Department of Electrical and Electronic Engineering
Kitami Institute of Technology
165 Koen-cho, Kitami, Hokkaido, 090-8507 Japan
Prof. Dr. Junji Tamura (M’86–SM’92) received his B. Sc. Eng. Degree from Muroran Institute of Technology, Japan, in 1979, and M.Sc. Eng. and Dr. Eng. degrees from Hokkaido University, Japan, in 1981 and 1984 respectively, all in electrical engineering. He became a lecturer in 1984, an Associate Professor in 1986, and a Professor in 1996 at the Kitami Institute of Technology, Japan. From 1991 to 1992, he had joined the Energy Systems Research Center of University of Texas at Arlington (UTA) as a visiting research Professor. He had been a chairman of the committee of Rotating Machinery of IEEJ (The Institute of Electrical Engineers of Japan) from 2008 to 2010, and he was a conference chair of International Conference on Electrical Machines and Systems 2012 (ICEMS 2012, Sapporo, Japan) in 2012. From 2006 to 2014, he had been a Vice President, and from 2014 to 2018 he had been an Executive Vice President of the Kitami Institute of Technology. He is currently a Professor and the Head of the Laboratory of Electric Machinery of the Kitami Institute of Technology, Japan. His main research interests and experience include analysis of synchronous machines, analysis and simulation of power system dynamics and stability, and analysis and control system design of wind power generation system. He has authored or co-authored about 180 peer-reviewed journal papers and presented about 220 papers in international conferences.
Title: Review and New Method of Virtual Synchronous Generator Control of Power Systems
In this keynote speech, firstly fundamental theory of the virtual synchronous generator (VSG) is reviewed. As renewable power sources like solar stations and wind farms which are controlled basically with power electronic inverters increase, conventional synchronous generators need to be decreased to keep balance between demand and supply in the power systems. However the power system inertia and synchronizing power, which have been supplied from the conventional synchronous generators, also decrease accordingly, and thus the stability of power system deteriorates. In order to solve this problem, the concept of VSG has been proposed and developed, in which the power electronic inverters are controlled to mimic the characteristics of conventional synchronous generators. Some representative strategies for constructing VSG which have been proposed and reported so far are introduced.
Next a new method for achieving the virtual synchronous generator control to enhance the stability of power systems is introduced, which is based on the power flow control of some equipment installed at power systems, i.e., High Voltage Direct Current (HVDC) transmission line, batteries, variable speed wind turbine generators, and LFC (Load Frequency Control) hydro power plant, etc. Output from these power equipment are controlled cooperatively according to the output command from the new virtual synchronous generator control system. The control system is based on PID Fuzzy Logic Controller and the output command is composed of three components, PDroop, PInertia, and PSynch, which are generated by the proportional, integral, and differential controllers and corresponding to damping, synchronization, and inertia effects of conventional synchronous generators respectively. The three components, PDroop, PInertia, and PSynch, are distributed to each power equipment according to their response speed and power capacity. For example, PInertia, which is corresponding to the virtual inertia control power is sent mainly to batteries and HVDC transmission line because their response speed is fast.
Finally effectiveness of the new VSG control system is demonstrated through simulation results obtained by using PSCAD /EMTDC software, in which it is shown that the power system stability with large-scale WF installed can be enhanced by the new VSG control system.