Research & Development AT Active Shielding Solution

An active magnetic shielding system is an electronic system that includes sensors and current loops that can monitor the magnetic field levels in a specific area and produce an opposing magnetic field.

The purpose of an active magnetic shielding system is to reduce magnetic field levels resulting from external electrical infrastructure (such as power lines) located in proximity to the area in interest, so that ultimately the equivalent magnetic field levels will meet the regulatory and/or the client's requirements.

An active shielding system provides a solution to two main situations: Situations in which the desired areas have magnetic field levels that exceed the required exposure values, and situations in which due to the proximity of a project to external electrical infrastructures there is difficulty in obtaining construction permits and approval from the authorities because of a potential for exposure deviations. Given that there is feasibility for installing such a system, then it will provide a solution in terms of magnetic field levels from the electrical infrastructures.

The first benefit of an active system is the solution itself - there are many cases for which no alternative solution can be found. For example, in the case of an existing structure near an overhead power line that cannot be modified in any way. Another advantage is in terms of costs, the cost of an active system is significantly cheaper than the costs of burying an overhead high voltage power line. There is also the advantage of schedules, planning and building an active protection system will usually take a few months compared to the schedules for burying a high voltage power line, which can be in the order of years. An active system will also maximize the project area, with an emphasis on the areas intended for continuous occupancy and without expropriation due to radiation levels.

The design of an active system will be adapted and designed in accordance with the characteristics of the overhead power lines and in accordance with the project outline. The more complex the interface between the power lines and the structure (different distances and angles), the more complex the system will be and may not provide a complete solution. An active shielding system may be less suitable in the case of a changing energy flow direction regime between the circuits, or it may be complex to implement, which can affect the cost of installation. However, it may still be a possible solution.

As stated, an active shielding system is a solution to a radiation problem. Usually because of at least one of two scenarios: First scenario - the problem already exists according to measured values ​​in the project area. Second scenario - the problem can arise according to a magnetic field exposure survey, i.e. a survey of high voltage lines carried out towards the project. The survey examines the feasibility of the voltage lines to affect the project area at various electricity consumption scenarios and not only according to the current consumption status.