08-10-2010, 10:40 AM
Carrier Based PWM Algorithm for
Indirect Matrix Converters
Bingsen Wang Giri Venkataramanan
Department of Electrical and Computer Engineering
University of Wisconsin-Madison
1415 Engineering Drive
Madison, WI 53706 USA
Abstract— In this paper, the indirect matrix converter is
systematically studied with the single-pole-multiple-pole
representation. A carrier based PWM algorithm is developed
in two steps. First, the continuous modulation functions for all
the throws are derived based on the desired sinusoidal input
currents. Then the switching functions are derived from the
modulation functions with focus on the zero current
commutation. The proposed PWM algorithm is verified by
numerical simulation and hardware experimentation on a
laboratory prototype matrix converter.
I. INTRODUCTION
Various attractive features of the matrix converter, such as
a potential for high power density through elimination of
bulky passive components, high quality input and output
current/voltage waveforms, are leading to continuous
research efforts to enable their adoption widely [1-6]. While
the matrix converter was first studied as a class of frequency
changers realized using controlled switches by Gyugyi [7],
significant progress in high frequency synthesis was made by
Venturini in 1980 [8-10], with voltage transfer ratio limited
to one half. An improved modulation strategy with a voltage
transfer ratio of 0.866 was published in 1989 [11, 12]. In
addition to Venturini’s modulation methods, indirect
modulation methods based on a fictitious dc link concept
[13-18] and space vector techniques have been developed
further [17, 19-23]. Irrespective of the modulation methods
used, robust commutation is critical, as has been extensively
investigated and examined [24-30]. As an alternative to the
standard 9-switch topology, the rectifier-inverter-without-dclink
structure and its variations have been carefully examined
[16, 31-37], leading to a simple and robust commutation on
the basis of its topological properties [34].
A space vector modulation scheme for the indirect matrix
converter (IMC) was developed with focus on the desired
output voltage in [34]. In this paper, a carrier based PWM
algorithm is proposed and derived based on the desired
sinusoidal input currents and output voltages. The derivation
proceeds with the calculation of modulation functions
followed by the generation of switching functions. Comparedto the space vector modulation scheme, the proposed carrier
based PWM algorithm demands less computational
complexity, while retaining the features of simple and robust
commutation. Thus, resources of the digital signal processor
commonly employed in the practical realization will be
available to assume complex computational tasks for the
controller rather than the modulator. Furthermore, with more
increasingly available field programmable gate array
(FPGA), the firmware implementation of carrier based PWM
algorithm may feature the reliability of hardware and the
flexibility of software.
The paper is organized as follows: In Section II the IMC is
represented using single-pole-multiple-throw (SPMT)
switches. The modulation functions are derived in Section III
followed by switching functions presented in Section IV. The
numerical simulation and the experimental results are
presented in Section V and Section VI, respectively. A
summary of the paper is presented in the concluding section.
http://ieeexplore.ieeeiel5/11209/36090/01712191.pdf