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

Single-Phase ReclosingAdvantage:When a single-phase-to-ground fault occurs on a line and three-phase auto-reclosing is applied, it results in higher switching overvoltages compared to single-phase reclosing. This is because three-phase tripping interrupts the current at zero-crossing, leaving residual charge voltages on the unfaulted phases—approximately equal to the peak phase voltage. Since the de-energized interval during reclosing is relatively short, the voltage on these unfaulted phases do

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

Cooling and Insulation of Dry-Type TransformersA dry-type transformer is a special type of power transformer characterized by the fact that its core and windings are not immersed in insulating oil.This raises a question: oil-immersed transformers rely on insulating oil for both cooling and insulation, so how do dry-type transformers achieve cooling and insulation without oil?First, let’s discuss cooling .Dry-type transformerstypically use two cooling methods: Natural air cooling (AN): When opera

Advantages and Disadvantages of Double-Busbar Configuration in SubstationsA substation with double-busbar configuration employs two sets of busbars. Each power source and each outgoing line is connected to both busbars via one circuit breaker and two disconnectors, allowing either busbar to serve as the working or standby busbar. The two busbars are interconnected through a bus tie circuit breaker (referred to as the bus coupler, QFL), as shown in the figure below.I. Advantages of Double Busbar

Solid-State Transformers (SST): The Future of Intelligent Power ConversionA solid-state transformer (SST), also known as a power electronic transformer (PET), is a static power conversion device that integrates power electronics, high-frequency transformation, and advanced control systems based on electromagnetic induction. It enables the conversion of electrical energy from one set of voltage, current, and frequency characteristics to another—while offering active control, bidirectional power f

Low-Voltage Vacuum Circuit Breakers: Advantages, Application, and Technical ChallengesDue to their lower voltage rating, low-voltage vacuum circuit breakers have a smaller contact gap compared to medium-voltage types. Under such small gaps, transverse magnetic field (TMF) technology is superior to axial magnetic field (AMF) for interrupting high short-circuit currents. When interrupting large currents, the vacuum arc tends to concentrate into a constricted arc mode, where localized erosion zones

Bundled Conductors DefinitionBundled conductors consist of multiple conductors per phase, grouped together by spacers to maintain spacing and enhance parallel connection for electrical transmission.Inductance ReductionReducing inductance through conductor bundling increases the line’s power transfer capacity and improves voltage regulation.Corona Discharge MitigationBundled conductors reduce the voltage gradient, decreasing the likelihood and effects of corona discharge, which is crucial in high