Search

ABB’s Power System Protection Practices

Electrical Protection Systems

Electrical power system operates at various voltage levels from 415 V to 400 kV or even more. Electrical apparatus used may be enclosed (e.g. motors) or placed in open (e.g. transmission lines). All such equipment undergo abnormalities in their life time due to various reasons.

Power System Protection Practices // ABB
Power System Protection Practices // ABB

For example, a worn out bearing may cause overloading of a motor. A tree falling or touching an overhead line may cause a fault.

A lightning strike (classified as an act of God!) can cause insulation failure. Pollution may result in degradation in performance of insulators which may lead to breakdown. Under frequency or over frequency of a generator may result in mechanical damage to it’s turbine requiring tripping of an alternator.

Even othervise, low frequency operation will reduce the life of a turbine and hence it should be avoided.

It is necessary to avoid these abnormal operating regions for safety of the equipment. Even more important is safety of the human personnel which may be endangered due to exposure to live parts under fault or abnormal operating conditions. Small current of the order of 50 mA is sufflcient to be fatal!

Whenever human security is sacrificed or there exists possibility of equipment damage, it is necessary to isolate and de-energize the equipment.

Designing electrical equipment from safety perspective is also a crucial design issue which will not be addressed here.

To conclude, every electrical equipment has to be monitored to protect it and provide human safety under abnormal operating conditions. This job is assigned to electrical protection systems. It encompasses apparatus protection and system protection.

Here, on this page you will find 10+ ABB’s power system protection practices that can be of great help to protection engineers and others. Guides are free to download.

No.DescriptionDownload
1Electrical Safety New
2Relay Coordination and Selective Protection New
3MV Feeder Short-circuit Protection New
4MV Feeder Earth-fault Protection New
5Protection of HV Transformers New
6Protection of Meshed Networks New
7Protection of Shunt Capacitors Banks New
8Motor Protection New
9Protection of Synchronous Generators New
10Backup protection New
11Automatic Reclosing New
12Impedance-based Fault Location New
Complete guide to the good protection of medium voltage networks New
Elements of power distribution systems New
Working with trip characteristic curves of low voltage circuit breakers New

SEARCH: Articles, software & guides

Premium Membership

Premium membership gives you an access to specialized technical articles and extra premium content (electrical guides and software).
Get Premium Now ⚡

Page edited by E.C. (Google).