Enhancing reliability and flexibility: the Kalasatama Smart Grid project

Helen Electricity Network Ltd. (Helen), serving over 430,000 customers in Helsinki, Finland, initiated the Kalasatama Smart Grid project in 2011 to enhance reliability and flexibility. A 10 kV primary substation was established to support the new suburb. To ensure high reliability, Helen implemented a medium voltage (MV) closed ring network with advanced protection schemes, including differential protection and earth fault current comparison. Substation automation was enhanced using IEC 61850 station bus technology. For the Kalasatama MV ring secondary substations, Helen adopted ABB’s UniGear Digital switchgear with Rogowski coils, voltage dividers, and Intelligent Electronic Devices (IEDs) featuring IEC 61850, GOOSE, and IEC 61850-9-2 process bus. The High-availability Seamless Redundancy (HSR) protocol ensures continuous Ethernet signalling. Commissioned between 2017 and 2018, the closed ring substations have operated reliably for seven years. Despite higher costs, the closed loop MV network offers significant reliability improvements. The use of sensors and the IEC 61850 process bus has proven beneficial, enhancing safety, compactness, and flexibility. Helen’s positive experience suggests a preference for these technologies, contingent on competitive vendor offerings.