High Voltage Engineering

Abstract

High-voltage engineering is knowledge about power transmission at high voltages and about stress on equipment used in high-voltage transmission systems. The basis for the design of high-voltage equipment is stress on the insulation by the electric field, whereby the stress magnitude depends on the voltage type. The electric field distribution is given by relative permittivity for alternating current () and by conductivity for direct current () and homogeneity of the electrode arrangement. Evaluation of the electric strength requires statistical and adjusted test methods. Basic knowledge about the breakdown behavior in gases is the basis for understanding the breakdown in fluids and solids. The breakdown of fluids is influenced by moisture, impurities, and stressed volume. Solids suffer from the same parameters, but thermal and erosion breakdowns and residual life time are of interest. Different kinds of insulation gases, fluids and solids, inorganic and organic, as well as impregnated solids are used in high-voltage insulation, and each of them has its own characteristics, which requires a careful selection depending on the equipment and the expected electric stress. Generation of test voltages requires specialized voltage and current generators for AC, DC, and impulse voltages. The measurement of different voltage types also requires specialized measuring circuits, including partial discharge and dielectric characteristics measurement.