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

General Overview of Automatic Reclosing ModesTypically, automatic reclosing devices are categorized into four modes: single-phase reclosing, three-phase reclosing, composite reclosing, and disabled reclosing. The appropriate mode can be selected based on load requirements and system conditions.1. Single-Phase ReclosingMost 110kV and higher transmission lines employ three-phase single-shot reclosing. According to operational experience, over 70% of short-circuit faults in high-voltage overhead li

Common Issues and Solutions for SPDs in Practical ApplicationsSurge Protective Devices (SPDs) are critical for protecting electrical systems from transient overvoltages. However, several common issues occur in real-world installations: Insufficient maximum continuous operating voltage (Uc): Uc is lower than the grid’s maximum possible voltage, leading to SPD overheating or failure. Voltage protection level (Up) exceeds equipment impulse withstand voltage (Uw): SPD cannot adequately protect sensi

With the rapid development of China's economy, the power industry has also gradually expanded in scale, increasing the requirements for both the installed capacity and the single-unit capacity of power transformers. This article provides a brief introduction to four aspects: transformer construction, transformer lightning protection, transformer faults, and transformer noise.A transformer is a commonly used electrical device capable of converting AC electrical energy. It can transform one form o

Function of Surge ArrestersWhen lightning-induced overvoltage travels along overhead power lines into a substation or other buildings, it can cause flashovers or even puncture the insulation of electrical equipment. Therefore, if a protective device—known as a surge arrester—is connected in parallel at the power inlet of the equipment (as shown in Figure 1), it will immediately activate when the overvoltage reaches the preset operating level.The arrester discharges the excess energy, limiting th

The 10kV high-voltage reactive power compensation device is an essential and indispensable component in modern power systems. By providing or absorbing reactive power, it effectively addresses issues such as low power factor, high line losses, and voltage fluctuations caused by reactive power demand, playing a key role in improving the economy, safety, and power quality of grid operation. High-voltage 10kV reactive power compensation is a critical device for ensuring safe and economical grid ope

Role and Selection of Microcomputer Integrated Protection Devices in High-Voltage SwitchgearIn recent years, the application of microcomputer integrated protection devices in medium- and high-voltage power distribution system projects has increased significantly. These devices are user-friendly and overcome the drawbacks of traditional relay protection, such as complex wiring, low reliability, and cumbersome setting and debugging procedures. Microcomputer integrated protection devices feature co

What is a microcomputer protection device?Answer: A microcomputer protection device is an automatic device that can detect faults or abnormal operating conditions in electrical equipment within a power system, and act to trip circuit breakers or issue alarm signals.What are the basic functions of microcomputer protection?Answer: Automatically, rapidly, and selectively isolate faulty equipment from the system by tripping circuit breakers, ensuring non-faulty equipment resumes normal operation qui

Retrofitting microcomputer protection devices in substations should follow specific steps and precautions. A possible retrofit plan is as follows: Investigate the current status: Understand the types, specifications, operating conditions, and existing issues of the microcomputer protection devices in the substation to provide a basis for the retrofit. Develop a retrofit plan: Based on the investigation and requirements, create a detailed plan including specific tasks, technical specifications, i

1. Selection of Test InstrumentsThe main test instruments for microcomputer protection devices are: microcomputer relay protection tester, three-phase current generator, and multimeter. For testing high-voltage microcomputer protection devices, it is recommended to use a microcomputer relay protection tester capable of simultaneously outputting three-phase voltage and three-phase current, and equipped with timing function for digital inputs. For testing low-voltage microcomputer protection devic

I. BackgroundWith the advancement of intelligent power systems, microcomputer protection devices have become core components in modern industrial power distribution systems due to their high precision, multifunctionality, and reliability. Taking the power distribution project of a natural gas recovery station in the Middle East as a case study, this paper explores the critical role of AM series microcomputer protection devices in enhancing system safety, reliability, and automation levels, and a