2023 TECHNICAL INSIGHTS
TRANSFORMER TRANSPORTATION AND HANDLING: BEGINNING OF FUTURE RELIABILITY
| Edition 4/2023, Issue 2
Transportation of power transformer from manufacturing plant is a challenging processes as it may caused severe damage when they are subjected to rigorous transport conditions such as troubled sea and rough road during transportation. This article will raise an awareness of the transportation procedure and mitigation actions whenever the conditions of handling and transportation indicate a potential damage to the transformer.
MOISTURE MANAGEMENT IN POWER TRANSFORMER: WHY IT MATTERS?
| Edition 4/2023, Issue 1
Moisture is the enemy for transformers as it will reduce the dielectric strength, cause contamination and lead to deterioration of the insulation system. In the long run, excessive moisture accelerates the ageing of paper insulation and weakens the hydrogen bonds of the molecular chain of the paper fiber. For this reason, it is important to maintain transformers in a reasonably dry state. This article will look at a holistic view of moisture management for power transformers and the effective solution to reduce the moisture content and thus extend the reliability of transformer operation.
2022 TECHNICAL INSIGHTS
HIGH VOLTAGE BUSHING: DESIGN, APPLICATION, AND DIAGNOSIS FOR TRANSFORMER RELIABILITY
| Edition 3/2022, Issue 4
Bushing is the component in the transformer that facilitates the passage of energized current carrying conductor through the grounded tank. Failure of this critical component is catastrophic due to exploding of the porcelain insulator can harm people working in the substation and possible damage to adjacent components. This article will look at the recent development in transformer bushing design, failure mechanism, and monitoring parameters that can be used to prevent the failure of transformer bushing.
APPLICATION OF ONLINE MONITORING SYSTEM FOR POWER TRANSFORMER HEALTH ASSESSMENT
| Edition 3/2022, Issue 3
With the rapid development in the field of electronic, software and communication technology, a great transformation in power network operation and maintenance has been seen over the last decades. Traditional time-based asset maintenance predominantly relied on off-line test techniques has now been moving into condition-based maintenance aided by on-line monitoring and diagnostic techniques.
A NEW APPROACH FOR DGA INTERPRETATION OF IN-SERVICE POWER TRANSFORMER
| Edition 3/2022, Issue 2
Over a decades, Dissolved Gases Analysis (DGA) has been used as a common techniques to detect the incipient faults in oil-filled power transformers. It has been proven that generation of certain gases in power transformer is an indication that a failure is pending. Nowadays, DGA has become standard practice as part of transformer maintenance for many electric power utility companies. Despite the sensitive and accurate of DGA measuring the gases, the proper use and interpretation of gas dissolved in oil is still not fully understood by many people. Moreover, the introduction of new interpretation techniques and standards has make the DGA interpretation is more complicated and may require experts to interpret it.
CORROSIVE SULPHUR IN TRANSFORMER: A SERIOUS PROBLEM?
| Edition 3/2022, Issue 1
In recent years, it has been reported a sudden and unexpected cases of power and distribution transformers failures causes by corrosive sulphur. Although the oil passes the standard corrosive sulphur test, the sulphur compound used as normal natural additive in the oil and non-reactive at normal operating conditions may reactive at extreme conditions in the transformer. The problems caused by corrosive sulphur, why the problem has resurfaced, detection of corrosive sulphur in transformer and remedies suggested to prevent further destruction was featured in this article
2021 TECHNICAL INSIGHTS
TRANSFORMER ON-SITE PARTIAL DISCHARGE MEASUREMENT: ISSUES AND CHALLENGES
| Edition 2/2021, Issue 4
Since decades, Partial Discharge (PD) testing has been used to asses the quality of insulation system in high voltage equipment as part of Factory Acceptance Test (FAT), site commissioning as well as diagnostic tool for condition based maintenance of aged assets. According to IEC 60270, PD can be defined as localised electrical discharge that only partially bridges the insulation between conductors or between conductor to ground. It is well established that different character of PD measurements enables identification of weak points in the insulation system.
DIGITALIZATION OF TRANSFORMER MAINTENANCE: SHAPING THE FUTURE
| Edition 2/2021, Issue 3
Condition based maintenance has allows the utilities to predict the health condition of in-service power transformer and allow maintenance actions to be taken at an early stages to prevent any potential failures. It collects condition data that reveals failure mechanisms and deterioration patterns either through online or offline monitoring systems. In today modern world, the implementation of advanced technologies such as big data, industrial internet of things, and analytics has bring improvements to existing processes and business models. Similarly, we have seen significant improvement in digitisation and digitalization of maintenance and management of power transformer over the last ten years.
TAP CHANGER: DESIGN, OPERATION & MAINTENANCE AND MONITORING (PART 2)
| Edition 2/2021, Issue 2
Based on an international survey on substation transformer failure done by CIGRE, 41% of transformer failure is caused by On-Load Tap Changer (OLTC). It is therefore, paramount for the transformer operator to be able to assure the reliability of the OLTC. Typically, extensive maintenance are conducted on serviced aged OLTC to reduce the unexpected unavailability and failure rate of power transformer. However, a routine maintenance is a major expenditure, both in resources and time. Thus, a condition-based maintenance is a better option to determine the condition of OLTC and observe operation characteristics. In recent years, many diagnostic techniques are developed aiming at measuring the contact quality and the mechanical behaviour, or at identifying the presence of degradation mechanisms through their symptoms. Cigre Brochure 445 presents an overview of the different diagnostic techniques for different OLTC types and defects
TAP CHANGER: DESIGN, OPERATION & MAINTENANCE AND MONITORING (PART 1)
| Edition 2/2021, Issue 1
Tap-changer plays an important roles in the operation of power transformer. The changes in load demand has change the electrical system voltage which may results in damaged equipment, electricity supply outage and customer complaint. Thus, the variation of voltage need to be maintained within the prescribed limits. The system voltage can be varied by changing the turn ratio of transformer by adding or cutting out turns off primary winding or secondary winding using the tap changer.
2020 TECHNICAL INSIGHTS
POWER TRANSFORMER FAILURES : WHY DO TRANSFORMER FAILS?
| Edition 1/2020, Issue 4
Transformer provides important link between the electricity generation plant and end customers. It is considered as most efficient and reliable high voltage electrical equipment in the network. Presently, the health condition of power transformer was assessed by various diagnostic tool and techniques. Changes in the measurement parameters require maintenance action performed on the transformer by the asset owner. Nonetheless, transformer also prone to failures due to many factors both internal and external. Thus, the analysis of failures is an important aspect of asset management where it can improve the ability to identify and eliminate the root cause of the failure and prevent its recurrence.
ENVIRONMENTAL FRIENDLY IN POWER TRANSFORMER DESIGN
| Edition 1/2020, Issue 3
With the future generation and distribution of energy are towards smart grid and greener technology, the used of eco-friendly transformer plays a major key role. The 3E concept; ecofriendly, efficient and economical nowadays are the ultimate goals in designing and manufacturing the new transformer. The greener transformer should be assembled using material that can reduce impact on natural resource availability. For the long sustainable operation, it must be designed for lower maintenance cost as well as with more energy-efficient operation and lower loss rates. Finally, eco-friendly transformer should last longer and when reach their end-of-life, they’re easier to recycle than ordinary transformer.
AGEING OF TRANSFORMER INSULATION: HOW TO MITIGATE IT?
| Edition 1/2020, Issue 2
The power utilities and plant operator over the globe faced an issues of an ageing transformer population within their network and the risk of failure increases exponentially proportions towards the end of the transformers life. It is essential to have better understanding and quantify the ageing kinetics and to learn how they may be controlled, so that costly maintenance and future investment can be minimised and optimised. It is recognised by IEEE that 80% of transformer failure occurs caused by failure of insulation system. Of all the component parts in transformer, cellulose paper insulation is the most vulnerable component. The ageing of cellulose material is irreversible and the life of transformer is forever shortened. Thus, anything we do to prevent or mitigate damage to the paper insulation will enhance the life of in-service transformer.
TRANSFORMER LIFE MANAGEMENT : ENSURING THE POWER CONNECTION
| Edition 1/2020, Issue 1
With the ageing population of power transformer, clearly determining the condition of in-service power transformer is tremendous importance to avoid the force outage and ensure the continuous of electricity supply. The asset operator face a challenges in managing the population of transformers; to reduce the maintenance costs and improve the transformer reliability and availability. The transformer life management nowadays has gained an increase acceptance and become important due to several reasons such as economic as well as technical and strategic factors. The key objective is to extend the service life of the transformer, maximising return on investment and lowering the operating cost.