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

Recently, the NSR-3611 low-voltage protection and control device and the NSD500M high-voltage measurement and control device—both developed by a Chinese protection and control equipment manufacturer—successfully passed the IEC 61850 Ed2.1 Server Level-A certification test conducted by DNV (Det Norske Veritas). The devices have been awarded the international Level-A certification by the Utilities Communication Architecture International Users Group (UCAIug). This milestone marks the manufacturer

1. What Is a Three-Phase Power Surge Protective Device (SPD)?A three-phase power surge protective device (SPD), also known as a three-phase lightning arrester, is specifically designed for three-phase AC power systems. Its primary function is to limit transient overvoltages caused by lightning strikes or switching operations in the power grid, thereby protecting downstream electrical equipment from damage. The SPD operates based on energy absorption and dissipation: when an overvoltage event occ

In the field of power equipment, three-phase voltage stabilizers play a crucial role in protecting electrical devices from damage caused by voltage fluctuations. Selecting the right three-phase voltage stabilizer is essential to ensure stable operation of equipment. So, how should one choose a three-phase voltage stabilizer? The following factors should be considered: Load RequirementsWhen selecting a three-phase voltage stabilizer, it is essential to clearly understand the total power demand of

Chinese reactor manufacturer successfully completed all tests in one go for the nation’s largest-capacity 750 kV, 140 Mvar stepped-controlled shunt reactor developed for the Turpan–Bazhou–Kuche II Circuit 750 kV transmission and transformation project. The successful completion of these tests marks a new breakthrough in the core manufacturing technology of 750 kV reactors by the Chinese manufacturer, pioneers a new field for 750 kV stepped-controlled shunt reactors in China, and lays a solid fou

Induction voltage regulators are classified into three-phase AC and single-phase types.The structure of a three-phase induction voltage regulator is similar to that of a three-phase wound-rotor induction motor. The key differences are that the rotor’s rotation range in an induction voltage regulator is limited, and its stator and rotor windings are interconnected. The internal wiring diagram of a three-phase induction voltage regulator is shown in Figure 2-28(a), which illustrates only one phase

1. Project OverviewThis project involves the construction of the new Jakarta–Bandung High-Speed Railway, with a mainline length of 142.3 km, including 76.79 km of bridges (54.5%), 16.47 km of tunnels (11.69%), and 47.64 km of embankments (33.81%). Four stations—Halim, Karawang, Padalarang, and Tegal Luar—have been constructed. The Jakarta–Bandung HSR mainline is 142.3 km long, designed for a maximum speed of 350 km/h, with a double-track spacing of 4.6 m, including approximately 83.6 km of balla

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

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 power grid construction, we should focus on actual conditions and establish a grid layout suitable for our own needs. We need to minimize power loss in the grid, save social resource investment, and comprehensively improve China's economic benefits. Relevant power supply and electricity departments should also set work goals centered on effectively reducing power loss, respond to energy conservation calls, and build green social and economic benefits for China.1.Current Status of China's Powe