According to experts'
estimates, there are about 40-50 lightning strikes per second. Lightning is not
only causes casualties to human, but also destroys properties, especially for
transmission lines and substations. Lightning will stop the power supply, have
an effect to power operation management, and to the economy.
In order to prevent the
incident at the substation by lightning, EVNNPT
has cooperated with DHK Ltd. to hold the above workshop. Attending the workshop,
there were representatives of functional departments of EVNNPT, Power Transmission Company 1, Northern Power Project
Management Board, and Transmission Engineering Services Company.
At the workshop, experts
from DEHN introduced the products explained about lightening prevention,
standard grounding systems and loss protection which caused by lightning strike
transmission. With the following main solutions:
(i) Direct lightning protection solutions
include lightning arrester, lightning conductors, grounding systems. Ensure the
equipotential principle.
(ii) Solutions for lightning
on transmission line to substation based on three main product levels and has
been tested by DEHN in a laboratory under the corresponding lightning
conditions.
- Type 1 with RADAX technology
flow spark gap works by voltage switching. Directional, lightning prevention
with T1 / T2 waveform = (10 / 350μs) without damage.
- Type 2 with MOV
technology (metal oxide varistor) working in the form of voltage limitation for
the surge arrester of 8 / 20μs waveform
- Type 3 with the ability
to protect power equipment from the impact of waveform overvoltage (1.2 / 50μs
open circuit breaker). switching power supply, generator start pulse) (8 / 20μs
pulse short-circuiting).
The workshop brought many
useful information about safety equipment as well as lightning solutions.
Questions and concerns related to mentioned topics provided by delegates were
answered satisfactorily. During the workshop, EVNNPT and DEHN hope to have future cooperation to improve the
protection of substations and the national power transmission system./.