Transformer short-circuit impedance, also known as impedance voltage, refers to the equivalent series impedance Zk=Rk+jXk between terminals in a pair of windings at rated frequency and reference temperature. Due to its value being determined through load testing in addition to calculation, it is commonly referred to as impedance voltage.When the…

What are the precautions for using a live cable identification device1、 Avoid direct contact with metal rods with handsWhen using a live cable identification device, we first need to connect the metal rod of the live cable identification device to the metal protective layer or metal shield of the faulty…

Power transformer is a static power equipment that changes the magnitude of AC voltage, and is one of the core equipment in the power system. In the process of energy transmission and distribution, power transformer is the core of energy conversion and transmission, and is a necessary path for various…

Precautions for power frequency withstand voltage test:1. Testers should divide their responsibilities, set a safe distance at the test site, carefully inspect the grounding of the tested object and the test transformer, and assign dedicated personnel to monitor safety and observe the status of the tested object.2. The main parts…

Electric wires and cables play a crucial role in the infrastructure construction of our country. Power cables are commonly used in urban underground power grids, power station outgoing lines, internal power supply of industrial and mining enterprises, and underwater transmission lines crossing rivers and seawater. They are composed of four…

With the increase of cable routes, the morning impact of cable faults on power supply reliability is increasing. Therefore, quickly and accurately detecting the location of fault points is of great significance to ensure the timely repair of faulty cables. The detection method for cable faults depends on the nature…

There are usually several measurement methods for grounding resistance testers: two wire method, three wire method, four wire method, single clamp method, and double clamp method, each with its own characteristics. In actual measurement, the correct method should be chosen as much as possible to ensure accurate measurement results.1. Two…

Grounding resistance is an important parameter used to measure whether the grounding state is good. It is the resistance encountered when the current flows from the grounding device to the ground and then flows through the ground to another grounding body or spreads to a distance. It includes the resistance…

The DC resistance tester is mainly used to test the DC resistance value of high-voltage electrical equipment such as power transformers. It has many characteristics such as fast testing speed, high accuracy, convenience, flexibility, and portability. It has always been a favorite equipment for many power workers, and there are…

The interference sources during the measurement of partial discharge of transformer include the interference of power supply network, interference of various electromagnetic field radiation, poor contact of test circuit, corona at various parts and internal discharge of test equipment, interference of earthing system, and interference of suspended discharge of metal…