Ph.D., Sapa Vladimir, master student, Wojciechowski
Alexey
Kostanai State University A.Baitursynov, Kazakhstan
Improving the electromagnetic environment at power
stations
The assessment
of the electromagnetic environment is developed and implemented protective
measures, which may include: 1. Optimization of the grounding device,
including:
- Restoration
of damaged and missing gasket grounding electrodes, - Installation of vertical
ear thing devices for lightning protection, surge arresters and surge arresters
- Cast of
grounding and potential equalization in buildings and premises in accordance
with modern requirements,
- Ensuring
lightning current spreading at a safe distance from power circuits and
communication, as well as the locations of the equipment,
- The
separation of grounding conductors for information technology equipment and
devices that can carry significant interference, such as cable entries with
radio masts,
- The gap
unnecessary constraints (for example, between the elements of the lightning
protection and filter joining high-frequency communications, cable TV, etc.)
2. Ensuring
proper installation of secondary circuits under the terms of electromagnetic
compatibility:
- Separate
laying of information and power circuits,
- Organization
screening (both - sided or grounding screens depending on site conditions)
- The use of
data cables with a high degree of symmetry ("twisted pair")
- Laying of
the cable to bypass areas with high levels of electromagnetic fields
- The use of
barrier ear thing, tire balancing capacity
- The use of
optical isolation
3.
Optimization of supply:
- Separation
of circuits and ground zero (the transition from a system of TN-C system for
TN-S and TN-CS),
- Reduction of
leakage current (to reduce the level of low-frequency magnetic fields and
interference in the communication cables)
- Installation
of stabilizers, isolating transformers and power backup devices, - The use of
secondary sources (uninterruptible power supplies, rectifiers) with high noise
immunity
- The organization
of a screened subnet for communication devices and automated control systems
(for example, through a separate phase stabilizer).
Figure 1. - Installation
of protective devices of classes B, C and D (on the classification of IEC) in
the network TN-CS 220/380V.
4.
Installation of surge protection: In recent years began to be used more
intensively surge suppression devices in the power supply and the exchange of
information. Such devices are carried out on the basis of the power components
with highly nonlinear current - voltage characteristic: arresters, varistors,
diodes. Nonlinearity of the current voltage characteristic allows you to
organize sanitation impulse noise on a "wire -to-wire" or "wire
-to-ground" by not allowing them to reach the input devices. Effective use
of such devices is largely determined by the organization of the system
grounding. Currently, the most effective noise reduction in the fuel system is
common to use the principle of the zone defense. He is to install safety
devices in several stages, each of which dissipates some of the energy of the
pulse (see Figure 1). As a result, the amplitude of the noise is reduced to
levels that are safe for the equipment, even not specifically intended to be
placed on energy facilities.
5. Shielding
sensitive equipment. Sometimes a high level of magnetic fields in a
short-circuit in the high-voltage network poses a direct threat to the
equipment. In this case, the options are usually considered placing the product
in special screening cabinets.
References:
1. EMC Basics:
a textbook for high schools / edited by Doctor of Technical Sciences, Professor
RN Karjakin; Alttaysky State Technical University named after II Polzunova. -
Barnaul: JSC "Altai Printing Plant", 2007.
2. Habiger E.
Electromagnetic compatibility. The basis of its support in technology:
Translated from the German / IP Kuzhekin; Edited by BK Maximov. - M. Energoatomizdat,
1995. - 304.
3.
Electromagnetic compatibility in power: Textbook / GJ Vaginas, AB Rags, A. A.
Sevostianov. - Moscow: Publishing Center "The Academy", 2010. – 224.