Tweet

Posted on 02 July 2019

Hardware-in-the-Loop Laboratory for Hands-on Learning of Power Electronics Controls

Free Bodo's Power Magazines!

 

 

 

From development and engineering departments in leading power electronics companies to major research and teaching institutions ultra-high fidelity Hardware-in-the-Loop technology is revolutionizing the way power electronics control is designed, optimized and tested.

By Prof. Kaushik Rajashekara and Prof. Bilal Akin, UT Dallas; Chris Clearman, Texas Instruments Inc., and Marko Vekic, Typhoon HIL Inc.

Introduction

We propose a unique Hardware-in-the-Loop based system for handson learning of power electronics that holds a promise to completely change the learning process according to the formula: play first and get quickly engaged while effortlessly developing intuition, and only then go for the in-depth exploration of power electronics theory and engineering principles.

This approach may appear to be counter intuitive at first; however it provides twofold benefit: through "playing," technical intuition is developed with ease together with motivation to understand both the theoretical concepts and design practices .

With ultra-high fidelity HIL400 real-time emulator, from Typhoon HIL, Inc., equipped with a rich library of power electronics components, and a TI DSP based controller board, this learning kit is a desktop alternative to expensive and dangerous power electronics laboratory. HIL based learning station, shown in Figure 1, comprises:

  • Typhoon HIL400 Real-time Emulator which models electrical machines, switching elements, passive elements, transformers, PV panels, batteries, super-caps, electrical grid etc.
  • Controller Docking Station from Typhoon HIL, Inc. with TI DSP TMS320F2808 control card with working examples of PE controllers, and
  • Power Electronics Practicum from Typhoon HIL, Inc. which covers theoretical background of PE converter control techniques with practical examples working on HIL400 and TI control card.

HIL 400 learnig kit

Control of Grid Connected Converters: Example Learning Module A two-level three-phase grid connected converter (GCC) shown in Figure 2. is an instructive example widely used for bidirectional control of power flow in grid connected converters, including renewable energy sources used in wind and solar, FACTS, grid storage devices, and micro grid applications. The learning module is divided into four independent sections that effortlessly guide students from application level understanding all the way to implementation details; from simple to complex control concepts.

Schematic block diagram of a grid connected converter system

Grid connected converter teaching module is divided into four sections that enable quick and enjoyable process of learning advanced control concepts and practice with full hands on experience. Indeed, the teaching module covers from application level exploration all the way to control loops implementation, theory, and control performance verification.

Section one: Application level exploration

First section is the introductory part of the teaching module. With minimal theoretical background required, students dive straight into hands-on, fully live, "laboratory" setup interacting directly with a wealth of scope signals. Hence, they can explore the application level aspects of converter design and control. Power stage is specified in Typhoon HIL schematic editor, shown in Figure 3, followed by circuit compilation for real-time execution on HIL hardware. After the circuit is compiled and loaded onto the HIL400, students can directly start controlling simulation via Control Panel, shown in Figure 4, that among other features enables easy analog and digital input/output configuration and routing, grid voltage programming etc.

Schematic diagram of Grid Connected Converter modeled in Typhoon HIL Schematic Editor

Control panel for simulation control, grid voltage programming and I/O configuration

Section two: Optimizing fast control loops

This section teaches the hands on optimization of the Phased Lock Loop (PLL) design, current control loop design, and dc voltage control design. Through experimental work, with interactive HIL setup, students develop intuitive understanding of the tradeoffs in the controller design and their influence on the design robustness against disturbances such as grid harmonics, frequency variations, current harmonics from nonlinear loads, controller parameter sensitivity and more.

Indeed, this section guides the users through every step of the closed loop control optimization, and verification by means of well documented tests that illustrate the performance and robustness of the controller implementation. In other words, the focus is on developing the intuition, through hands-on experimentation, while the theory is only introduced later on in the section three. For example, Figure 5 illustrates the system response to a step change in current reference from 0 to 2A which is just one example of numerous experiments covered.

HIL400 learning kit experimental results: grid connected converter response to a step change in current reference

Section three: Connecting the theory with experiments

This teaching module section offers in-depth coverage of theoretical foundations with theory behind the current loop control structure, Park transformation, and several approaches for calculating and optimizing PI controller parameters as illustrated in Figure 6.

Theoretical explanation from Typhoon HIL Power Electronics Practicum

In addition, this section goes into more in-depth issues about implementation of the control algorithms from Figure 6 using Texas Instruments Code Composer Studio 5.

Section four: Industrializing the controller design

In the final part, we offer a wealth of ideas on how to improve and optimize the original controller design and how to systematically verify the system response against various disturbances encountered in industrial application. Also, basic grid compliance concepts and several dynamic grid support requirements are introduced and controller designs are tested in an automated fashion.

Snippet of the C-code implementation of the PI regulator in TI DSP

The most important aspect of the learning kit is that it is fully interactive (any change is immediately experienced), completely safe (nothing to explode), applicable to power ranging from W to MW, yet praxis oriented and based on industrial grade controller design approaches running on real controller hardware system.

HIL based Power Electronics Teaching Laboratory at UT Dallas

Conclusions

Experiences from the University of Texas at Dallas’s Typhoon HIL and Texas Instrument based Teaching Laboratory as shown in Figure 8, reveal a new and unexpected ways to enrich the power electronics learning experience in a completely safe (+/-5V) yet fully interactive, flexible, and ultra-high fidelity environment with real control hardware, firmware and software.

 

VN:F [1.9.17_1161]
Rating: 0.0/6 (0 votes cast)

This post was written by:

- who has written 791 posts on PowerGuru - Power Electronics Information Portal.


Contact the author

Leave a Response

You must be logged in to post a comment.