Development and Testing Results of Automated Control System for Supercapacitor-Based Energy Storage System

Abstract

Significant and prolonged voltage drops during emergencies in external power supply grids of industrial companies result in disruptions of continuous production processes that use asynchronous motors. Voltage drops normally last from hundreds of milliseconds to several seconds. The use of supercapacitor-based (SC-based) energy storage systems (ESS) in internal power supply grids of industrial companies can compensate for voltage drops in key load buses and maintain normal values. The economically feasible SC discharge time is up to 10 seconds due to the high unit cost of the electric energy stored. The rapid evolution of transient processes during emergencies requires the SC-based ESS to have a short response time and to select the correct triggers for ESS protection systems for providing its effective and reliable operation. This article presents the results of the development and testing of an automated control system (ACS) for SC-based ESS with a power rating of 7 MW used in an internal power supply grid of an industrial company to compensate for voltage drops in 6 kV buses. Different approaches have been developed for the selection of ESS parameters, ESS ACS operating algorithm, and composition, and ways to improve their response time. The deployment of SC-based ESS helped to provide a reliable power supply to key loads in the industrial company considered during emergencies in external power supply grids and prevent significant losses associated with their disconnection.