1. WP 3.1 Flexibility management and control
Introduce myself:
Bachelor: Physics.
Master: Energy & Environmental Sciences.
Now: PhD University of Groningen.
Group: Smart Manufacturing Systems.
Supervision: prof. Claudio De Persis.
Sebastian Trip
Claudio De Persis

2. Overview Past: Frequency control. (Transmission grid and microgrids)
Current: Voltage control and lossy lines. (Distribution grids)
An optimisitic future.

3. Overview Past: Frequency control. (Transmission grid and microgrids)
Current: Voltage control and lossy lines. (Distribution grids)
An optimisitic future.

4. Output agreement on networks
Frequency regulation in powergrids
Frequency regulation in microgrids

5. Output agreement on networks

6. How to design… ? Non-trivial.
Sufficient conditions for a class of systems and disturbances
Bürger & De Persis: Dynamic coupling design for nonlinear output agreement and time-varying flow control. Automatica.
De Persis & Jayawardhana: On the internal model principle in the coordination of nonlinear systems. IEEE Transactions on control of Network Systems.

7. A class of dynamical systems
are incrementally passive if there exists a storage function such that
Provides framework for comparing solutions.
Is a natural property of many systems.
Examples:
All passive linear systems.
Some primal-dual optimization algorithms.
Some nonlinear systems: e.g. Power systems!

8. Disturbances Disturbances are generated by exosystems that satisfy
Example 1: Constant disturbance

9. Disturbances Disturbances are generated by exosystems that satisfy
Example 2: Sinusoidal disturbance

10. Disturbances Disturbances are generated by exosystems that satisfy
Example 3: Superposition

11. Frequency converges to 50 / 60 Hz.
Power grid
Frequency controller
Unknown load
Frequency converges to 50 / 60 Hz.
Generator
Power flows

12. Transmission grid Swing equations:
Higher order models (voltage dynamics) & minimize generation costs.
Trip, Bürger & De Persis: An internal model approach to frequency regulation in power grids. arxiv.org/abs/

13. with time-varying voltages.
Microgrids
Simpson-Porco, Dörfler et. al
Others
Extended:
Higher order model
with time-varying voltages.
Bürger & De Persis: Dynamic coupling design for nonlinear output agreement and time-varying flow control. Automatica.

14. Inverter dynamics
Schiffer, Ortega, Astolfi, Raisch & Sezi: Conditions for stability for droop-controlled inverter-based microgrids. Automatica.

15. Voltage control still an open question.
Change of desired active power
Change of desired reactive power
Voltage control still an open question.

16. Possible collaboration
Visit to Aalborg

17. Overview Past: Frequency control. (Transmission grid and microgrids)
Current: Voltage control and lossy lines. (Distribution grids)
An optimisitic future.

18. Lossy lines
Lossless assumption seems reasonable in transmission grids.
More doubtful for distribution grids.
Lossless line
Lossy line

19. Main issue
Stability analysis.
Cosine is an even function.

20. Voltage control
Control of voltage in distribution grids becomes more important.

21. Voltage control

22. Main issue How to model nodes and lines (lossless or lossy)?
Maybe as PQ (load) or PV (sources) bus?
Islanded microgrid of inverters

23. Overview Past: Frequency control. (Transmission grid and microgrids)
Current: Voltage control and lossy lines. (Distribution grids)
An optimisitic future.

24. Integrate frequency and voltage control
Frequency control in transmission grids
Voltage control in distribution grids
Capacity and voltage constraints

25. Thank you!