Maximizing the integration of renewables and optimizing technical losses through improved control implemented in a smart transformer

The tests were carried out at the SYSLAB laboratory at the Technical University of Denmark as part of the ERIGrid research project, which provides access to leading laboratories in Europe. The coordinated control of smart transformers and distributed energy resources (DERs) such as photovoltaics (PV), wind power, battery energy storage systems (BESS), flexible loads, and electric vehicles (EVs) was experimentally demonstrated to reduce technical losses caused by reverse power flow and improve grid stability and grid code compliance, while integrating a high share of renewable energy generation.

transforma.smart   20/0.4kV, 630kVA; 2 wind turbines of 10 and 11kW 3 arrays x 10kW; Diesel generation group, 24kW; style=”color: #000000;”>Converter B2B, 26kW; Vanadium battery, 12kW; Controllable load banks, 18kW; EV charging station and 3 electric vehicles

Ormazabal Solution and Challenge:

To clearly determine the advantages of the control techniques, a set of representative key performance indicators was defined:

1. Maximize the volume of renewable energy generation on the grid (hosting capacity, kW-h)
2. Reduce technical electricity losses (financial incentive for the distribution operator)
3. Improve grid stability increasing the useful life of the equipment.

Rural (R) and urban (U) network scenarios were considered using three strategies for voltage control: no control (N), tap control (T), tap control + reactive power (QT), based on real-time measurements from different nodes. Subsequently, to verify the feasibility of the control system in a real-world environment, a 24-hour flexible test setup was carried out that included almost all the resources available in the laboratory.

Key Customer Benefits:

• Coordinated control of a smart transformer and DERs significantly improves grid reliability, increases renewable energy integration, and extends the lifespan of power system equipment.
• Tap control of a smart transformer alone facilitates the integration of renewable generation by 61.65% compared to the baseline case when no control is used.
• Combined control of reactive power and taps reduces technical losses by up to 9%.