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Development targetsThe e-Storage System provides multiple usage scenarios as battery tester, battery emulator and e-motor/inverter testing facility. The sys-tem has to satisfy such criteria as high dynamics, broad voltage range (typically 8-800 V), low residual ripple and stability despite the variety of possible loads. Variability of possible use cases, automated testing processes and real-time fail-safe operation require usage of special-ized microcontrollers for digital control of power electronics system. To fulfi ll the described requirements, the development team has to be focused simultaneously on three key system elements, which are scalable hardware design, reliable application software and control strategy.

The most challenging task to utilize the dynamic bandwidth of the designed power electronics hardware is designing an advanced con-troller. Modern approaches allow reducing hardware components size and costs, but have to be thoroughly verifi ed in simulation. On the design stage, software simulation tools allow different parasitic effects and nonlinearities to be factored into. But still, implementation of the control algorithm on respective target MCU/DSP hardware requires an environment where the switching behavior of the control plant is simulated in real-time.

Embedded software development approach using HILTo ensure prompt verifi cation of the control software, Hardware-in-the-Loop testing approach has been chosen, with Typhoon HIL600 system as core of the testing platform. Relative simple adaptor boards act as an interface between AVL power controller unit (PCU) and Typhoon HIL600 system, making it possible to evaluate the compu-tational power of used microcontroller directly. HIL testing not only provides the closed-loop control verifi cation, but also gives the pos-

sibility of application software testing and debugging at early stages of development in the development lab environment (Figure 1 shows the HIL testing setup). The control loop runs side by side with other tasks required by application software (communication, safety supervision, etc.).

Software development with HIL approach fundamentally decreases the typical costs and risks of power electronics development, avoiding the hazard of damaging the system. Simultaneously, the fl exible eval-

Hardware-in-the-Loop testingas a Key Element in the

Development of High Performance Battery Emulators

The AVL e-Storage System family is a significant player on the market of dynamic power supplies in automotive industry. To fulfill the growing performance requirements,

leading-edge control strategies are introduced in the new generation of AVL products. Hardware-in-the-Loop testing is an important tool for the development team, helping to

reduce control algorithm and software verification time and effort.

By Maksym Shkadron, Oliver König and Roland Greul; BU Electrification and Racing Test Systems; AVL List GmbH

TEST AND SIMULATION

Figure 1 - HIL working environment: AVL power controller unit in a loop with HIL600

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uation platform enables software verifi cation under various operating conditions and makes it easier to fi nd appropriate hardware confi gura-tion for the desired performance requirements. It is worth mentioning, that measurements obtained from prototype hardware setup, were almost the perfect match with HIL simulation.

Considering the importance of Hardware-in-the-Loop testing in the embedded software development workfl ow for AVL e-Storage System (which is shown in the Figure 2), it can really be called the key ele-ment in it.

ConclusionsThe effi ciency of the described workfl ow using Typhoon HIL600 could be leveraged during the development of AVL e-Storage Systems. The classical V-model of system engineering and verifi cation can be improved by using HIL testing on different system maturity levels. In context of power electronics product development, HIL simulation was particularly benefi cial because embedded software design was running in parallel to prototype hardware development and assembling. Owing to the fact of early porting of controller algorithm to the real target hardware, a large number of issues, especially in control hardware confi guration, can be solved prior to system integration phase. This results in signifi -cant development time and cost benefi ts.

www.avl.comContact:BU Electrifi cation and Racing Test Systems; AVL List GmbHHans-List-Platz 1, 8020 Graz, Austria; maksym.shkadron@avl.com; oliver.koenig@avl.comroland.greul@avl.com

TEST AND SIMULATION

Figure 2 - AVL embedded software development workfl ow using HIL