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Who's Watching your load?

Hardware    Software

For most utilities, measuring the amount of electrical current from discrete points within their distribution grid is a significant undertaking.  Despite the fact that most distribution substations are instrumented with Supervisory Control And Data Acquisition (SCADA) systems that measure electrical current (“the load”), virtually no measurement of the load occurs downstream of the SCADA system except at the customer’s meter located on the side of their house or business.  Even then, demand side meter readings are most often only monthly. This presents the utility with a large operational unknown, mainly, “…is the interconnected equipment located between the substation and the customer’s meter overloaded at any time, especially under high load conditions?”  The other side of the issue is very important as well, “is there large excess capacity (over-engineering) at the peak load time?”

Historically, monitoring the distribution load downstream of the SCADA point has been economically and technically challenging.  Conventional methods to measure electrical current on overhead electrical lines use iron core instrument transformers which are difficult to mount, have significant size and weight (which increase as the applied voltage increases), and can present safety constraints to personnel as well as interconnected equipment.  The physical hazards associated with conventional iron-core devices, when coupled with the complexity of installation, have typically precluded their use within medium-voltage distribution systems.

Airak, Inc. of Ashburn, Virginia has developed a small optical current sensor (OCS) that  is economical for electrical distribution monitoring.  The OCS is a significant improvement over conventional iron-core instrument transformers or Rogowski coils, and offers a number of major advantages:

Ö       Safe and easy to install on energized overhead lines

Ö       Small and lightweight, independent of the applied system voltage

Ö       Increased dynamic range and bandwidth

Ö       Zero risk of explosive failure

Ö       Elimination of ferroresonance

Ö       Elimination of open-secondary electrocution

Ö       Far less cost than alternatives.

Find out more about the visualization software by clicking here

Find out more about the hardware that make it happen by clicking here

Page Modified Wednesday August 01, 2007