Digital Medium Voltage Switchgear

Author: Benton Vandiver III, ABB, USA

The electric power industry has been developing and implementing the concept of Smart Grids for some time based on the advances in computer and communications technologies in order to meet the requirements for improved reliability, security and efficiency of the electric power system. However, meeting these goals is not possible by just using microprocessor based multifunctional Intelligent Electronic Devices (IEDs) and communications. Improving return on investment includes reducing capital costs in equipment, as well as the cost of transportation, installation and maintenance.

Another important cost factor is safety, improving personnel safety working in proximity to the substation equipment is a key cost driver.

Medium voltage (MV) switchgear needs to meet many different requirements due to the wide range of its applications. While it is predominantly used in distribution substations, it is also used in industrial installations, commercial facilities, university campuses, as well as for the interconnection of distributed energy resources. This means that the switchgear needs to be flexible and accurate over a wide range of currents and voltages, while at the same time being safe and reliable, with minimum maintenance requirements.

Combining microprocessor technology, advanced communications, IEC 61850 and non-conventional instrument transformers allows moving medium voltage switchgear into the era of the Smart Grid.

BeijingSifang June 2016