6 September 2024

Powering Reliability: Transformer Insulation Paper Insights with Weidmann’s Marko Kaiser

In this exclusive Q&A, Marko Kaiser, Product Manager at Weidmann Electrical Technology, shares insights into his role and his expertise on transformer insulation paper. Learn how these innovative paper solutions improve transformer performance, reliability, and future industry trends.

What is your role at Weidmann Electrical Technology?

I am the Product Manager for all types of insulation paper solutions in the Europe/Africa region. This role links Production and its manufacturing capabilities, Sales and their customer relationships, and R&D with their innovation focus.

The Product Management teams are the first point of contact regarding any product-related information and data. In addition, we continuously monitor market conditions and manage and optimize our portfolio based on the current situation and our expectations for the near and mid-term future.

Besides these tasks, we balance significant aspects of the business. That means, on one side, focusing on providing our customers with maximum product value. On the other side, we are responsible for margins and the economic success of each product we produce.

We are also constantly working on new, innovative products, and my role is to help push these ideas through the development process, manage the product launch, and advise the pricing strategy.

What are the enjoyable/challenging aspects of your role?

Both aspects are close together. In this role, you bring people from different departments, regions, and levels together to achieve one aim. I really like being part of a global company and working with so many people from different cultures. And, of course, it is also a challenge to balance all these differences and to find a solution that satisfies all the stakeholders.  

What are the primary applications for electrical grade papers?

The applications for electrical grade papers are small, medium, and large transformers, cables, bushings, and instrument transformers. These papers are used in distribution transformers for residential and light commercial applications, small transformers for solar and wind applications, large step-up transformers in nuclear or fossil plants (coal, oil, gas), and substation transformers of any power rating.

Are there certain papers that will improve the reliability of transformers, and how?

The performance of papers is based on their electrical and mechanical properties. During the lifetime of a transformer, the paper material shows an aging effect. This effect leads to decreased values in elongation and mechanical strength. To control and reduce the physical impact of paper aging, thermally upgraded (thermo-stabilized) paper types can be used – these age considerably slower with identical transformer thermal design, or they allow for higher operational temperatures (thus increased power/overload capability) with the same lifetime. While the degree of polymerization (DP) of new insulation paper is somewhat important, slow degradation behavior (i.e. slow DP reduction in operation) is key. Using high-quality papers and keeping the transformer’s active part as dry as possible is critical to managing this effectively. The usage of micro crepe paper can also increase the reliability of the transformer because this class of paper can absorb a high level of mechanical stress in case of strong transformer load changes or short circuit events.

Why do we crepe, coat, laminate, slit, cuff, and crease our papers?

With technologies like creping and coating, we change the behavior of paper products. These measures have the purpose of adding enhanced properties; for example, creping increases the elongation of the paper from 3 % to up to 200 %. Coatings with epoxy resin are used to bond the paper layers, increasing the paper’s strength. Technologies such as slitting to width and cuffed papers are services we provide so that the papers can be directly used for specific parts and areas of a winding. For example, low-voltage and high-voltage winding, end fill strips, and other winding applications.

What future innovation opportunities are there for electrical grade paper?

The current market shows a very strong demand for all types of transformers and related technologies. The challenge now is to reduce production times to a minimum and to be able to satisfy the enormous demand. Innovative insulation paper with significantly lower impregnation and drying times is an excellent solution to support the OEMs.

Another innovation opportunity would be cost-efficient paper for high-temperature solutions, especially for renewable applications.