Integral Approach for Overvoltage Management Based on Field Data and Modelling

Abstract

The requirements for the power network to be flexible and to be able to transmit more power are becoming more important as a consequence of high share of the renewables. Therefore, to maintain the level of reliability of the power network, it is necessary to monitor more and more data as well as to better understand the phenomena that might exist in the power system, such as transients. One of the points that are of interest are interaction between power transformer and the other components in the network. A failure of such component may lead to power network unavailability and high economic cost. According to the CIGRE WG A2.37, high portion of the transformer failure may have been caused by the overvoltage. Therefore, it is important to handle overvoltage in the power network with high care. In this paper, an integral approach for power transformer overvoltages management based on field measurements and advanced electromagnetic transients (EMT) modelling is presented. It consists of simulating overvoltages using detailed power network models, including the high frequency transformer models and continuous monitoring of overvoltage events at the places of interest in the power network. This work gives a framework for dealing with overvoltages in the power network that could be implemented by power utilities.