Compared with ACDCAC converter, matrix converter (MC) has several advantages for its bidirectional power flow, controllable power factor, and the absence of large energy storage in dclink. The topology of MC includes direct matrix converter (DMC) and indirect matrix converter (IMC). IMC has received great attention worldwide because of its easy implementation and safe commutation. Space vector PWM (SVM) algorithm for indirect matrix converter is realized on DSP and CPLD platform in this paper. The control of the rectifier and inverter in IMC can be decoupled because of the intermediate dclink. The space vector modulation scheme for IMC is discussed and the PWM sequences for the rectifier and inverter are generated. And a twostep commutation of zero current switching (ZCS) in the rectifier is achieved. Input power factor of IMC can be changed by adjusting the angle of the reference current vector. Experimental tests have been conducted on a RBIGBT based indirect matrix converter prototype. The results verify the performance of the SVM algorithm and the ability of power factor correction.
AC/AC conversion has two main types: ACDCAC converters and direct AC/AC converters. ACDCAC converters include the current and voltage source topologies with a capacitor or inductor in the dclink. Direct AC/AC converters include the cycloconverter of highpower applications and matrix converters in low power range [
The topologies of matrix converter, including direct matrix converter and indirect matrix converter [
Topology of indirect matrix converter using RBIGBT.
The PWM strategies in [
In the applications of indirect matrix converter, [
In this paper, the rectifier is controlled as a currentsource converter and inverter is controlled as a voltagesource converter. SVM is applied for the rectifier and SVPWM is applied for the inverter. The PWM sequence for indirect matrix converter is achieved. Twostep commutation of zerocurrent switching for the rectifier is presented. The principle of the input power factor correction for IMC is discussed. The design and implementation of indirect matrix converter prototype using RBIGBT are introduced. The experimental results are shown to verify the performance of the proposed PWM algorithm and the ability of PFC.
The control of the rectifier and inverter for IMC can be decoupled because of the dclink. The rectifier is controlled as a currentsource converter, and the inverter can be seen as an inductive load in dclink, shown in Figure
Control principle of the rectifier.
Three phase input currents can be defined as follows:
In (
Switching functions of the rectifier.
Number 




1  1  0  −1 
2  0  1  −1 
3  −1  1  0 
4  −1  0  1 
5  0  −1  1 
6  1  −1  0 
7  0  0  0 
The statues of
Current space vector can be defined as follows:
From (
The principle of space vector modulation (SVM) is shown in Figure
Current space vectors of the rectifier.
According to the principle of space vector PWM,
In (
In order to ensure the sinusoidal input current, the modulation index
In order to maintain the input power factor as unity, phase angle of
In (
The inverter is controlled as voltage source converter, and the rectifier can be seen as a voltage source in dclink. The conventional SVPWM algorithm can be used in the inverter, shown in Figure
SVPWM for inverter when
In (
From (
Generally, a bidirectional switch in matrix converters is constructed by two IGBTs and two diodes or two RBIGBTs. Commutations between two bidirectional switches need four steps with voltage/current signal. Figure
Fourstep commutation for bidirectional switches of RBIGBT with voltage signal.
In IMC, the inverter is a conventional voltage source converter and its commutation is traditional. When the inverter is on zerovector state, the current of dclink is zero. The commutation of the bidirectional switches in the rectifier can be achieved during this period, and zerocurrent switching commutation can be realized. The PWM sequence of IMC is shown in Figure
PWM sequence for IMC.
Twostep commutation for bidirectional switches of ZCS.
Compared with the conventional PWM algorithm [
In order to realize the SVM algorithm and commutation strategy, a control platform based on DSP and CPLD is implemented, shown in Figure
Control platform based on DSP and CPLD.
The input sectors Sci1~Sci6 and output sectors Svo1~Svi6 are determined with the angle of input voltage and output voltage with DSP. And 8 PWM signals, which are shown in Figure
PWM segments generated by DSP.
According to the SVM algorithm for rectifier, the commutation of bidirectional switches occurs between the upper bridges (
According to the SVM algorithm, power factor of IMC can be controlled by changing the angle of the reference input current vector, shown in Figure
The principle of power factor control.
It is assumed that, on the input side,
And the reference input currents are
The active power on input side is
From (
From Figure
The sectors of input current space vector can be divided by the angle of input voltage space vector, which is shown in Table
Sectors of input current space vector.
Input sector  Phase angle 

1 

2 

3 

4 

5 

6 

According to Table
Relationship of line voltage and phase angle.
Sector  Lineline voltage  Phase angle 


1 



2 



3 



4 



5 



6 



Input voltage interval and sector of input current space vector.
Input voltage intervals
Sector of input current space vector
In order to maintain the dclink voltage being positive, the regulation range of
Simplified circuit of input
In Figure
From Figure
Then, the input source current
Considering the fundamental part of input current and ignoring harmonics current and dynamic process, input source current is expressed as
The amplitude and angle of input source current can be got as follows:
From (
The prototype of RBIGBT based indirect matrix converter has been developed, shown in Figure
Prototype of RBIGBT based indirect matrix converter.
In order to verify the proposed PWM algorithm and sequence, experimental tests on IMC prototype have been carried out. The parameters of the input filters are
Figure
Experimental waveforms of proposed PWM algorithm.
Input phase voltage (25 V/div) and current (5 A/div)
Output linetoline (25 V/div) and current (5 A/div)
The voltage (25 V/div) across RBIGBT and the dclink current (5 A/div) during zerocurrent switching.
The waveforms of input voltage and current when the power factor angle is setting as −2
The experiment waveforms of input (25 V/div) and current (5 A/div) when power factor angle is −2
The experiment waveforms of input (25 V/div) and current (5 A/div) when power factor angle is zero.
The experiment waveforms of input (25 V/div) and current (5 A/div) when power factor angle is 2
The power factor angle of experiment can be shown in Table
Comparison of theoretical value and experimental result of power factor angle.
Setting power factor angle  Calculated by ( 
Experimental result 










In this paper, a SVM algorithm for indirect matrix converter with zerocurrent switching commutation for bidirectional switches is realized based on a control platform of DSP and CPLD. SVM for the rectifier and SVPWM for the inverter stage are described. PWM sequence of the SVM algorithm can achieve twostep ZCS commutation for the rectifier bidirectional switches. The realization of PWM sequence by DSP and decoding process for drive signals of RBIGBTs by CPLD are explained in detail.
Based on the modulation strategy, input power factor correction of IMC is discussed. Because the inverter of IMC is VSI, the dclink voltage should be positive and the regulation range of power angle is
The author declares that there is no conflict of interests regarding the publication of this paper.