DEE-34206 Dynamics and Control of Grid-Connected Converters, 5 cr

Additional information

Courses DEE-33116 Power Electronics Converters and DEE-34107 Modeling and Analysis in Power Electronics has to be completed before taking this course. Exceptions may be made in case of exchange students (ERASMUS etc.) and PhD students. However, the student needs to demonstrate good command on analysis and modeling of DC-DC converters.
Suitable for postgraduate studies. The implementation will not be executed during the academic year 2019-2020.

Person responsible

Tuomas Messo, Jenni Rekola

Lessons

Implementation Period Person responsible Requirements
DEE-34206 2019-01 - Tuomas Messo
Jenni Rekola
Teuvo Suntio
The course is graded based on final paper exam, completed simulation tasks and laboratory work assignment.

Learning Outcomes

The course gives basic knowledge on dynamic modeling of three-phase grid-connected converters in such a way that the student knows basic terminology, control principles, as well as can perform simple control design based on the small-signal model. The student understands the principle of power-hardware-in-the-loop simulations and can test stability of self-tuned controllers in the laboratory. The student understands the basic constraints related to control of grid-connected converters, such as control delay, dynamical anomalities (RHP-poles), unbalanced grid voltages and impedance-based interactions. The student becomes aware of different current control and grid synchronization methods. After taking the course the student has the ability to model three-phase converters and knows how the dynamic model can be utilized to yield stable converter in terms of small-signal stability. Moreover, the student will have the necessary tools to analyze and model more advanced three-phase converter topologies.

Content

Content Core content Complementary knowledge Specialist knowledge
1. Modeling of three-phase passive circuits in stationary and synchronous reference frames.  Understanding the mapping between different stationary and synchronous reference frames.  Instantaneous power theory. The effect of scaling factors in space-vector transformations. 
2. Developing average and linearized models of three-phase converters in the synchronous reference frame. Developing dynamic models for current and voltage-fed inverters and active rectifier.  Constructing and solving reduced-order dynamic models of three-phase converters. Constructing three-port models based on reduced-order model.  Constructing and solving full-order dynamic models of three-phase converters. Constructing two-port MIMO models based on full-order model. 
3. Design of stable feedback control based on dynamic model.  Design of stable cascaded control loops. Understanding the limitations of cascaded control structure. Understanding the effect of control delay.  Control design constraints caused by RHP-pole in the control loop and the effect unbalanced grid voltages. 
4. The concepts of decoupling gains, grid-voltage feedforward and grid synchronization.  Design of stable grid synchronization.Understanding the problems caused by unbalanced grid voltages and basic mitigation principles.  Constraints related to fast grid synchronization.  
5. Impedance-based interactions in three-phase AC systems analyzed in the synchronous reference frame.  The effect of grid synchronization to inverter output admittance and the associated risk of impedance-based instability.  The effect of grid-voltage feedforward to inverter output admittance. Full-order admittance model of grid-connected inverter. 

Study material

Type Name Author ISBN URL Additional information Examination material
Book   Power Electronic Converters: Dynamics and Control in Conventional and Renewable Energy Applications   Suntio, T., Messo, T., Puukko, J.   9783527340224     Few copies available at the library as hard copies. Online version available through University's library.   Yes   
Lecture slides     Tuomas Messo       Available in Moodle after course starts.   Yes   

Prerequisites

Course Mandatory/Advisable Description
DEE-34107 Modeling and Analysis in Power Electronics Mandatory   1
DEE-33116 Power Electronics Converters Mandatory    

1 . DEE-34106

Additional information about prerequisites
Before taking this course the student should be familiar with the following: Basic operational principle, basic topologies and modulation methods of DC-DC and DC-AC converters. Dynamic modeling and frequency-domain analysis related to DC-DC converters. Basic principles of control theory and control design of dynamic systems.

Correspondence of content

There is no equivalence with any other courses

Updated by: Ullgren Sini, 02.04.2019