High and low voltage switchgear plays a crucial role in the power system, and its safety and reliability are directly related to the stable operation of the power grid. To ensure the safe operation of the switchgear, it is usually necessary to conduct a power on test bench. This article will analyze several common safety faults of high and low voltage switchgear during power on test bench testing, and explore their causes and preventive measures.
1、 Insulation fault
Fault description:
Insulation failure refers to the insufficient insulation strength caused by a decrease in the performance of insulation materials inside or outside the switchgear, resulting in electrical breakdown or leakage.
Cause analysis:
Aging of insulation materials: Long term operation or harsh environmental conditions (such as high temperature and humidity) can accelerate the aging of insulation materials.
Mechanical damage: During installation or maintenance, insulation materials may be damaged.
Pollution accumulation: Dust, salt mist and other pollutants accumulate on the insulation surface, reducing insulation performance.
Preventive measures:
Choose high-quality insulation materials and conduct regular insulation testing.
Strengthen operational norms during installation and maintenance to avoid mechanical damage.
Regularly clean the interior of the switchgear to prevent the accumulation of pollutants.
2、 Overheating fault
Fault description:
Overheating fault refers to the phenomenon of overheating of internal components (such as circuit breakers and busbars) in switchgear due to excessive current or poor heat dissipation.
Cause analysis:
Overload operation: The equipment operates at an overload, causing the current to exceed the design value.
Poor contact: Poor contact between conductive components, resulting in contact resistance and local heating.
Insufficient heat dissipation: The ventilation and heat dissipation design of the switchgear is unreasonable or the ventilation holes are blocked, resulting in the inability to effectively dissipate heat.
Preventive measures:
Avoid prolonged overload operation and allocate load reasonably.
Regularly check the connection of conductive components to ensure good contact.
Optimize the ventilation and heat dissipation design of the switchgear to maintain unobstructed ventilation holes.
3、 Mechanical failure
Fault description:
Mechanical failure refers to the failure of mechanical components (such as operating mechanisms and switch handles) in the switchgear, which affects normal operation.
Cause analysis:
Mechanical component wear: After prolonged use, mechanical components may experience wear or deformation.
Improper operation: Improper operation can cause uneven or damaged mechanical components.
Insufficient lubrication: Mechanical components lack lubrication, resulting in increased running resistance and affecting operational flexibility.
Preventive measures:
Regularly inspect and replace worn mechanical components.
Strengthen operator training and standardize operating procedures.
Regularly lubricate and maintain mechanical components to ensure their flexible operation.
4、 Circuit breaker failure
Fault description:
Circuit breaker failure refers to the inability of the circuit breaker to open or close normally, affecting the protection function of the circuit.
Cause analysis:
Operating mechanism malfunction: The mechanical components of the operating mechanism are damaged or malfunctioning, causing the circuit breaker to malfunction.
Electrical fault: The internal electrical components of the circuit breaker (such as coils and contacts) are damaged and cannot function properly.
Control power issue: Control power failure or unstable voltage, affecting the normal operation of the circuit breaker.
Preventive measures:
Regularly inspect and maintain the operating mechanism, and replace damaged parts in a timely manner.
Regularly inspect the internal electrical components of circuit breakers to ensure their reliable performance.
Ensure stable and reliable control power supply to avoid excessive voltage fluctuations.
5、 Ground fault
Fault description:
Ground fault refers to a problem with the grounding system of a switchgear, resulting in excessive grounding resistance or poor grounding.
Cause analysis:
Ground wire breakage: The ground wire breaks due to mechanical damage or corrosion.
Unstable grounding: The grounding terminal is not firmly connected, resulting in an increase in grounding resistance.
Aging of grounding grid: After long-term use, the grounding grid ages and the grounding performance decreases.
Preventive measures:
Regularly check the integrity of the grounding wire and promptly repair any broken parts.
Ensure that the grounding terminal is firmly connected and tighten the grounding bolt regularly.
Regularly inspect and maintain the grounding network, and update it if necessary.
conclusion
The safe operation of high and low voltage switchgear in the power system is crucial, and common safety faults mainly include insulation faults, overheating faults, mechanical faults, circuit breaker failures, and grounding faults. By taking reasonable preventive measures, such as selecting high-quality materials, regular maintenance and testing, and standardizing operating procedures, faults can be effectively reduced, ensuring the safe and reliable operation of the switchgear. Power on test bench testing is an important means of discovering and preventing these faults, and must be taken seriously and operated in a standardized manner.
