IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 47, NO. 2, MARCH/APRIL 2011 853
Real-Time FPGA-Based Hardware-in-the-Loop
Simulation Test Bench Applied to Multiple-Output
Power Converters
Óscar Lucía, Student Member, IEEE, Isidro Urriza, Luis. A. Barragán, Denis Navarro,
Óscar Jiménez, Student Member, IEEE, and José M. Burdío, Member, IEEE
Abstract—This paper presents a hardware-in-the-loop (HIL)
simulation technique applied to a series-resonant multiple-output
inverter for new multi-inductor domestic induction heating
platforms. The control of the topology is based on a system-
on-programmable chip (SoPC) solution, which combines the
MicroBlaze embedded soft-core processor and a customized pe-
ripheral that generates the power converter control signals. The
firmware is written in C, and the customized peripheral is de-
scribed using a hardware description language. Simulating the
whole system using digital or mixed-signal simulation tools is a
very time-consuming task due to the embedded processor model
complexity, and additionally, it does not support tracing C in-
structions. To overcome these limitations, this paper proposes a
real-time simulation test bench. The embedded processor core,
peripherals, and the power converter model are all implemented
into the same field-programmable gate array (FPGA). Using the
hardware and software debugging tools supplied by the FPGA
vendor, currents and voltages of the power converter model are
monitored, and firmware C instructions are traced while running
on the embedded processor core. Then, it is presented a design
flow that is proven to be an effective and low-cost solution to verify
the functionality of the customized peripheral and to implement a
platform to perform firmware verification.
Index Terms—Electromagnetic induction, field-programmable
gate arrays (FPGAs), modeling, resonant inverters.
I. I NTRODUCTION
T
HE IMPLEMENTATION of multiple-inductor power
converters requires often the development of specific-
purpose control architectures to obtain the most of the con-
verter. These are usually based on a processor, which provides
software (SW) flexibility, and specific-purpose hardware (HW),
which provides customized functionalities. In addition, recent
Manuscript received April 17, 2010; revised July 12, 2010 and
September 16, 2010; accepted September 27, 2010. Date of publication
December 30, 2010; date of current version March 18, 2011. Paper 2010-IPCC-
140.R2, presented at the 2010 IEEE Applied Power Electronics Conference and
Exposition, Palm Springs, CA, February 21–25, and approved for publication
in the IEEE TRANSACTIONS ON I NDUSTRY APPLICATIONS by the Industrial
Power Converter Committee of the IEEE Industry Applications Society. This
work was supported in part by the Spanish Ministerio de Educación y Ciencia
under Project TEC2010-19207 and Project CSD2009-00046, in part by the
Diputación General de Aragón under Project PI008/08, and in part by the Bosch
and Siemens Home Appliances Group.
The authors are with the Department of Electronic Engineering and Commu-
nications and the Aragon Institute of Engineering Research (I3A), University
of Zaragoza, 50018 Zaragoza, Spain (e-mail: olucia@unizar.es).
Color versions of one or more of the figures in this paper are available online
at http://ieeexplore.ieee.org.
Digital Object Identifier 10.1109/TIA.2010.2102997
trends suggest the integration of both functionalities in a single
chip using an embedded processor, intellectual property (IP)
cores, and some customized peripherals, providing a so-called
system-on-programmable-chip (SoPC) solution [1].
The power converter and the embedded processor can be
simulated using mixed-signal [2] and cosimulation [3] tools.
Another approach is the holistic one, which proposes the use of
a unique description language during the whole development
procedure [4]. These approaches allow full visibility of internal
signals. However, they do not allow tracing the C instruc-
tions, and simulations are extremely slow due to the embedded
processor cycle accurate model. Another approach is to con-
nect the power converter to the field-programmable gate array
(FPGA) and make real-time SW debugging of the embedded
processor; however, the power converter can be damaged due
to any malfunction of the SW algorithm.
The utilization of FPGA embedded processors requires SW
debugging in addition to HW verification tools. Some HW/SW
coverification tools are available, such as Seamless FPGA form
Mentor Graphics [5]. Another approach to speed up simulation
and debug the SW system at HW speeds while eliminating the
risk of damaging the actual power converter is the utilization
of HW-in-the-loop (HIL) simulation [6]–[11]. HIL is based on
adding at least one actual subsystem into the loop.
Some works have been developed using an FPGA in the loop
[3], [12]–[16] or using the commercially available dSPACE
solution [9]. In [12], [13], the power converter model is im-
plemented in fixed point on an FPGA, and the digital controller
runs on an external DSP [3], [12] or CPU [13]. In [14], the
FPGA is used as a high-speed peripheral input/output device. In
[15], the controller is implemented in the FPGA, but the power
converter model runs on a PC. In [16], the plant model and the
power converter are implemented in fixed point into the same
FPGA. However, none of these digital controllers use an FPGA
embedded processor.
The aim of this paper is to provide a design flow to obtain
a real-time FPGA-based test bench to perform HW/SW verifi-
cation for the proposed SoPC system. The design flow verifies
the functionality of the customized peripherals and the power
converter model without the need of simulating the embedded
processor cycle accurate model. Thus, it accelerates simulation
of the whole system, shortens the verification time, and allows
SW development while avoiding the risk of damaging real
prototypes. The main benefit of the proposed test bench is the
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