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Safety And Reliability Of HV Switchgear Cabinet

Jul 11, 2017

High-voltage switchgear is a very important electrical equipment in power system. The deterioration of the operation condition of the switchgear is one of the reasons causing the malfunction of the power system. So, what are the common malfunctions of high voltage switchgear?

(i) Outdoor and indoor type

From the High-voltage switchgear cabinet placement to divide, can be divided into outdoor and indoor two types, 10KV and the following more than the use of indoor type. High Voltage Switchgear According to the different A-line scheme, it can be divided into the outlet switch cabinet, the contact oil switch cabinet, the bus section cabinet and so on. 10KV into the outlet switch cabinet to install less oil circuit breaker or vacuum circuit breaker, circuit breaker is equipped with the operating mechanism of the spring operating mechanism or electromagnetic actuator, also with manual actuator or permanent magnet actuator. Different switch cabinets have a large difference in structure, High Voltage Switchgear which will affect the selection and installation of sensors.

(ii) Stationary type and displacement

From the use of high-voltage switchgear to divide, can be divided into fixed and open type. In the past, the power plant's power system used in the use of switch-open switchgear, and the system has more fixed cabinets. With the progress of science and technology and the continuous development of new products, many habits and usages are also changing. For example, the metal armored switch cabinet is developed on the basis of stationary switchgear. Metal Armored removable switch cabinet for the entire closed structure, High Voltage Switchgear each function small room separated from each other, normal operating performance and prevent misoperation function hundred perfect and reasonable, overhaul convenient, its operation of safety and reliability greatly improved.

(iii) Development of high voltage switchgear

In recent years, with the development and popularization of small-scale vacuum circuit breaker technology, the new development of the middle-type switchgear as a metal closed armored switch device has been developed rapidly. The advantages of the cabinet are more, High Voltage Switchgear the most important is the handcart miniaturization and the mechanization of the production process, so that handcart and guide the production of more accurate. There are even many manufacturers of products, its handcart including the main circuit breakers and cabinets do not need to be in the factory to debug, when the factory is shipped to the scene, is also easy to debug success, High Voltage Switchgear the same can ensure handcart access flexibility and convenience. Because the product interchangeability is good, affected by the ground level conditions of the site is very small. This type of metal armored switch cabinet is safe and reliable to operate and maintenance is convenient. Therefore, the power supply system is used more and more.

Five prevention, usually refers to the High-voltage switchgear cabinet "Five prevention" or change the distribution room of "Five prevention and one pass."

1, prevent the load points, close the isolation switch. (Circuit breaker, load switch, contactor closing state can not operate isolation switch.) )

2, to prevent error points, false circuit breakers, load switches, contactors. (only the operation instruction corresponds to the operating device to operate the operated equipment)

3, prevent the grounding switch in closed position when closing circuit breaker, load switch. (only if the grounding switch is in the gate state, High Voltage Switchgear can the isolating switch or handcart be able to enter the work position, can operate the circuit breaker, load switch closes)

4. Prevent false grounding switch when charged. (only in the circuit breaker state, can the isolation switch or handcart to operate from the work position to the test position, to close the grounding switch)

5, to prevent the misuse of electric space. (only when the compartment is not electrified can the door open into the compartment)

Substation of the "Five prevention" that is, fire, waterproof, High Voltage Switchgear lightning protection, snow prevention, small animals. "One pass" is to maintain good ventilation.

The realization of electrical "five-prevention" function has become one of the important measures of electric power production. With the continuous development of the power grid and the continuous updating of technology, the device has been continuously improved and perfected.

The design principle of the anti-misoperation device is that the High-voltage electrical equipment which may cause misoperation should be fitted with a protective device and a corresponding error-proof electrical latching circuit.

Conventional anti-misoperation locking device

There are 4 types of conventional anti-false locking methods: Mechanical latching, program lock, Electric interlock and electromagnetic lock.

1. Mechanical latching

is in the switch cabinet or outdoor knife operating parts between the control and linkage of the mechanical mechanism to achieve the blocking requirements of the movement. Mechanical locking in the operation process without the use of keys and other ancillary operations, High Voltage Switchgear can be achieved with the operation of the correct order, automatic step unlock. In the case of misoperation, automatic locking can be realized to prevent misoperation. Mechanical locking can achieve forward and reverse locking requirements, with locking intuitive, not easy to damage, small overhaul workload, easy operation and so on.