The length of time a transformer can operate normally under rated voltage and rated load is called the service life of the transformer. Materials used in transformer manufacturing fall into two main categories: metallic materials and insulating materials. Metallic materials generally can withstand relatively high temperatures without damage, but insulating materials will rapidly age and degrade when the temperature exceeds a certain value. Therefore, temperature is one of the main factors affect

Maintenance Procedures for Dry-Type Transformers Put the standby transformer into operation, open the low-voltage side circuit breaker of the transformer to be maintained, remove the control power fuse, and hang a "DO NOT CLOSE" sign on the switch handle. Open the high-voltage side circuit breaker of the transformer under maintenance, close the grounding switch, fully discharge the transformer, lock the high-voltage cabinet, and hang a "DO NOT CLOSE" sign on the switch handle. For dry-type trans

High-Voltage Circuit Breakers: Classification and Fault DiagnosisHigh-voltage circuit breakers are critical protective devices in power systems. They rapidly interrupt current when a fault occurs, preventing damage to equipment from overloads or short circuits. However, due to long-term operation and other factors, circuit breakers may develop faults that require timely diagnosis and troubleshooting.I. Classification of High-Voltage Circuit Breakers1. By Installation Location: Indoor-type: Insta

Overvoltage Fault Analysis in Inverter Voltage DetectionThe inverter is the core component of modern electric drive systems, enabling various motor speed control functions and operational requirements. During normal operation, to ensure system safety and stability, the inverter continuously monitors key operating parameters—such as voltage, current, temperature, and frequency—to guarantee proper equipment function. This article provides a brief analysis of overvoltage-related faults in the inver

"Selecting a High-Quality Motor" – Remember the Six Key Steps Inspect (Look): Check the motor’s appearanceThe motor’s surface should have a smooth, even paint finish. The nameplate must be properly installed with complete and clear markings, including: model number, serial number, rated power, rated current, rated voltage, allowable temperature rise, connection method, speed, noise level, frequency, protection rating, weight, standard code, duty type, insulation class, manufacturing date, and ma

Our 220 kV substation is located far from the urban center in a remote area, surrounded primarily by industrial zones such as Lanshan, Hebin, and Tasha Industrial Parks. Major high-load consumers in these zones—including silicon carbide, ferroalloy, and calcium carbide plants—account for approximately 83.87% of our bureau’s total load. The substation operates at voltage levels of 220 kV, 110 kV, and 35 kV.The 35 kV low-voltage side mainly supplies feeders to ferroalloy and silicon carbide plants

1.SF6 Electrical Equipment and the Common Problem of Oil Leakage in SF6 Density RelaysSF6 electrical equipment is now widely used in power utilities and industrial enterprises, significantly advancing the development of the power industry. The arc-quenching and insulating medium in such equipment is sulfur hexafluoride (SF6) gas, which must not leak. Any leakage compromises the reliable and safe operation of the equipment, making it essential to monitor the SF6 gas density. Currently, mechanical

I. Permissible Operating Conditions for Current Transformers Rated Output Capacity: Current transformers (CTs) must operate within the rated output capacity specified on their nameplate. Operation beyond this rating reduces accuracy, increases measurement errors, and causes inaccurate meter readings, similar to voltage transformers. Primary Side Current: The primary current may continuously operate up to 1.1 times the rated current. Prolonged overload operation increases measurement errors and m

In power circuits, voltage transformers (VTs) are often damaged or burned out. If the root cause is not identified and only the transformer is replaced, the new unit may quickly fail again, disrupting power supply to users. Therefore, the following checks should be performed to determine the cause of VT failure: If the voltage transformer has ruptured and oil residue is found on the silicon steel laminations, the damage was likely caused by ferroresonance. This occurs when unbalanced voltages or

Analysis and Handling of DC System Grounding Faults in SubstationsWhen a DC system grounding fault occurs, it can be classified as single-point grounding, multi-point grounding, loop grounding, or reduced insulation. Single-point grounding is further divided into positive-pole and negative-pole grounding. Positive-pole grounding may cause misoperation of protection and automatic devices, while negative-pole grounding may lead to failure to operate (e.g., relay protection or tripping devices). On