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

Recently, a Chinese generator circuit breaker manufacturer has successfully developed generator circuit breakers for 1,000MW hydropower and thermal power units, which have passed the group's appraisal and acceptance. Their comprehensive performance has reached the international leading level, filling the domestic gap. This is another major breakthrough following the group's mastery of the technology for large-capacity generator circuit breaker complete sets for 400MW, 600MW, and 800MW units, mar

1. IntroductionSF₆ is widely used in electric power transmission and distribution systems, such as gas-insulated switchgear (GIS), circuit breakers (CB), and medium-voltage (MV) load switches. It possesses unique electrical insulation and arc-quenching capabilities. However, SF₆ is also a potent greenhouse gas, with a global warming potential of approximately 23,500 over a 100-year time horizon, and therefore its use is regulated and subject to ongoing discussions regarding restrictions. Consequ

High-voltage vacuum circuit breakers, owing to their excellent arc-quenching characteristics, suitability for frequent operation, and long maintenance-free intervals, have been widely applied in China’s power industry—particularly in urban and rural power grid upgrades, as well as in chemical, metallurgical, railway electrification, and mining sectors—and have received widespread acclaim from users.The primary advantage of vacuum circuit breakers lies in the vacuum interrupter. However, the char

It has been reported by a Chinese column-type circuit breaker manufacturer that its independently developed LW62-420/T5000-63 column-type circuit breaker has successfully passed the full set of type tests in accordance with IEC standards, marking the birth of China’s first double-break, grading-capacitor-free circuit breaker at Pinggao.In recent years, the Chinese column-type circuit breaker manufacturer has focused on breaking through key technologies such as high-breaking-capacity, low-operati

Good news has come from a Chinese tank-type filter manufacturer: its independently developed 550 kV tank-type filter bank circuit breaker has successfully passed all type tests, marking the official completion of the product’s development.In recent years, with the continuous growth of electricity demand, power grids have placed increasingly higher performance demands on electrical equipment. Keeping pace with the times, the Chinese tank-type filter manufacturer has actively responded to the nati

Many people have asked me: “What’s the difference between a recloser and a pole-mounted circuit breaker?” It’s hard to explain in one sentence, so I’ve written this article to clarify. In fact, reclosers and pole-mounted circuit breakers serve very similar purposes—they are both used for control, protection, and monitoring on outdoor overhead distribution lines. However, there are significant differences in the details. Let’s examine them one by one.1.Different MarketsThis may be the biggest dis

1. What is a Recloser?A recloser is an automated high-voltage electrical switch. Similar to a circuit breaker in household electrical systems, it interrupts power when a fault—such as a short circuit—occurs. However, unlike a household circuit breaker that requires manual reset, a recloser automatically monitors the line and determines whether the fault has cleared. If the fault is temporary, the recloser will automatically reclose and restore power.Reclosers are widely used throughout distribut

1.Blocking Principle of Ultra-High-Voltage Converter Valves1.1 Working Principle of Converter ValvesUltra-high-voltage (UHV) converter valves typically employ thyristor valves or insulated-gate bipolar transistor (IGBT) valves to convert alternating current (AC) to direct current (DC) and vice versa. Taking the thyristor valve as an example, it consists of multiple thyristors connected in series and parallel. By controlling the triggering (turn-on) and turn-off of thyristors, the valve regulates

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

Common Faults of High-Voltage Circuit Breakers and Mechanism Pressure LossCommon faults of high-voltage circuit breakers themselves include: failure to close, failure to trip, false closing, false tripping, three-phase asynchronism (contacts not closing or opening simultaneously), damage to the operating mechanism or pressure drop, oil spraying or explosion due to insufficient interrupting capacity, and phase-selective circuit breakers failing to operate according to the commanded phase."Circuit