04520328_1.pdf

2007 IEEE Canada Electrical Power Conference N e w Routing Mechanism ofEnabling DNP3 for Smart Distribution System Collaborative Computing Todd Mander, Helen Cheung, Alexander Hamlyn, Richard Cheung also implements additional cyber-security. Abstract - Residential secondary service m a y account f o r Increasing numbers o f Intelligent Electronic Devices (IEDs) potentially thousands o f devices through networked load- a r e being located outside o f substations to support smart management collaborative computing to realize a smart distribution system operations [ 3 ] [5]. I n particular, a focus o f distribution system. Although TCP/IP-based networks c a n this paper i s residential loads with potentially hundred provide t h e communication infrastructure f o r these devices, a severe security issue will present, a s these devices a r e vulnerable thuad o f etwrkenal ed s h w l andlesmr t o being compromised b y cyber-attackers. U s e o f a disjoint metering, time-of-use scheduling, dispersed generation, etc. protocol such a s DNP3 f o r SCADA networks provides a n These IEDs c a n b e used f o r t h e collaborative management o f effective solution t o t he security issue. However, DNP3 does n o t distribution system operations, including a t t h e secondary- have adequate peer-to-peer networking t o support t h e service level. The IEDs c a n be use to optimize local collaborative computing. This paper proposes a n extension operating conditions through distributed a n d parallel protocol layer f or DNP3 t o facilitate th e collaborative computing. operaing citi tru distribu t e d a n d parAlle This extension offers a routing mechanism that utilizes a variable processing with th e distribution system control center. As a address structure t o create a routing path between result, t he distribution system will become more efficient i n communicating devices. T h e routing path eliminates protocol handling real-time demands a n d more robust t o provide overhead typically associated with network layers a n d provides a enhanced self-healing t o equipment failures [ 3 ] [5]. unique network address f o r every device i n th e distribution An example application f o r load-management collaborative system. T h e routing mechanism i s interoperable with DNP3- computing f o r the smart distribution system operations i s based devices a n d does n o t alter t h e DNP3 specification. dispersed generation pooling within residential load areas [6]. Index Terms--Computer networks, Computer network With collaborative computing during power outages, the IEDs management, Computer network security, Power system could negotiate power reductions with consumers. communication, Power system security, Protocols, Security. Concurrently, t h e IEDs would negotiate increased dispersed generation into th e distribution system t o balance t h e load . INTRODUCTION demand. F o r example when t h e feeder power rerouting i s n o t T HI S paper proposes a routing mechanism f o r Distributed possible, i f o n e local area h ad a small power deficit a n d a Network Protocol (DNP3), a popular North American neighboring load area h a d a surplus o f dispersed generation, utility protocol [1], as a n extension protocol below t h e DNP3 t he power could b e transferred into the deficit area t o balance data-link layer. T h e routing mechanism does n o t rely o n I P t he load. T h e smart distribution system collaborative routing capabilities a s i s typically relied o n f o r DNP3 routing computing in this example minimizes the effects o f power [2]. T h e routing mechanism supports t he potentially vast outages. number of network-enabled devices that will eventually Load-management collaborative computing also presents facilitate collaborative computing f o r smart distribution potential significance i n data a n d operation abstraction. F o r system operations, e.g. particularly f o r residential areas with example, typical distribution system operations f o r a control dynamic load management a n d distribution of dispersed center would only require the net power generation o r generation. T h e routing mechanism also provides support f o r consumption within a residential load area, b u t n o t the collaborative computing data/operation abstraction that will individual home generation a n d consumption information that reduce the amount o f data that needs t o b e handled b y utility i s needed only a t t h e e n d o f a billing period. Additionally, i n operators [3]. Th e routing mechanism utilizes a variable regard t o t he power outage example, a control center does n o t address structureto definethe data transmission path amongst require t h e details o f t h e power negotiation. T h e control center the DNP3 devices. T h e variable address structure supports a n only requires knowing which residential load areas a r e address space potentially larger than IPv4 a n d close t o that o f maintaining power a n d h o w longthey will b e able t o maintain IPv6. Th e routing mechanism extends DNP3 capabilities t o t he power. support t h e recommendation o f U.S. National Institute o f Although TCP/IP-based protocols, e.g. I E C 61850 a n d Standards a n d Technology (NIST) f o r using disjoint protocols DNP3 over TCP/IP, could b e utilized to support t he f o r Supervisory Control a n d Data Acquisition SCADA) collaborative computing there a r e cyber-security issues that networks, creating in-depth defense f o r smart distribution would b e raised. T h e majority o f t h e smart distribution system systems [4]. T h e routing mechanism proposed in this paper 1EDs would b e located a t t h e secondary-service level. Since thesedevices ar e located outside o f utility facilities, they a r e a t high risk of being physically compromised b y cyber-attackers. T . Mander tmankdcr eciyrsow c a ) i s with University o f Teesside, U.K. a n d Cyber-attackers could utilize Internet-based attacks t o target Ryerson University, Canada. H. Cheung, A . Hamlyn, and R . Cheung ar e with Ryerson University. a n d disrupt smart distribution system operations, such a s 1-4244-1445-8/07/ 25.OO ©2007 IEEE 1 8 9

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