Liao, Yicheng

PhD student Yicheng Liao

PROJECT TITLE: Stability and Control of Grid-interactive Converters

PhD period: 2020.03.15 – 2021.03.14.
Section: Power Electronic Systems
Research Programme: Electronic Power Grid (eGrid)
Supervisor: Xiongfei Wang
Contact Information

Collaborator: Huawei Technologies Co.
Funding: Aalborg University-Huawei Energy Innovation Center


With the increase of renewable energy sources, power electronic converters play more and
more significant roles in future power grids. Different control strategies, such as gridfollowing
control and grid-forming control can be utilized in power converters to provide
power supply to various consumers. Differing from the traditional synchronous generators,
power converters have flexible controllability in wide timescales, which result in complex
dynamics and can lead to instability issues in a wide frequency range. Consequently, it is
significant to understand the dynamic behavior of power converters, which helps to
implement design-oriented analysis for stability enhancement.
This PhD project aims to study the stability and control of grid-interactive converters, by the
means of small-signal modelling and frequency-domain analysis. The general methodology
of the frequency-domain modelling and stability analysis for three-phase converters will be
developed. Based on several case studies on grid-following and grid-forming converters, the
instability mechanism caused by converter-grid interactions will be revealed, and robust
control schemes to enhance the system stability will be proposed.


Publications in journals and conference papers may be found at VBN.