High Operability of Power Electronic Converter Dominated Power Systems (HOPE)
The power system is currently rapidly transforming from a fossil-fuel dominated generation portfolio towards a system in which renewable energy sources (RES) are the leading energy source. RES-based generators are often connected to the grid via power electronics converter (PEC). The massive deployment of PECs leads to a hybrid ac/dc transmission system and bring challenges in operation and planning of power system, especially in the transient time frame. The high penetration level of PECs reduces the inertial response capability and the short circuit power of the grid and consequently reduces the level the level of transient stability of the power system. In order to deal with such issues, transmission system operators (TSO) established grid connection requirements for PEC-interfaced generators to remain connected during contingencies and providing ancillary services during faulted conditions. The optimal delivery of such services by PEC-interfaced generations in the context of control parameters, grid properties, and operation scenarios remains a challenge.
One essential factor in terms of the optimal implementation of required ancillary services is the applied control strategy of the PECs, which can be subcategorized into grid following and grid forming control. This work will investigate an optimized control strategy for PECs to guarantee the transient stability of the future power system considering the stochastic nature of system variables such as wind and load. First, stability at individual PE converter level with different control concepts (grid following and grid forming) will be investigated. Then, a multiple PE converters system is modeled and mutual effects among them will be investigated.
Finally, this work will study the stability of a hybrid ac/dc PEC-dominated power system from a system-level point of view. For that, multi-time-scale controller coupling of different conventional equipment and PECs will be studied. A synthetic model (generic component models, parameters from literature/self-tuning) of a European power system will be investigated, with the main purpose to validate the control approach in terms of system scale-up. The readiness of the proposed control algorithms will be subsequently assessed by deploying the proposed control strategy in real-time on laboratory scale.
This project is part of the MIGRATE project, under supervision of Dr. Arjen van der Meer, Dr. Jose Rueda Torres and Prof. Mart van der Meijden.
Nakisa Farrokhseresht received her double degree MSc in energy engineering from KU Leuven, Belgium, and Royal Institute of Technology KTH, Sweden granted by EIT KIC scholarship in 2015. After her graduation, she worked as a research assistant at the electricity market group of the electrical engineering department of KTH. Since 2016, she is pursuing her Ph.D. degree from the Delft University of Technology under the MIGRATE project. Her research interests include modelling and control of power electronic converter and stability in renewable-dominated power system.