Electricity + Control July 2019

round up DRIVES, MOTORS + SWITCHGEAR

Drives and electric machines

With engineering support for customers’ preferred motors or generators, the company continues to assist system integrators and OEMs in winning their projects. Serving diverse applications in electrification of marine and heavy industries, the design opportunities with Danfoss drives are now even broader. Enquiries: Danfoss Drives, visit: www.danfoss.com

Danfoss Drives has extended its product portfolio to include Danfoss electric machines as an additional choice of motor or generator type. At the same time, the company maintains its commitment to support customers fully in their choices, should they prefer to use other types of motors or generators. SRPM-based Danfoss electric machines offer the highest efficiency on the market, with standard or project-based designs. They operate at maximum torque from any speed, even from standstill, tolerate extreme mechanical vibration and shock, and are liquid-cooled to facilitate compact and robust design. Available in seven frame sizes, they cover the power range 20 kW to 6 MW. Combined with ac drives from Danfoss Drives, the Danfoss electric machines provide an opportunity to optimise many diverse applications in marine electrification and similar fields. As customers of Danfoss Drives, system integrators and original equipment manufacturers (OEMs) already enjoy a high level of component choice and depth of knowledge sharing when preparing to bid on projects. As an independent player, Danfoss Drives enables them to select the ideal combination of motors, PLC and cloud system to optimise each individual drive appplication fully. Danfoss product development is ongoing, bringing new levels of performance to maintain a competitive edge. With the new offering, Danfoss Drives continues to support its customers in optimising competitiveness at the same high level.

Danfoss electric machines introduce an alternative to motors and generators.

Largest stator rewind completed

Coutts has world class capability, as this project showed,” says Botton. “We could also contribute our specialised equipment and supply chain – elements that often present a challenge to external service providers if they are appointed to conduct this kind of project work in South Africa.” Enquiries: Marthinusen & Coutts, visit: www.mandc.co.za The repair contract at Eskom’s Ingula pumped storage hydro-electric plant involved the complete rewind of a 373 MVA stator for one of the plant’s four 14-pole motor generators.

Marthinusen & Coutts carried out the work with a 14-man team, completing the project in November 2018 after 100 days on site. The company’s extensive preparation included establishing training jigs at its Johannesburg facility, to support the customised training for all technicians involved in the project. “We also conducted detailed testing, and refurbishment where necessary, of all the winding equipment we would use on site,” says Botton. “This contributed to smooth and uninterrupted operations, making us self-sufficient in rolling out the contract.” Working closely with original equipment manufacturers (OEMs) and Eskom, Marthinusen & Coutts took ownership of the rewind project from start to finish, he notes. The contract was successfully completed on-time with all test criteria well within specification. “With our in-country expertise, supported by our Centres of Excellence in Benoni and Cleveland, Marthinusen &

In what has been described as the largest winding installation ever conducted in South Africa, Marthinusen & Coutts, a division of ACTOM, has completed a major repair at Eskom’s Ingula pumped storage hydro-electric plant. The contract involved the complete rewind of a 373 MVA stator for one of Ingula’s four 14-pole motor generators. According to Richard Botton, Managing Director at Marthinusen & Coutts, the 342MWunit is among the biggest in South Africa with a core diameter measuring five metres, a core length of 3.2 metres and a rotor mass of 500 tonnes. “As the stator is located deep in the turbine floor, all the winding had to be conducted on site,” says Botton. “In this complicated repair, each replacement coil set was fitted, connected and brazed on site from pre-manufactured and pre- packed components supplied by the OEM. The most painstaking process, conducted to the highest standards, was the resistive brazing on 1 824 joints.”

Electricity + Control

JULY 2019

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