As technology advances and network capabilities increase, we’ve seen a great deal of change in the technology that utilities can use to monitor their electrical networks. Now, utilities have access to data that allows them to be proactive rather than reactive to their ever-changing requirements.
While kiosk transformers have a raft of expensive (and in some cases less than specifically designed) transformer monitoring options, with pole top distribution transformers, traditionally the only monitoring available was via an analogue maximum demand indicator (MDI).
As standard the MDI was mounted up the pole close to the transformer and only had its reading taken when crew were available to visually take a reading and reset the unit.
This single or three phase device only gives one maximum demand current indication that happened sometime between when it was last reset and the time the reading was taken.
Then came the electronic maximum demand indicator (eMDI). This device is solar powered with three phase current connections (via split core current transformers), recording data such as minimum, maximum and average current; transformer temperature; and ambient temperature.
The eMDI utilises driveby wireless data download, and can store up to two years worth of data at ten minute intervals. The eMDI has operated on the Australian electricity network since 2012.
The next development in distribution transformer monitoring came from WF Energy Controls, in the form of the AM10. This device is an asset management tool designed specifically to monitor kiosk and pole top transformers, with a reference to voltage, current and temperature.
The device can record and display voltage, current, voltage unbalance, power factor, frequency, sag/swell, harmonics to the 32nd harmonic, THD, phase angle and two temperatures.
Connecting directly to the transformer for voltage, the current connections can be via the existing current transformers (CTs), split core CTs or Rogowski coils.
The transformer temperature sensors are easy to install, using a magnet. The Rogowski option is preferred by many utilities for the ease of retrofitting where there are no insitu CTs available and space is tight.
The most recent iteration of the AM10, the PAM10 (pole asset manager) is a pole top mounted transformer monitoring device, especially developed for pole top applications, housed in an IP65 slim line discreet enclosure.
The PAM10 has Rogowski or CT input, with 3G and wifi comms and voltage input directly or via a voltage transformer. The device measures, monitors and records voltage, current, frequency, harmonics, THD, power, power factor, phase angle, voltage unbalances, transformer and ambient temperature and more.
This device is due for release in June 2016 and utilises the same RPMS management software also available fromWF Energy Controls.
Key benefits of the WF Energy Controls distribution transformer monitors include:
- The eMDI is a simple, solar powered device with easy drive by communications that provides considerably more data than traditional analogue MDIs
- The AM10 records large amounts of annual profile data for a range of sites, and with 3G communications, it’s a powerful device that can quickly add a lot of value to the network
- Both devices are compact and purpose built with inbuilt communications, transformer and ambient temperature monitoring
- RPMS software is available to enhance the reporting of the data and more importantly to make better decisions about network assets.
WF Energy Controls is a privatelyowned company specialising in the design and manufacture of current and voltage transformers for the low to medium voltage electrical industry. Based in Sydney, NSW, WF Energy Controls supply network and electric companies worldwide.
For more information visit www.wfenergycontrols.com.au or phone 1300 665 374.