New smart-grid operation-based network access control

Changes due to increasing use of equipment with communication capability in electricity distribution systems, development of microgrids, government-imposed electricity-market open access competitions, etc., have let electricity utilities in a greater reliance on communication networks for smart-grid operations that include monitoring, protection, control, and time-of-use metering. This paper presents a new smart-grid network access control strategy and a new operation-based access model in order to increase the grid-access security and grid-operation efficiency. The new access model extends the network access control from a traditional single security domain to multiple domains specifically designed for interconnected microgrids. A security policy to simplify power-grid network security administrations is proposed, the authorization is independently defined and separated from policy representations as well as implementation mechanisms, and digital credential is introduced to establish trust and role assignments for users in different microgrid domains. The proposed smart-grid operation-based network access control has significant advantages over the standard role-based access control for application on smart-grid operations. This paper presents case studies for illustrating this new smart-grid operation-based network access controls.

I. Introduction

Electricity utilities have been undergoing significant changes due to technological and political inspirations. In the technological aspect, there has been rapidly increasing use of intelligent (smart) devices/systems with communication capabilities for electricity power system operation and automation with improved efficiency, reliability and control accuracy, facilitated as these smart devices can communicate directly with power-grid networks for high-speed operations for events control. In the political aspect, many electricity utilities as imposed by governments have to provide their customers or third parties with open access to their power systems for electricity diversified/distributed generation, transmission, and trading, as leading to the creation of microgrids [1]. Increased use of network-controlled devices, government-imposed open access competition and deregulation, and rapid development of microgrids have resulted utilities in a greater reliance on computer networks for proper grid operations [2]. However, security and reliability concerns of the smart-grid computer networks increase rapidly and need to be addressed urgently, as the demands for access to the network have been rising swiftly. Under open access environment, the power-grid computer networks, originally isolated and used by qualified utility staff, have to become more accessible to a wider range and number of users and this increases the risk of a power-grid network be attacked. With increasing use of smart devices with autonomous communications to the power-grid computer networks, the power system operations can be endangered if any significant network errors occur.