Protection relays.

Independent testing gives guarantee. Protection relays should operated during pure sine wave conditions and during transient conditions.

Influencing factors
During normal operation of the network the measured quantities are sine waveforms. However during a network fault or component fault the network or component will have a transient response. Current transformers may saturate due to DC-components, capacitive voltage dividers will have a transient response due to the sudden voltage collapse or an arc voltage may be present during a non-metallic arc fault. Also the fault itself may change; a single phase to ground fault may evolve into a two-phase to ground fault. It is expected that a protection relay can deal with all these different influences. It should be fast and selective in all cases.

Operation environment
With the ongoing development of electronic components with faster processors, bigger memories, smaller components and decreasing power consumption protection relays will also become more sensitive to its environment compared to the electromechanical relays in the past. Electronic circuits may be influenced by temperature and may be disturbed by continues and transient electromagnetic phenomena. During normal operation and maintenance protection relays will be subjected to continues and transient electromagnetic phenomena; radio frequency transmitters may be in the neighbourhood, a maintenance engineer can be electrostatic charged and will use his mobile phone. Switching operations of disconnectors and circuit breakers produce oscillatory waves and fast transients in the power and signal cables. Lightning strikes cause surges in the primary and secondary installations.

Guarantee
KEMA plays a leading role in protection relay testing all over the world. We offer manufactures as well as end-users advanced independent test capabilities, to perform certification testing and application testing of protection equipment and systems. A manufacturer wants to prove the qualities of the relay for technical and commercial reasons and has to comply with international standards (IEC 60255 series and ANSI IEEE C37 series). End-users will be interested in the utilization, specific requirements and operating conditions of the protection devices.

Testing at KEMA provides confidence in the equipment for developers and end-users and thereby opens new markets for you.

More information? Contact us.