Expansion of FRT Operation Range
for Grid-Tied Matrix Converter System
Jun-ichi Itoh, Kyota Asai, Tsuyoshi Nagano, and Takuya Kataoka
Department of Electrical Engineering
Nagaoka University of Technology
Niigata, Japan
itoh@vos.nagaokaut.ac.jp, k_asai@stn.nagaokaut.ac.jp

Abstract— This paper proposes a control method to expand afault-ride-through (FRT) operation range for a grid-tied matrix
converter. In the conventional method, the generator current islimited because the q-axis current is only controlled whereas thed-axis current is kept to zero. Consequently, the matrix converter
cannot satisfy the FRT requirements for the grid reactive current
due to the limitation of the generator current. Therefore, in the
proposed method, the d-axis current is injected in order to beable to increase the generator current as well as the grid reactive
current. This results increase the maximum grid reactive current
by 15% as compared to that of the conventional method. Fromthe simulation and experimental results, the proposed method
expands the FRT operation range from 43 % to 100%, the FRT
operation range is expanded by 57pt.
Keywords—matrix converter; fault ride through; generator;
reactive current; three-phase voltage sag

I.

INTRODUCTION

Nowadays, a wind turbine system and a distributed power
generation system, a low-head hydro power unit have attracted
many attentions as a sustainable energy system [1]. In thesesystems, the fault-ride-through (FRT) requirements for the
grid-tied converters are applied in many countries in order toavoid a power interruption in a large scale when only a local
grid fault occurs [2]. A power converter of the grid-tied system
employed must satisfy the FRT requirements as following: 1)
the grid-tied converter needs to continue to operate during thegrid voltage sag when the remaining voltage and its duration
are within a limitation defined by the grid requirements; 2) areactive current is delivered to the grid dependently on theremaining voltage. Moreover, in the wind turbine system, thegenerator torque needs to be maintained regardless of the gridstate in order to avoid unexpected acceleration and vibration of
the wind turbine [3]. In addition, in the distributed power
generation system and the low-head hydro power unit, thegenerator cannot react to a quick torque disturbance caused by
the grid voltage sag [4]. Thus, the grid-tied converter is also
required the following capability aside from the FRT
requirements: 3) the grid-tied converter has to maintain thegenerator torque during the grid voltage sag as same as that in
the normal operation.

Meanwhile, a matrix converter has also attracted many
attentions as a high-performance AC-AC converter [5-8]. The
matrix converter is expected to achieve higher efficiency,
smaller size and longer life-time compared to a conventional
back-to-back (BTB) system. In previous works, grid-tiedsystems using the matrix converter for the wind turbine or the
distributed power generation system have been reported [9-11].
However, generator terminal voltage of the grid connectedmatrix converter is forced to be lower during the grid voltage
sag because the matrix converter is a step-down converter.
Thus, it is difficult for the matrix converter to realize the FRT
operation.
Some literatures about the FRT method of the matrix
converter have been published [12-19]. A conventional FRT
control method for the matrix converter has been proposed toachieve 1) the stable FRT operation, 2) the grid reactive current
control and 3) the generator torque control in the same time
during the voltage sag [19]. However, in this control method,
the generator current amplitude is limited because the active (qaxis) current is only controlled whereas the reactive (d-axis)
current is kept to zero. Consequently, the matrix converter
cannot satisfy the FRT conditions of more than the voltage sagof 43% for the grid current due to the limitation of thegenerator current.
This paper proposes a control method to expand a FRToperation range for the grid-tied matrix converter. The q-axis
current is flown into the snubber circuit and the d-axis current
is flown into a voltage source inverter (VSI) of an indirect
matrix converter (IMC). The proposed method maintains the qaxis current and increases the d-axis current of the generator inorder to increase the generator current. In consequence, the grid
reactive current can be increased in order to expand the FRT
operation range. This paper is organized as following; first thecontrol strategy of the grid-tied matrix converter during the
FRT operation is explained. Second, the control of the d-axis
current in the generator to increase the grid reactive current is
explained. Finally, the effectiveness of the proposed control
method is confirmed by the simulation and experiments.

CIRCUIT CONFIGURATION

Power
grid

ir
is
it Lf

LC filter Cf

Fig. 3 shows a modulation block diagram of the matrix
converter for the FRT operation. A single-phase modulation is
employed to the CSR in order to modify the grid power factor
reference during the voltage sag [5]. This results in the same
modulation scheme of the CSR in both the grid normal
operation and the voltage sag. On the other hand, the VSI has
to change the modulation strategy in response to the grid state.
Fig. 4 shows the operation of the VSI in the voltage sag. In
the conventional method, the generator current is limited
because the q-axis current is only controlled whereas the d-axis
current is kept to zero. Consequently, the matrix converter
cannot satisfy the FRT requirements for the grid reactive
current due to the limitation of the generator current. Therefore,
in the proposed method, the generator current as well as thegrid reactive current is increased due to inject the d-axis current.
In order to adjust the d-axis current, the control of the matrix
converter is separated into three modes; a) the generator power
factor control mode (only one line is short-circuit), b) the DClink conduction mode, and c) the freewheeling mode. In a) the

iw

Srp

Ssp

Sup Svp Swp

Stp
edc

Srn

Ssn

Lg

vuv
Sun Svn Swn

Stn

Generator

Power Current source
Voltage source
grid rectifier (CSR)
inverter (VSI)
Fig.2. Circuit diagram of indirect matrix converter.

CSR modulation
3

Line tophase
conversion

3

3

3

CSR pulses

ir*
is*
it*

CarrierPulse
patternconversion 63
idc_rip*

VSI modulation

vα*
vβ*

vu*
vv*
3φ
x
2
3
3
vw*
αβ

q

Variable carrier
generator
6

Sign.

k

6

VSI pulses

ssn

stp 
............... (1)stn 

iv

Vsnb

Sectordicision

ssp

iu

idc

atan

sun 
 s
svn   rpsswn   rn

Lg

Bidirectional switches
Generator
Fig.1. Circuit configuration of a matrix converter.

MAX

ssu
ssv
ssw

stu   sup
stv    svp
stw   swp

Csnb

Sru
Ssu
Stu
Srv
Ssv
Stv
Srw
Ssw
Stw

FAULT-RIDE-THROUGH CONTROL METHOD FOR GRIDTIED MATRIX CONVERTER

Fig. 2 shows a circuit diagram of the indirect matrix
converter (IMC) which is used to employ the proposed FRT
method. The modulation method for the matrix converter
during the voltage sag uses a virtual indirect control method [5].
The virtual indirect control treats the matrix converter
illustrated in Fig. 1 as the IMC which consists of a current
source rectifier (CSR) and the voltage source inverter (VSI).
This replacement simplifies a consideration about themodulation method during the voltage sag. Note that the LC
filters is eliminated and the snubber circuit is composed of adiode bridge and a DC voltage source in Fig. 2. Then, in orderto yield the same waveforms between the matrix converter andthe IMC at the input and output terminals excluding an effectof the LC filter in Fig. 1, (1) should be satisfied.
 sru
s
 rv
 srw

Rbrk

Vsnb

ABS

III.

Brake circuit

Table 1

Fig. 1 shows the matrix converter which is used for aninterface converter between the power grid and the generator.
During the voltage sag, the active power supplied from thegenerator to the grid becomes zero because only the reactive
current is flown to the grid. However, the same torque of thegenerator should be maintained as same as that before thevoltage sag. Therefore, a brake system consisting of an IGBT
and a braking resistor is employed in order to absorb the active
power provided from the generator. In particular, the IGBT in
the brake circuit is turned on during the voltage sag and theactive power provided from the generator is consumed by thebraking resistor Rbrk. It is note that this braking circuit isrequired not only in the system employing the matrix converter
but also in the conventional BTB system. Hence, theadvantages of the matrix converter compared to theconventional BTB system does not degrade.

Snubber circuit

Duty cal.

II.

iu
iv
iw

Fig.3. Modulation block diagram in FRT mode.
Freewheeling mode
DC-link conduction mode
Generator power
factor control mode
1
VSI carrier

dX+dY+dlink
dX+dY
dX
0

dfw

dlink

dY

dX

dX

dY

Fig.4. VSI operation in short voltage sag.

dlink

dfw

generator power factor control mode, the dq-axis currents ofthe generator are controlled. In b) the DC-link conductionmode, the VSI and the CSR are connected in order to let thegrid reactive current circulate in the matrix converter. On theother hand, c) the freewheeling mode let the reactive current
circulate only in the VSI, which helps adjust the amplitude of
the grid reactive current.

Dup

Sup

Svp

Swp

Sun

Svn

Swn

Dvp Dwp

VSI

M

vuv

a)

Mode 1: Generator power factor control mode
Fig. 5 shows an equivalent circuit of VSI and the snubber
circuit in the generator power factor control mode. In this mode,the virtual DC-link voltage becomes zero because the active
power on the power grid is zero during the voltage sag.
Therefore, the CSR is not considered in Fig. 5. The q-axis
current is flown into the snubber circuit and the reactive d-axis
current is flown into the VSI. In the conventional FRT method,
the VSI switches are controlled in only two states; all turned onor all turned off. On the other words, the d-axis current in theconventional method is always zero, i.e. the unity power factorof the generator. Therefore, the VSI is modulated in order toadjust the d-axis current in the proposed method. This enables
the control of the generator power factor, and then increases thegenerator current.

Dun

Snubber circuit
Fig.5. Equivalent circuit for VSI of IMC and snubber circuit.
Table I. VSI pulse table.
Conduction state ofdiode rectifier[D u , D v , D p ]vX vY  vY vX .......................... (2)dY  vX v  v vX

vX vY  vY vX .......................... (3)Conduction state of

VSI pulse

diode rectifier(S u , S v , S w )[D u , D v , D p ]VSI pulse(S u , S v , S w )V1 [1 0 0]

(X 0 0)V4 [0 1 1]

(X 1 1)V2 [1 1 0]

(1 1 X)

V5 [0 0 1]

(0 0 X)

V3 [0 1 0]

(0 X 0)V6 [1 0 1]

(1 X 1)※ 1:Upper arm (Dxp, Sxp) ON 0:Lower arm (Dxn, Sxn) ON X:OPEN
x = u,v,w

Table I shows the VSI pulse generation based on the
conduction states of the diode rectifier during the generator
power factor control mode. By selecting the short-circuit
pathway of the generator, the current direction flow into thediode rectifier and the generator voltages are controlled, i.e. thecontrol of the d-axis current. In particular, the conduction statesof the diode rectifier define six space vectors from V1 to V6.
The VSI controls the generator power factor by a current
regulator (ACR) as following; two vectors from V1 to V6
which are adjacent to the voltage references vα*, vβ* are selected.
Then the duties dX , dY of the output voltage vector vX , vY are
expressed by (2) and (3) based on these two selected vectors,
whereas the DC-link conduction duty dlink is expressed by (4),and the freewheeling duty dfw is expressed by (5).

d X  v vY  vY v

Dvn Dwn

Vsnb
idc
Srp

Ssp

Sup Svp Swp

Stp
edc

Srn

Ssn

vuv
Sun Svn Swn

Stn

iu
iv
iw M
iu>0
iv<0
iw<0

Fig.6. Current path in DC-link conduction mode.

Vsnb
idc=0

dlink  k (1  d X  dY ) 0  k  1 ................................ (4)d fw  (1  k ) (1  d X  dY ) 0  k  1 ......................... (5)

Srp

Ssp

Sup Svp Swp

Stp
edc

vuv

iu
iv
iw M
iu>0
iv<0
iw<0

where k is a constant decided by the ratio between the DC-link
conduction mode and the freewheeling mode. Therefore, kadjusts the amplitude of the grid reactive current. In summary,the proposed method maintains q-axis current to be constantand increases the d-axis current of the generator by controlling
the generator power factor. Thus the generator current
amplitude is increased, which leads to the increase in the
maximum grid reactive current. However, the achievable rangeof the generator power factor is still limited to be less than cos
/6 due to the limitation of the current flowing into the dioderectifier.

the case of Fig. 6, the dc-link current idc becomes the u-phasecurrent iu. Therefore, the constant idc is obtained by changing
the VSI vector, and the average voltage of the dc-link is zeroper 1/6 of the grid period. Consequently, by using this mode,the constant dc-link current is obtained and the generator
terminal voltage equals to the dc-link voltage, because allphases of the generator side are connected to the dc-link.

b)c)Mode 2: DC-link conduction mode
Fig. 6 shows a current path in the dc-link conduction mode.
This mode is controlled by the dc-link conduction duty dlink. In

Srn

Ssn

Stn

Sun Svn Swn

Fig.7. Current path in freewheeling mode.

Mode 3: Freewheeling mode
Fig. 7 shows a current path in the freewheeling mode. In
this mode, a zero vector is chosen to obtain a circulating path

id*
Vsnb*

PI

iq

PI

*

PI

vd*

dq

vq*

vu*
vv*
vw*

3
3φ

3φ
αβ

FRT duretion

iu
iv
iw
Vsnb

3

Fig.8. Control block diagram for snubber voltage control and generator
current control.

Reactive
ActiveTable II. Conditions of simulation and experiment.
Input line voltage

200 V

FRT duration

100 msRated power

1500 W

Voltage sag

30%

Snubber voltage

400 V

Carrier frequency

10 kHz

Grid side
filter L (Lf)

2.15 mH(2.53%)

Generator
back e.m.f.

140 V

Grid side
filter C (Cf)

7.92 mF(6.64%)

Generator
inductance (Lg)

3.86 mH(9.28%)

d-axisq-axisTable III. Feedback control parameters.

Normal mode
(Field oriented control)

FRT
mode

Snubber voltage
control

d-axis current reference

0 p.u.

q-axis current reference-1.0 p.u.

Proportional gain

1.2 p.u.

Integral time

26.6 ms

Voltage reference

400 V

Proportional gain

2.0 p.u.

Integral time

16.5 ms

Fig.9. Simulation results of matrix converter during FRT operation.

feedback controls, the stable FRT operation and the generator
torque control are achieved during the voltage sag.

d-axis current reference -0.577 p.u.
Generator
current control

Proportional gain

1.2 p.u.

Integral time

1.65 ms

for the generator current. Consequently, the dc-link voltage andthe generator terminal voltage become zero.
IV.

FEEDBACK CONTROLS DURING VOLTAGE SAG

Fig. 8 shows a feedback control block diagram for the FRT
operation. As shown in Fig. 1, it is required to control thesnubber voltage and the generator current stably during thevoltage sag in order to obtain a stable FRT operation and adesired generator torque. Hence, this paper uses two feedback
controls for the snubber voltage and the generator current. In
particular, the snubber voltage control is defined as an outer
loop and the generator current control is set as an inner loop.
When the braking IGBT is turned on during the voltage sag,the snubber voltage reference Vsnb* is determined according to
the active power consumed by the braking resistor Rbrk, whichis equivalent to control the generator torque. On the other hand,
inner loop controls the generator dq-axis current according to
the voltage sag. PI controllers are employed in to the snubber
voltage and the generator current controls. By introducing theseV.

SIMULATION RESULTS

Fig. 9 shows the simulation results of the matrix converter
during the FRT operation under the ideal condition (DCvoltage source snubber, ideal commutation and no delay of thevoltage dip detection). Table II and III show simulation
conditions and control parameters. Note that inductors and athree-phase AC voltage source are used instead of thegenerator and the q-axis current of the inductors is used toevaluate the generator torque. The theoretical maximum power
factor of the generator is cos /6. In addition, the power factor
is slightly decreased in order to obtain the grid reactive currentof 1 p.u.. Therefore, the waveforms are not affected by thepower factor. The red waveforms of the grid R-phase current
and the generator terminal voltage (U-V) in Fig. 9 show theaveraged waveforms by using a low pass filter with a cut-off
frequency of 1 kHz. In Fig. 9, the voltage sag of 70% occurs
and the matrix converter operates with the proposed FRT
modulation method during this period. During the FRT
operation, the grid active current is reduced to almost zero andthe grid reactive current is generated by the zero power factor
modulation of the virtual CSR and the DC-link conduction
mode of the virtual VSI. The generator terminal voltage (U-V)
and the generator current during the voltage sag are sinusoidal
waveform. Note that the q-axis current during the voltage sag is

Fig. 10 shows the relationship between k and the grid
reactive current value during the voltage sag. The proportional
relationship between the grid reactive current and the ratio k isachieved in both the conventional and proposed FRT method.
Therefore, the maximum value is reaches 1.0 p.u.. In theconventional method, the maximum value of the grid reactive
current is 0.86 p.u., whereas the maximum value of the grid
reactive current in the proposed method increases by 15%.
VI.

EXPERIMENTAL RESULTS

Table II and III show experimental conditions and control
parameters. This session presents experimental results using a
prototype depicted in Fig. 1 to confirm the FRT capability, thegrid reactive current and the generator torque controls with theproposed FRT method. Note that inductors and an AC voltage
source are used instead of the generator and q-axis current of
the inductors is evaluated as the generator torque inexperiments. The voltage sag amplitude is set to 70%, i.e. theremaining voltage of 30%. dlink is calculated by dlink = k(1– dX –dY) in order to obtain the maximum grid reactive current.
Fig. 11 shows the operation waveform of the matrix
converter during the three-phase voltage sag. In Fig. 11, thevoltage sag of 70% occurs and the matrix converter operates
with the proposed FRT method during this period. The gridcurrent and the generator current during the voltage sag are
confirmed to be sinusoidal waveform. In addition, the grid
power factor is zero during the voltage sag. The grid reactive
current is controlled by the zero power factor modulation of thevirtual CSR and the dc-link conduction mode of the virtual VSI.
Fig. 12 shows the responses of the snubber voltage and thegenerator q-axis current. The snubber voltage reference is set to
400 V in order to obtain the same generator torque as before
the voltage sag by using the braking resistor. As shown in Fig.
12, the snubber voltage and the generator q-axis current follow
their references. As a result, a stable FRT operation is
confirmed by the proposed control.
Fig. 13 shows the dq-axis current responses of the generator.
The q-axis current reference during the voltage sag are kept to1 p.u. in both the normal mode and the FRT operation in orderto maintain the constant torque of the generator. As mentioned
above, the active power generated from the generator during
the FRT operation is transferred to the braking circuit bysetting the snubber voltage reference to 400 V. Consequently,
it is confirmed that the proposed FRT method obtains the samegenerator torque as before the voltage sag. Note that the ripple
component in the dq-axis currents is caused by a zero-phasevoltage fluctuation due to a two-phase modulation. On theother hand, the proposed method increases the generator d-axis
current of 0.577 p.u. in order to obtain the power factor cos /6,

Grid reactive current[p.u.]

kept to 1 p.u. during both the normal state and the FRT
operation. This results in the constant generator power of 1500
W, i.e. the constant generator torque. On the other hand, theproposed method increases the d-axis current of the generator
in order to obtain the power factor cos /6, i.e. the condition toachieve the maximum grid reactive current. Therefore, theexpansion of the FRT operation range is achieved by the
proposed control.

1.0

Proposed method
Max : 1.0 p.u.

0.8

15% increase

0.6
0.4

Conventional method
Max : 0.86 p.u.

0.2
0.0
0.0

0.2

0.4

0.6

0.8

1.0

k [-]
Fig.10. Grid reactive current characteristic with respect to k.
Normal mode

FRT mode

Normal mode

Grid phase voltage 250V/div
0
Grid current 10A/div
0

Snubber voltage 250V/div
0020ms/div

Generator current 10A/div

Fig.11. Operation waveform of matrix converter during three-phasevoltage sag.
Normal mode
480

FRT mode

Normal mode

Snubber voltage reference (400V) 160V/div

320
160

Snubber voltage 160V/div

00-0.4 Generator q-axis current 0.4p.u./div
-0.8
-1.2
Generator q-axis current reference 0.4p.u./div

20ms/div

Fig.12. Responses of snubber voltage and generator q-axis current.
Normal mode

FRT mode

Normal mode

Generator d-axis current reference 0.2p.u./div
Generator d-axis current 0.2p.u./div
0

-0.4

-0.8

-1.2
Generator q-axis current 0.2p.u./div
20ms/div
Generator q-axis current reference 0.2p.u./div

Fig.13. Generator dq-current response.

i.e. the condition to achieve the maximum grid reactive current.
The effectiveness of the proposed control method in theexperiments is confirmed as same as the simulation. In
particular, the proposed method expands the FRT operation
range for the grid-tied matrix converter.
Fig. 14 shows the relationship between the voltage sag andthe reactive current requirement. The above applies outside a
10% dead band around grid voltage. According to the grid
requirements, the reactive current needs to be injected by 0.02
p.u. in response to each 1% of the grid voltage reduction. The
range of the conventional FRT method is 43% or less, whereas,
the range of the proposed method is 100%. As a result, therange of FRT is expanded by 57pt.
VII. CONCLUSION
This paper proposed the FRT method for the grid-tied
matrix converter in order to expand the FRT range. The
proposed method maintained the q-axis current to keep thegenerator torque constant and injected the d-axis current inorder to adjust the generator power factor. This increased the
maximum grid reactive current, which expanded the FRT range.
From the simulation and experimental results, the proposed
method realized the stable FRT operation during the voltage
sag of 70%. Furthermore, the maximum value of the grid
reactive current was increased by 15% as compared to that of
the conventional method. Consequently, the range of the FRT
operation was expanded by 57pt from 43 % or less to 100%.
REFERENCES
[1]

[2]

[3]

[4]

[5]

[6]

[7]
[8]

F. Blaabjerg, K. Ma: "Future on Power Electronics for Wind Turbine
Systems", IEEE Journal of Emerging and Selected Topics in PowerElectronics, Vol. 1, No. 3, pp. 139-152 (2013)
M. Tsili, S. Papathanassiou: "A review of grid code technicalrequirements for wind farms", IET Renew. Power Gener., Vol. 3, No. 3,
pp. 308-332 (2009)
Z. Chen, J. M. Guerrero, F. Blaabjerg: "A Review of the State of the Art
of Power Electronics for Wind Turbines", IEEE Trans. Power Electron.,Vol. 24, No. 8, pp. 1859-1875 (2009)
S. Kusagawa, D. Sekine, J. Baba, S. Numata, A. Denda, T. Nitta, E.
Masada: "Frequency Spectrum Based Coordinate Control Scheme for
Several Types of Distributed Power Generation Systems in a MicroGrid", Proc. EPE-PEMC2006, pp. 1442-1447 (2006)
J. Itoh, I. Sato, H. Ohguchi, K. Sato, A. Odaka, N. Eguchi: "A Control
Method for the Matrix Converter Based on Virtual AC/DC/AC
Conversion Using Carrier Comparison Method", IEEJ Trans. D, Vol.
124, No. 5, pp. 457-463 (2004) (in Japanese)
P. W. Wheeler, J. Rodriguez, J. C. Clare, L. Empringham: "Matrix
Converters: A Technology Review", IEEE Trans. Ind. Electron., Vol. 49,
No. 2, pp. 274-288 (2002)
T. Friedli, J. W. Kolar: "Milestones in Matrix Converter Research", IEEJ
Journal I. A., Vol. 1, No. 1, pp. 2-14 (2012)
J. Itoh, I. Sato, A. Odaka, H. Ohguchi, H. Kodachi, N. Eguchi: "A Novel
Approach to Practical Matrix Converter Motor Drive System With

Reactive current requirement [p.u.]
Voltage dead band
FRT regulation
1.00
0.86
57pt increase
0.50
Conventional
method
0

0.10

0.43

Proposed method
0.50

1.00
Voltage sag [p.u.]

Fig.14. Grid reactive current characteristic with respect to k.
Reverse Blocking IGBT", IEEE Trans. Power Electron., Vol. 20, No. 6,
pp. 1356-1363 (2005)[9] S. M. Barakati, M. Kazerani, J. D. Aplevich: "Maximum Power
Tracking Control for a Wind Turbine System Including a Matrix
Converter", IEEE Trans. Ener. Conv., Vol. 24, No. 3, pp.705-713 (2009)[10] R. Cardenas, R. Pena, J. Clare, P. Wheeler: "Control of the Reactive
Power Supplied by a Matrix Converter", IEEE Trans. Energy
Conversion, Vol. 24, No. 1, pp. 301-303 (2009)[11] H. Nikkhajoei, M. R. Iravani: "A Matrix Converter based Micro-Turbine
Distributed Generation System", IEEE Trans. Power Delivery, Vol. 20,
No. 3, pp. 2182-2192 (2005)[12] E. P. Wiechmann, R. P. Burgos, J. Rodriguez: "Continuously MotorSynchronized Ride-Through Capability for Matrix-Converter
Adjustable-Speed Drives", IEEE Trans. Ind. Electron., Vol. 49, No. 2,
pp. 390-400 (2002)[13] C. Klumpner, F. Blaabjerg: "Experimental Evaluation of Ride-Through
Capabilities for a Matrix Converter Under Short Power Interruptions",
IEEE Trans. Ind. Electron., Vol. 49, No. 2, pp. 315-324 (2002)[14] H. J. Cha, P. N. Enjeti: "Matrix Converter-fed ASDs", IEEE Industry
Applications Magazine, Vol. 10, No. 4, pp. 33-39 (2004)[15] R. Prasad: "Low Voltage Ride-Through Capability for Matrix Converter
fed Adjustable-Speed Induction Machine Drives for Industrial and Wind
Applications", Ph.D. dissertation, Dept. Elect. Eng., Univ. Minnesota,
Minneapolis, MN, USA, (2011)[16] P. W. Wheeler, J. C. Clare, M. Apap, L. Empringham, L. de Lillo, K. J.
Bradley, C. Whitley and G. Towers: "Power supply loss ride-throughand device voltage drop compensation in a matrix converter permanent
magnet motor drive for an aircraft actuator", Proc. 35th PESC 2004,
Vol. , No. , pp. 149-154 (2004)[17] D. Orser, N. Mohan: "A Matrix Converter Ride-Through Configuration
Using Input Filter Capacitors as an Energy Exchange Mechanism",
IEEE Trans. Power Electron., Vol. 30, No. 8, pp. 4377-4385 (2015)[18] C. Klumpner, F. Blaabjerg: "Short Term Braking Capability During
Power Interruptions for Integrated Matrix Converter-Motor Drives",
IEEE Trans. Power Electron., Vol. 19, No. 2, pp. 303-311 (2004)[19] H. Takahashi, J. Itoh: "FRT Method for Matrix Converter to Ensure
Compatibility between Generator Torque Control and Grid Reactive
Current Control", IEEJ Trans. D, Vol. 136, No. 1, pp. 71-78 (2016) (inJapanese)