160 likes | 364 Views
Application of a RTU for load tap changer monitoring and control. ECE 504 Alejandro Schnakofsky Raleigh, NC. Content. Motivation and objectives What is an RTU What is a load tap changer Components The DNP3 protocol Signal list Functionality Demo. Motivation and objectives.
E N D
Application of a RTU for load tap changer monitoring and control ECE 504 Alejandro Schnakofsky Raleigh, NC
Content • Motivation and objectives • What is an RTU • What is a load tap changer • Components • The DNP3 protocol • Signal list • Functionality • Demo
Motivation and objectives • Learn about RTUs and their application • Program RTU to: • Monitor LTC • Control LTC • Serve LTC data via a communication protocol • Automatic voltage adjustment logic
What is an RTU? • A remote terminal unit is a device that collects information regarding a process • Voltage • Current • Status indications (position of a breaker) • It then reports that information to a higher level system such as SCADA, DCS, etc
What is an RTU? • Inputs: • Binary • mA • RTD • Outputs: • mA • Contact • Communications: • DNP • Modbus • IEC61850 • Profibus • Spa • RS232 • RS485 • Modem • Ethernet
What is Load Tap Changer? • Load tap changer is a device that has the capability of changing the turns ratio of a transformer or auto transformer • By varying the turns ratio the voltage at the load terminal can be adjusted.
What is Load Tap Changer? • Load tap changer is a device that has the capability of changing the turns ratio of a transformer or auto transformer • By varying the turns ratio the voltage at the load terminal can be adjusted.
Components • ABB RTU 560 • Binary input card • mA input card • Binary output card • DNP protocol and PLC licenses • Howard Industries SVR-1 voltage regulator • ASE2000 DNP protocol test set • Laptop
The DNP3 protocol • A master-slave protocol for data acquisition and control applications • 3 Layers • Link • Transport • Application • Functions • Read • Select • Operate
The DNP3 protocol • Data is divided into objects • Object 1: binary inputs • Object 30: analog inputs • Object 60: class data • Object 12: operate relay • Several indexes inside objects representing data
Functionality • Report status signals via DNP3 • Handle commands from DNP3 • Handle commands from local interface • Local/Remote Logic • Auto/Manual Logic • Determine tap position • Automatic tap change logic • WebHMI interface to easily view status information of tap changer