Advanced Approach To Mitigate Magnetic Fields And Your Health

This chapter deals with the epidemiological reports, which associates exposure to magnetic field and the risk of fatal diseases such as brain cancer, leukemia, breast cancer, depression and miscarriage. In addition to exposure to magnetic field associated with high voltage transmission lines, possible relationship between health hazard and exposure to residential magnetic field such as electric blanket, hair dryer, toaster and many more have also been discussed.

Occupational and non-occupational exposure to magnetic field and how an office worker’s health may be in danger by sitting near to some office equipment have been studied.

Finally, a relation between central nervous system cancer and environmental exposure has been established. This study also establishes a possible relation between modern equipments and heart attack.

Electricity has gone through lots of changes since it has been in use. But, the hazardous effects of high voltage transmission line magnetic field have always been of deep concern to scientists. In this chapter, a mathematical modeling has been established, by which a hundred percent mitigation at any point of consideration would be achievable. The developed equations are also capable of producing simultaneous reduction of magnetic field at other points within the center of the right-of-way.

First, a procedure to obtain the total magnetic field contributed by the three- phase high voltage transmission line has been established and then the angular frequency at which maximum magnetic field occurs is developed.

In order to achieve the mitigation, an auxiliary mitigating loop has been implemented and the required equation to calculate the mitigating magnetic field is developed. The optimum value of this loop impedance is set. Since the designed auxiliary mitigating loop is of passive type, no especial feedback equipments are needed to compensate for the changes of the load currents.

In order to illuminate the capability of the developed equations a flat configuration of 230 KV transmission line has been utilized.

Mitigating magnetic field is caused by the mitigating current in the auxiliary mitigating loop. This current is achieved by dividing the mitigating loop voltage by the mitigating loop impedance. The mitigating loop voltage is the result of the flux induced by each phase of the three phases of the transmission line.

In this chapter, the flux induced by each phase has been thoroughly investigated and the geometrical location of the auxiliary mitigating loop with respect to the power line has been scrutinized and the related equations are established. The vector sum of these three fluxes results in obtaining the total flux penetrating through the mitigating loop and the corresponding equation is set. Finally, an equation to calculate the mitigating loop voltage is developed. It is worth mentioning that phases A, B, and C are at 0°, -120° and +120° respectively.

A numerical illustration has been set up to demonstrate the applicability of the developed equations to calculate the mitigating magnetic field. A point in the space having a coordinate of (9, 1) has been selected as the point of consideration.

The total flux induced by the three phases of the transmission line is calculated, from which the mitigating loop voltage is achieved. In order to achieve our attempt of establishing a hundred percent cancellation of the magnetic field, optimal value of the loop impedance is determined.

Variation of unmitigated magnetic field over one complete cycle in depicted and simultaneous variation of unmitigated magnetic field and mitigated magnetic field is also shown.

The influence of the mitigating magnetic field produced by the loop on the other locations is also investigated and the results are tabulated. Effect of angular frequency on producing magnetic field at other location is studied.

Effect of geometrical location of the auxiliary mitigating loop with respect to the three phases of the transmission line is scrutinized. In this process, the mitigating loop is first placed above and then below the two outer phases of the power line and a comparative approach has been established. Positions of maximum and minimum values of the mitigated magnetic fields with respect to the geometrical location of the loop are also investigated. A 230 KV flat transmission line has been utilized and effect of mitigation at the other points has also been studied.

Process of mitigation with respect to the geometrical location of the auxiliary loop and the correlation between the three types of magnetic fields has also been studied and the related figures and Tables are depicted.

In order to demonstrate the capability of the developed approach on any types of transmission line, delta configuration power line has been investigated and numerical illustration is established. The results are tabulated and the related figures are depicted. In this chapter, characteristics of the magnetic fields and effect of the altitude of the auxiliary mitigating loop with respect to the power line are studied. Finally, relationship between the three types of the magnetic fields for delta - connected configuration has been scrutinized and the depicted figure illuminates the discussions

In this chapter, for further illumination of the developed approach to mitigate magnetic field associated with high voltage transmission line, bundled-conductors configuration has been scrutinized.

Each sub-conductor is separately analyzed and an equation to calculate the total unmitigated magnetic field is achieved from which, angular frequency responsible to generate maximum value of unmitigated magnetic field is set. An approach to calculate the mitigating loop impedance is also established.

The applicability of the developed method has been illustrated and effect of mitigation at seven different locations within the right-of-way has been thoroughly investigated.

Process of mitigation and variation of the three types of the magnetic fields with respect to each other has been studied and the related figures and Tables are depicted.

A comparative illustration between a flat configuration of 230 KV single conductor per phase and a bundled-conductor has been established. The obtained results which, are tabulated show that the mitigated magnetic fields remain unchanged for both the configurations.

Effect of ground wire as an auxiliary mitigating loop has been investigated.

In order to demonstrate the feasibility of the developed approach, a case when the mitigating loop is placed at the ground level is thoroughly studied. A flat configuration of 230 KV transmission line has been used and effect of mitigation at seven different locations within the right-of-way has been scrutinized and the related figures and Tables are illustrated. The loop voltage, which is the result of induced fluxes, is determined. Implementation of the previously derived equation results in achieving the value of the mitigating loop impedance. The correlation between the three types of magnetic fields has also been investigated. Finally, a comparative method when the auxiliary mitigating loop is installed above, below and at the ground level is also established and the result is shown in a Table

In this chapter, vertically arranged conductors are investigated. The total unmitigated magnetic field contributed by the three phases is calculated. The mitigating loop voltage is calculated. This calculation reveals the fact that there will be no mitigation when the auxiliary loop is installed symmetrically with respect to the Y-axis. The capability of the developed approach is well illustrated once the loop’s geometrical position is changed. The fluxes induced by the three phases of the power line are well capable of producing mitigating loop voltage. Consequently, this voltage results in achieving the mitigating magnetic field, Subsequently, the mitigated magnetic field is calculated.