INTERNATIONAL ISLAMIC UNIVERSITY CHITTAGONG DEPT. OF ELECTRICAL AND ELECTRONICS ENGINEERING

PRESENTATION ON

SUPERVISORY CONTROL AND DATA ACQUISITION (SCADA)

Power System Operation and ControlEEE-4875

Presented by

Towfiqur RahmanET091010

8th Semester

OBJECTIVES:

• To discuss the concept of SCADA and its branches• Protection for SCADA • Future of SCADA

INDEX TERMS:

1. Definition

2. Main Functions of SCADA

3. Controlling Process

4. Components of SCADA

7. SCADA architectures

8. Security issues

9. Future of SCADA system

WHAT IS SCADA?

SCADA stands Supervisory Control and Data Acquisition. As the name indicates, it is not a full control system, but rather focuses on the supervisory level. It is a computer system for gathering and analyzing real time data.

SCADA systems can be relatively simple, such as one that monitors environmental conditions of a small office building, or incredibly complex, such as a system that monitors all the activity in a nuclear power plant or the activity of a municipal water system.

SCADA systems are used to monitor and control a plant or equipment in industries such as telecommunications, water and waste control, energy, oil and gas refining and transportation. A SCADA system gathers information, such as where a leak on a pipeline has occurred, transfers the information back to a central site, alerting the home station that the leak has occurred, carrying out necessary analysis and control, such as determining if the leak is critical, and displaying the information in a logical and organized fashion.

OVERVIEW OF SCADA SYSTEM:

MAIN FUNCTIONS OF SCADA:

• Data acquisition, • Alarms and event monitoring, • Database and data logging, • Operator interface, • Non real time control, • Logging, • MMI (men- machine interface) use, • Automation, and • Report generation

CONTROLLING PROCESSES :

• Industrial processes include those of manufacturing, production, power generation, fabrication, and refining, and may run in continuous, batch, repetitive, or discrete modes.

• Infrastructure processes may be public or private, and include water treatment and distribution, wastewater collection and treatment, oil and gas pipelines, electrical power transmission and distribution, wind farms and large communication systems.

• Facility processes occur both in public facilities and private ones, including buildings, airports, ships, and space stations. They monitor and control HVAC, access, and energy consumption

COMPONENTS OF SCADA

o HMI (Human Machine Interface): It is an apparatus that is operated by human to monitor and control various processes.

o PLC (Programmable Logic Controller): This controller is used because they are very flexible, and economical than Remote Terminal Units

o Supervisory System: It collects process data and sends control commands to the process.

o RTU (Remote Terminal Units): This process is connected with sensors to convert sensor signals into digital and sends digital data to Supervisory System

o Communication Infrastructure: It is connecting Supervisory System to RLU’s.

SCADA architectures:SCADA systems have evolved in parallel with the growth and sophistication of modern computing technology. The following sections will provide a description of the following three generations of SCADA systems:

I. First generation: Monolithic II. Second generation: DistributedIII. Third generation: Networked

First generation: Monolithic System; when SCADA systems were first developed, the concept of computing in general centered on “mainframe” systems. Networks were generally non-existent, and each centralized system stood alone. As a result, SCADA systems were standalone systems with virtually no connectivity to other systems. Wide Area Networks were later designed by RTU vendors to communicate with the RTU. The communication protocols used were often proprietary at that time. The first-generation SCADA system was redundant since a back-up mainframe system was connected at the bus level and was used in the event of failure of the primary mainframe.

Model of Monolithic System:

Second generation: Distributed; the next generation of SCADA systems took advantage of developments and improvement in system miniaturization and Local Area Networking (LAN) technology to distribute the processing across multiple systems. Multiple stations, each with a specific function, were connected to a LAN and shared information with each other in real-time. These stations were typically of the mini-computer class, smaller and less expensive than their first generation processors.

Model of Distributed System:

Third generation: Networked; The current generation of SCADA master station architecture is closely related to that of the second generation, with the primary difference being that of an open system architecture rather than a vendor controlled, proprietary environment. There are still multiple networked systems, sharing master station functions. There are still RTUs utilizing protocols that are vendor-proprietary. The major improvement in the third generation is that of opening the system architecture, utilizing open standards and protocols and making it possible to distribute SCADA functionality across a WAN and not just a LAN.

Model of Networked System:

SECURITY ISSUES:

The following are TSI’s (The Security Institute, a United Kingdom based professional body for security professionals) recommendations to address some lingering security issues for SCADA:

1. Security of network communications: Implementation of strong encryption over the SCADA network communications, to ensure that both monitored data and control commands are encrypted.

2. Turning on security: Implementation of security features with devices on the network, especially authentication. Using secure protocols whenever possible.

3. Knowing your SCADA network: Identifying all connections to external networks including wire-less networks, corporate LANs and WANs, and the Internet. Also, securing the network by eliminating all unnecessary connections to external networks.

4. Hardening of the SCADA environment: Removing all unnecessary services from the hosts on the network. Also, just as in the corporate network environment, ensuring that all systems are patched and up to date.

5. Conducting regular security audits: Ensuring that security practices and procedures, such as incident response, are defined and implemented. Penetration testing of the network environment should also be prudently conducted with inspection for potential back doors into the SCADA network.

6. Implementing real-time threat protection: With the increasing number and complexity of attacks, it's insufficient to simply patch the systems or maintain access/service control. One alternative is to implement real-time threat protection in the form of network intrusion-prevention systems. Unlike standard packet-filter firewalls, these systems perform application-layer inspection to identify attacks that are carried in the payload and block the offending traffic in real time.

THE FUTURE OF SCADA SYSTEM:

The large territories and huge volumes of data SCADA can handle form a formidable combination. Today’s SCADA systems can manage anything from a few thousands to one million of input/output channels. The technology is still evolving in terms of sophistication as well. SCADA systems as they are now can perform a large variety of tasks and some systems have artificial intelligence built into them. They are also more network-enabled, thus paving the way for voice-data-control data convergence. With proper planning and a custom-made installation, a SCADA system becomes a valuable asset.

THANK YOU ALL