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

In order to actively respond to the development requirements of the power industry, our company has intensified its investigation into grid construction faults in a certain area and provided operation and maintenance support for DC UHV transmission and transformation projects in high-altitude regions by installing and optimizing UHV transmission equipment design schemes. The total land area of the construction site is 2,541.22 m², with a net land area of 2,539.22 m². The geological strata at the

Recently, a Chinese high-voltage circuit breaker manufacturer, in collaboration with numerous renowned enterprises, successfully developed a 550 kV capacitor-free arc-quenching chamber circuit breaker, which has passed the full suite of type tests on its first attempt. This achievement marks a revolutionary breakthrough in the interrupting performance of circuit breakers at the 550 kV voltage level, effectively resolving the long-standing “bottleneck” issue caused by reliance on imported capacit

Impact of GIS Disconnector Operations on Secondary Equipment and Mitigation Measures1.Impacts of GIS Disconnector Operations on Secondary Equipment 1.1Transient Overvoltage Effects During opening/closing operations of Gas-Insulated Switchgear (GIS) disconnectors, repeated arc reignition and extinction between contacts cause energy exchange between system inductance and capacitance, generating switching overvoltages with magnitudes 2–4 times the rated phase voltage and durations ranging from tens

Power Off and Power On Sequence in the Distribution RoomPower-off sequence:When de-energizing, first disconnect the low-voltage (LV) side, then the high-voltage (HV) side. When de-energizing the LV side:First open all LV branch circuit breakers, then open the LV main breaker. Additionally, disconnect the control circuits before de-energizing the main power circuits. When de-energizing the HV side:First open the circuit breaker, then open the isolating switch (disconnector).If the HV incoming lin

The impact of harmonic THD errors on power systems must be analyzed from two aspects: "actual grid THD exceeding limits (excessive harmonic content)" and "THD measurement errors (inaccurate monitoring)" — the former directly damages system equipment and stability, while the latter leads to improper mitigation due to "false or missed alarms." When combined, these two factors amplify system risks. The impacts span the entire power chain — generation → transmission → distribution → consumption — af

Core Standards for Calibration of Online Power Quality Monitoring DevicesThe calibration of online power quality monitoring devices follows a comprehensive standard system, encompassing mandatory national standards, industry technical specifications, international guidelines, and requirements for calibration methods and equipment. The following provides a structured overview with practical recommendations for real-world applications.I. Core Domestic Standards1. DL/T 1228-2023 – Technical Require

Transformers and Power Quality MonitoringThe transformer is a core component of the power system. Power quality monitoring is fundamental to ensuring transformer safety, improving system efficiency, and reducing operation and maintenance costs—directly impacting the reliability and performance of the entire power network.Why Perform Power Quality Testing on Transformers? Ensure Safe Transformer OperationPower quality issues—such as harmonics, voltage fluctuations, and load imbalance—can cause ov

This paper briefly outlines the advantages and technical characteristics of GIS (Gas-Insulated Switchgear) equipment, and elaborates on several critical quality control points and process control measures during on-site installation. It emphasizes that on-site withstand voltage tests can only partially reflect the overall quality and installation workmanship of GIS equipment. Only by strengthening comprehensive quality control throughout the entire installation process—especially in key areas su

1. Maintaining and Restoring the Factory Insulation ConditionWhen a transformer undergoes factory acceptance tests, its insulation condition is at its optimal state. Thereafter, the insulation condition tends to deteriorate, and the installation phase may be a critical period for sudden degradation. In extreme cases, the dielectric strength may drop to the point of failure, leading to coil burnout immediately upon energization. Under normal circumstances, poor installation quality leaves behind

As altitude increases, air density, temperature, and atmospheric pressure decrease accordingly, leading to reduced dielectric strength of air gaps and external insulation performance of porcelain components. This results in degraded external insulation performance for high-voltage electrical equipment. Since most high-voltage equipment is designed for installation at altitudes below 1,000 meters, using such equipment at elevations exceeding 1,000 meters may compromise reliable insulation perform