BIO
Chris Wembridge is a PhD candidate at the University of Tasmania, affiliated with the Centre for Renewable Energy and Power Systems and the ARC Future Grids Training Centre. He is also an experienced Senior Power Systems Engineer with ten years of industry experience in the power sector and four years of academic teaching experience. His research interests and focus are in machine theory, protection of power systems, power electronic systems and the grid integration of renewable energy resources. He is also a representative for CIGRE, committee group C4 - Power System Technical Performance and working group member for the Technical Brochure ‘Advancements in Frequency Protection’. He is affiliated with Engineers Australia as a Chartered Engineer, a Senior Member of IEEE and also a member of IET and EESA.
PROJECT TITLE
Inverter responses during system faults
SUPERVISORY TEAM
Assoc. Prof. Evan Franklin
Prof. Michael Negnevitsky
Dr. Sarah Lyden
Dr. Waqas Hassan
Adjunct Assoc. Prof. Mark Davies (TasNetworks)
PROJECT SUMMARY
With the increasing connection of converter interfaced generation to power systems, further requirements are being placed on converters to both improve system reliability and fault ride-through performance. Most existing control strategies for six-pulse bridge inverters employ a balanced positive sequence control that injects positive phase sequence current only and suppresses negative phase sequence current delivery. This results in two major challenges for the converter and for the grid during network faults: (1) high second harmonic ripple on the dc bus voltage, resulting in significant stress on the converter and control performance; and, (2) exposure of the network to excessive voltage rise on the healthy phase(s), resulting in temporary over-voltage and equipment stress or disconnection. This project aims to develop a closed loop converter that can independently deliver positive and negative sequence current during a fault and demonstrate the benefits of such an approach for both grid and converter. This converter will be modelled via EMT and real-time simulation and validated through hardware testing. Ultimately, this will define a set of criteria that can be used to ensure equitable performance that benefits both power system and converter, and demonstrating that these criteria can all be satisfactorily met, this research will help shape future grid code requirements.