Electric power generation, transmission and distribution: Electric utilities detect current flow and line voltage, to monitor the operation of circuit breakers, and to take sections of the power grid online or offline.
Buildings, facilities and environments: Facility managers use SCADA to control HVAC, refrigeration units, lighting and entry systems.
Manufacturing: manage parts inventories for just-in-time manufacturing, regulate industrial automation and robots, and monitor process and quality control.
Mass transit: regulate electricity to subways, trams and trolley buses; to automate traffic signals for rail systems; to track and locate trains and buses; and to control railroad crossing gates. Water and sewage: State and municipal water utilities use SCADA to monitor and regulate water flow, reservoir levels, pipe pressure and other factors. Traffic signals: regulates traffic lights, controls traffic flow and detects out-oforder signals.
SCADA control
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SCADA Systems for Power Grid
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A SCADA system performs four functions: 1. Data acquisition 2. Networked data communication 3. Data presentation 4. Control These functions are performed by three kinds of SCADA components: 1. Remote terminal units (RTUs) 2. Master Station / RCC (Region Control Center) 3. The data telecommunications network
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Example: Lamp indication(SCADA)
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SCADA - Other Advantage SCADA systems other advantage is the ability to limit the amount of data transferred between Master Station and RTU. This is done through a procedure known as exception reporting where specific data is sent only when the data changes that exceed the limit setting, such as the frequency value can only be changed if there is a change of 0.05 Hertz. if there is a change whose value is very small there will be no change in frequency. This is to anticipate the hysteresis properties of the system so that the actual frequency value can be read clearly.
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When operation is performed from Master Station, the first to do is confirm that the equipment selected is appropriate, followed by the selection of the operation to be performed. Master Station Operators in the action based on a procedure called the method "select before execute (SBXC)", as shown below: 1. Dispatchers at Master Station choosing RTU. 2. Dispatchers choose the equipment that will be operated. 3. Dispatchers sends the command. 4. Remote Terminal Units to know the equipment to be operated. 5. Remote Terminal Units perform the operation and send a signal back to the Master Station indicated by color changes on the VDU(Video Display Unit) screen and prints a message on the printer logging.
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If an interruption in the RTU, message will be sent from RTU that is misbehaving earlier to the Master Station, and the normal scan will be delayed long enough for Master Station prioritize messages and nuisance alarms turned on in order operators can take the necessary action as soon as possible.
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At other times, in most cases, the status of all equipment on the RTU can be monitored every 2 seconds, giving information system condition which is going on at the operator control center (RCC).
