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

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

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

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

Output agreement on networks

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.

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!

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

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

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

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

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/1403.7019.

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.

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

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

Possible collaboration Visit to Aalborg

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

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

Main issue Stability analysis. Cosine is an even function.

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

Voltage control

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

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

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

Thank you!