Three 1.2 MW ACS880 mill drives and one 355 kW regenerative batch centrifugal drive have been remotely hot commissioned at Illovo Sugar Africa’s biggest Southern African mills, at Nakambala in Zambia and Ubombo in Eswatini.
ABB reports that the drives were to be commissioned under load in April, at the start of the crushing season. However, the company’s Southern Africa service team was unable to gain access to the sites after lockdowns were implemented in South Africa and subsequently in Eswatini, in late March and early April respectively.
The ACS 880-17 regenerative drive family offers a power range from 55 to 3 200 kW.
Illovo Sugar Africa had awarded the contract for the variable speed drives to ABB, for the modernisation of its mills and centrifuges. The contract scope included ABB’s remote monitoring solution, a condition-based maintenance service that predicts when drive components need replacing.
For operations extending to remote areas across the sub-Saharan African region, condition-based maintenance provides precise, high-quality data that enables the delivery of an efficient, targeted maintenance programme. Analysis is easier and faster, and maintenance activities are planned based on actual needs.
Sugar centrifuge applications have one of the highest cyclic overload requirements in industrial motor control. ABB’s advanced motor control algorithm – DTC (Direct Torque Control) – in the ACS880 drive ensures rapid response time to setpoint change/load rejection. The ACS880-17 regenerative drive uses the DTC algorithm on both the motor control inverter and the regenerative supply unit, ensuring excellent motor control performance as well as clean and reliable loading on the supply.
These unique control elements of the ABB drive help equipment owners achieve the shortest possible cyclic time, which results in a high production capacity from the same machine. In this application for Illovo Sugar Africa, the drives exceeded performance requirements, and offered a common technology platform across the range.
The easy-to-configure software and user-friendly human-machine interface (HMI) made it simple for the onsite users to navigate through the drive to extract key application data, and the use of ABB’s DTC motor control platform allowed for easy integration with the existing non-ABB motors onsite.
Remote commissioning for the mills required an onsite network to be set up. This was installed by the site personnel under the direction of the ABB service engineer remotely. The remote monitoring hardware (part of the ABB Ability™ Remote Services for Drives product suite) was set up during the installation supervision phase by the ABB drives service department in anticipation of the wet commissioning.
Set-up and tuning of the drives under full load was achieved successfully via a stable NETA-21 VPN connection to the customer’s LAN. The batch sugar centrifuge is a special application demanding precise parameterisation under load, due to very high inertia and high cyclic loading with full regenerative capabilities. The mill tuning under load demands high intermittent overloading and verified no resonances or torque pulsations.
In today's sugar industry, constantly increasing competition and growing pressure for higher efficiency are forcing producers to find new ways to achieve long-term success. ABB’s solution of VSDs, motors, gearing and bearings supports key processes such as cane milling or beet slicing, extraction and crystallisation, and enables energy savings, improved productivity and reduced costs.
In this project the customer was able to start-up its essential food services plants without any downtime due to the lockdown. The current partnership between ABB and Illovo Sugar Africa ensures high productivity at its plants, efficient maintenance planning, and avoidance of unplanned downtime, while maximising the life of the equipment.
For more information contact ABB South Africa.
Tel: +27 (0)10 202 6001
Visit: https://new.abb.co/africa
