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

1. Causes of Failure in Agricultural Distribution Transformers(1) Insulation DamageRural power supply typically utilizes 380/220V mixed supply systems. Due to the high proportion of single-phase loads, distribution transformers often operate under significant three-phase load imbalance. In many cases, the imbalance exceeds the permissible range specified in standards, causing premature aging, deterioration, and failure of transformer winding insulation, ultimately leading to burnout.When distrib

Transformer Commissioning Tests Procedures1. Non-Porcelain Bushing Tests1.1 Insulation ResistanceSuspend the bushing vertically using a crane or support frame. Measure the insulation resistance between the terminal and the tap/flange using a 2500V insulation resistance meter. The measured values should not deviate significantly from factory values under similar environmental conditions. For capacitor-type bushings rated 66kV and above with voltage sampling small bushings, measure the insulation

No-Load Full-Voltage Switching Impulse Testing for Newly Commissioned TransformersFor newly commissioned transformers, besides conducting necessary tests according to handover test standards and protection/secondary system tests, no-load full-voltage switching impulse tests are typically performed before official energization.Why Perform Impulse Testing?1. Check for Insulation Weaknesses or Defects in the Transformer and Its CircuitWhen disconnecting a no-load transformer, switching overvoltages

Power transformers are core primary equipment in power systems that realize electrical energy transmission and voltage conversion. Through the principle of electromagnetic induction, they convert AC power of one voltage level to another or multiple voltage levels. In the transmission and distribution process, they play a critical role in "step-up transmission and step-down distribution," while in energy storage systems, they perform voltage step-up and step-down functions, ensuring efficient pow

1 IntroductionPower transformers are among the most critical equipment in power systems, and it is essential to maximize prevention and minimize the occurrence of transformer failures and accidents. Insulation failures of various types account for more than 85% of all transformer accidents. Therefore, to ensure safe transformer operation, regular insulation testing of transformers is necessary to detect insulation defects in advance and promptly address potential accident hazards. Throughout my

1. Definition of Condition-Based MaintenanceCondition-based maintenance refers to a maintenance approach where repair decisions are determined by the real-time operational status and health condition of equipment. There are no fixed schedules or predetermined maintenance dates. The prerequisite for condition-based maintenance is the establishment of equipment parameter monitoring systems and comprehensive analysis of various operational information, enabling reasonable maintenance decisions base

1. Development Trends of Power Transformer Manufacturing Technology in ChinaPower transformers are primarily developing in two directions:First, development toward extra-large ultra-high voltage transformers, with voltage levels advancing from 220kV, 330kV, and 500kV toward 750kV and 1000kV.Second, development toward energy-saving, miniaturized, low-noise, high-impedance, and explosion-proof types. These products are mainly small and medium-sized transformers, such as the new S13 and S15 distrib

1. Judgment and Analysis of Abnormal Transformer SoundsDuring normal operation, a transformer typically emits a uniform and continuous AC humming sound. If abnormal sounds occur, they are generally caused by internal arcing/discharge or external instantaneous short circuits.Increased but uniform transformer sound: This may be caused by single-phase grounding or resonance in the power grid, resulting in overvoltage. Both single-phase grounding and resonant overvoltage in the grid will increase th

1. Structure Forms and Classification of BushingsThe structure forms and classification of bushings are shown in the table below: Serial No. Classification Feature Category 1 Main insulation structure Capacitive Type Resin-impregnated paperOil-impregnated paper Non-capacitive Type Gas insulationLiquid insulationCasting resinComposite insulation 2 External Insulation Material PorcelainSilicone Rubber 3 Filling Material Between Capacitor Core and Exte

1. Mechanical Direct Towing of Large Power TransformersWhen large power transformers are transported using mechanical direct towing, the following work shall be properly completed:Investigate the structure, width, gradient, slope, inclination, turning angles, and load-bearing capacity of roads, bridges, culverts, ditches, etc. along the route; reinforce them when necessary.Survey overhead obstacles along the route such as power lines and communication lines.During loading, unloading, and transpo