Overhead power lines magnetic field reducing in multi-story building by active shielding means

Self Cite

Aim. For the first time the method of adjustment of three circuit system of the active shielding of the magnetic field based on experimentally determined space-time characteristics to increase the shielding factor in a multi-storey building located near a single-circuit overhead transmission lines with a wires triangular arrangement was developed. Methodology. When synthesizing the laboratory model of system of active shielding the coordinates of spatial arrangement and of three shielding coils, the currents in shielding coils and resulting magnetic flux density value in the shielding space were calculated. The synthesis is based on the multi-criteria game decision, in which the payoff vector is calculated on the basis on quasi-stationary approximation solutions of the Maxwell equations. The game decision is calculated based on the stochastic particles multi swarm optimization algorithms. Results. Computer simulation and experimental research of the space-time characteristics of laboratory model of three circuit system of active shielding of magnetic field, generated by overhead power lines with phase conductors triangle arrangements in multi-storey building are given. The possibility of initial magnetic flux density level reducing to the sanitary standards level is shown. Originality. For the first time the synthesis and adjustment of laboratory model of three circuit system of active shielding of magnetic field based on experimentally determined space-time characteristics to increase the shielding factor in a multi-storey building located near a single-circuit overhead transmission lines with a wires triangular arrangement carried out. Practical value. Practical recommendations from the point of view of the implementation of developed method of adjustment of the three circuit system of the active shielding of the magnetic field based on experimentally determined space-time characteristics in a multi-storey building located near a single-circuit overhead transmission lines with a triangular arrangement of wires are given.

Section: Introductionmentioning

confidence: 80%

Method of adjustment of three circuit system of active shielding of magnetic field in multi-storey buildings from overhead power lines with wires triangular arrangement

Kuznetsov

Nikitina

Bovdui

et al. 2022

Self Cite

“…These studies use both experimental methods and computer simulations. The latter is widely used in various fields of electrical engineering [4,5].…”

Section: Introductionmentioning

confidence: 99%

Computer simulation of operation plant effective modes for water disinfection by electrical discharges in gas bubbles

Boiko,

Tatkova

2024

Purpose. Determination by means of computer simulation of the most efficient modes of operation of the installation for water disinfection using discharges in gas bubbles, in which (modes) the amplitude of voltage pulses at the processing unit and on the layer of treated water is not less than the voltage amplitude immediately after the switching discharger. Methodology. To achieve this goal, we used computer simulation using Micro-Cap 10. We used two different electrical circuits that simulate the operation of the experimental setup in two different modes: in a mode with a restoring electrical strength of the discharge gap in the gas bubble between two adjacent voltage pulses on the discharge node and in the mode without restoring this dielectric strength. In computer simulation, we varied the following factors: the maximum simulation step, inductances, capacitances, active resistances, wave resistance of a long line, and the delay time for the operation of a spark gap simulating a discharge gap in a gas bubble. Results. Computer modeling has shown that in order to increase the voltage amplitude at the treatment unit and on the layer of treated water, it is necessary to reduce the load capacitance – the capacitance of the water layer in the treatment unit to 10 pF or less, to increase the active resistance of the water layer to 500 W or more. An important factor for increasing the voltage and electric field strength in the discharge unit and, consequently, for increasing the efficiency of treated water disinfection is the discharge delay time in gas bubbles. The most rational delay time for the operation of the arrester, which is the gap in the gas bubble inside the water, under the conditions considered by us is 4–5 ns. It is with this delay time that the amplitude of voltage pulses at the node of disinfecting water treatment and on the layer of treated water is maximum, all other things being equal. Furthermore, with such a delay time this amplitude of voltage pulses significantly exceeds the voltage amplitude directly after the main high-voltage discharger, switching energy from the high-voltage capacitive storage to the processing unit through a long line filled with water. Originality. Using computer simulation, we have shown the possibility of increasing the voltage at the discharge unit of the experimental setup by 35 % without increasing the voltage of the power source. This provides a higher efficiency of microbiological disinfection of water by nanosecond discharges in gas bubbles and lower specific energy consumption. Practical value. The obtained results of computer simulation confirm the prospect of industrial application of installations using nanosecond discharges for disinfection and purification of wastewater, swimming pools and post-treatment of tap water.

“…This problem remains insufficiently developed both theoretically and practically. Therefore, a certain step in its solution was the development by the authors of a mathematical model of the MF in the area of work without removing the voltage under the load [16], and the methodology for its calculation, which are based on the results of previously performed studies of the MF of various technical objects [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. The latest research by the authors [16] confirms the relevance of solving the problem of protecting workers from the effects of the MF in Ukraine when performing work on PTLs without de-energizing.…”

Section: Introductionmentioning

confidence: 99%

Protection of workers against the magnetic field of 330-750 kV overhead power lines when performing work without removing the voltage under load

Rozov,

Reutskiy,

Kundius

2024

Problem. One of the acute problems that needs to be solved when performing repair work under voltage on power transmission lines (PTLs) is the protection of workers’ health from high-intensity electromagnetic fields. Goal. The purpose of the work is to develop the methodological foundations for the protection of workers from the magnetic field (MF) of the 330-750 kV PTL during repairing work without removing the voltage and under loading. Methodology. A methodology for calculating the maximum allowable PTL loading factor has been developed. It limits the flux density of the MF in the working area of the power transmission line to the maximum permissible level of sanitary standards for the given period of work at the potential and the minimum thickness of the protective layer between the wires and the worker’s body. Originality. Methodological principles for protecting workers from magnetic fields have been created. They are based on the joint use of the developed method of mode load minimization and the method of increasing the working distance, and the developed method of calculating the maximum allowable loading factor of PTLs. Practical value. The graphic dependence of the maximum allowable loading factor of the PTL is proposed as a function of the required working time and the thickness of the introduced additional protective layer between the wires and the body of the worker. It allows one quickly determines the maximum allowable loading factors to conform the accepted limit-allowable normative level of flux density of MF for various types of PTLs 330-750 kV. References 45, tables 1, figures 10.