The magnetic field of a three-phase power line with an ordinary and triangular arrangement of wires

Power lines are sources of magnetic fields, which requires attention to ensure safety for people and to consider electromagnetic compatibility. In this article the nondimensional form expressions for calculation of magnetic field strength of a three-phase line with an ordinary and triangular arrangement of wires were obtained what makes it possible to calculate the necessary distance to the core of the line if the maximum permissible level of magnetic field strength is provided. The approximate expression of magnetic field strength at large distance from the line was considered. It is valid with the measurement accuracy less than 1%, which shows the proportion between magnetic field strength and distances between wires and inverse proportion of square distance to the wire core. It was determined that the triangular arrangement of three-phase line wires has lower magnetic field strength than the arrangement of wires in row due to more compact arrangement of wires.