Today, more than ever countries, organisations and industries are committed to Environmental and Social Sustainability strategies (ESS) to decarbonise our planet. In industry, becoming energy efficient is seen as an enabler of de-carbonisation, however, sustainably reducing energy usage and costs without compromising product quality or operational productivity remains challenging. Recent studies by the International Energy Agency (IEA) indicate that industrial applications account for 30% of the world’s electricity consumption with an estimated 300 million-plus electric motors globally consuming 65% of all industrial electricity. Sustainable energy efficiency and productivity improvements cannot be achieved overnight and is a concerted effort over time.

ElectroMechanica (EM) has the vision to advance the lives of every person in Southern Africa through the efficient electrification and agile automation of industry at scale, digitally and sustainably. “Our purpose is to solve problems such as unsafe power distribution, inefficient energy consumption, manual electrical processes, and unreliable and costly supply chain by bringing the innovations of our manufacturers to end-users in Southern Africa, supported by people passionate about service”, says EM’s Head of Business Development, Rikus Botha.

Applying a Variable Speed Drive (VSD) to both Variable Torque (VT) motor loads such as pumps, fans and compressors or Constant Torque (CT) motor loads, such as conveyors and mills, have the potential to result in energy savings, as well as productivity improvements. However optimal electricity savings are most often achievable through VSDs applied to VT motor loads. “VT applications are frequently oversized to ensure the future expansion of a system is possible or to counter design uncertainties and other anomalies in industrial processes and systems,” says Rikus Botha. Either way, a VSD solution applied correctly has the potential to pay for itself from the monetary savings generated through reduced electricity consumption.

EM has been the exclusive distributor of the Delta Industrial Automation range in SADC since 2006. The product portfolio is extensively supported through EM’s stockholding, training, technical support and System Integrator partners. “Delta is proud of the long-standing partnership with ElectroMechanica and is pleased to deepen the collaboration with the launch of the Delta Medium Voltage (MV) VSD range in Southern Africa”, adds Paul Lee, Business Development Director of MV Drives at Delta Electronics.

The MVF23 and MVF20 series are suitable for both VT and CT electric-motor loads in the industry. The proven Cascaded H-bridge topology and switching technology employed in the MV VSD solution enables near-sinusoidal output motor waveforms reducing motor losses, vibrations, torque pulses and overheating. This capability ensures that the MV VSD solution is widely suitable to be matched with new or existing induction, slip-ring or synchronous motors in retro-fit applications where Direct-On-Line systems are converted.

The MVF23 and MVF20 series consist of multiple low voltage modular power cells connected in series (cascaded) to achieve the required motor voltage output integrated with an in-panel low harmonic phase-shifting transformer which can also be used as a step-down transformer to match supply and motor voltages where required. This high-efficiency phase-shifting transformer meets IEEE-519 compliance and ensures overall system efficiency >96.5% with the inherent power-factor correction capability of the VSD also ensuring an input supply power factor >0.96 throughout the electric-motor load range.

The MVF23 Series MV VSD is a Compact all-in-one solution available in standard output configurations of 3.3kv and 6.6kv from 36 A to 215 A – or 160 kW to 2000 kW with Voltage step down capabilities from 13.8kv. The MVF20 Series MV VSD is an In-Line design solution available in standard output configurations of 11kv, from 36 A to 350A – or 560 kW to 5500 kW with Voltage step down capabilities from 13.8kv. The MVF20 Series MV VSD In-Line design solution also includes standard configurations of 3.3kv and 6.6kv from >215<350A – or 1000 kW to 3300 kW with Voltage step down capabilities from 13.8kv. Sizes >350A<720A – or 1650 kW to 11 000 kW are available if required. 

The small footprint of the MVF23 series makes the challenge of finding space for a retro-fit VSD in existing MV rooms a thing of the past. Both the MVF23 and MVF20 series also require no rear or side entry to perform repairs or maintenance which means the solution can be installed against walls or placed back-to-back to optimise space in existing rooms. Supply and motor cable entry is also possible from the top, bottom or side of the VSD if required.

“A number of normally customised options are included as standard options to optimise uptime, safety and reliability”, adds Rikus Botha. These include an integrated 10” HMI (Multi-language, full colour touch screen), IP42, Conformally Coated boards, Mechanical key-interlock (spare lock and key provided for switchgear integration) and EtherNet/IP as the standard CI Protocol. The HMI also provides a fault-finding interface with advanced status messaging, indicating the current operating conditions of the system.

The MVF23/20 has the option to exist as a standalone solution or to be integrated with an overarching PLC/SCADA system with any of the major CI Protocols available as options (ProfiNet, Profibus DP, DeviceNet, ModBus RTU).To further enhance uptime both the MVF23 and MVF20 series have automatic power cell bypass as a built-in option that can be activated. In the event of a power cell failure, the system immediately pin-points and indicates the faulty cell, automatically bypassing the faulty cell and the additional cells to balance the output voltage. Although this action will reduce the output torque, the VSD is allowed to operate until such time that the repair can be carried out conveniently. Redundancy options are also available where an additional 3 power cells are integrated into the design for applications in which the output torque needs to remain at 100%.

All MVF23 or MVF20 VSD solutions sold by ElectroMechanica are engineered to order in partnership with Delta Electronics application engineers taking supply and application requirements into account. All solutions are individually tested to 100% load and capacity, and according to the relevant End-User standards in Delta's state-of-the-art MV factory and testing facility in Jiangsu, China. EM also invites customers to attend Factory Acceptance Tests or facilitate attendance virtually.