# Industrial/PhD Course: Modeling and Control of Grid-Connected Converters

## Time

27.05.2020 kl. 08.30 - 29.05.2020 kl. 16.00

## Description

### Organizer

Professor Xiongfei Wang

### Lecturers

Prof. Lennart Harnefors, ABB Corporate Research/KTH, Sweden

Prof. Xiongfei Wang, Aalborg University, Denmark

### ECTS: 3

### Description

Grid-connected converters have commonly been used with renewable power generations, flexible ac/dc power transmission systems, regenerative drives, etc. As the increasing use of converters in electrical grids, the dynamic modeling and control of converters become critical for building a stable power-electronic-based power system. This course thus devotes to provide a design-oriented analysis on the control dynamics of grid-connected converters, covering the fundamental and state-of-the-art of modeling, stability analysis and control topics, including:

- Vector current control
- Complex-valued frequency-domain modeling
- Impedance-based stability analysis
- Grid synchronization control and its stability impact
- DC-link and ac-bus voltage control
- Robust damping control techniques

Day 1: Vector Current Control, Prof. Xiongfei Wang (3 hours), Prof. Lennart Harnefors (3 hours)

- Space vectors and coordinate transformation
- Small-signal modeling of converter power stage
- Design of vector current controller and its anti-windup
- Influences of time delay and LCL-filter resonance
- Harmonic current control and practical design

Day 2: Grid Synchronization and Power Control, Prof. Lennart Harnefors (3 hours), Prof. Xiongfei Wang (3 hours)

- Phase-Locked Loop (PLL): small-signal modeling and parameter tuning
- Influence of PLL on grid-converter interactions
- Impedance-based modeling and stability analysis
- Stability of DC-link Voltage Control (DVC)
- Stability of AC-bus Voltage Control (AVC)

Day 3: Robust Damping Control, Prof. Xiongfei Wang (3 hours), Prof. Lennart Harnefors (3 hours)

- Virtual impedance control
- Passivity-based current control
- Power-synchronization control
- Step-by-step design cases

### Prerequisites

Prior knowledge of three-phase systems, power electronics fundamentals, feedback control theory are preferred.

### Form of evaluation

Exercises and report

### Registration

### Price

6000 DKK for PhD students outside of Denmark and 8000 DKK for the Industry.

### Host

Department of Energy Technology

### Address

Aalborg University, Pontoppidanstræde 101, room 1.015, 9220 Aalborg East