DESCRIPTION / METHODOLOGY

The working process of the IDAS is initiating from the measurement of water flow before entering into the dam. The Controlling mechanism of the dam is to monitor and control the gate channel for delivering the water. The system is also used to determine the water level, flow rate, temperature of the dam. The entire process is enhanced with automation control by using PLC and DCS monitoring system comprised with SCADA to get centralized control.

Process Implementation in single dam:

The gate valve of all channels of the dam is interfaced using a stepper motor drive of PLC module. By using stepper motor drive, it is possible to get very précised positioning of the gate valve of the dam. The drive system also has a better feedback circuit, which improves the further precisión of the motor drive. Automation control made by encoding the ladder logic program to the stepper drive using HMI to the system. The gate valve opening and closing is done by a regular interval of a frequency which is in response to the availability of water level in the dam. This helps the system to be always under precise control using ultímate automation interface. The output devices of sensors uséd for detection of level of water, pressure, water flow rate and temperature are also interfaced with the PLC controller unit. The PLC controller unit is corresponded with a datábase that interfaced with DCS and it also receives triggering signal from the centralized SCADA control área.

Input system: Input modules examine the state of physical quantities and input devices like flow, level sensors give input signáis to the DCS through the PLC controlling unit and DCS. The PLC can take a number of input ranges from the channels of the dam. The number of input devices depends on the number of channels present in the dam. All the dam gate valve channel is provided with an indicator light to show if the particular input is ON or OFF.

Output system: The control signáis fed from PLC system is sent to the motor drive through DCS o/p module. The output also be interfaced with DCS to get continuous process feedback and to enhance changes in the operation of the dam at an emergency time. The output system also supported with interrupt HMI to control the function of the system.

The DCS system is used to study the continuous performance of the dam, respectively with the effective measurement of level of water and its flow rate. Various sensors interfaced with DCS to get exact output in digital means from various analog signáis. The default setup to be installed with the DCS system, which rapidly takes care of the performance of the PLC controlling unit. The important reason for using DCS is that well suited to have a combinational automation system with PLC. It also able to easily adapt with the desired PLC controlling system. The DCS system also enabled the generation of frequent datábase regarding the functional quality of the dam and its important parameters. The operational flow of single dam implementation is shown in Fig 2..

Tools Description

The different tools to be used for this automation design are

• Programmable Logic Controller (PLC) '

• Distributive Control System (DCS)

• Supervisory Control and Data Acquisition System (SCADA) These subsystem of the process will be discussed as follow,

Programmable Logic Controller (PLC)

Control engineering has evolved over time. In the past humans were the main methods for controlling a system. More recently electricity has been used for control and early electrical control was based on relays. These relays allow power to be switched on and off without a mechanical switch. It is common to use relays to make simple logicál control decisions.

The development of low cost computer has brought the most recent revolution, the Programmable Logic Controller (PLC). PLCs have been gaining popularity on the factory floor añd will probably remain predominant for some time to come. Most of this is because of the advantages théy offer,

• Cost effective for controlling complex systems.

• Flexible and can be reapplied to control other systems quickly and easily.

• Computational abilities allow more sophisticated control.
• Troubleshooting aids make programming easier and reduce downtime.

• Reliable components make these likely to opérate for years before failure.

The system of PLC is fíxed with the input and output devices to control the channel shutter valve open/close sequence in proper manner with feedback of water level sensor valúes.

The water level could be measured using ultrasonic water level sensor ,which predominantly determines the level of water in very accurate manner. The shutter valve which incorporated with stepper drive of high torque transmission to withstand the load capacity of dam shutter gate valve.

Distt ibutive Control System (DCS)

A distributed control system (DCS) refers to a control system usually of a manufacturing system, process or any kind of dynamic system, in which the controller elements are not central in location (like the brain) but are distributed throughout the system with each component sub-system controlled by one or more controllers. The entire system of controllers is connected by networks for communication and monitoring. DCS is a very broad term used in a automation system, to monitor and control distributed equipment. Likely, in this IDAS system the input/output devices and its setup are mutually connected to DCS for the real time control by centralized SCADA system.

A DCS typically uses custom designed processors as controllers and uses both proprietary interconnections and Communications protocol for communication. The processor receives information from input modules and sends information to output modules. The input modules receive information from input instruments in the process (or field) and transmit instructions to the output instruments in the field. Computer buses or electrical buses connect the processor and modules through multiplexer or demultiplexers. Buses also connect the distributed controllers with the central controller and finally to the remote station Human-machine interface (HMI) or to the fnaster SCADA system.

Supervisory Control and Data Acquisition (SCADA)

The SCADA system is the centralized master unit from which the signáis to be transferred to DCS of remote unit and also receive the Uve status of operation of remote dam system. The communication is carried through satellite based or through cable system. The monitoring and signal processing for different dam at different places is to be evaluated by this master SCADA system. The overall structure of a SCADA system being supported with following setups, ( Shown in Fig 1)

• Field instrumentation

• PLCs and / or RTUs

• Communications networks

• SCADA host software

The IDAS is a setup to control and monitor two or many dams located at different places. The integration of various dams could be possible by trans-receiving the data and controlling signáis between main centralized controlling station and individual dam automation system. The DCS of each dam unit will be collectively integrated with the SCADA system at the control station. The SCADA system will also command the DCS to the controlling program to the PLC controller unit. The signáis regarding various parameters and condition of operation of the dams aré transmitted to centralized system by means of satellite communication likely GPRS or GSM. The signáis before transmitting to the central controlling system and after receiving at each dam, they are processed under the concept of digital signal processing (DSP) system. The DSP of the corresponding signáis, which help to transmit the signal to a longer range of distance with more accuracy. Each individual dam systems also assisted with a feedback of level of water, which initially decides the operation condition of the dam. The receiver end present in each dam system will actúate by triggering signal and triggering module fixed at each dam system for its individual working. The integrated system is briefed in Fig 3.

CLAIMS

Claim 1: We Claim, The invention is "Integrated Dam Automation System", which is proposed design to achieve ultímate automation technology in Dam/Reservoir monitoring and control system.

Claim 2: As per Claim 1, the system is an automation technology to reduce water wastage through various calamities of nature and to ensure safety with high level maintenance of Dam.
Claim 3: In reference with Claim 1 and Claim 2, the system supported with tools like Programmable Logic Controller (PLC), Distributed Control System (DCS) and Supervisory Control and Data Acquisition (SCADA) technology to attain best monitoring and automation system of Dam.

Claim 4: This automation system may créate a new field technique in the water resource management sector to regúlate the available water resource in a very useful way, that results to the welfare of public Uves.

Claim 5: The controlling of Dam system through automation technology will always needs the complete detail about the live status of the dam to update its controlling signáis , and so the invention is to be assisted with complete monitoring system via Distributed Control System (DCS) and Supervisory Control and Data Acquisition (SCADA).

Claim 6: From Claim 3,the PLC is master controller for operation of dam gate valve automatic open/close sequence with stepper drive to withstand load capacity , where the PLC module will be totally feed with the controlling ladder logics.

Claim 7: As we claimed the Integration in Claim 1, our project is for the control and monitoring of various dams situated at different places with in contact of a single integrated station, from which the controlling signáis to different dams is carried and live monitoring of those dams also received at the integrated station.

Claim 8: In assurance to the Claim 7, The integration of the dam automation system is possible by high bandwidth of digital signal processing and satellite communication methodology.

Claim 9: The system of this invention of centralized dam system develops surface water distribution in a rapid manner and even during summer season.