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

General Rules for GIS Grounding and bondingIn most Gas - Insulated Switchgears (GIS), there are two grounding grids: The station grounding grid, which is analogous to that in a typical Air - Insulated Switchgear (AIS) installation. The GIS grounding mesh, a closely - spaced grounding grid embedded in the concrete slab where the GIS is installed.Typical rules for GIS grounding and bonding are as follows: All grounding conductors should be kept as short as feasible. The grounding mesh and its inte

What is Capacitive Voltage Transformer?Definition: A capacitive voltage transformer (CVT), also known as a capacitive potential transformer, steps down high - voltage input signals to provide low - voltage signals that can be easily measured by measuring instruments.The capacitive potential divider, inductive element, and auxiliary transformer are the three main components of a capacitive potential transformer.Why is a Capacitive Voltage Transformer (CVT) Needed?When measuring high voltages abov

Very Fast Transient Over voltage(VFTO) wave common characteristics in HV& EHV GISSteep wavefront, with a rise time typically ranging from 2 to 20 nanoseconds: When restriking occurs in the contact clearance of a disconnector, the arc - reignition process is extremely rapid. As a result, the voltage waveform injected into the power grid exhibits a very high ascending or descending steepness.Theoretically, the amplitude of Very Fast Transient Overvoltage (VFTO) can reach up to 3.0 per - unit.

Dual Trace OscilloscopeDefinition: In a dual - trace oscilloscope, a single electron beam generates two traces, which are deflected by two independent sources. To produce these two separate traces, two main methods are employed: the alternate mode and the chopped mode. These are also referred to as the two operating modes of the switch.A question then arises: why is such an oscilloscope necessary?When analyzing or studying multiple electronic circuits, comparing their voltages is crucial. One op

What is Electronic Voltmeter?DefinitionAn electronic voltmeter is a voltmeter that utilizes an amplifier to enhance its sensitivity. It is capable of measuring the voltages of both AC and DC devices. Thanks to its high input resistance, the electronic voltmeter provides accurate readings.A moving - coil voltmeter struggles to detect low voltages, but the electronic voltmeter overcomes this limitation. The electronic voltmeter has high input impedance, enabling it to detect signals of extremely w

Ground switches feature a moving contact that creates or closes a gap between the high - voltage conductor and the enclosure. At the enclosure and the conductor, sliding contacts equipped with suitable electric - field shields are incorporated.A “maintenance” ground switch can be operated either manually or via a motor drive. It takes several seconds to open or close, and when fully closed, it can carry the rated short - circuit current for the specified time period (either 1 or 3 seconds) witho

What is Differential Voltmeter ？Definition: A voltmeter that measures the difference between a known voltage source and an unknown voltage source is called a differential voltmeter. It operates based on the principle of comparing the reference voltage source with the unknown voltage source.The differential voltmeter offers very high accuracy. Its operating principle is similar to that of a potentiometer, and thus it is also known as a potentiometer voltmeter.Construction of Differential Voltmete

SteelThe enclosure has two fundamental functions: maintaining internal gas pressure and ensuring gas - tightness to prevent the release of SF6 into the atmosphere. Sheet steel materials are well - suited for fulfilling these functions. In contrast, cast steel has porosity issues and cannot guarantee the high - level gas - tightness required for Gas - Insulated Switchgear (GIS).Steel is relatively easy to weld and shape. Steel enclosures are typically fabricated by mechanically forming steel shee

Differential Protection of a TransformerTransformers are among the key components in power systems. As static, fully - enclosed, and typically oil - immersed devices, faults on them are relatively infrequent. However, even a rare fault can have severe consequences for a power transformer. Thus, safeguarding power transformers against potential faults is of utmost importance.Faults on transformers are mainly categorized into two types: external faults and internal faults. External faults are swif

Requirements for Larger Tank Enclosure in VCB Vacuum breakers permit the use of insulation media other than SF6. When insulating gases such as dry air, nitrogen, or CO2 are chosen, their insulation performance will be inferior compared to that of SF6 at the same pressure. Stray capacitances to the tank negatively impact voltage division within the vacuum interrupter (VI). This may necessitate a larger, higher - rated - voltage VI.Considerations When Applying VCB in GIS Stray capacitances from th