Экспериментальное исследование путей повышения эффективности импульсного дефектографирования для контроля состояния обмоток высоковольтных трансформаторов

Abstract

The energy efficiency and reliability of electric power systems depends in many respects on the condition of high-voltage transformer equipment. Defective condition of one transformer unit is often the cause of a sudden emergency stoppage of the entire technological chain of an integral production process. To prevent such situations, an efficient technology for monitoring the condition of transformer windings is necessary. Standard methods show poor efficiency in detection of winding defects at their early development stages. An approach to a winding defect diagnosing methodology based on the use of a nanosecond probing pulse with a steep front is proposed. It is shown that by probing the windings with a pulse of 100 ns duration and a front of about 20 ns it is possible to reveal both mechanical and electrical defects. Experiments performed on a power transformer physical model have shown that the proposed method has the necessary sensitivity to minor changes in capacitive elements caused by defects at their initial development stage. It has been established that the nanosecond pulse method sensitivity increases significantly with decreasing the probing pulse duration and increasing its front steepness.