I. Common Fault Types and Diagnostic MethodsElectrical Faults Circuit Breaker Failure to Operate or Maloperation: Check the energy storage mechanism, closing/tripping coils, auxiliary switches, and secondary circuits. High-Voltage Fuse Blown: Measure voltage across the fuse terminals; inspect busbar joints, cable terminations, and protection relay settings. Busbar Discharge or Insulator Damage: Listen for discharge sounds, check temperature at busbar connections, and visually inspect insulators

Types and Common Fault Analysis of High-Voltage SwitchgearHigh-voltage switchgear is a critical electrical device in power systems. Deterioration in switchgear operation is one of the main causes of power system failures. What are the common faults in high-voltage switchgear?(1) Outdoor and Indoor TypesBased on installation environment, high-voltage switchgear can be classified as outdoor or indoor types. Equipment rated at 10 kV and below is mostly installed indoors. According to primary circui

Oil-Immersed Transformers: Overview, Features, and ApplicationsAn oil-immersed transformer is a widely used type of power transformer that employs a liquid—typically insulating oil—as both an insulating and cooling medium.Key Features of Oil-Immersed Transformers: Insulating Oil: Insulating oil serves as the primary dielectric medium, electrically isolating the windings from the core and ground. With its high dielectric strength, it effectively prevents electrical breakdown between windings or b

The absorption ratio is defined as follows: When operating a megohmmeter (insulation resistance tester), rotate the handle at a speed of 120 revolutions per minute. Record the insulation resistance reading at 15 seconds (R15) and then at 60 seconds (R60). The absorption ratio is calculated using the formula:Absorption Ratio = R60 / R15, which should be greater than or equal to 1.3.Measuring the absorption ratio helps determine whether the insulation of electrical equipment is damp. When insulati

I. Operational Analysis1.1 Operating ScopeHigh-voltage disconnect switches are classified into outdoor and indoor types based on installation location, and into three-pole or single-pole configurations according to the number of poles. During operation, attention must be closely paid to the switch’s operating current and voltage.If the operating voltage exceeds the rated value, discharge may occur within the porcelain insulator. The degree of heating is closely related to the operating current a

During the operation of high-voltage disconnect switches, arcs may form between the contacts when they separate while current is still flowing. The high temperature of the arc not only damages the switch contacts but can also ignite surrounding flammable materials, leading to safety accidents.Arc formation is influenced by various factors, including the type of current (DC or AC), the inductive and capacitive characteristics of the circuit, and the properties of the contact materials. In DC syst