INTERNET ENABLES REMOTE CONTROL INA FAMILIAR OPERATING ENVIRONMENT

Today, it is possible to monitor and operate power systems with a web browser.This enables networks to be managed efficiently and cost effectively over theinternet.

Users are increasingly requesting distributed andremote monitoring and control capabilities in theSCADA system they have. They want to have asystem that is easy to use and runs in a familiarenvironment. To allow this, some standard technol-ogy is needed. The answer is web browser andinternet technology. This way existing communica-tion media can be used efficiently and easily, andfamiliar user interface with remote and distributedcapabilities can be created.

The ABB solution

ABB’s MicroSCADA control system, is developedand used within both SCADA (Supervision ControlAnd Data Acquisition) systems of electrical distribu-tion networks and automated substation systems.The system offers real-time information about thepower process and includes automated functions fore.g. alarm indications and process events.

In ABB’s MicroSCADA control system the abovementioned is implemented by using:

• Microsoft Windows NT Terminal Server + CitrixMetaframe package and the Citrix ICA client.

• Java API to transfer information from/toMicroSCADA.

The Microsoft Windows NT Terminal Server supple-mented with a Citrix Metaframe package providesaccess to MicroSCADA pictures and dialoguesthrough a standard Web browser. This means thatthe users can deal with, remote monitoring and

control issues through the standard MicroSCADAtools and also have access to station pictures dis-played in the browser.

The response time for events and updating on thelocal screen is short, since only the data that haschanged is sent to the browser. On slow phone linesthis can be very important. Also, the browser/internet interface is familiar to the operator, minimis-ing training needs. For security issues, an addi-tional data encryption package is available and canbe used in the Citrix Metaframe solution. TheMetaFrame thin-client/server system softwareincorporates Citrix’s Independent Computing Archi-tecture (ICA) protocol. Installing MetaFrame will notinterfere with the functions of a computer running

Terminal Server. This means that clients can con-nect and execute programs on the server regardlessof whether they are running the Citrix ICA protocol,or the standard Terminal Server client using RDP(Remote Desktop Protocol). The main differencesare in the features that each protocol and its respec-tive clients support. The Java API technology ena-bles the user to connect over the LAN and to usethe web-based technology to provide differentapplication types. This could be, for example, en-ergy reports, event lists or similar. Typically, a sys-tem owner such as an electric utility having aMicroSCADA based network control solution wouldhave their system connected through the elementsdescribed above. Security issues such as user loginis obviously an important element. The owner of thesystem must know who connects and when. Thesecurity features provided by both operating sys-tems and MicroSCADA support this particular issue.The above described solution means that the sys-tem could be connected over a LAN to a dial-upmodem pool or similar WAN system. For securityreasons it is recommended that the system is con-nected to the Intranet, rather than the publicInternet. The features and functionality are howeverthe same as when connecting to the Internet. Ifconnecting over the public internet, either encryptionor VPN (Virtual Private Network) solutions providinga more secure connection is recommended.

From the user point of view, the MicroSCADA sys-tem implemented this way provides the duty officerincreased control over the system. The web browserbased MicroSCADA system makes the duty officersare more mobile and allow them to do remote con-trol, monitoring and even testing when they are onsite.

Innovative technologies such as GPRS (GeneralPacket Radio Service) improve the transfer andconnectivity speeds of the mobile connection. Thisleads to a greater connectivity even from placeswhere a public phone line is not available. Thehardware requirements for such a system would bea portable computer with either dial-up modem or amodem with the capability of using the mobile GSMtechnology. The utilisation of mobile technology iscommon in today’s MicroSCADA control systems.The web browser functionality is complementedwith, for example, web camera and SMS (ShortMessage Service) via GSM phones. When SMS isused, the duty officer receives an alarm to his GSMphone and can then log in to the utility’s intranet (orvia public internet) from his portable PC via web

browser to access the MicroSCADA system.

ABB’s MicroSCADA is a scalable solution, thatserves the information and control needs in thewhole power process from substation monitoringwith accessing substation information throughserving as a gateway between the process and theupper level information system to enabling remotecontrol of power networks and secondary substa-tions. Thus MicroSCADA allows steady informationflow between different levels of the power system. Inthe substation level MicroSCADA based systemprovides local and remote supervision, includingevent and alarm handling, reporting, disturbancerecord upload and analysis as well as parametersetting. In conjunction with intelligent electricaldevices (eg. protection and control terminals) itprovides a quick overview of the system, which isparticularly valuable in a fault situation, reducing thetime needed to locate the fault and restore theprocess.

Finnish and Estonian applications based oninternet technology

Finnish utility, Kainuun Sähkö Oyj, provides a goodexample of a utility that has successfully imple-mented a control system based on the web-enabledtechnology described above. “Our whole networkcan be supervised from the web browser whilestaying at home,” says Vilho Hartikainen, the headof network automation at Kainuun Sähkö Oyj. Helives quite a distance from the office, and finds itvery convenient to use the intranet connection to getinformation about the distribution network. Conse-quently, he has used the browser function fre-quently. Vilho Hartikainen finds that the conventionalphone connection via modem is fast enough for his

routine activities, for example, checking the status ofthe network and reading the events and alarms. Forthe duty officer, however, ISDN connection is usedto speed up the connection times and minimisedelays in the data transmission.

In Estonia, where MicroSCADA is used for control-ling the whole distribution network of Eesti EnergiaAS, the system is also built on the web browsertechnology. The benefits are quite similar to thoseexperienced at Kainuun Sähkö Oyj. “Since our userinterface has become web browser based, thedistribution of information for needs other than justsystem control purposes is easy. Additionally, thisfeature enables the system to be operated no matterwhere you are, which again results in better cus-tomer service and reduced overall costs”, says

Tõnis Tikk from Eesti Energia AS. The networkcontrol system in Eesti Energia AS consists ofseveral levels: substation automation systems, localand regional control systems and the main controlcentre, which is located in Tallinn. Communicationbetween the different levels is handled via TCP/IPconnection in WAN network. This enables fastconnections to the databases in different parts ofEstonia eg. from Tallinn. Also, data mirroring is usedso that it is possible to automatically transfer therequired data about the changes in the process fromthe lowest level of the system to the database of themain control centre, which is located in Tallinn.Server based licence management and user au-thorisation assure security.

ABB Substation Automation OyP.O.Box 699FIN-65101 VAASAFinlandTel. +358 10 224 000Fax. +358 10 224 1094www.abb.com/substationautomation P

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