Sparks Electrical News July 2018

STANDBY AND EMERGENCY POWER

18

TALKING ELECTRICITY WITH ANDREW LUKE DAPSHIS

HYBRID GENERATORS: THE FUTURE OF BACKUP POWER

D iesel and gas generators have been at the height of industry’s movement towards backup, emergency and remote power solutions in a country where power isn’t always a constant. After many years of load shedding and blackouts it has become the norm for South African businesses to rely on additional power sources to maintain the load required. Many businesses and homeowners have, over the years, turned to diesel generators, and the subject of additional licensing required by government is a current hot topic when it comes to generators and solar panels. In a nutshell, the Department of Energy is attempting to get legislation passed to make it a requirement to register any device capable of generating electricity with the National Energy Regulator of South Africa. This will be like a car or television license, requiring it to be renewed for a fee. So even Oom Frikkie with his wind pump dynamo set up to a single light will be forced to get a license and renew it. Yet even the possibility of registration does not take away from our need for dependable, reliable back-up power options. A more recent addition to this has

been the hybrid diesel generator. In the past, switching on a diesel generator for whatever reason, would mean a diesel motor was started and left at a constant rpm at either 1 500 (50 Hz) or 1 800 (60 Hz), supplying the same constant load using the same amount of fuel, no matter how much current was being drawn. Hybrid generators linked to the correct battery packs and control systems can sustain high or low load systems without wasting fuel. This gives a much higher efficiency as well as a delay in maintenance, with some generator companies giving up to thousand hour runtimes before services. The idea is that the batteries will sustain the small loads and the engine will only start once the required load starts to exceed the capabilities of the batteries or the battery charge starts to drop below a sustainable level. Maintained by the control system in place, some are so far advanced it is possible to download an app to your phone in order to have real time updates sent from your generator’s communication panel displaying fuel levels, battery levels, alarm codes or load drawn. But cutting-edge technology comes at a high price and

the space required for these setups is immense. Correct installation and relevant maintenance will be required to sustain the life and warranty of the machines, and some can literally last for years without major failure. But costs for the device, maintenance, parts, and possibly additional licensing, will mean in South Africa it would not be as cost efficient as it could be. A factor to consider is emission standards. Most First World countries are on the road to Tier 5 emissions and hoping for these to be sustainable by 2020. In South Africa, we are permitted to install and use lower tiers as our focus has always been more on taxation and licensing than environmental damage, noise and emissions. Therefore, in South Africa, backup options are expensive, require maintenance and, soon, a payable license, but nevertheless are essential for communications towers, remote installations, disaster recovery areas and anyone living off the grid. The more you are willing to pay, the more reliable and sustainable your options will be.

COMBINED TTR AND WINDING RESISTANCE TESTER IN ONE BOX T he Megger MWA3 Series Trans- former Winding Analyzer is de- signed to perform transformer former test system that reduces set- up time, increases job-site safety and delivers improved productivity versus individual instrument testing.

easy-to-learn test method. The following tests are easily per- formed with the MWA3 Series, all with one instrument and one three-phase lead-set connection: 3-phase turns ratio, 3-phase winding resistance, auto vector detection, heat-run test, OLTC/ continuity (make-before-break), core demagnetisation, magnetic balance/ flux distribution, excitation current, polarity, and phase angle deviation’ There are two interface options avail- able. The externally-controlled model MWA300 is a ‘black box’ style package that is remotely controlled by PowerDB software running on an external PC (not provided). The MWA330A model features a built-in 300 mm industrial touch-screen computer. PowerDB software provides the unit with a common user interface to minimise operator training and delivers a seamless interface to the computer application. PowerDB Lite software is included with the MWA3 Series. Typical end users of the MWA3 Series include power utilities, electrical testing companies and field commissioning, service and maintenance personnel.

ratio and winding resistance testing in one box quickly and efficiently. It is an advanced three-phase portable trans-

The unit’s light weight (15 kg) and small size (280 x 280 x 460 mm)

makes it 40% lighter to carry and offers 55% more space in vehicles than other equipment on the market today. The ease and convenience of using the same set of test leads eliminates the need for frequent ladder trips and mistakes with lead connections from one lead set to another; one set of leads equals one ladder climb. The MWA3 Series provides complete ratio, phase and winding resistance measure- ments for a three-phase trans- former. All ratio and winding resistance tests are performed in one instrument with one three-phase lead-set connec- tion. Testing complex three- phase transformers becomes easier with the MWA3 Series, as the operator uses one setup, one connection and one com- mon test form for a consistent,

ENGINEERING OPTIMAL ENERGY SOLUTIONS FOR AFRICA

ZEST WEG GROUP combines its local manufacturing capa- bility with WEG’s range of world class products to engineer energy solutions for customers around Africa, according to the group’s integrated solutions executive, Alastair Gerrard. Gerrard emphasises Zest WEG Group’s extensive network of agents and distributors across the continent, who provide vital insights into local conditions, needs and constraints. “Our solutions are not off-the-shelf. They are tailor made for individual application requirements,” he says. “Our team spends time gaining an in-depth understanding of what the customer really needs, and what the operational constraints are. In this process, we collaborate with reliable, in-country partners who have local knowledge and experience. This local presence also facilitates quick response times and 24/7 after-sales support.” Gerrard also underscores the use of parent company, WEG’s range of motors, variable speed drives and soft starters, as well as its low voltage and medium voltage switchgear. These products are an integral part of the fit-for-purpose solutions, as is Zest WEG Group’s South African manufacturing capability in terms of generator sets, transformers, substations and other mobile energy solutions. “Operating a local gen set manufacturing facility staffed by experienced engineers allows us the flexibility to package this offering with an engine and alternator combination to suit customer preference,” he says. Zest WEG Group also offers a standard off-the-shelf range of gen sets. Forming part of Zest WEG Group’s manufacturing operations in South Africa is WEG Transformers Africa which has two facilities capable of producing transformers up to 45 MVA/132 kV and a range of mini substations up to 33 kV. Also, part of the group is Shaw Controls, which is a leading local manufacturer of custom electrical panels,

motor control centres (MCCs), containerised electrical solutions and E-houses. He says that E-houses have become popular in Africa as these are pre-assembled and tested in a factory prior to being transported to site by truck. The focus is on providing integrated solutions in four main areas, says Gerrard. These are power generation, electrical infrastructure, mobile energy solutions and group product packages. Power generation options include diesel, gas, steam, hydro and renewable energy generation solutions, while the electrical infrastructure offering ranges from supply and refurbishment of outdoor and indoor substations to the provision of overhead lines. Mobile energy solutions, which are engineered to meet specific customer and site needs, are popular in the mining industry but are relevant to any application where operations need flexibility when deploying electrical systems such as gen sets, substations, skid type solutions or circuit breakers.

Enquiries: www.megger.com

Enquiries: +27 (0) 11 723 6000

SPARKS ELECTRICAL NEWS

JULY 2018