By combining the advanced technology of ABB’s newly released all-in-one protection relay REX640 with the medium-voltage SafePlus switchgear, Stadtwerke Münster is able to meet novel secondary distribution requirements.
Having noticed a trend towards secondary switchgear increasing in functionality to be able to manage today’s distribution networks that are growing in both size and complexity, German utility company Stadtwerke Münster called on the expertise of ABB to develop a unique switchgear solution for its secondary switchgear applications.
With meshed networks being increasingly adopted, and already widely used in Germany, distance protection is becoming the preferred protection to be able to ensure high power quality when cable distances are increasing.
Stadtwerke Münster needed a compact switchgear for secondary distribution applications, with two deviations.
Firstly, the compact switchgear had to be based on circuit breakers. Secondly, distance protection was a requirement, which is usually found only in primary switchgear. Due to its small size and since it was intended to be used in network nodes located far from the primary substations, it could also not be regarded as primary switchgear.
In fact, Stadtwerke Münster’s solution could rather be regarded as a hybrid in that it represents a very small-sized secondary switchgear, possessing atypically advanced functionality.
Equipping ABB’s compact SafePlus switchgear with REX640 – designed for protection and control in advanced power generation and distribution applications – creates a unique switchgear solution. Combining advanced protection technology with sensor technology for current and voltage measurements, the focus being on secondary power distribution applications, allows Stadtwerke Münster to meet their changing network requirements.
“The pilot with Stadtwerke Münster represents true collaboration on finding new ways to meet evolving network requirements,” said Alessandro Palin, Managing Director of ABB’s Distributions Solutions business line. “Installing our most advanced protection relay in a compact secondary switchgear is a great example of thinking out of the box.”
ABB’s sensors have been designed for secondary switchgear to ensure perfect linearity throughout the whole measurement range. This allows high-accuracy current and voltage measurements, which maximizes the performance of advanced protection functionality such as distance protection. The sensors are compact, lightweight and immune to saturation.
By choosing sensors instead of conventional current transformers (CT) and voltage transformers (VT), Stadtwerke Münster was able to reduce switchgear dimensions by 25 percent as no metering panel was required, save roughly 5-10 percent in total costs, and benefit from the latest within advanced protection and control technology.
To date, a four-panel SafePlus switchgear, equipped with two REX640 protection relays, has successfully been put into service. The pilot will be followed by approximately a dozen additional switchgear, each equipped with one or two REX640 relays, within the next year.
Advanced technologies such as these change the ways we work, produce, move, and power the world. Visit ABB’s booth at Hannover Messe, Hall 11, A35, to learn more about ABB’s smart, safe and sustainable offering.