Case study: Failure of a transformer & switchgear buses due to a ferroresonance event

First of all, it’s good to know that the possibility of a transformer ferroresonance condition rapidly increases as the transformer is closer to generator zone. This condition may occur when…...

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Aug 23, 2019 | Edvard

Practical implementation of the six most common transformer protection principles

This technical relies on the previously published article (6 alarms coming from a substation transformer you MUST take very seriously), but is much more dedicated to the implementation of relay… Read more

Jul 24, 2019 | Edvard

6 alarms coming from a substation transformer you MUST take very seriously

Transformers are the most expensive piece of apparatus in a power substation and therefore must have appropriate protection equipment installed to guard against various faults. This technical article explains a… Read more

Jul 22, 2019 | Edvard

MV/LV transformers – The most common power supply in low voltage networks

The general term power supply in LV networks refers to the supply of electrical energy. The power supply, and more generally the different supplies, are provided by sources (mains supply,… Read more

Jun 24, 2019 | Edvard

Fuses as the oldest and simplest method of protecting rural distribution systems

Fuses are the oldest and simplest methods of protecting rural networks. There is no method as simple as fuses, but don’t be tricked, modern fuses are very reliable devices. All… Read more

Jun 19, 2019 | Edvard

The case of phase-to-phase fault in a 13.8 kV switchgear caused by heavy rain

In this case study we describe a 13.8 kV switchgear phase-to-phase fault due to by heavy rain evolving into a three-phase fault that was cleared by transformer numerical relays. The…...

PREMIUM Membership Required

This content is available for Premium members only. Premium membership gives you an access to specialized technical articles and other extra premium content (electrical guides and software). Apply 20% discount code: EEP08PR (Expires on August 30th 2019) Login ♛Register ♛

May 17, 2019 | Edvard

The basic protection schemes for 4 typical transformer types in power system

The degree of transformer protection provided depends to a great extent upon the size and functional importance of the unit. A further important factor is the economic aspect. The cost… Read more

May 13, 2019 | Edvard

Three good examples of the application of modern relays to transformer protection

This technical article provides three examples of the application of modern relays to transformer protection. As there are many modern protection relays nowadays that provide advanced software to simplify the… Read more

Apr 22, 2019 | Edvard

7 routine tests for a dry-type transformer you should perform during commissioning

This technical article briefly describes seven very important tests you should perform during commissioning of a dry-type transformer. Usually tests are performed in the factory where transformers are produced. The… Read more

Apr 03, 2019 | Edvard

Transformer no-load loss and excitation-current measurements

A transformer dissipates a constant no-load loss as long as it is energized at constant voltage, 24 h a day, for all conditions of loading. This power loss represents a… Read more

Mar 27, 2019 | Edvard