18-12-2012, 01:56 PM
Security Framework for Wireless Communications in
Smart Distribution Grid
Security Framework for Wireless Communications.pdf (Size: 1.07 MB / Downloads: 76)
Abstract—
Communication networks play a critical role in smart
grid, as the intelligence of smart grid is built based on information
exchange across the power grid. In power transmission segments
of smart grid, wired communications are usually adopted to ensure
robustness of the backbone power network. In contrast, for
a power distribution grid, wireless communications provide many
benefits such as low cost high speed links, easy setup of connections
among different devices/appliances, and so on. Connecting power
equipment, devices, and appliances through wireless networks is
indispensable for a smart distribution grid (SDG). However, wireless
communications are usually more vulnerable to security attacks
than wired ones. Developing appropriate wireless communication
architecture and its security measures is extremely important
for an SDG. Thus, these two problems are investigated in this
paper. Firstly, a wireless communication architecture is proposed
for an SDG based on wireless mesh networks (WMNs). The security
framework under this communication architecture is then
analyzed.More specifically, potential security attacks and possible
counter-attack measures are studied. Within the security framework,
a new intrusion detection and response scheme, called smart
tracking firewall, is developed to meet the special requirements of
SDG wireless communications. Performance results show that the
smart tracking firewall can quickly detect and respond to security
attacks and is thus suitable for real-time operation of an SDG.
INTRODUCTION
AS COMPARED TO traditional power grid, smart grid is
distinguished by several features. Smart grid is robust
to load fluctuations, and the supply-demand balance can be
properly maintained via intelligent real-time dispatching mechanisms,
large-capacity high-performance battery, distributed
energy, and close customer-grid interactions. Smart grid is
also resilient to equipment failure, which prevents a single
failure from developing into power outage or blackout.
SECURITY FRAMEWORK FOR WMN-BASED SDG
To ensure proper operation of an SDG, a number of critical
servicesmust be supported by a secure communication network.
Several typical scenarios are listed below.
1) Collect power usage information from smart power meters
for the purpose of billing, power dispatching, and grid
optimization. This function has already existed in some
power distribution grids, especially for billing purpose,
via PLCs. However, higher communication throughput and
812 IEEE TRANSACTIONS ON SMART GRID, VOL. 2, NO. 4, DECEMBER 2011
more flexible networking interfaces are desired due to frequent
interactions among grid, customers, smartmeters, inverters,
and renewable energy sources.
2) Monitor the status of electric equipments. For example, the
grid-tied inverters, transformers, switches, and so on need
to be monitored by measuring parameters such as voltage,
current, and phase. Such information needs to be sent back
to a control center for maintaining grid stability and power
quality.
SMART TRACKING FIREWALL
No matter how secure the communication protocols can be
in WMNs, security attacks can still happen. Thus, intrusion detection
and response is an important security measure to protect
WMNs.When an SDGis considered, the intrusion detection and
response process must be quick enough to ensure real-time operation
of an SDG. In this section, a new intrusion detection and
response scheme, called smart tracking firewall, is developed. It
adopts the concept of secure firewall, but more importantly the
firewall is adaptively mobile to track an intruder.