Tutorials

• Changfu Zou, Chalmers University of Technology, Gothenburg, Sweden
• Yizhou Zhang, China Euro Vehicle Technology AB, Gothenburg, Sweden 
• Abhijit Kulkarni, Aalborg University, Aalborg, Denmark
   

Abstract

This tutorial addresses the critical role of battery systems in advanced mechatronic and power electronics, essential to the operation of electric vehicles, personal devices, smart homes, and smart grids. Effective management of these systems hinges on advanced battery management systems (BMS) that intersect the disciplines of electrochemistry, modeling and simulation, control theory, artificial intelligence, and electrical engineering.

Participants will be introduced to next-generation BMS designed for robust health and safety management. At the core of this tutorial is the exploration of an intelligent platform capable of accurately simulating, estimating, and predicting battery conditions. We will delve into innovative approaches such as Model-Integrated Neural Networks (MINN), digital twin technology, and the strategic incorporation of cell-level actuators for health management. The session will also cover comprehensive risk assessment strategies to ensure the safe operation of battery systems.

Attendees will gain insights into the future of battery management, which is increasingly relevant as the demand for sustainable and reliable energy solutions grows. This tutorial will empower participants with the knowledge to design and implement BMS that are not only intelligent but also integral to the sustainability and safety of power electronic systems.
 

Contents

Thema 1.- Physics-based machine learning with applications to battery modeling

• State-of-art battery models
• Physics-based machine learning
• MINN: a new physics-based learning architecture
• Three application examples of MINN:
  • Lithium-ion battery model
  • Solid-state battery model
  • Phase-field model of electrode materials

Thema 2.- Battery aging prognosis and fast charging: Leveraging AI for real-world vehicle usage

• Data-driven battery aging diagnostics and prognostics
  • Battery state of health estimation using on-board measurements.
  • Battery aging trajectory based on fleet usage information.
  • Battery performance indicators extraction from field data using machine learning.
• Data-driven battery health conscious fast charging
  • Lifelong plating potential estimation
  • Health-aware fastest battery charging

Thema 3.- Smart Battery (SB) architecture for enabling the implementation of AI powered next-generation battery management system

• Design of SB hardware: Overview, challenges and solutions.
• SB communication system with wireless architecture and embedded AI edge device.
• Features and capabilities of the BMS in SB architecture for accurate state estimation, protection and diagnostics.
• Application example of incorporating SB in electric vertical takeoff and landing (eVTOL) aircraft for urban air mobility applications.

• Xiongfei Wang. IEEE Fellow and Professor, KTH Royal Institute of Technology, Sweden
• Heng Wu, Assistant Professor, AAU Energy, Aalborg University, Denmark

Abstract

The grid-forming (GFM) technology is emerging as a promising approach for massive integration of inverter-based resources (IBRs) into electrical grids. Being controlled as a voltage source behind an impedance, GFM-IBRs can provide adequate services to enhance the reliability and resilience of the power network, and they also feature higher stability robustness against grid strength variation than conventional IBRs. In recent years, there is a growing consensus on the need of GFM-IBRs in the future power electronic dominated power systems. Many research and development (R&D) efforts have been initiated, by governments, power system operators, energy developers, and vendors of IBRS, on the technical specifications/grid codes, hardware and control solutions for GFM-IBRs.

This tutorial intends to cover both the basics and advances in GFM-IBRs that can fit the requirements of the evolving technical specifications/grid codes. The tutorial will be divided into 3 sections. It will start with the basic principles and typical control architectures of GFM-IBRs, which will then be followed by the small-signal modeling and stability analysis of GFM-IBRs under various grid strengths. In the end, the dynamics analysis of GFM-IBRs under large grid disturbances, e.g., grid faults and phase jumps, will be performed, covering the transient stability analysis and current limitation strategies.

Contents

Thema 1.- Grid forming Power Converters Concepts and Implementation

• Challenges and trends in power electronics dominated power grids
• Grid following (GFL), grid supporting (GSP) and grid forming (GFM) power converters
• Review of some popular implementations of GFM converters

Thema 2.- Small Signal Stability and Control of Grid Forming Converters

• Small signal dynamics of GFM converter
• Impedance shaping by virtual admittance control
• Control interactions between GFL and GFM converters

Thema 3.- Dynamic Analysis of GFM Converters Under Large Disturbances

• Functional requirement of GFM converters under large grid disturbances
• Transient stability analysis of GFM converters
• Impact of current limitation in GFM converters
• Coordination between transient stability and GFM capability of converters

• Prof. Dr.-Ing. Stig Munk-Nielsen, AAU Energy, Aalborg University, Aalborg Denmark.
• Prof. Dr. Thomas Ebel, Centre For Industrial Electronics, Institute of mechanical and electrical engineering, SDU, Sønderborg Denmark.

Abstract

Hydrogen production using electrolyzer technology in the so called application Power to X (PtX) is a needed future technology to fullfill the gobal climate goals. To produce hydrogen with the highest energy and cost efficiency, modern sophisticated power electronics is needed further a better understanding of the related lectrochemistry of the electrolyzter stacks it self are needed.

According to International Renewable Energy Agency (IRENA) 100 billion USD needs to be invested into green hydrogen technologies from 2023 to 2030 (1 billion USD in 2022) to secure an x500 increase in total installed electrolyzer capacity of more than 400 GW in 2030 (~1 GW in 2022).

This tremendous upscaling in electrolyzer capacity includes power supplies, electrolyzer stacks, and balance of plants. This tutorial dives into the perspectives and challenges related to upscaling power supplies for electrolyzer plants. The state-of-the-art high-power converter intended for Power-to-X applications is dominated by the 24/48-pulse silicon-controlled rectifier (SCR) technology.

The toturial addresses the possibilities and challenges of modern power electronic technologies using wide band gap devices like high voltage 10 kV SiC power modules and relate topologies for MV grid connected converter designs and DC/DC converters for electrolyzer purposes. Further different electrolyzer technologies for the mega watt range will be presented and the interfaces of the power electronics with the electrochemical electrolyzer stacks and the grid will be discussed.

Contents

• Theme 1.- Electrolyzer electrochemistry
• Theme 2.- Properties of different electrolyzer technologies
• Theme 3.- Interphase power electronics electrolyzer
• Theme 4.- Power electronics for electrolyzer
• Theme 5.- Topologies for electrolyzer plants
• Theme 6.-  Connection of electrolyzers to the grid and conclusion

• Jinjun Liu, Xi’an Jiaotong University, China
• Zeng Liu, Xi’an Jiaotong University,China

Abstract

The primary objective of the coordinative control for the distributed energy source converters in a microgrid is to ensure the system voltage to be within a nominal magnitude/frequency range while at the same time with adequate output power sharing among all these energy sources.  It is still very often expected to realize the coordination through autonomous control, i.e., every source converter and transfer equipment is controlled by its own and without getting or sensing any information from others or a center controller of the microgrid/large grid, so that a higher reliability and an easy-to-implement plug-and-play feature could be achieved.  There are two types of autonomous control that have been developed so far for the coordination within a microgrid, i.e. master-slave control and droop control.  The focus of this tutorial will be the droop control, which is also called grid-forming autonomous control and more widely used because of its advantages over the master-slave control. 

The first half of the tutorial will be on the operation principles and advanced techniques of droop control.  The basic principles will be introduced with DC bus power grids as examples, through detailed illustrations based on the simplest system structure of 2 paralleled source converters and one common load.  These principles will then be extended to AC bus power systems, where droop control is implemented in two channels: active power and reactive power.  Several major technical issues that need to be dealt with in droop control will then be identified and some of them will be discussed extensively.

The second half of the tutorial will focus on the deriving of a small-signal terminal characteristic model for the inverters with droop-control in the synchronous reference (dq) frame, accurately covering the dynamics of the power controller, the voltage and current control loops, and all circuit components, where a new set of terminal characteristics is proposed to characterize the small-signal dynamics of fundamental frequency introduced by the fundamental frequency vs. active power droop scheme.  Based on the terminal characteristics of individual inverters, the stability of parallel grid-forming inverters can be predicted by the generalized Nyquist criterion. Furthermore, to simplify the system stability analysis process and reduce calculation complexity, a single-input single-output (SISO) stability analysis approach is proposed by exploring the interaction among the droop-controlled parallel inverters through analyzing mathematical feature of the proposed terminal characteristic model of individual inverters as well as the return ratio of the parallel inverters, which uses d-d channel element of system return ratio matrix and Nyquist criterion to predict the stability.

Contents

Thema 1.- Introduction and autonomous control (by Jinjun Liu)

• Introduction
• Basics of Autonomous Control of Microgrid-Forming Inverters
• Advanced Techniques for Autonomous Control in Microgrid-Forming
  • Secondary Control for Frequency Restoration
  • Reactive, Unbalanced and Harmonic Power Sharing
  • Selection of Small-AC-Signal
  • Successive Approximation for Power Sharing

Thema 2.- System stability (by Zeng Liu)

• Small-Signal Interactions among Microgrid-Forming Autonomous Inverters
• A new method for stability analysis
  • Terminal Characteristics Definition of Inverters
  • Modeling and Stability of Parallel Inverters Based on Terminal Characteristics
• Detailed Modeling Process and Simplification
  • Terminal Characteristics Modeling of Microgrid-Forming Inverters
  • SISO Stability Analysis Approach for Parallel Inverters

• Fernanda de Morais Carnielutti, Prof. Dr., Federal University of Santa Maria, Brazil
• Caio Osório, Dr. Engineer, Typhoon HIL
• Humberto Pinheiro, Prof. Dr., Federal University of Santa Maria

• Dimas Alã Schuetz, Me. Eng., Federal University of Santa Maria

Abstract

Join us for a comprehensive hands-on tutorial exploring the intricacies of designing and testing grid-tied converters. Beginning with a rigorous examination of theory, participants will gain insights into the underlying principles and methodologies of synchronization algorithms and digital current controllers. Using the TyphoonSim™ offline simulator, concepts will be immediately put to the test, allowing for a dynamic validation and refinement of the concepts and designs. As the tutorial progresses, attendees will learn how to export controller C code from the model to an external Digital Signal Processor. This critical step bridges the gap between offline simulation and real controller implementation, ensuring seamless integration of theoretical concepts into practical application. Finally, we will transition to real-word testing by deploying real-time hardware-in-the-loop simulation to validate our closed-loop systems with the utmost accuracy.

Led by a seasoned professor, this tutorial offers a unique educational opportunity for those seeking to deepen their understanding of grid-tied converter applications. Join us for an enriching experience that combines theory with hands-on practice. Attendees are expected to have basic knowledge of power electronics, control systems, C language, power converter modeling, and discrete-time domain analysis. It would be a great differential if you took the course Digital Control of Grid-Tied Converters at HIL Academy as preparation for this tutorial. The course can be found in

https://hil.academy/courses/digital-control-of-grid-tied-converters/

Contents

• Thema 1 - Current controllers for digital control of grid-connected converters
  • Design principles and methodologies
  • How to implement and simulate current controllers on the TyphoonSim™ (hands-on).
• Thema 2 - Synchronization algorithms for digital control of grid-connected converters
  • Introduction to synchronization algorithms
  • How to implement and simulate synchronization algorithms on the TyphoonSim™ (hands-on).
• Thema 3.- Implementation of the grid-tied converter current controller in a Texas Instruments DSP 28379D using Typhoon Auto Code generation tool
  • HIL simulation using TI launchpad and HIL Interface board connected to a HIL 402/404 (demo tutorial)
• Thema 4.-  Discussion and Q&A session
  • Particular questions about digital control of grid-tied converters with Typhoon HIL

• Sebastian Hubschneider, R&D Dr. Engineer, OPAL-RT
• Marija Stevic, R&D Engineer, OPAL-RT
• Giovanni de Carne, Prof. Dr. Ing., Karlsruhe Institute of Technology

Abstract

Digital Real Time Simulators (DRTS) are powerful tools that enable the connection between the digital and real world. Large and complex systems, such as electrical grids, can be simulated in real time, where the digital simulators can compute their model solutions with relatively small time steps (10~50µs or below).  These small time steps permit to interface the simulated electrical networks with real hardware, such as grid controllers or power devices, with reasonable time fidelity and response. Interfacing these simulators with external devices by means of sensors and digital or analog communication, such as in Hardware-In-the-Loop (HIL) testing, allows to exchange digital- or hardware-measured variables between the digital and real world.

While digital real time simulation has clear potential to flexibly test any hardware in realistically simulated grid conditions, its limitations must be considered. On the opposite of off-line simulations, where a larger size of the simulated network or more complex and detailed power electronics models make the simulation computations only slower, DRTSs must respect hard real time constraints. These constraints mean that the simulated system solution shall be delivered within the desired time step and any overrun results in the interruption and failure of the simulation. As a consequence, the size of the simulated system must stay relatively small to meet computational timing constraints. Increasing the simulation details, e.g. power electronics switches or high-order generator equations, decreases the system scale, that can be solved in a certain time step. These restrictions are exacerbated with simulation of switching power electronics due to computational cost of solving models of their non-linear nature.

This tutorial’s goal is to train the researchers approaching digital real time simulation in performing computational time-efficient and accurate simulations of electrical networks, and in particular of power electronics-based ones. The tutorial is structured with a system-to-component level approach. In the first section, we will provide guidelines to the modelling of grid connected converters so to minimize the computational effort while maintaining the accuracy required by the specific design or analysis objective. In this section we will focus on test scenarios (e.g. primary frequency regulation) that require the modelling of large power systems with a high number of converters. Those models target a time step of a few tens of microsecond.

While in the first section we will mainly focus on averaged converters models and control representation, in the second section we will work on the switching representation of power converters, particularly for complex systems such as Solid State Transformers, and we will analyze how the different modelling approach affect the computational effort. We will then focus on scenarios that require a switching representation of power converters. The focus will still be on analysis and systems that require a microseconds level time resolution.

In the third section we will work on the application of this models for experimental testing by means of Power Hardware In the Loop (PHIL) technique. We will provide an overview of the PHIL approaches and we will highlight the challenges in performing stable and yet accurate PHIL testing. Exemplary large-scale testing results in PHIL will be shown, focusing on the advantages in using PHIL for a realistic performance assessment of energy technologies.

Contents

• Thema 1.- Introduction to power electronics modeling for real time simulations
  • How to implement models
  • How to reduce computational time
• Thema 2.- Real-time simulation of power electronics systems
  • Modelling power converters in real-time
  • Modulation and control loops implementation
• Thema 3.- Power Hardware In the Loop potential and challenges for realistic testing
  • Interfacing hardware with the simulation loop
  • Challenges and solutions in real implementations
• Thema 4.- Discussion and Q&A session
  • Discussion about practical details and specific solutions

• Dipl. Math. Dirk Kordtomeikel, Head of Industry Management Energy, Beckhoff Automation GmbH & Co. KG
• Dr. Fabian Assion, Product Management Energy and Power, Beckhoff Automation GmbH & Co. KG
• Master of Science Nils Johannsen, Head of Technical Development Energy, Beckhoff Automation GmbH & Co. KG
• Dipl. Ing. Karl Stapelfeldt, Specialist for Power measurement and wind turbine grid integration, Beckhoff Automation GmbH & Co. KG

Abstract

1. We are introducing our technology, starting with a brief introduction of the company and the principles of New Automation Technology.
2. This lecture will present our basic technologies regarding hardware. Starting with a deeper look into the technologies, followed by a product overview of components which are useful for the power and grid industry and the research on it.
3. Some basic ideas to perform a faster reaction of renewables to grid faults.
4. What is TwinCAT and how can be used for research and development.
5. Hands on different applications as power measurement, sub stations, converters and wide area grid measurement

Contents

• Introduction, EtherCAT and products for power measurement
• eXtreme fast wind farm networking and TwinCAT
  • TwinCAT Modules: modular engineering and runtime
  • Open Automation Technology: Open IT standards in the OT world
• Coffee break
• TwinCAT Energy
  • Power measurement devices
  • Solutions for sub stations
  • Solutions for converters
  • Solutions for wide area grid measurement (Phasor Measurement Unit)

• Niklaus Felderer, Plexim GmbH
• Christopher Ranisch, University of Applied Sciences Darmstadt
• Prof. Dr.-Ing. Christian Weiner, University of Applied Sciences Darmstadt

Abstract

Designing a power electronic system is a multidisciplinary task, involving not only the power stage design, but also the development of the control algorithms, which are often implemented on a microcontroller (MCU). Increasing controller complexity contrasts with today’s fast-paced market demands in industry. As a result, the handwritten codebase often lacks modularity, clear structure, documentation and testing.

PLECS in conjunction with the PLECS Coder enables engineers to intuitively model and simulate controls for power electronics systems and implement them on selected MCUs. This automatic code generation workflow eliminates the need for in-deep software development skills or specialized knowledge of MCU peripherals. The iterative development approach using a PLECS simulation model allows a design to evolve from an initial concept to a robust implementation, with the model serving as the definition and the documentation of the control algorithm.

Testing and validating control firmware is increasingly employed on digital real-time simulators, without the actual power stage being available. The actual power circuit, which represents the controlled system, is replaced by an appropriate dynamic model computed on the real-time simulator. The same PLECS simulation model, that already has been used to generate code for the controls, can be used to perform a real-time simulation of the power stage.

The tools mentioned above support the power electronics engineer throughout the entire design process, from implementation to verification of the control firmware.

Participants are welcome to bring laptops for a hands-on walkthrough of the PLECS toolchain. After minimal lecture material is provided for laying out the basic theoretical background, attendees will build a simple closed-loop control model, generate code for an STM32 MCU target, and verify its performance in a real-time simulation. PLECS licenses and MCU hardware will be distributed during the tutorial. Further, practical applications and their real-time simulation on a HIL system will be demonstrated.

Contents

1. Introdcution to offline control system modeling in PLECS (15 minutes)
   • Signal conditioning blocks
   • State machine environment
   • Advanced blocks
2. Introduction to PLECS code generation workflow (45 minutes)
   • Exploration of Target Support Package block libraries
   • Control task execution and timing
   • Multitasking environments
3. Build-up closed loop controller model (30 minutes)
   • PLECS based model and peripheral configuration
   • PLECS Coder target selection and code generation
4. Coffee break (15 minutes)
   • 1 to 1 help with PLECS installation
5. Deployment of control code and interaction with target (20 minutes)
   • Discretization step-size discussion
   • External mode and data acquisition in PLECS
   • Online tuning of control gains
6. Overview and introduction to HIL (30 minutes)
   • Introduction to hardware-in-the-loop simulations for controller testing with PLECS RT Box
7. Example demo of typical industry application (10 minutes)
   • Walk-through of control algorithm model
   • Hardware-in-the-loop simulation on the PLECS RT Box
8. Wrap-up and Q&A (15 minutes)