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

I. Analysis of the Principle of Power System Voltage RegulatorsBefore analyzing the principle of power system voltage regulators, it is necessary to analyze the excitation regulator and draw conclusions through comparison. In practical application, the excitation regulator uses voltage deviation as a feedback quantity for adjustment, thereby keeping the generator terminal voltage within the standard range. However, this type of voltage regulator, especially during grid faults, requires a large a

1 IntroductionAccording to the provisions of the national standard GB/T 1094.3-2017, the primary purpose of the line terminal AC withstand voltage test (LTAC) for power transformers is to evaluate the AC dielectric strength from the high-voltage winding terminals to ground. It does not serve to assess inter-turn insulation or phase-to-phase insulation.Compared with other insulation tests (such as full lightning impulse LI or switching impulse SI), the LTAC test imposes a relatively more stringen

How to Select and Set Circuit Breakers1. Types of Circuit Breakers1.1 Air Circuit Breaker (ACB)Also known as a molded frame or universal circuit breaker, all components are mounted within an insulated metal frame. It is typically open-type, allowing easy replacement of contacts and parts, and can be equipped with various accessories. ACBs are commonly used as main power supply switches. Overcurrent trip units include electromagnetic, electronic, and intelligent types. They provide four-stage pro

SST High-Frequency Isolated Transformer Core Design and Calculation Material Characteristics Impact:Core material exhibits varying loss behavior under different temperatures, frequencies, and flux densities. These characteristics form the foundation of overall core loss and require precise understanding of nonlinear properties. Stray Magnetic Field Interference:High-frequency stray magnetic fields around windings can induce additional core losses. If not properly managed, these parasitic losses

ransformer Capacity Selection: Ensuring Reliable and Efficient Power System OperationTransformer capacity refers to the apparent power at the transformer’s main tap position. The value indicated on the nameplate is known as the rated capacity, typically expressed in kilovolt-amperes (kVA). In practical operation, improperly sized transformers can lead to either under-loading (due to oversizing) or overloading/overcurrent conditions, which may result in equipment overheating, reduced efficiency,

The capacitive current is mainly determined by the length of the feeder, the cross-sectional area of the conductor, the dielectric constant, the height above the ground, and the rated voltage. The specific estimation methods are as follows: Estimation of capacitive current of overhead lines: For overhead lines of 3 - 35 kV, the capacitance per phase to ground is usually 5000 - 6000 pF/km. Based on this, the value of the single-phase grounding capacitive current per kilometer for lines of differe