Speaker: Lior Marcus
M.Sc. student under the supervision of Prof. Weiss George
Wednesday, February 12th, 2020 at 15:00
Room 011, Kitot Bldg., Faculty of Engineering
System Architecture, Software Design and Implementation of a Synchronverter
Abstract
This thesis demonstrates a specific design and software implementation of a synchronverter, an inverter which behaves like a synchronous generator. The paper focuses on the architecture of the overall software in charge of actuating the different tasks the synchronverter’s CPU does.
A synchronous generator (SG) once synchronized, stay synchronized unless strong disturbances destroy the synchronism. This is one of the features that have enabled the development of the AC electricity grid at the end of the XIX century. Unfortunately, due to the proliferation of power sources that are not SGs, the stability of the whole power grid is threatened. These power sources mostly use inverters to deliver power to the grid, and are designed to deliver maximum power from the source with no consideration of the grid stability. As such, they introduce disturbances due to the intermittent nature of the power source and they increase the sensitivity of the grid to other disturbances such as changes in loads and faults in generation or transmission.
As a result, the stability of networks of SGs that are coupled with various types of loads and other types of power sources (such as renewables) that are operated with the help of multiple control loops, is an area of high interest and intense research, see for instance (J. Alipoor, 2013), (F. Blaabjerg, 2006), (J. M. Guerrero, 2009), (P. Kundur, 1994), (A. Ulbig, 2014). An inverter which behaves like a synchronous generator can simplify the overall system behavior during sudden disturbances and increase its stability. Such inverters, sometimes called synchronverters, have been proposed in (R. Hesse, 2007), (K. Visscher, 2008), (K. Visscher and S. W. H. de Haan, 2008), (Q. -C. Zhong P. -L. Z., 2014). Actually, the control algorithms proposed in these papers are different and the term synchronverter refers to inverters controlled as in (Q. Zhong and G. Weiss, 2011).
The design shown in this thesis includes two main parts, the power unit and the DSP program. The power unit, which in charge of the switching process and power flow from and to the AC grid, will only be shortly described. The DSP program, which is the software running on the CPU of the synchronverter, is in charge of running the algorithm presented in (V. Natarajan and G. Weiss, 2017). This thesis describes the overall software system architecture, which has been designed, implemented and tested in large part by the author, in order to achieve that goal. It will include a detailed account of the program’s six blocks, each designed to allow the DSP program to interact with different parts of the synchronverter or execute different tasks that improve the overall performance of our synchronverter design.
