Khazraj, Hesam

PROJECT TITLE: Control Tuning of Phase Measurement Units - based Protection Systems with VSC-HVDC Controls to Mitigate Instability of System 

PhD period: 2015.06.01 – 2018.05.31.
Section: Electric Power Systems
Research Programme: Modern Power Transmission Systems
Supervisor: Filipe Miguel Faria da Silva 
Co-Supervisor: Claus Leth Bak 
Contact Information

Funding: Dept. of Energy Technology and AAU.

ABSTRACT

Power system state estimation (SE) is a process used to determine the state of a network by using measurements and models of the grid. The state estimation approaches developed in this project will include DC measurements and converter control inputs, as a seamless combination of AC and DC devices or networks, provides a higher degree of redundancy. As AC/DC conversion involves no inertia and power settings of HVDC links can be changed quasi-instantaneously, modulating of active power flow through the HVDC-links has been proposed to improve power system stability. Some applications which combines the Wide-Area Measurements System (WAMS) and control of VSC-HVDC will be implemented, for instance WAMS with embedded VSC-HVDC control for oscillation damping. With a proper redundancy level, SE can eliminate the effects of bad data and produce reliable state estimates in order to help operators and support other analysis functions in energy management systems (EMS).

The project is divided into three parts. First part includes a synthesis of wide-area stability monitoring, instability concepts, and coordination between protective system and VSC-HVDC to mitigate instability. The project will use Wide Area Measurement system coordinated between HVDC link controller and protective system to damp power oscillations. The set-points of the controllable devices are the inputs and the speed signals of certain generators are the outputs.

Second part includes different control strategies of VSC-HVDC to mitigate instability of system and also the validation of the control schemes with different voltage instability scenarios. Third part contains tuning parameters of additional PI-controller and optimization of mixed control (p_dc&Q_dc). 

PAPERS

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