Electricity + Control December 2020

TRANSFORMERS, SUBSTATIONS + CABLES : PRODUCTS + SERVICES

Faster turnaround on transformer oil analyses

Digitalisation of transformers Hitachi ABB Power Grids has launched the TXpert™ Ecosystem for digitalisation of transformers. The manufacturer-agnostic ecosystem is designed to support greater flexibility, efficiency and resilience in electricity networks by enabling data-driven intelligence and decision-making in the operations and maintenance of transformers and power grids. It is a complete suite of products, software, services and solutions that work together and can integrate with new and existing digital equipment from other manufacturers. Condition monitoring specialist, WearCheck, recently invested several million rand in four new laboratory instruments for its transformer division laboratories in Johannesburg, Durban and Cape Town. WearCheck Managing Director Neil Robinson says the company’s investment in the equipment has relieved some of the current sample volume pressure and reduced turnaround times in line with customers’ expectations, ensuring that transformer oil samples are processed and analysed even faster than before. The company’s transformer division now has an additional two new high-speed gas chromatographs (GCs) in the company’s Johannesburg and Durban laboratories, an additional new PCB (polychlorinated biphenyl) chromatograph in the Cape Town laboratory, and an additional new HPLC (high performance liquid chromatography) instrument in the Durban laboratory. “Getting the analytical test results and diagnoses to our customers as fast as possible is a priority for us,” says Robinson, “and our investment in the new instruments has enabled us to more than double our transformer sample testing capacity. Our transformer division also recently moved to a new, larger laboratory in Westville, where we offer a wide range of specialist transformer monitoring techniques.” ThenewPerkinElmerGCs –designedandmanufactured in The Netherlands – each have a carousel that can hold 120 prepared samples and standards. Added to the 80-sample capacity of the two existing GCs in the Durban laboratory, this means more samples are being processed

Transformer Laboratory Technician, Zamaswazi Dlamini, operates the new high-speed gas chromatograph (GC) at the Durban laboratory. at any given time, and the sample turnaround time has been significantly reduced. “One of the great advantages of the new GCs is that they can be pre-loaded with samples before a weekend, and they will continue operating for 48 hours. Our older models require reloading every 24 hours,” says Transformer Division Manager, Gert Nel. “The primary function of the GC is to perform dissolved gas analysis (DGA) – a highly effective preventive mainte- nance tool which has formed part of WearCheck’s condition monitoring programmes for more than 10 years,” says Nel. He explains further, “The new PCB instrument determines the presence of PCB in electrical equipment containing insulating oil, which must be tested at least once and after every maintenance event to determine the PCB level. According to the latest version of SANS 290:2017, the current maximum allowed PCB level in oil is 50 ppm (parts per million or mg/kg). If the PCB level “Building on deep experience, we have pioneered the scalable TXpert™ Ecosystem to bring together customers, partners and industry peers on an open platform developed on strict cybersecurity standards, enabling simple steps in their digitalisation journey,” said Bruno Melles, Managing Director, Transformers business unit at Hitachi ABB Power Grids. “By giving transformers the knowledge and intelligence derived from designing and servicing thousands of transformers, the system will help to reduce costs and risks, optimise operations, extend life expectancy and enhance environmental performance, contributing to a sustainable energy future.” Faults in transformers are usually in the windings, tap-changers and bushings. The TXpert™ Ecosystem provides options to mitigate all of these. For example, failure of bushings can lead to transformer tank rupture and explosions, requiring millions of dollars in repairs and settlement costs for a utility, while the cost of replacing a high-voltage bushing would be a few percentage points of this. Using TXpert™ Ecosystem solutions for digital asset management of bushings, the real-time status of the bushings’ health can be monitored and corrective action taken before failure probability becomes high.

At the heart of the ecosystem is the TXpert™ Hub a data monitoring and diagnostics device.

28 Electricity + Control DECEMBER 2020