Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

1 IntroductionTo meet the rapidly growing demand for electric energy, power generation, transmission, and distribution systems must develop accordingly. One of the critical issues arising from this development is the rapid increase in short-circuit currents. The rise in short-circuit currents leads to several hazards:overheating of series-connected devices along the fault path;increased transient and recovery voltages during current interruption, which may damage insulation systems;generation of

Common Faults and Maintenance Methods for Low-Voltage Pole-Mounted Circuit BreakersLow-voltage pole-mounted circuit breakers, as key protective devices in distribution networks, are widely used in connection, segmentation, and branch locations of 10kV overhead lines. Operating long-term in harsh outdoor environments, they face multiple challenges including electrical performance degradation, mechanical component wear, and the impact of environmental factors.Structural Features and Working Princi

Insulators are typically made of porcelain material and are therefore also known as porcelain insulators. They have a dense structure with a glazed surface to enhance electrical insulation performance. Insulators for different voltage levels have varying effective heights and surface configurations. The higher the voltage level, the longer the insulator and the greater the number of sheds.1. Functions of InsulatorsHigh-voltage insulators must possess sufficient electrical insulation strength and

An insulator is a special type of insulating component that serves the dual purpose of supporting conductors and preventing current from grounding in overhead transmission lines. It is widely used at the connection points between transmission towers and conductors, as well as between substation structures and power lines. Based on the dielectric material, insulators are classified into three types: porcelain, glass, and composite. Analyzing common insulator faults and preventive maintenance meas

What is GIS Equipment?GIS is the English abbreviation for Gas Insulated Switchgear, which is fully translated into Chinese as Gas-Insulated Metal-Enclosed Switchgear. It typically uses sulfur hexafluoride (SF6) gas as the insulating and arc-quenching medium. GIS integrates, through optimized design, the main primary equipment in a substation—excluding the transformer—such as circuit breakers (CB), disconnectors (DS), earthing switches (ES/FES), busbars (BUS), current transfor

1. Gas System FaultsThe most critical type of fault in environmentally friendly gas-insulated ring main units is related to the gas system, primarily involving gas leakage and pressure anomalies. Gas leakage in nitrogen-insulated ring main units mainly stems from seal material aging and welding process defects. Statistics indicate that approximately 65% of gas leakage faults are related to O-ring aging, while 30% are caused by inadequate welding. Gas leakage not only affects insulation performan

1. Integrated Operation and Maintenance Strategy for Medium-Voltage Distribution EquipmentTo effectively prevent discharge faults in distribution equipment, it is essential to establish a corresponding operation and maintenance (O&M) strategy. This strategy should focus on air-insulated ring main units (RMUs) as the primary subject, utilizing live-line detection as a key method and aiming for closed-loop defect elimination. This approach establishes a scientific and effective closed-loop man

1. Introduction to 10kV SF6 Ring Main Units (RMUs)A 10kV SF6 ring main unit typically consists of three main parts: the gas compartment (tank), the operating mechanism compartment, and the cable connection compartment. The gas compartment is the core component of the RMU. It is filled with SF6 gas and houses critical elements such as the load switch, busbars, and switch shaft. The load switch features a three-position design—comprising closing, opening, and grounding functions&mdas

SF6 Fully Insulated Gas-Insulated Ring Main Units (hereinafter referred to as RMUs) primarily consist of load switch units and high-voltage AC load switch-fuse combination appliances (hereinafter referred to as combination appliances). Depending on user requirements, they can be configured as either common-tank or unitized structures.In practical engineering applications, electrical connections are typically established using either top-mounted solid-insulated busbars or side-mounted plug-in bus

A 25 MVA electric arc furnace transformer at a certain company is an equipment imported from the former Soviet Union. It consists of three single-phase transformers, each rated at 8.333 MVA, with a connection group of D,d0. The primary voltage is 10 kV, and the secondary voltage ranges from 140 to 230.4 V. The tap-changing method is on-load tap changing with 21 steps (steps 11, 12, and 13 are combined as one step, totaling 23 positions). Each phase can be regulated independently, allowing separa