Working schematic of on-line UPS

Distribution networks, characterized by their wide distribution, large number of equipment, and low insulation level, are prone to insulation accidents caused by overvoltage. This not only reduces the stability of the entire distribution system and the insulation performance of the lines but also has a significant adverse impact on the safe operation of the power grid and the healthy and sustainable development of the power industry.From a circuit perspective, apart from the power source, the po

Substance of Second - harmonic Restraint in Overcurrent ProtectionThe substance of second - harmonic restraint in overcurrent protection is to use the second - harmonic component to judge whether the current is a fault current or an excitation inrush current. When the percentage of the second - harmonic component to the fundamental - wave component is greater than a certain value, it is judged to be caused by the excitation inrush current, and the overcurrent protection is blocked.Therefore, the

Typical Wiring Diagram of 35kV Line Radial π ConnectionWhen a 35kV line adopts a radial power grid structure, a single - side power supply or a double - side power supply radial type can be used according to the situation of the power supply points, and a loop - out interval is reserved at the end of the line.Typical Wiring Diagram of 35kV Line Radial T - ConnectionFor double - radial lines, it is advisable to select a double - side power supply. When the power supply points do not meet the r

Fault Transfer VoltageIn low - voltage distribution systems, there is a type of personal electric shock accident where the accident occurrence point and the system fault point are not at the same location. This kind of accident occurs because after a ground fault happens elsewhere, the generated fault voltage is conducted to the metal casings of other equipment through the PE wire or PEN wire. When the fault voltage on the metal casing of the equipment is higher than the human - body safe voltag