the fault current is broken, and it has been widely used.

Circuit breaker accessories.

Miniature circuit breaker: Miniature circuit breaker, abbreviated as MCB, is one of the most widely used terminal protection appliances in building electrical terminal power distribution devices.

MCCB: The MCCB is able to automatically cut off the current after the current exceeds the trip setting. Plastic shell refers to the use of plastic insulator as the outer shell of the device, which is used to isolate the conductors and the grounded metal parts.

MCCBs usually contain a thermomagnetic trip unit, while larger MCCBs are equipped with a solid-state trip sensor.

Frame circuit breaker.

Intelligent universal circuit breaker.

It is important to note that low-voltage circuit breakers are also frequent.

To be maintained. It is maintained, and the life time that I use it so much. Longer.