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

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 “

Definition of Islanding EffectWhen the utility grid power supply is interrupted due to faults, operational errors, or scheduled maintenance outages, distributed renewable energy generation systems may continue operating and supplying power to local loads, forming a self-sustained “island” that is beyond the control of the utility company.Hazards Caused by Islanding Effect Loss of Voltage and Frequency Control: The utility cannot regulate voltage and frequency within the islanded section. If thes

What Happens When a Vacuum Interrupter Loses Its Vacuum?If a vacuum interrupter loses its vacuum, the following operational scenarios should be considered:a.Contacts openingb.Closing operationc.Closed and operating normallyd.Opening and interrupting normal currente.Opening and interrupting a fault currentCases a, b, and c are relatively straightforward. In these situations, the system is generally unaffected by the loss of vacuum.However, cases d and e require further discussion.Assume a three-p

What is the Thomson Effect?Thomson effect definitionThe Thomson effect is an important part of the phenomenon of thermoelectricity, which describes the phenomenon of heat absorption or release in a conductor (or semiconductor) in the presence of a temperature gradient when an electric current is passed through the conductor.Working principleWhen an electric current passes through a conductor with a temperature gradient, the electrons (or other charge carriers) experience a different thermal envi

What is the Carnot Cycle?Carnot efficiency definitionCarnot efficiency refers to the maximum thermal efficiency that an ideal heat engine can achieve when working between a heat source and a cold source. It is an important concept in thermodynamics, and the Carnot efficiency is the theoretical limit, beyond which the efficiency of any practical heat engine will not exceed this limit.Carnot efficiency formulaPeculiarity Maximum efficiency: The Carnot efficiency gives the maximum possible efficien

What is the Paltier Effect?Definition of the Paltier effectPalber effect refers to when a current passes through a circuit composed of different conductors, in addition to irreversible joule heat, heat absorption and heat release will occur respectively at the junction of different conductors with the direction of the current.Working principleThe Paltier effect was discovered by the French physicist Paltier in 1834. It is based on the properties of thermoelectric materials, that is, when an elec

Skin Effect DefinedSkin effect in transmission lines is the phenomenon where AC current concentrates near the conductor’s surface, increasing its effective resistance.Skin effect is defined as the tendency of an AC current to distribute unevenly over the cross-section of a conductor, such that the current density is highest near the surface of the skin of the conductor and decreases exponentially towards the core. This means that the inner part of the conductor carries less current than the oute

What is the Ferranti Effect?Ferranti Effect DefinitionThe Ferranti effect is defined as the increase in voltage at the receiving end of a long transmission line compared to the sending end. This effect is more noticeable when the load is very small or there is no load (open circuit). It can be described as a factor or a percentage increase.In general practice, current flows from higher potential to lower potential to balance the electrical potential difference. Usually, the sending end voltage i

What are the Applications of Hall Effect ?Hall Effect DefinitionThe Hall effect is defined as the deflection of charge carriers in a current-carrying conductor when placed in a magnetic field.Determine the Type of SemiconductorThe direction of the Hall voltage helps identify if a semiconductor is n-type or p-type.Calculate the Carrier ConcentrationThe Hall effect is used to find the concentration of electrons and holes in a semiconductor.Determine the Mobility (Hall Mobility)The Hall coefficient

What is Schottky Effect?Schottky Effect DefinitionThe Schottky effect is defined as a reduction in the energy needed to remove electrons from a solid surface in a vacuum when an electric field is applied. This boosts electron discharge from heated materials and impacts the thermionic current, surface ionization energy, and photoelectric threshold. Named after Walter H. Schottky, this effect is crucial for electron emission devices like electron guns.Thermionic EmissionTo understand the Schottky