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

Recently, the world’s first 500kV/90kA cost-effective high-voltage AC current limiter, jointly led by Guangzhou Power Supply Bureau of Guangdong Power Grid and developed by China High-Voltage AC Current Limiter Manufacturer, successfully completed artificial short-circuit tests and has been officially connected to the grid for trial operation on the Shunguang Jia Line at the 500kV Guangnan Substation. As a key project under China’s National Key R&D Program, the successful completion of the “

1.Introduction1.1 Basic Function and Background of GCBThe Generator Circuit Breaker (GCB), as the critical node connecting the generator to the step-up transformer, is responsible for interrupting current under both normal and fault conditions. Unlike conventional substation circuit breakers, the GCB directly withstands the massive short-circuit current from the generator, with rated short-circuit breaking currents reaching hundreds of kiloamperes. In large generating units, the reliable operati

The generator circuit breaker is a critical component in power systems, and its reliability directly affects the stable operation of the entire power system. Through research and practical application of intelligent monitoring systems, the real-time operational status of circuit breakers can be monitored, enabling early detection of potential faults and risks, thereby enhancing the overall reliability of the power system.Traditional circuit breaker maintenance primarily relies on periodic inspec

1.Protects the GeneratorWhen asymmetric short circuits occur at the generator outlet or the unit bears unbalanced loads, the GCB can quickly isolate the fault to prevent generator damage. During unbalanced load operation, or internal/external asymmetric short circuits, twice the power frequency eddy current is induced on the rotor surface, causing additional heating in the rotor. Meanwhile, the alternating electromagnetic torque at twice the power frequency induces double-frequency vibration in

In industrial production, emergency rescue, commercial buildings, and other scenarios, silent-canopy diesel generator sets serve as the “core backup” for stable power supply. The quality of on-site installation directly determines the unit’s operational efficiency, noise control performance, and service life; even minor oversights may lead to potential faults. Today, based on practical experience, we outline the complete standardized procedures and critical details for on-site installation of si

Gas accumulation: Free gas is present in the transformer oil. Response: The gas in the liquid rises and accumulates in the Buchholz relay, compressing the transformer oil. As the liquid level drops, the float also descends. The movement of the float drives a switch element (magnetic contact), thereby triggering an alarm signal. However, the float is not affected, because a certain amount of gas can flow through the pipe into the storage chamber.Fault: Due to leakage causing loss of transformer o

Units with a capacity of 300MW and above are usually connected in a generator-transformer unit configuration and connected to the power system through the circuit breaker on the high-voltage side of the transformer. During the normal operation of the unit, the circuit breaker may trip automatically due to various reasons. Operators must make correct judgments and take timely measures to ensure the safe operation of the unit.1. Causes of Automatic Circuit Breaker Tripping Tripping due to relay pr

With the continuous development of power transformer insulation technology, vegetable oil transformer products using green, environmentally friendly, and high-flash-point vegetable oil as insulation medium are gradually replacing mineral oil transformers. These vegetable oil-based transformers minimize carbon emissions to the greatest extent and effectively extend the service life of power transformers, which is of great significance for helping achieve the "dual carbon" goals.Recently, led by a

1. Key Points for Debugging High-Voltage Power Distribution Cabinets in Power Systems1.1 Voltage ControlDuring the debugging of high-voltage power distribution cabinets, voltage and dielectric loss show an inverse relationship. Insufficient detection accuracy and large voltage errors will lead to increased dielectric loss, higher resistance, and leakage. Therefore, it is necessary to strictly control the resistance under low-voltage conditions, analyze current and resistance values, and avoid ex

The Daquan Line has a large power load, with numerous and scattered load points along the section. Each load point has a small capacity, with an average of one load point every 2-3 km, so two 10 kV power through lines should be adopted for power supply. High-speed railways use two lines for power supply: primary through line and comprehensive through line. The power sources of the two through lines are taken from the dedicated bus sections fed by the voltage regulators installed in each power di