Line Voltage Regulator from Hitachi Energy enables BKW Power Grid to boost efficiency and effectiveness of the distribution grid

The innovative Line Voltage Regulator (LVR) with RESIBLOC® technology

BKW Power Grid plans, builds, and operates grid and metering infrastructures. To resolve challenges in the distribution grid resulting from increasing integration of renewable source of energy, BKW Power Grid collaborated with Hitachi Energy to co-create a solution.

Following the co-creation process, Hitachi Energy’s transformer plant in Brilon, Germany recently designed, manufactured and supplied an 8 MVA medium-voltage Line Voltage Regulator (LVR) to BKW Power Grid to help regulate voltage fluctuations in the distribution grid of Energieversorgung Talschaft Lötschen AG at Kippel in Lötschental, Switzerland.

The rapidly increasing generation of electricity from renewable resources is causing a change in the structure of the electrical energy supply. With this, the traditional centralized system with a few large electricity producers is transitioning to become a decentralized system with many small producers that feed directly into the local distribution grid. In addition, increasing power demand by newer technologies like EV (Electric Vehicle) charging add further complications. This results in frequent and strong voltage fluctuations that exceed the permitted, standard deviations from the nominal voltage. As a result, the feed-in power must often be limited or interrupted. Feeding full power to the grid without taking such measures could result in adverse grid conditions and failure of customer installations.

Conventional measures to overcome this would be to install a new feeder which would be very expensive as well as unfavorable to the environment and surrounding areas. Moreover, it would take a long period of time for completion which would mean signification loss of productivity and efficiency.

A Line Voltage Regulator (LVR) from Hitachi Energy is specially designed to solve this problem with the use of a “booster / feeder” technology in combination with mechanical switching devices.

The LVR offers reliable intervention in the event of such strong fluctuations and adjusts the voltage to the required levels. The LVR is equipped with dry-type transformers and other components from Hitachi Energy. It meets the highest environmental requirements. In addition, voltage regulation in the medium-voltage network often solves voltage problems in the lower-level low-voltage networks at the same time. Moreover, the line voltage regulator losses are minimal. And, with a standardized containerized design, the LVR is the most feasible, cost effective and simple solution to a complex problem.

“We are proud to have collaborated with BKW Power Grid and support them in resolving challenges of voltage fluctuations in the medium-voltage network.” Said, Stephane Schaal, Global Product Group Manager for Dry & Traction Transformers at Hitachi Energy. “Our LVR technology is a reliable and efficient solution which is a significantly more economical and less environmentally impactful compared to conventional grid expansion, especially for wind and photovoltaic applications. Moreover, due to its complete dry operation, there is total safety from risk of oil-spillage or fire for the environment and people.”

To sustain the extreme climatic and geographical conditions such as the danger of snow and avalanches at the installation site, it was decided to equip the dry-type transformers of this LVR with RESIBLOC® winding technology along with an extremely robust and resilient concrete station. RESIBLOC® winding technology, which customers have relied on for more than 40 years. It provides unmatched reliability, durability and performance.

The challenge in implementing this project was that the electricity consumption in the Lötschental fluctuates greatly due to the generation of snowmelt and the energy consumption of the ski-lifts. For this reason, an energy-efficient voltage regulation with intelligent control system to stabilize the main voltage was necessary. “At BKW Power Grid, we focus on energy efficiency and in the accelerated expansion of renewable energies. By taking advantage of the new opportunity presented Hitachi Energy’s LVR, we were able to overcome hurdles of integrating clean, sustainable and renewable energy in the Lötschental.” Said Gilles Russi, Manager Projects Upper Country, BKW Power Grid. "Efficiently integrating more renewables and electric vehicle charging stations is a major challenge for distribution system operators. In some cases, an LVR offers the opportunity to avoid further grid reinforcement and higher infrastructure investment."