Coordinating DSO operation and TSO services

This project aims to assure that all DSO (Distribution System Operator) grid assets operate within voltage and current limits while exploiting as much as possible of the flexibility offered by low voltage battery storages to the TSO (Transmission System operator). 

Variable Renewable Energy Sources (V-RES) – mainly wind and solar electricity generation – expand rapidly as a part of the energy transition. Their variability calls for increasing volumes of balancing in several time scales: Inertial response of synchronous generator happens in fractions of a second. The fluctuations in solar generation due to clouds are in the time scale of seconds to a minute, and when wind and solar generation deviate from their forecasts this is about minutes to hours. Battery storages can easily contribute to balancing in all these time scales and are spreading rapidly, with exactly these TSO balancing services as an important revenue stream. But caught between the TSO and the battery storages are the distribution networks, where managing the loading of transformers and lines is becoming increasingly difficult. The fact is that the DSO mostly can influence neither how battery storages are installed, nor how they are operated. This project will investigate technical solutions for the DSO to protect its transformers and lines by constraining – in real-time – the balancing services performed by the battery storages.

Control algorithms

In previous projects at Lund University, algorithms have been developed to curtail generation or up-regulate consumption to handle the new power flow variations caused by new V-RES. These algorithms will be modified to also include frequency-related system services from battery storages. A critical part is to decide in which order the different flexible assets – generation, load and storage – are allocated. Explicitly expressing this order as a priority list, will clarify and resolve the goal conflict between DSO and TSO.

Communication requirements

Congestion management involves communication due to the inherent distance between the monitored bottleneck – typically a transformer or cable – and the resources to be controlled at what is often termed “the grid edge”. The faster time scale of the frequency-related services will emphasize the importance of delays in the chosen communication solution.

Field test

While simulations efficiently illustrate a control concept, it needs final evaluation through physical implementation and a field test. The collaboration between academic and industrial partners makes an SESBC project the perfect setting for this.

Involved in the project

Postdoc to be recruited, Olof Samuelsson, Emil Hillberg, Industrial Electrical Engineering and Automation, Lund University

Partners

Lund University, DNV, Göteborg Energi, Svenska Kraftnät, Vattenfall, Volvo Cars

Funders

DNV, Göteborg Energi, Svenska Kraftnät, Vattenfall, Volvo Cars