Detection method of internal faults of switch cabinet

Abstract

The invention relates to a detection method and a detection device of internal faults of a switch cabinet, belonging to the field of power transformation and distribution. For the switch cabinet which is in hot-line operation when a cabinet door is in a closed state, the gas in the internal space of the cabinet body is extracted by utilizing a through hole of the cabinet body of the switch cabinet from the external part of the cabinet body; and by extraction, measurement and data comparison of the gas in the internal space of the cabinet body in the hot-line operation state, each numerical value of the unbalanced voltage representing a characteristic gas concentration item is compared with the numerical value of the unbalanced voltage representing the characteristic gas concentration itemof ambient environment air and / or other switch cabinet freight spaces, thereby discovering the accident in the early stage or early accident potential in the switch cabinet as soon as possible to prevent the accident from expanding or further spreading. By adopting a gas acquisition mode, the invention can sensitively detect the common operation faults of the switch equipment in the cabinet. Whenthe switch cabinet operates, the switch cabinet in the operation state does not need to be stopped, and the existing switch cabinet equipment does not need to be changed, thus the implementation costis low, and the normal operation of the existing equipment can not be affected.

Description

technical field [0001] The invention belongs to the field of power transformation and distribution, and in particular relates to a fault detection method for electric energy transmission / distribution equipment. Background technique [0002] With the rapid development of my country's economy, the basic electric power industry has also achieved long-term and rapid development. As one of the important equipment in electric power construction, the application of enclosed combined electrical appliances is becoming more and more popular, and at the same time, higher requirements are put forward for the safe / stable operation of enclosed combined electrical equipment. [0003] Air-insulated switchgear is a kind of closed combination electrical appliances, which are widely used in 10~40.5KV switchgear. [0004] However, due to the characteristics of its closed box structure, the air-insulated switchgear also has certain shortcomings, mainly because it is difficult to find the intern...

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Problems solved by technology

[0004] However, due to the characteristics of its closed box structure, the air-insulated switchgear also has certain shortcomings, mainly because it is difficult to find the internal electrical abnormality in the early stage.

If it cannot be detected and dealt with in time, it will usually cause damage / burning of the switchgear and its auxiliary parts, and even affect the operation of the entire system and the safety of personnel / equipment of the entire substation / substation.

[0005] Specifically, the air-insulated switchgear generally adopts a box-type structure, which places all the components of the power distribution equipment inside the cabinet. The problem brought about by this structural form is that it is impossible to know the inside of the cabinet in a timely / intuitive manner from the outside of the cabinet The operating status of the equipment (the cabinet door is closed during normal live operation), the most common faults of the primary equipment, such as joint heating, sulfur hexafluoride gas leakage, and partial discharge abnormalities, cannot be intuitive and obvious outside the cabinet. It is discovered or manifested in a timely manner, and when it is discovered, it has often led to serious consequences

[0006] For example, for the leakage fault of sulfur hexafluoride insulating gas, only when the pressure is lower than the alarm or blocking value, can it be indirectly displayed through the optical plate and indicator light; and for the partial discharge fault, although the high-frequency ultrasonic detection method can be used detection, but the accuracy and sensitivity of the detection are not satisfactory; another example, for joint heating faults, there is currently no good online detection method other than opening the cabinet door and using direct aiming non-contact infrared measurement; Although some units have developed a detection device and measurement method that installs temperature detectors on the contacts of switch cabinets, circuit breakers, trolleys, etc., and transmits temperature signals wirelessly, the shortcomings of this device are also obvious, and the equipment must be installed one by one. Power failure, high cost of installation work, and because the substations / stations are all in the area of ​​strong electromagnetic wave interference, there are also problems with the reliability and life of the device itself

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