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Polycast Metering CT/Bushing Assemblies Installed at Ontario Utility Substation Upgrade  

August 2014

One of Polycast’s 15 kV/110 kV BIL Instrument Transformer (CT)/bushing product designs was recently selected to retrofit one of Ontario’s major electrical substations. Polycast was chosen by the Ontario utility as the supplier for the project based on its ability to customize a solution to provide an Industry Canada approved revenue metering CT/bushing assembly that fit the existing tight and special bus structure requirements at the substation.

The Polycast CT/bushing assembly (pictured below) replaced the old Ferranti Packard assembly which was becoming susceptible to failure and had come to its’ end-of-life after over 40 years of service.

Hydro One Picture - Web

“Working with Polycast was a very positive experience. Their engineers were able to design a solution that was a great fit, given the circumstances, and went to all ends to try to meet our exact requirements”, commented the Utility’s Instrument Transformer Technical Specialist.

Based on the success of this installation Polycast is looking forward to future orders for similar revenue metering CT/bushing assemblies at other substations in Ontario and in other North American markets.

 

Polycast CT/Bushing Assembly used Globally in On-Line Fault Location System

For the past several years Manitoba Hydro’s HVDC Research Centre has been incorporating a low voltage air core CT/ bushing assembly manufactured by Polycast as part its dcLFL, an On-Line Fault Location System designed to find and repair faults in HVDC overhead power lines.

The dcLFL was initially developed for use on the Nelson River HVDC system in Manitoba. The Nelson River HVDC Transmission System, also known as the Manitoba Bipole, is an electric power transmission system of two high voltage, direct current lines in Manitoba, Canada, operated by Manitoba Hydro as part of the Nelson River Hydroelectric Project. Bipole 1 runs a distance of 895 kilometres (556 mi) with a maximum power of 1620 megawatts, and Bipole 2 transmission line runs 937 kilometres (582 mi) with a maximum power of 1800 MW.

When installed on an overhead HVDC transmission line, the dcLFL locates faults within 500 meters of its placement. Using a highly accurate GPS clock coupled with a custom-built electronic wavefront detector, the dcLFL transmits line fault information the moment the fault occurs, enabling rapid response by the utility.

Polycast’s CT/bushing assembly, which includes two low voltage bushings and a differentiating air core current transformer, provides linear response to primary current signal.

“The CT/bushing assembly manufactured by Polycast for the Line Fault Locator demonstrates how our diverse capabilities go well beyond traditional epoxy casting.” said Roman Gossow, Polycast’s Assistant General Manager. “We look forward to continuing to work with Manitoba Hydro on building and refining the design of the CT/bushing assembly to meet their current and future requirements.”

The dcLFL has been a success due to its effectiveness in detecting and reporting line faults and its use has expanded beyond Manitoba’s borders. Utilities in Malaysia, Australia, New Zealand, India and China are now using the dcLFL to effectively monitor their HVDC power lines.