Application Background Printer Friendly Version
Electricity Utility companies need to monitor the high voltage transmission towers for several reasons.
There is often a need or desire to monitor the transmission voltages and currents to assist with the management of the transmission network.
There may also be a need to monitor the physical stability of the tower by using accelerometers or some other seismic instrument which may measure earth tremors, and any local condition which causes instability, for example high winds, floods or perhaps vandals damaging the structure.
There are some circumstances where vandals damage the towers by removing / stealing parts of the structure to be sold as scrap metal. Aluminum may be stolen and copper especially is often stolen as it is a valuable metal.
As well as sensors it may be desirable to have some level of video surveillance.
Unidata has received many requests for enhanced remote monitoring with images for remote measurement industrial equipment Such requests are driven by the need to see what is happening on the sites to confirm measurement instrument readings, and to have a regular, perhaps daily, image of the tower base to check for any damage.
The ambient weather conditions can also be measured, especially the wind speed and direction and this measurement can be achieved simply with a modern ultrasonic weather transmitter, which does not have any moving parts.
The voltage and current monitoring application is routine, and can be accomplished using a direct connection to conductors to measure the voltage or by measuring the field effect surrounding a high voltage conductor. For the direct connection there are many instruments designed to measure direct voltages, however installation of such devices required special safety planning which may be difficult.
For the field effect method, there is no direct connection to the conductor required. The higher the voltage on the conductor, the stronger the field and the greater distance from which it can be detected, for example a typical overhead distribution line at 11,000 volts and 11 meters up in the air, the average electric field strength beneath the line would be 11,000 volts / 11 meters or about 1000 volts/meter. There are many other factors affecting the measurement but the example illustrated the process.
The tower stability can be measured using any general purpose accelerometer, which detects small movements in the tower structure. If the tower is in a region prone to earthquakes, seismic instrument can be added to monitor earth movements.
To monitor the any vandals stealing metal parts, a low resolution video camera or cameras can be added to take a photograph of the structure every hour as a permanent record of the structure, to be available for engineers at a central location to view routinely to check for any damage to the structure.
All of the instruments can be used together to determine the stability of the structure, for example a brief disturbance in the structure would be recorded by the accelerometer and the data from all the sensors can be correlated to determine the likely cause. All of the instruments would be mounted on the tower structure, along with a small solar panel and backup battery so the power system remained independent.
A Neon Remote Terminal would be connected to the sensors via SDI 12, Modbus and or Analog and digital inputs, along with a choice of cell phone or satellite modem equipment, to scan the instruments and check for any unusual out of limits readings and also routinely send the data to a central Neon Server at the headquarters of the electricity utility for display on a web browser. The data could also be sent, perhaps once per minute, via web services or FTP to other processing systems for example to the main SCADA system used by the electricity utility.
|Options for Application Specific Instruments / Inputs||Unidata Part Number||Description|
|Vaisala Weather Transmitter WXT520 measures barometric pressure, humidity, precipitation, temperature and wind speed & direction||6501V-H||Vaisala Weather Transmitter RS232/422/485 SDI-12|
|Field Effect Voltage Sensors||Various||Analog or Digital Outputs|
|Accelometers||Various||Analog or Digital Outputs|
|Small Power Monitor RTU||Various||Modbus Output Field Effect Meters|
|Seismic Instrument||Various||Analog or Digital Outputs|
|RS232 Camera with 3G NRT||2502A-3E-L||Neon Camera System with 3G NRT|
|Ethernet Camera||2502B||IP Camera|
|Options for Neon Telemetry - NRT / RTU / Field Units||Unidata Part Number||Description|
|Cellular RTU 3G||2013F-AB03||Neon Metering Module 3G with Antenna and Li Battery|
|Cellular RTU 4G||2013F-AB04||Neon Metering Module 4G with Antenna and Li Battery|
|Cellular RTU 3G - Industrial||2016F-AB03||Neon Remote Terminal 3G with Antenna and Li Battery|
|Cellular RTU 4G - Industrial||2016F-AB04||Neon Remote Terminal 4G with Antenna and Li Battery|
|Low Earth Orbit Satellite Globalstar||2015E-AB0||Neon Remote Terminal - Satellite Globalstar Modem with Antenna and three Li Batteries|
|Ethernet||2017E-0B0-1 or 3||NRT Ethernet with single or triple Ethernet Ports|
with three Li Batteries
|Equatorial Orbit Satellite - Inmarsat||2018E-AB0-1 or 3||NRT Ethernet with single or triple Ethernet Ports|
with three Li Batteries
|LCD Display||2500E||NRT LCD Display|
|NRT Field Termination Strip||2103F||2015E,2016F,2017E, and 2018E NRT FTS|
|NRT Firmware Option||2303A-8M||8M Extended Memory Option|
|NRT Firmware Option||2303A-8M-CAM||8M Extended Memory & Serial Camera Option|
|NRT Firmware Option||2303A-CAM||Serial Camera Option|
|Options for Neon Application Software - Customer Server||Unidata Part Number||Description|
|Neon Application Software||2302A||Neon Server Software Licence Incl 5 NAL |
|Neon Application Software||2302A-10||Additional 10 NRT Access Licences|
|Neon Application Software||2302A-20||Additional 20 NRT Access Licences|
|Neon Application Software||2302A-50||Additional 50 NRT Access Licences|
|Options for Neon Application Software - Unidata Server||Unidata Part Number||Description|
|Neon Application Software||2301A||Neon Data Initial Subscription Setup Fee|
|Neon Hosting Service||2301A-01||Neon Data Service Fee for 1-50 NRTs|
|Neon Hosting Service||2301A-02||Neon Data Service Fee for 51-100 NRTs|
|Neon Hosting Service||2301A-10||Neon Data Service Fee Metering|
|Options for Conventional Dataloggers / Field Units||Unidata Part Number||Description|
|Standards Starlogger||6004D-11||Red Logger 512K with Alkaline Battery|
|Display Starlogger||6004D-21||Blue Logger 512K with LCD and Alkaline Battery|
|Prologger||7001D-11||Green Logger 1M with LCD and Alkaline Battery|
|Starlogger Field Termination Strip||6103E||6004D FTS|
|Prologger Field Termination Strip||7100E||7001D FTS|
|Starlog V4 Management Software||6308A-AUE||Starlog V4 Full Licence Key|