A Greener Network with NOJA Power - Electrolink Cover Feature

26th May 2023

Pictured: The world's first backwards compatible recloser controller was installed in New Zealand!

As power distribution companies look to opening their networks to generation supplied from multiple renewable sources, one company has already developed an advanced auto-reclosing outdoor circuit breaker system to more effectively protect and control supply from 11kV to 38kV.

Designed from the ground up by a team of highly experienced engineers in Brisbane, the OSM recloser range from NOJA Power reduces the complexity and cost of connecting renewables to the grid and increases the hosting capacity of distribution networks utilising NOJA intelligent switchgear.

Distributed in New Zealand by OHUG, the new generation RC-20 recloser controller delivers economic gains while ensuring environmental and security protections required for distributed generation are met, says director Steve Rigby. By capturing high-resolution, real-time network data the RC-20 can provide protection, control, and monitoring solutions far in advance of a conventional SCADA system.

Rigby says this real-time management can also improve the reliability of any network by eliminating unplanned outages and cutting SAIDI and SAIFI penalties and lost revenue by up to 80 percent.

No toxic gases
While the electricity industry focuses on environmental concerns, NOJA Power is already more than one step ahead. Throughout its 20 years of innovation, Rigby says NOJA Power has not only designed its recloser range and VisiSwitch load break switch to support green generation, the company has also eliminated the use of SF6 as an insulating medium in these products.

Many manufacturers use SF6 in circuit breakers, transformers, ring main units and other high voltage products but, because SF6 creates highly toxic by-products, NOJA Power rejected its use from the outset and pioneered solid dielectric technology as a safer means of insulation.

Rigby says SF6 is also regarded as one of the worst greenhouse gases because a single kilogram of SF6 released into the atmosphere has the equivalent greenhouse effect of over 23.5 tonnes of CO2 and will remain active in the environment for up to 3,200 years.

He says the risks of using SF6 are amplified for operators and line crews where they can be exposed to toxic by-products during operational work and equipment maintenance. These by-products can form when the gas is exposed to arcing and include compounds such as highly cytotoxic disulfur decafluoride.

“By specifying NOJA products, network companies can take the practicable step of eliminating these long-standing health hazards from their workplaces. In doing so, they can reduce their carbon footprint while improving the control of their networks at the same time.”

Pictured: NOJA Power's new EcoLink is a live-tank single phase reclosing circuit breaker designed to replace fuses

Three products in one

Reclosers in the OSM series can be supplied from OHUG with a three phase, two-wire single phase, single phase earth return or single triple configuration. The latest RC-20 model is now available in either pole-mount or ground-mount options.

OHUG director, Nanette Russell, says the new ground-mount kiosk variant is proving very effective in large jobs where industrial demand is having an adverse effect on power quality. Russell says the cost of a NOJA installation is significantly lower than a traditional system because the primary and secondary systems are integrated in a single package. An RC-20 is in effect three products in one: a recloser, a full-featured sectionaliser to reduce the number of ICPs affected by an outage, and an automated load break switch.

“When you buy a RC-20 you can reconfigure it to operate as any one of these because all the technology is built in, and it's directional. It is a complete package including the relay.”

Russell says more network companies are using NOJA Power reclosers in bigger applications and are, for example, using a RC-20 on a pole as a recloser in one direction - but if the current is going the other way, they are using it as a sectionaliser.

“Legacy systems for medium voltage switchgear have met the basic needs of the past but lack the versatility, simplicity, safety and faultfinding capability engineers need to keep the lights on. The NOJA RC-20 delivers this and is also designed to automatically clear transient faults. It is the only solid, dielectric-insulated, autoreclosing circuit breaker with vacuum interruption and arc fault venting on the market, and it is scarily fast.”

Network design can also be simplified with a NOJA structure which reduces the number of pole spacing options required.

Installation costs are further reduced and safety is improved by having an RC-20 split system with the maintenance-free stainless steel tank up the pole and linked by a single heavily shielded cable to the controller cabinet down below.

All firmware developments are backwards compatible so innovations like synchro checking, broken conductor protection and admittance protection, can significantly extend the life of older OSM units by a decade or two simply by upgrading firmware in the controller to the latest versions at minimal cost.

Synchrophasor technology measures and transmits high-resolution PMU data to cloud storage via an integrated 4G modem and SIM card. This new technology allows engineers to access live, real-time distribution network data at a granularity a hundred times higher than traditional data acquisition methods such as SCADA.

Russell says as data and communication standards are evolving, NOJA Power solutions are keeping network owners ahead of the game and protecting their network operations with the highest level of encryption to protect the communications between the reclosers.

Pictured: To connect solar and wind farms, NOJA Power’s GMK (Ground Mount Kiosk) provides a high voltage circuit breaker, protection relay, power quality monitor, SCADA RTU, and interlocked earth switch - all in a pad-mount kiosk

“The units are super smart and exceptionally safe to install, operate and maintain. A live-line specific configuration is also available.”

To ensure continuous operation, the RC-20 also has a monitored and well-protected UPS onboard. She says OHUG supplies every RC-20 as a complete recloser solution in a box.

“In that box is the controller, tank, connecting cable and pole mounting frame - as well as arresters, bushing covers and everything to complete the installation.”

OHUG holds NOJA Power stock in New Zealand and provides all the support needed to ensure the successful implementation of a system.

Pictured: another NOJA Power installation on a solar energy farm. Eco-conscious, sustainable, and cost-effective technology are proving central to a growing industry, better yet when they go hand-in-hand - as seen on the cover of Electrolink Issue 155

Engineering support

NOJA Power Group managing director Neil O’Sullivan says the company’s entire focus is on developing the most advanced medium voltage pole mounted switchgear in the world.

“Every power utility in Australia has standardised on a NOJA Power solution and there are already over 100,000 NOJA Power reclosers deployed in 104 countries.”

O’Sullivan says NOJA Power is an engineer-rich technically skilled company focussed on continual research and development.

“We work closely with power companies to increase the stability and control of their networks with ever smarter technology. During the COVID lockdowns we released two entirely new categories of products - the EcoBreaker Substation Circuit Breaker and the EcoLink, a fuse link mounted recloser. All are type-tested to industry standards.”

Pictured: The new SCB (Substation Circuit Breaker) EcoBreaker brings SF6-free technology to the substation. It offers full parallel redundancy and has provision for six current transformers per phase

NOJA Power head of marketing, Martin van der Linde, is also an electrical engineer. As part of the NOJA Power team he has worked with many utilities in the field, developing and testing new features and functionality then building that into a technical specification to extend the performance of their products.

He says a key advantage provided by the NOJA architecture and suite of products is the control of the entire distribution system.

“This gives you control of the entire signal path and a higher resolution of the voltage and current measurements. This greater visibility delivers more useful analysis, more precise fault location and more reliable integration of renewable energy as grids become more complex.”

Van der Linde says OHUG has all the capability to supply NOJA Power solutions and welcomes further engagement with New Zealand network companies. NOJA Power regularly hosts technical staff from utilities at their regional factory facility in Brisbane.

Pictured: OHUG provides on-site training in NOJA Power solutions throughout the country - check out OHUG's demonstration of the latest NOJA Power technology at EEA 2023!

“Because we work so closely with utilities in our research and development, we continue to offer New Zealand network companies the most advanced, responsive and reliable recloser systems in the world. We look forward to hosting more Kiwi engineers and showing how the technology we have developed for them will more effectively meet their needs now and in the future.”

Will you be the next network to remove SF6 from your grid? Contact OHUG Power Equipment - your local NOJA Power experts - to discuss all the ways we can make this work for you!

Image Credits: Images supplied by NOJA Power and NOJA Power Customers, excepting the OHUG On-Site Training image

Article originally published in Electrolink Issue 155 (May-June 2023).