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

Common Faults and Causes in Routine Inspection of Distribution TransformersAs the terminal component of power transmission and distribution systems, distribution transformers play a critical role in supplying reliable electricity to end users. However, many users have limited knowledge of power equipment, and routine maintenance is often carried out without professional support. If any of the following conditions are observed during transformer operation, immediate action should be taken: Excess

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 Fault Diagnosis Methods1. Ratio Method for Dissolved Gas AnalysisFor most oil-immersed power transformers, certain combustible gases are produced in the transformer tank under thermal and electrical stress. The combustible gases dissolved in oil can be used to determine the thermal decomposition characteristics of the transformer oil-paper insulation system based on their specific gas content and ratios. This technology was first used for fault diagnosis in oil-immersed transformers.

1. SF6 gas leakage occurred in the ABB LTB 72 D1 72.5 kV circuit breaker.Inspection revealed gas leakage at the fixed contact and cover plate area. This was caused by improper or careless assembly, where the dual O-rings slipped and were misplaced, resulting in gas leakage over time.2. Manufacturing Defects on the Outer Surface of 110kV Circuit Breaker Porcelain InsulatorsAlthough high-voltage circuit breakers typically have their porcelain insulators protected with covering materials during tra

35 kV Distribution Transformers: Core Grounding Fault Analysis and Diagnostic Methods35 kV distribution transformers are common critical equipment in power systems, carrying important electrical energy transmission tasks. However, during long-term operation, core grounding faults have become a major issue affecting the stable operation of transformers. Core grounding faults not only impact transformer energy efficiency and increase system maintenance costs, but may also trigger more serious elec

According to statistics, the vast majority of faults on overhead power lines are transient, with permanent faults accounting for less than 10%. Currently, medium-voltage (MV) distribution networks commonly employ 15 kV outdoor vacuum automatic circuit reclosers in coordination with sectionalizers. This setup enables rapid restoration of power supply after transient faults and isolates faulty line segments in the event of permanent faults. Therefore, it is essential to monitor the operational sta

With the improvement of social productivity and people's quality of life, the demand for electricity is continuously increasing. To ensure the effectiveness of power grid system configuration, it is necessary to reasonably construct distribution networks based on actual conditions. However, during the operation of distribution network systems, 17.5kV ring main units play a very important role, so the impact caused by failures is extremely significant. At this point, it is essential to adopt reas

This article introduces a case of 35kV ring main unit busbar insulation breakdown failure, analyzes the failure causes and proposes solutions [3], providing reference for the construction and operation of new energy power stations.1 Accident OverviewOn March 17, 2023, a photovoltaic desertification control project site reported a ground fault trip accident in the 35kV ring main unit [4]. The equipment manufacturer arranged a team of technical experts to rush to the site to investigate the cause

Five Common Defects of H61 Distribution Transformers1.Lead Wire DefectsInspection Method: The three-phase DC resistance imbalance rate significantly exceeds 4%, or one phase is essentially open-circuited.Remedial Measures: The core should be lifted for inspection to locate the defective area. For poor contacts, re-polish and tighten the connection. Poorly welded joints should be re-welded. If the welding surface area is insufficient, it should be enlarged. If the lead wire cross-section is inade

In recent years, the accident rate of H59 distribution transformers has shown an upward trend. This article analyzes the causes of failures in H59 distribution transformers and proposes a series of preventive measures to ensure their normal operation and provide effective assurance for power supply.H59 distribution transformers play a vital role in power systems. With the continuous expansion of power system scale and the increasing single-unit capacity of transformers, any transformer failure n