Electricity and Control December 2022

ENERGY MANAGEMENT + THE INDUSTRIAL ENVIRONMENT

Digital transformation for energy efficiency

In South Africa, the energy crisis currently facing the country makes it increasingly critical for businesses across all industries to implement energy-efficient systems and processes. Environmental, social and governance considerations are also becoming more important for organisations looking to sustainability. Iritron, a company that provides electrical, instrumentation and control systems, says organisations in South Africa need to embrace technology at a faster pace, to enable greater efficiencies and energy and cost savings. Keith Watson, Eurotherm Product Manager at KVM Tech.

K eith Watson, Eurotherm [1] Product Manager at KVM Tech (which is part of the iCubed Group, as is Iritron), says, “Any steps towards digital transformation can result in efficiencies and, in turn, energy savings. It is important to take a long-term view, looking not only at energy savings and reduced maintenance costs but also reduced CO 2 emissions, in line with ESG considerations.” Within the mining, metals and minerals cluster, pro cesses using kilns, ovens, glass lehr baths and furnaces for extracting, drying, melting and heat treatment are big consumers of electricity. And although 82% of mining CEOs are confident about their company’s prospects for revenue growth over the next 12 months (according to PwC’s 25th Annual Global CEO Survey), they will consider their invest ments carefully, in light of rising energy pressures. Watson says plant managers need to be aware of the many variables in electrical supply. He highlights the crit ical impact of managing and improving the power factor in supply systems, in order to reduce energy consumption and its impact on peak demand charges. He refers specif ically to energy saving and the challenges presented by legacy thyristor power controls. At control outputs below 100%, analogue thyristors cause high harmonic distortion on the power supply and a poor power factor, reducing energy efficiency. Hence, energy is wasted and, as well as straining passive filters and capacitor banks, this leads to unnecessary utility

costs. Watson adds that analogue thyristors can struggle with temperature stability and accuracy, causing process repeatability issues. Industry 4.0-enabled thyristor control returns investment within two years: in an electric vacuum furnace, as a case in point, a substantial 10% energy reduction was achieved. Watson refers to a European CIRED ( Congrès International des Reseaux Electriques de Distribution , or International Conference on Electricity Distribution), study that analysed the impact of non-linear loads on a 500 kVA distribution transformer and the resultant derating of its K-factor due to the eddy current effect, overheating of cables, busbars, switch breakers and related elements, and the destruc tion of passive filters and capacitor banks. Importanty too, he highlights that with any single instance of peak demand exceeding 15 minutes, a plant or factory or business incurs punitive billing for the next 12 months. For furnace applications, Eurotherm’s award-winning EPower™ offers a patented Predictive Load Management control system using a high-speed CanBUS network. It continually samples data that allows the main drive to dis tribute furnace zone firing cycles, keeping demand as low as possible while ensuring product quality is maintained. In addition, through advanceddiagnostics, the resistance of each element is measured continually for possible local failure, giving maintenance teams proactive warning to correct that element phase and remediate an unbalanced

In the mining, metals and minerals cluster, furnaces are big users of energy.

10 Electricity + Control DECEMBER 2022