A Three-Port Interface Converter by Using an Indirect Matrix Converterwith the Neutral Point of the Motor
Goh Teck Chiang

Jun-ichi ItohStudent Member, IEEE
Nagaoka University of Technology
1603-1 Kamitomioka,
Nagaoka Niigata, 940-2188, Japantcgoh@stn.nagaokaut.ac.jp

Senior Member, IEEE
Nagaoka University of Technology
1603-1 Kamitomioka,
Nagaoka Niigata, 940-2188, Japan
itoh@vos.nagaokaut.ac.jp

Abstract – This paper proposes a new three-phase powersystem that is applicable in various motor drive systems
including HEV. The main circuit is based on an Indirect Matrix
Converter (IMC) and the neutral point connection of a motor isutilized by connecting to an additional DC/DC converter. The
DC link part of the IMC connects a boost-up type DC/DC
converter and batteries to perform as a secondary power source
to drive the motor. In addition, the proposed control method canutilize the leakage inductance of a motor as a boost-up reactor
which will replace a common reactor in a boost-up chopper. The
proposed converter has been simulated and validated
experimentally using a 750W-prototype that driven by an
induction motor with V/f control. The total harmonic distortion(THD) of the input current is 4%, the THD of the output
current is 3.7% and the efficiency is 96%.
Index Terms— Indirect Matrix Converter, DC/DC Boost
Converter, Leakage inductance of a motor, Neutral pointconnection of a motor, Zero vectors, Positive-phase sequence,
Negative-phase sequenceI.

INTRODUCTION

Environmental responsibility has been a great concern forcommunities. The developments of the renewable power
energies, such as wind turbines and Hybrid Electric Vehicles(HEVs), are growing rapidly. One of the most common
applied converters in hybrid systems is AC/DC/AC converter
because it has the ability for connection of two different
power sources. The generator mainly supplies a constant
power to the load and the battery is used as an alternate
power to drive an electric motor and also to absorb the powerfluctuation at the high peak energy demands.
Fig.1 shows a conventional AC/DC/AC power converter
typically consists of a PWM rectifier, a DC link capacitor anda PWM inverter, also known as the back to back (BTB)
system [1]. The PWM rectifier is often used to reduce theharmonic currents in a generator and to control the DC link
voltage [2-5]. In order to obtain high performance under anadjustable speed drive system, a constant DC link voltage isrequired in a BTB system because the voltage fluctuation of
the DC link part will cause an output voltage error. A typicalmethod of reducing the voltage fluctuation is to place a large
electrolytic capacitor into the DC link part as a filtering
device between the rectifier and the inverter. However, the978-1-4244-2893-9/09/$25.00 ©2009 IEEElarge electrolytic capacitor has a relatively limited operating
lifetime and high maintenance cost.
One of the approaches uses to reduce the capacity of theelectrolytic capacitor is by applying a high speed DC voltage
controller into the rectifier control [6]. However, the control
response is limited by the delay of the voltage detection and adigital controller, the electrolytic capacitor is still required. In
addition, the capacitor is reduced when the DC link capacitor
is dominated by the capacitor current. As a result, a large
amount of space is needed for installing the capacitor in a real
product. Especially, the electrolytic capacitor is not suitable
for the high temperature installation such as in HEV. These
disadvantages are affecting the reliability of the converter.
For the secondary input power source, a boost converter
consists of batteries and a boost-up reactor is connected to theDC link part of BTB. The boost converter increases thebattery voltage, and then injects the battery power into theDC link part. Many studies in wind turbines [7]-[9] haveshown that in a DC/DC boost converter, the boost-up reactor
depends on the switching frequency and the current response
and these factors are limited by the efficiency and controller.
As a result, a large boost-up reactor is required.
This paper demonstrates and describes a new circuit
topology which composed of an indirect matrix converter anda DC/DC boost converter that connects to the neutral point ofa motor. Indirect matrix converter is high efficiency and easy
to configure in compared with the conventional method [10][13]. It does not require a DC link electrolytic capacitor tomaintain a stable DC link voltage.
Furthermore, this paper proposes an appropriate control
over the inverter that is possible to connect the DC chopper tothe neutral point of a motor and to operate as a DC/DC
converter [14]. The proposed circuit utilizes the neutral pointof a motor in the boost converter because the leakage
inductance of the motor can be used as a reactor. By
removing the electrolytic capacitor and the boost-up reactor,
the remaining part of the proposed circuit is only constructedby silicon components which are the IGBTs.
As a result, the proposed circuit is low cost and highreliability. The simulation results and the experimental results
clearly demonstrate that the proposed circuit is capable ofproviding sinusoidal waveforms for the input and the output
and achieves high efficiency and high power factor.

3282

Fig. 1. Back to Back converter.

II.

Fig. 2. Proposed circuit topology.

PROPOSED CIRCUIT TOPOLOGY

Fig.2 shows the proposed circuit configuration. The
indirect matrix converter can be simply divided into primarystage and secondary stage. The primary stage for the AC
power source consists of twelve units of reverse blocking
IGBT [15] also known as a current source rectifier. The
secondary stage for the motor consists of six units of IGBT,
which is similar to a standard voltage source inverter. The
indirect matrix converter has one advantage over a matrix
converter is to having a DC link part. In the proposed
method, the DC link part is utilized by adding a boost
converter into the indirect matrix converter. The boost
converter connects to the battery, and then the other terminalof the battery is connected to the neutral point of a motor.
Moreover, a snubber circuit is included in the DC link part toabsorb energy from the reactive elements in the circuit suchas voltage overshoot [15]. It should be noted that the capacityof the snubber capacitor is smaller than the DC link capacitor
in a BTB system because the ripple current of the DC linkpart does not flow in the snubber capacitor.
The boost converter is not a stand-alone circuit in this
proposed circuit. The operation is strongly depended on thesecondary side of the indirect matrix converter. Zero vectors
output in the secondary side are the key factor to link the
boost converter into the indirect matrix converter. The zero
vector controls the amplitude of the output voltage. Besides,
there are two functions of the zero vectors output into thesecondary side. The first is to implement zero current
switching on the primary side, so the switching losses atprimary side do not occur. The second involves in theoperation of the boost converter, which will be descried in thelater chapter.
III. CONTROL BLOCK DIAGRAM
Fig. 3 shows the control block diagram of the proposed
circuit. The primary side, the DC chopper and the secondaryside are controlled individually by their own commands. A
carrier comparison method is used as the PWM generator
according to the control strategy [16]. The relations between

the output voltage and the input voltage are obtained by (1).
The secondary side operates as a four-phase voltage source
inverter by adding the DC chopper as the fourth leg,⎡vu ⎤ ⎡ sup⎢v ⎥ ⎢ s⎢ v ⎥ = ⎢ vp
⎢vw ⎥ ⎢ swp⎢ ⎥ ⎢⎣vc ⎦ ⎣⎢ scp

sun ⎤svn ⎥⎥ ⎡ srp
swn ⎥ ⎢⎣ srn⎥
scn ⎦⎥

ssp
ssn

⎡vr ⎤
stp ⎤ ⎢ ⎥vs .
stn ⎥⎦ ⎢ ⎥⎢⎣ vt ⎥⎦

(1)
where sxy stands for the switching function of the switches.
When sxy is turned on, sxy = 1 and when sxy is turned off, sxy =0.
The primary side controller is designed with a current type
PWM rectifier command. It is a pulse pattern conversion toconvert the PWM pulses of the voltage source type rectifier
into the PWM pulse of the current source type rectifier. A
stable DC link voltage can be achieved by using this method.
Further, the single leg modulation is used to reduce theswitching losses to π/3 per period [15].
A conventional controller method for voltage source typeinverter is applied to the DC chopper and the inverter with alean controlled carrier modulation. This carrier modulation
forms a new carrier where the peak position of the triangle
carrier is controlled by the duty ratio of the rectifier sidepulse. Then, this new carrier is used in the secondary side andthe DC chopper as a normal PWM comparison method. It
also called as inverter carrier.
Additionally, a PI controller is designed in the DC chopper
to control the battery current. Note that since the DC chopperis controlled as the fourth leg of the inverter, the DC choppercommand is compared by the same carrier with the inverter
voltage commands. Fig. 3 shows the control block diagram
which is explaining above.
Fig. 4 shows an example of the relations between thenormal carrier applied into the primary side and the new
inverter carrier applied into the secondary side. There are two
ways to generate an inverter carrier; Fig. 4(a) represents thesymmetrical type which contains approximately double
switching frequency of the rectifier switching frequency andFig. 4(b) shows the asymmetrical way which contains the3283

same switching frequency of the rectifier switching frequency[17].
In Fig. 4(a), the bottom peak position of the triangularcarrier is controlled by the duty ratio of the rectifier pulse as
shown at the upper graph. The chopper commands along with
the inverter output voltage commands are compared with thisnew inverter carrier to obtain the desired switching patterns.
The zero vector periods are shown at the lower graph in Fig.
4(a). The switching pulses of the secondary side attained thezero vectors for every carrier cycle. The primary side arms
will switch at every zero vector periods.
In addition, the upper arm of the chopper will switch ON at
every zero vector periods. During zero vector periods, theboost converter is operated at On-state, the battery current
will be charged thru by the leakage inductance of a motor.
During the non-zero vector periods, the accumulated batteryenergy will be released into the indirect matrix converter, also
known as the Off-state operation.
When the switching frequency of the rectifier is 10kHz, theapplied control method generates a new carrier whichcontains approximately 20 kHz switching frequency at every
carrier. It is approximately double of the primary sideswitching frequency. In Fig. 4(b), an inverter carrier can beformed that is based on the duty of the rectifier command but
contains only 10 kHz per carrier cycle using a symmetricalcarrier. This inverter carrier can improve the efficiency by
reducing the switching losses in the inverter side and the
chopper side.
By comparing between the symmetrical inverter carrier
and the asymmetrical inverter carrier in Fig. 4, note that thezero current switching in the rectifier does not affect by theDC linkripple cal

Primary
controller

10 kHzCarrierir*
Singleleg
mod.

Input current is*commands
it*

Carrier
generator

1/X

Secondarycontroller

+

DC/DC
converter
controllerib*
Choppercommands
ib

Pulse
patternconversion
Rec_duty

+
-

-

PI

X

+
-

vu*

X

Outputvv*
voltagecommands

+
-

X

+
-

X

+
-

vw*

inverter carrier because both carrier are formed follow therectifier duty. Since every carrier time is longer in theasymmetrical inverter carrier, the sequence of the zero vector
periods becomes slower. That is, the boost converter willachieve a better efficiency, however the current ripple in thebattery will be increased.
The other disadvantage of the asymmetrical inverter carrieris the detection of the load current. Normally, the averagevalue of the load current appears at the peak of thesymmetrical inverter carrier. It can be easily detected byusing symmetrical inverter carrier. However, in asymmetricalcarrier, the average current point does not agree with the peakof the asymmetrical carrier. In order to detect the average
current, a low-pass-filter is required. Consequently,
performances of the control will be decreased.
IV. UTILIZATION OF THE NEUTRAL POING OF A MOTOR
The importance of the zero vectors explains the behaviorof the boost converter along with the neutral point of the
motor. The boost converter will operate at every zero vectorsof the secondary side of the converter. A three-phase inverter
has eight output voltage space vectors including two zero
vectors. The zero vectors are two particular vectors thatgenerate zero line voltage to the motor. The neutral point
voltage v0 of the motor based on the neutral point of the DC
link part is obtained as (2)Edc⎧
When all upper arms are ON⎪⎪vo = 2(2)⎨⎪v = - E dc
When
all
lower
arms
are
ON
o
2
⎩⎪
where Edc is the DC link voltage and vo is the voltage of theneutral point of the motor based on the neutral point of theDC link part.
The proposed circuit has two difference sequences during
the zero vectors, a positive-phase sequence and a zero-phasesequence. Fig. 5 shows the positive-phase sequenceequivalent circuit and Fig. 6 shows the zero-phase sequenceequivalent circuit. In the positive-phase sequence, thesecondary side works normally as a three-phase inverter witha motor. It will control the motor speed and torque.
On the other hand, in the zero-phase sequence, no voltage
goes to the motor because the line voltage is zero and the
motor can be considered as a leakage inductance.
Additionally, the secondary side of the converter can beconsidered as a single leg topology. The battery current firstgoes into the secondary side and flows out through the neutralline and charge or discharge the battery. The battery current
can be controlled by the PI controller. A new expression of
the secondary side current is formed as follows

Fig. 3. Control block diagram.

3284

Fig. 4(a). Symmetrical inverter carrier.
Fig. 4(b). Asymmetrical inverter carrier.
Fig. 4. Relations between the zero vectors and boost converter operation.

ibat⎧⎪iu = ia + 3
⎪⎪
ibat
.
(3)
⎨ iv = ib +3⎪
⎪i = i + ibat⎪⎩ w c 3
where ia, ib, ic are the inverter current and ibat is the battery
current;
Since high DC link voltage is compulsory in order tocontrol the zero vectors, the relations between the DC link
voltage Edc, the inverter line voltage (vinv) and the battery
voltage (Vbat) will be discussed. The inverter output voltage,vu, vv, vw referred to the neutral point voltage of the dc link isexpressed as
Edc⎧⎪ vu = a 2 sin ωt + vo
⎪
2π
Edc
⎪
sin(ωt −) + vo .
(4)⎨ vv = a
2
3
⎪
⎪
Edc
4π
⎪ vw = a 2 sin(ωt − 3 ) + vo⎩
where
a is the modulation index of the motor phase voltage, 0< a <1

vo is neutral point voltage of the motor (during zero phasesequence) and ω is inverter output angler frequency
Then, the inverter line voltage is given byπ3
Vdc sin ωt + .
(5)
2
6
For a three-phase inverter, the DC link voltage Edc is requiredas (6) when a sinusoidal modulation is used.
vuv = a2

Edc > 2

3

Vinv .

(6)

The maximum line voltage between the inverter leg andchopper leg can be obtained as

vux =

2

Vinv + Vbat .
(7)
3
Since vux must be smaller than Edc , the inverter voltage andbattery voltage are constrained by (8)2Vinv + Vbat .
(8)
3
As a result, the DC link voltage of the proposed circuit mustsatisfy both requirements as shown below

3285

Edc >

⎧ 2
2Vinv
Vinv
When
≥ Vbat⎪2
3⎪ 3.
Edc >⎨2Vinv⎪ 2< Vbat⎪ 3 Vinv + Vbat When3⎩

inductances, is used in the simulation. The symmetricalinverter carrier is used in simulation.
Fig. 7 shows the battery discharging mode where thebattery current is controlled from 0.5 A to 2 A. These two
waveforms show the input power supply voltages vr, vs, vt ,the input currents ir, is, it, the output line voltages (vuv(LPF),
vvw(LPF)), vwu(LPF)) through a low pass filter, which has the cut
off frequency of 1 kHz, to observe the low frequency
components, the output currents iu, iv, iw and the battery
current ib. The results show that both the input current andoutput current are good sinusoidal waveforms. It should be
noted that at time 20 ms, the input current magnitudedecreases due to the increment of ib, which means that theincreasing of the battery power leads to a decreasing in
generator power.
On the other hand, in Fig.8 the ACR controls the battery
current to from 0.5 A to -2 A. The battery is being charged
from a generator in this condition. The results also provedthat when in charging mode, both the input current and output
current obtain good sinusoidal waveforms. At 20 ms, as the ib
decreases, the input current forces to increase because alarger energy is required to charge the battery. These two
waveforms proved a good power management picture
between the generator and the battery.

(9)

Fig. 5. Positive phase sequence equivalent circuit.

Fig. 6. Zero phase sequence equivalent circuit.
TABLE ISIMULATION PARAMETERS
Input voltage
200 V
Input frequency
50 Hz
Carrier frequency
10 kHzInverter frequency
20 kHzDC source
100 V
Output voltage
173 V
Output frequency
35 Hz
Leakage inductance
5 mH

Fig. 7. Simulation results (Battery=Discharge mode).

V. SIMULATION RESULTS
Table I shows the simulation parameters for both results.
The proposed circuit was simulated under two conditions; thebattery discharging and charging. An ACR controller controls
the battery current into a desired value of positive or
negative. An ideal battery current ib is purposely adjusted at
specific time of 20 ms to confirm the proposed circuit
performance. The motor model, which consists of three setsof voltage sources as back electro motive forces and leakage

3286

Fig. 8. Simulation results (Battery=Charge mode).

VI. EXPERIMENTAL RESULTS
A 750-W prototype was built and tested in two operation
modes same to simulation section. Mode I is the battery
discharges under motoring operation and Mode II is thebattery charges under motoring operation. Both conditions
were verified using the parameters shown in table II. The
controller was using asymmetrical format to generate the 10kHz inverter carrier. Indirect matrix converter can achieve a
better THD values by applying this method. Table III shows
the motor specification data. Note that it is an ordinary motor;
no particular setting is required for the neutral pointconnection.

frequency and larger battery current resulted the losses are
increasing.
Fig. 14 shows the asymmetric inverter carrier loss analysis
results. It was simulated under the same condition with Fig.
13. The loss in secondary side decreases about 20% and theloss in chopper decreases about 25%. The total loss for the
TABLE II
EXPERIMENTAL PARAMETERS
Input voltage
200 V
Input frequency
50 Hz
Carrier frequency
10 kHzOutput frequency
35 Hz
Inductor
1.7 mHCapacitor
2.5 μF
DC source
100 V
LC Filter Cut-off frequency
2.4 kHzA.

Fundamental Operations
Fig. 9 and Fig. 10 show the Mode I operation and theMode II operation, respectively. In Fig. 9, the DC power
supply is set to 100 V and the battery current is controlled to
2 A. Likewise in Fig. 10, the battery current is controlled to 2 A. Good sinusoidal waveforms have been achieved in the
input and the output current of both operation modes. Fig. 11
shows the input power factor of discharge mode and charge
mode. Both modes achieved the input power factor more than
98%, which can be considered as a unity power factor. The
input power factor decreases during the discharge mode isbecause the input current becomes smaller in comparison
with the charge mode.
Fig. 12 shows the input current total harmonics distortion(THD) and the output current THD for both modes. The
lowest output current THD obtains during the charge mode is
3.6% and during discharge mode is 4.0%. As for the lowest
output current THD obtains during the charge mode is 3.0%
and during discharge mode is 3.7%.

TABLE III
MOTOR PARAMETERS (FUJI: MLH6085M)
750 W

Poles

4/ 50 Hz

RPM

1420

Rated current

3.6 A

Rated voltage

200 V

Leakage inductance

4.42 mH

Input voltage vr

250 [V/div]

Input current ir

5 [A/div]

Output current iu

10 [A/div]

Battery current ib

2.0 [A/div]

0
0

B.

Efficiency and Loss Analysis
This section will discuss the loss analysis of the proposed
circuit which is calculated by using a circuit simulator (PSIM,
Powersim Technologies Inc.) and DLL files (Dynamic Link
Library) [18]. The analysis was conducted in two categories
by applying the symmetrical and asymmetrical inverter
carrier respectively. Figs. 13, 14, 15 and 16 show the loss
analysis results simulated under the same parameter as shownin Table I. The output power is 750 W and the input power
ratio is 9:1 in Figs. 13 and 14.
Fig. 13 shows the detail of the switching losses when
applying the symmetrical inverter carrier. The zero current
switching is implemented in the primary side, and therefore
only conduction loss occurs into it. The total loss for thedischarge mode is approximately 27 W and the total loss forthe charge mode is approximately 29 W. The analysis provesthat the converter can achieve an efficiency of 96.4%.
Two reasons are found about the higher losses insecondary side. The first reason is that the switchingfrequency in the secondary side is 20 kHz by using thesymmetric method as discussed in chapter III. The second
reason is because the inverter current contains of the battery
current during zero phase sequence. Higher switching

Motor Power

0

0

3287

10 ms
Fig. 9. Experimental result (Mode I= Battery discharge).

Fig. 10. Experimental result (Mode II = Battery charge).

discharge mode is 23 W and the total loss for charge mode is25W. An efficiency of 96.9% can be achieved, which isapproximately 0.5% improvement.
Fig. 15 and Fig. 16 show calculations of the loss analysis
by powering with various input power ratio, as given from
10:0 to 1:9, where it represents the ratio of generator power tobattery power. At the ratio 9:1, it means that the total input
power is 90% supplied from the generator power and theremaining 10% from the battery power. In this case, the input
voltage gradually reduces as the battery voltage increases.
In Fig. 15, the asymmetric method, it is obvious from thegraph that the loss in the DC chopper increases sharply as thebattery current increases. However, the loss in primary does
not reach zero, it drops to a constant 4 W from 7 W.
On the other hand, as the generator power is lesser than
225 W, the loss in the secondary side starts to decrease. Thisis because in the indirect matrix converter, the output voltage
ratio is directly depending on the input voltage. As the input
voltage ratio decreases, the magnitude of the output voltage
decreases as well. However in the proposed circuit, the boost
converter maintains the DC link voltage even the generator

power drops. Therefore, the output side can remain at its
power.
Fig. 16 illustrates a chart that is the same analysis with thesecond condition but it applies the symmetric format. As
expected, the loss in the primary side remains unchanged.
However, the loss in secondary side reduces about 18%
compared to Fig. 15. When the battery is at the full power,
the loss reduces about 25%.
VII. CONCLUSION
This paper proposed a new control method by utilizing theneutral point of a motor and connected to an indirect matrix
converter for motor drive applications. The control over the
inverter zero vector periods allows an additional chopper leg
to perform as a boost converter with the connection to theneutral point of a motor. The simulation and the experimental
results demonstrated good sinusoidal waveforms andconfirmed the validity of the proposed method. Furthermore,
the loss analysis in the proposed circuit estimates efficiencyof 96%.

1.00

25

0.96

Switching frequency = 10 kHz
Input power ratio = 9:1
Output Power = 750W

Input frequency = 50 Hz
Output frequency = 35 Hz

Recovery loss

20

0.94

Loss[W]
[W]
Loss

Input
InputPowerPowerFactor
Factor

0.98

0.92
0.90
0.88

Switching loss
(Turn-on)
Switching loss
(Turn-off)
Conduction loss

15
10
5

0.86
200

300

400
500
Output Power

600

700

0

(Discharge)(Charge)Primary(Discharge)(Charge) (Discharge)

Secondary(Charge)

ChopperFig. 13. Loss analysis – Switching device losses (Symmetric method).

Fig. 11. Input power factor.
9

25

8

20

Loss
Loss [W]

THD [%]

7
6
5
4
3

15
10
5

2
200

300

400

500

600

0

700

Output Power [W]
Fig. 14. Loss analysis – Switching device losses (Asymmetric method).

Fig. 12. Input & output current THD values.

3288

REFERENCES

40
35

Loss [W]

30
25
20
15
10
5
0

Fig. 15. Loss analysis – Changes in input ratio (Symmetric method).
40
35
30

Loss [W][1] Anders Carlsson (1997), “The Back-to-back Converter - Design andControl”, TEIE-1017, Industrial Electrical Engineering and Automation,
Licentiate Theses 1998
[2] Gi-Taek Kim and Lipo T.A, “VSI-PWM Rectifier/Inverter System with a
Reduced Switch Count”, in IEEE Industry Applications Conference, Vol3, pp 8-12, Oct 1995
[3] Imori. K, Shinohara. K, Muroya. M and Matsushita.Y, “Zero Switching
Loss PWM rectifier of converter without DC link Components for
Induction motor drive”, in Power Conversion Conference, Japan, Vol 2,
pp. 409-414, 2002[4] Ogasawara. S, and Akagi. H, “Suppression of Common-mode Voltage ina PWM Rectifier/Inverter system”, in IEEE Industry Applications
Conference, Chicago, USA, Vol 3, pp. 2015-2021, Sept 2001
[5] Hyunjae Yoo, Kim J.H and Seung-Ki Sul, “Sensorless Operation of a
PWM Rectifier for a Distributed Generation”, IEEE Trans. PowerElectronics, Vol 22, pp. 1014-1018, May 2007
[6] Yao Chen and XiMin Jin, “Modeling and Control of Three-phase Voltage
Source PWM Rectifier”, in Power Electronics and Motion Control
Conference, Shanghai, Vol 3, pp.1-4, Aug 2006
[7] Hiquichi. Y, Yamamura. N, Ishida. M and Hori. T, “An Improvement of
Performance for Small-Scaled Wind Power Generating System with
Permanent Magnet Type Synchronous Generator”, in Industrial
Electronic Society, Japan, Vol 2, pp. 1037-1043, Oct 2000
[8] Z. Chen and E. Spooner, “Grid Power Quality with Variable Speed Wind
Turbine”, IEEE Trans. on Energy Conversion, Vol 16, No 2, June 2001
[9] Hao. S, Hunter.G, Ramsden. V and Patterson. D, “Control System Design
for a 20kw Wind Turbine Generator with a Boost Converter and Battery
Bank Load”, in Power Electronics Specialists Conference, Canada, Vol4, pp. 2203-2206, June 2001[10] Wei. L, and Lipo. T.A, “A Novel Matrix Converter Topology with
Simple Commutation”, in Industrial Electronic Society, USA, Vol 3,
pp. 1749-1754, Oct 2001.
[11] Jussila. M, Salo. M, Tuusa. H, “Realization of a Three-Phase Indirect
Matrix Converter with an Indirect Vector Modulation Method”, inPower Electronics Specialist Conference, Vol 2, pp. 689-694, June
2003[12] Friedli. T, Heldwein. M.L, Giezendanner. F, and Kolar. J.W, “A High
Efficiency Indirect Matrix Converter Utilizing RB-IGBTs”, in PowerElectronics Specialist Conference, pp. 1-7, June 2006[13] Kolar. J.W, Schafmeister. F, Round. S.D, and Ertl. H, “Novel ThreePhase AC-AC Sparse Matrix Converters”, IEEE Trans. PowerElectronics, Vol 22, pp. 1649-1661, Sept. 2007[14] Jun-ichi Itoh, and Fujita. K, “Novel Unity Power Factor Circuits Using
Zero-Vector Control for Single-Phase Input Systems”, IEEE Trans.
Power Electronics, Vol 15, No. 1, January 2000
[15] Jun-ichi Itoh, Sato. I, Odaka. A, Ohguchi. H, Kodachi. H, and Eguchi.
N, “A Novel Approach to Practical Matrix Converter Motor Drive
System with Reverse Blocking IGBT”, IEEE Trans. Power Electronics,
Vol 20, pp. 1356-1363, Nov. 2005[16] Jun-ichi Itoh, Ikuya. S, Hideki. O, Kazuhisa. S, Akihiro. O, and Naoya.
E, “A Control Method for The Matrix Converter based on virtual
AC/DC/AC Conversion Using Carrier Comparison Method”, IEE
Trans. in Japan, Vol 152, pp. 65-73, Jun 2005[17] Jun-ichi Itoh, and Kato. K, “Control Method for A Three-port Interface
Converter Using an Indirect Matrix Converter with an Active Snubber
Circuit”, in Power Electronics and Motion Control Conf. 2008, pp. 581588, Sept 2008.
[18] Jun-ichi Itoh, Iida. T, and Odaka. A, “Realization of High Effieiency
AC Link Converter System Based on AC/AC Direct Conversion
Techniques with RB-IGBT”, in IEEE Industrial Electronics Conf., Paris,
pp. 1703-1708, Nov. 2006

3289

25
20
15
10
5
0

Fig. 16. Loss analysis – Changes in input power ratio (Asymmetricmethod).