Coupling Transmission Lines for Wave-Shape Adjust in High-Voltage Surge Tests

High-voltage (HV) tests are usually required for evaluating electrical withstand of equipment, such as power transformers. These tests are based on standards that suggest values for the parameters of the voltage surge wave shape to be applied. However, for the personnel of HV laboratory, the adjustment of the wave shape is not an easy task. Although standards usually have some flexibility for the parameters of the wave shape for some transformers, it may be even impossible to reach any wave shape that may be minimally acceptable. Based on this problem, this paper presents a conceptual solution that is a special coaxial transmission line to be inserted between the equipment and the impulse generator. The proposed line has a special design in view of matching properties of the impulse generator and the equipment to be tested. Simulation results from the proposed configuration are presented with a discussion of its theoretical performance.