Noise levels on high voltage power lines

Question

I'm doing Signal Processing on signals from high voltage transmission lines but I'm unsure of what noise levels I should be expecting and which types of noise occur in a power system (impulse, harmonic etc.)

The idea is to get signals from current and voltage transformers at substations to do fault detection and classification but the methods I employ are dependent on the noise I should be expecting.

I have seen various SNR values thrown around in different papers but I'm wondering whether anyone could point me to a good source on this topic or perhaps give a brief explanation.

Answer 1

There are a few standards which seek to describe what electromagnetic immunity is necessary for equipment in power/substation environments. I would recommend looking to IEC 61000-6-5 for generic power station/substation EMC immunity requirements. This will in turn point you to the appropriate levels in other IEC 61000-4-x standards.

IEC standards are copyrighted, so unfortunately I assume I cannot provide example values here.

Other standards describing immunity in substations for various specific circumstances:

• IEC 60870-2-1
• IEEE 1613 (which specifies many of the IEEE C37.90.x standards)
• IEC 60255-26