Utility of SCADA in Power Generation and Distribution System M.L.Dewal
Kalpana Saini
Assistant Professor, Deptt.of EED. lIT Roorkee Roorkee, India
[email protected]
Research Scholar, Deptt.of EED. lIT Roorkee Roorkee, India
[email protected]
Rajeev Kumar Senior Lecturer, Deptt.of ICE dept. GCET Greater Noida, India
[email protected]
Abstract- SCADA is an acronym for Supervisory Control and
the reservoir), transfers the information back to a central site, then alerts the home station that the water level is going up or down, carrying out necessary analysis and control, such as determining if the water level is critical, and displaying the information in a logical and organized fashion. These systems can be relatively simple, such as one that monitors environmental conditions of a small office building, or very 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 consist of: One or more field data interface devices, usually RTUs, or PLCs, which interface to Field sensing devices and local control switchboxes and valve actuators A communications system used to transfer data between field data interface devices and control units and the computers in the SCADA central host. The system can be radio, telephone, cable, satellite, etc., or any combination of these. A central host computer server or servers (sometimes called a SCADA Center, master station, or Master Terminal Unit (MTU) A collection of standard and/or custom software [sometimes called Human Machine Interface (HMI) software or Man Machine Interface (MMI) software] systems used to provide the SCADA central host and operator terminal application, support the communications system, and monitor and control remotely located field data interface devices. Supervisory control and data acquisition (SCADA) allows a utility operator to monitor and control processes that are distributed among various remote sites. The goal of this paper is to develop a management paper work that uses existing probabilistic control of production methodology to quantify the Number of panel of the plant to production utility SCADA systems. This system also useful to save the natural source of electrical energy like water, coal, gas etc. SCADA system owners bear the ultimate responsibility for protecting what they manage. They have participated in vulnerability assessments, have made improvements and continue to do so. Through vulnerability assessments and responding to research questions, they also provide the information that gives direction for other stakeholders. Typical control system architecture of power systems is given in Figure 1. The vertical hierarchical architecture of the information system closely mirrors the hierarchical structure of the classical power grid. If present day SCADA
Data Acquisition. SCADA systems are used to monitor and control
a
plant
or
equipment
in
industries
such
as
telecommunications, water and waste control, energy. A typical SCADA system comprises of 1/0 signal hardware, Controllers, software, network & communication. Supervisory control and data acquisition system is a system in which message or commands that are individual are sends to the external world. Provides a host control functions for the supervisor to control and define settings. The basic natural sources like Coal, gas, Diesel, atomic etc are single time useable due to which the quantity of these sources is decreases day by day. The emissions of these fuels
•
are also responsible for air pollution. On the other hand if we use the water power and solar power to generate the electricity. We can reduce the pollution as well as the generation cost of
•
the energy. The quantity of the water is varies in the rivers according to the season and the sunlight intensity is vary according to the day hours. So we have developed a system in which consumers are connected to different type of power plant via a grid. The grid load and plants are monitored and controlled
by
the
SCADA
system.
This
provides
•
the
uninterrupted power supply at minimum power generation cost.
•
Keywords-controllers; data acquisition; supervisory; atomic
I.
INTRODUCTION
To meet increased demands of energy as well as requirements of preservation of our environment and natural resources future utilities have to incorporate Renewable Energy Resources (RES) and Distributed Generation (DG) to a much greater degree than today. Furthermore, due to deregulations and increased dependability, the energy systems of today show an increased brittleness. To cope with the combinations of needed flexibility and increasing brittleness new kinds of supporting information infrastructures and intelligent components of future energy systems are presently investigated. [3] SCADA (Supervisory Control and Data Acquisition) system is an automation field. SCADA system was being used in industries to Control easily and simply. These systems encompass the transfer of data between a SCADA central host computer and a number of Remote Terminal Units (RTUs) and/or Programmable Logic Controllers (PLCs), and the central host and the operator terminals. A SCADA system gathers information (such as how is a water level in
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understanding the demand and helpful to develop an economic power generation plant. This power generation and distribution system (PGDS) is consists of three power generation plants (Hydro, thermal and solar power plant) and consumers. Here the generation capacities of these plants are hydro power plant (50MW), Thermal power plant (50 MW) and solar power plant (50MW) and the maximum load on the grid is 125 MW. All three power generation plants are connected to each other as well as to the consumers by a Ring Main system. Ring main system is an electrical supply serving a series of consumers and returning to the original source, that each consumer has an alternative path in the event of a failure. Ring main system is a system which provides the uninterrupted power supply at low cost.
systems were as simple as Figure 1 suggests, the vulnerabilities would be limited. But in reality, SCADA networks are intertwined with cooperate networks, vendor connections, business partner connections, related websites, accounting and business process applications, and corporate databases. In practice, most SCADA systems live in a messy world of interdependent information systems. Access to SCADA networks has steadily grown as productivity needs have increased, the number of business partners has grown, and the ease of networking has prompted public utilities, energy companies, and power operators to connect everything to else. Communication has improved efficiency and lowered costs, but it has also opened SCADA to network intrusion. It has added more vulnerability to the infrastructures it was designed to enhance.
• Figure I. Standard control system architecture (SCADA) of power systems and its components consisting of computers, networks, databases, Remote Terminal Units (RTUs),and software.
Figure 2. Ring main Power grid system
A.
The focus of the paper is to introduce the dependability of the ring main system on SCADA systems. The small power generation station like hydro, thermal, solar and wind are connected to the consumers by a grid. To maintain uninterrupted power supply at low cost to the consumers the power generation should be according to the power demand and try to generate electricity by renewal energy source like solar or hydro of this system. The monitoring and controlling of this complete grid and power generation plants have done by SCADA System. During 2003 at least three major power-system blackouts happened in August-September, that is, the blackouts in US - Canada, Italy, and Sweden - Denmark. But this system is consists of more than one sending end and SCADA system collect and report the supporting information to enable new energy based business process and grid protections. II.
Hardeare
As shown in fig. 2 we connect all the plant!, plant2, plant3 and consumer!, consumer2, consumer3, consumer4, consumer5 by a ring grid. This system is called the ring main system. Through the Ring main system we can connect more then one plant to a single grid. Ring main system also provides two receiving end to the consumers that's why this system is more reliable to provide un interrupted power supply to the consumers. when any one of the fault occur at the grid then only that particular part may be isolated without any power un interruption to the other consumers. Here we develop a hardware in which three plants are installed. Each plant is the combination of one motor and one generator. Motors are supplied by input and it works as a prime mover for the respectively generator and generator supply to the bulb. Also there are three blue bulb (B[, B2, B3) connected to the generators or plant respectively. This blue bulb shows the status of the respective plant for example if the bulb B[ is glow it means respective Plant! is running. A set of three read bulb (b[, b2, and b3) also setup and shows the plants output or total input to the ring main Grid.
EXPERIMENTAL SET-UP
monitoring power distribution and generation system. Also provide unit sharing operation which provide the unit maintenance without un- interruption in the power generation. This paper may assist decision makers in
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B.
Software
displays of present water level in the reservoir and the site temperature. To show these parameters there are six box labeled WLR, SVW, ETV and TSPV. WLR shows the current water level in the reservoir, SVW set point value of water level in the reservoir. ETV represents the environmental temperature, and STY (set temperature value) and TSPV shows the temperature set-point value set by the administrator. There are also three displays labeled Tpl, Tp2 and TP3. TPI, Tp2 and TP3 show the time duration for which hydro power plant, solar power plant and thermal power plant was running respectively. There is two another indicators in the monitor room labeled as OLI (Over load indicator), ULI (Under Load Indicator) and LTV (Low Temperature Value). The complete experimental setup has hardware PLC, and SCADA software as shown in fig 4.
We have used two software, one is PLC software RSlogix500 (by Rockwell) and other is SCADA RSview32 (by Rockwell). RSView32 [10] is an integrated Human Machine Interface
for monitoring and controlling automation machines and processes. Its versatility shows with seamless integration to other Rockwell Software and Microsoft products as well as third-party applications. RSView32 have distinctive features: i. Powerful graphics editor. ii. Graphic import/export wizard. iii. Customize the look of graphic displays. iv. Comprehensive alarms editor. v. Full-featured data log editor. vi. Sophisticated logic and control editor. RSLogixSOO [11] was the first PLC programming software
to offer unbeatable productivity with an industry-leading user interface. RS Logix 500 comes in two editions: a Standard edition that provides basic ladder logic editing functions, and a Professional edition that provides additional functions to expand your automation solutions and make editing ladder logic simple. i. Microsoft Visual Basic for Applications support. ii. Custom Graphical Monitor. iii. Editing project databases using Microsoft Excel. iii. Logic Trace. .I" xl
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Figure4. Experimental Set-Up
1000
III.
PGDS SYSTEM OPERATION
First The PGDS system for performing the operation is the combination of hardware and the software programming which we have done. There are many sensors and relays are connected to detect failure or plant, Over Load, under load, water level, solar intensity etc. If there is over load is appear on the grid then over load relay will be activate and RTU send the information to the master. Master performs data processing and sends the control command to the RTU to start power generation
�o 00
Figure3. Window representing the controlling and monitoring
accordingly and also activates the respective alarm. There is a provision for administrator of SCADA that it will use the spare unit with the other two main units for generation. For this task there is a different programming of PLC. If the low load is appear on the grid then under load relay will be activated and RTU send the information to the master. Master performs data processing and sends the control command to the RTU to shot down the power generation accordingly and also activates the respective alarm.
We deign a window for above hardware to controlling the operation and monitoring plants output. In control room there are controlling switches start I, start 2 and start 3 to start the plant.I, plant.2, plant.3 respectively. Switch Em. Start is for starting all the units at a time. Similarly Em. Stop switch is to stop the complete plant. If an operator start these units manually from then we also provide facility to the Manager to stop any one or all units by STOP 1, STOP 2 and STOP 3 switches respectively. Through these switches administrator can over ride the plant from the control room. We also provide a monitoring room where
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Indicator) and LTV (Low Solar/Temperature Value). The complete experimental setup When the ULI indicator ON and LTV OFF (it means the grid load is low and the solar intensity is normal) then Solar power plant is only running and the other hydro power plant and thermal power plant remain OFF i.e. the grid input is 50% of the normal input as shown in table 1. During 12:0- 3:0PM When both OLI, ULI indicators are OFF and ETV is less then equal to STV and WLR is greater than equal to SVW (it means grid normal load appear on the grid and the solar intensity is normal ) then solar power Plant and hydro power plant will run and the thermal plant remain OFF .i.e. the grid input is 100% of the normal input as shown in table 1. During 9:0- 12:0AM When the grid load is minor grater then the normal load (i.e. load is 125% of the normal load )and WLR is greater than equal to SVW and the solar intensity is low (solar plant is not running with full capacity), then thermal plant must be start with the solar and hydro power plant as shown in table.1 during 6:0- 9:0 AM. Tablel shows the results. As far as there is normal Demand than any two of three units are ON and one of these remains OFF.
When there is requirement of more generation. If such type of condition occurs than the spare unit works with all other two main units. Two main units working as it is but with the combination of an extra unit just for increasing the generation. The two operations are independent of each other. According to requirement operation shifts intelligently from one state to other. When due to fault or any other reason any one of the plant is shut down and interrupt the generation, SCADA will starts the spare unit So that uninterrupted generation will be achieved and isolate the shutdown plant. As shown in below fig.5. There are six power transistor and solar plant, hydro plant, thermal plant all the three power generation plants connected to the RTU. Field relayl, field relay 2, field relay3 gives the information to the RTU that the solar plant, hydro plant, thermal plant are in shut down or start condition. Power transistors are work as a Isolated switch in the system which are mounted on the hardware.
Power Transistor 1
Table I. Operation of generation plant according to solar intensity, water level,and Demand.
Power Transistor 2
Time 0:0-3:0
Power Transistor 3
Solar
Water
Intensity
level
NiIl
Norm.
NiIl
Norm.
Low
Norm.
Solar
Hydro
Thermal
Plant
Plant
Plant
Low
OFF
ON
OFF
Low
OFF
ON
OFF
ON
ON
ON
ON
ON
OFF
ON
OFF
OFF
Demand
AM 3:0-6:0
AM 6:0-9:0
AM
Power Transistor 4
9:0-12:0
Minor High
Norm.
High
Norm.
Low
Low
Norm.
High
ON
ON
ON
NiIl
Norm.
Norm.
OFF
ON
ON
NiIl
Low
Low
OFF
ON
OFF
Norm
AM 12:0-3:0
Low
PM 3:0-6:0
PM
Power Transistor 5
6:0-9:0
PM 9:0-12:0
PM
Power Transistor 6
Figure5. Block diagram for operation of Power Generation Plants
IV.
RESULTS
There are two another indicators in the monitor room labeled as OLI (Over load indicator), ULI (Under Load
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a smart way, i.e. it decrease the power generation cost. In this paper we also concentrate the utilization of the river water and solar energy for power generation and save the other natural source of Energy like Coal, Desiel, Gas, Nuclear fuel etc also control the air polution as well as the water pollution. The additioanal advantage is that there is a monitoring with controlling. So authority user may change the control settings according to reqiurement.
Saving of fuel in production according to water level, Solar Intensityl temperature and demand 140 120 100 80 60 40 20 0
o Demand (MW) • Solar plant O/P in (%)
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