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

The operational status of high-voltage disconnectors directly impacts the safety and stability of power grids. Currently, the operation and maintenance (O&M) of high-voltage disconnectors face numerous challenges—traditional O&M methods are inefficient, slow to respond, and struggle to accurately predict faults. Against this backdrop, developing a remote monitoring and fault early-warning system for high-voltage disconnectors is of great significance.1. Overall Design of the Remote Monit

35kV Outdoor Wind-Resistant High-Voltage Disconnector— Suitable for wind farms, overhead line pole-mounted applications, and substation installations.Model series: GW5-40.5 outdoor high-voltage disconnector (hereinafter referred to as “disconnector”).This disconnector is designed for use in 50Hz, 35kV power systems to open or close circuits under no-load voltage conditions. The pollution-resistant variant meets the requirements of users in heavily polluted areas and effectively mitigates polluti

How to Select Low-Voltage Electrical Apparatus: Two Key Principles and Four Important ConsiderationsWhen selecting low-voltage electrical devices, two fundamental principles must be followed: safety and economy. Additionally, there are several critical factors to consider. Those unfamiliar with the process should refer to the guidelines below.I. Two Core Principles for Selecting Low-Voltage Electrical Apparatus Safety PrincipleThe selected low-voltage devices must operate accurately and reliably

Single-phase grounding, line break (open-phase), and resonance can all cause three-phase voltage unbalance. Correctly distinguishing among them is essential for rapid troubleshooting.Single-Phase GroundingAlthough single-phase grounding causes three-phase voltage unbalance, the line-to-line voltage magnitude remains unchanged. It can be classified into two types: metallic grounding and non-metallic grounding. Inmetallic grounding, the faulted phase voltage drops to zero, while the other two phas

The solid-state transformer (SST), also known as a power electronic transformer (PET), uses voltage level as a key indicator of its technological maturity and application scenarios. Currently, SSTs have reached voltage levels of 10 kV and 35 kV on the medium-voltage distribution side, while on the high-voltage transmission side, they remain in the stage of laboratory research and prototype validation. The table below clearly illustrates the current status of voltage levels across different appli

There is extensive literature on the analysis of overvoltage at transformer neutral points under lightning surge conditions. However, due to the complexity and randomness of lightning waves, an accurate theoretical description remains elusive. In engineering practice, protective measures are typically determined based on power system codes by selecting appropriate lightning protection devices, with abundant supporting documentation available.Transmission lines or substations are susceptible to l

Basic Composition and Function of Circuit Breaker Failure ProtectionCircuit breaker failure protection refers to a protective scheme that operates when the relay protection of a faulty electrical device issues a trip command but the circuit breaker fails to operate. It uses the protection trip signal from the faulty equipment and the current measurement from the failed breaker to determine breaker failure. The protection can then isolate other relevant breakers within the same substation in a sh

Maintenance Procedure for Low-Voltage Power Distribution FacilitiesLow-voltage power distr ibution facilities refer to the infrastructure that delivers electrical power from a power supply room to end-user equipment, typically including distribution cabinets, cables, and wiring. To ensure the normal operation of these facilities and guarantee user safety and power supply quality, regular maintenance and servicing are essential. This article provides a detailed introduction to the maintenance pro

I. Routine Maintenance and Inspection(1) Visual Inspection of Switchgear Enclosure No deformation or physical damage to the enclosure. Protective paint coating shows no severe rust, peeling, or flaking. Cabinet is securely installed, clean on the surface, and free of foreign objects. Nameplates and identification labels are neatly affixed and not falling off.(2) Check of Switchgear Operating Parameters Instruments and meters indicate normal values (comparable to typical operating data, with no s

Insulation Withstand Voltage Test Standards for Vacuum Circuit BreakersThe main purpose of the insulation withstand voltage test for vacuum circuit breakers is to verify whether the insulation performance of the equipment under high voltage is qualified, and to prevent breakdown or flashover accidents during operation. The test process must be strictly carried out in accordance with power industry standards to ensure equipment safety and power supply reliability.Test ObjectsThe test objects incl