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ISSN: 2393-994X
KARPAGAM JOURNAL OF ENGINEERING RESEARCH (KJER)
Volume No.: II, Special Issue on IEEE Sponsored International Conference on Intelligent Systems and Control (ISCO’15)
Design and Implementation of Multilevel Matrix Converter
P.Sarath Chandran1, R.Mahendran2
1
PG Student, [email protected], P.S.R. Engineering College, India.
Assistant Professor, [email protected], P.S.R. Engineering College, India.
2
Abstract - A Matrix Converter (MC) is an array of controlled semiconductor switches that directly connect input
phase to output phase, without any intermediate DC link. It provide bidirectional power flow. Due to this, we can get
a balanced output voltages and desired frequency and amplitude.A Multilevel Matrix Converter (MMC) can generate
multilevel voltage waveforms and improves the output voltage quality. The output voltage can reach higher levels
with low cost, easy available low voltage device, while reducing the size and increasing the performance of the
converter because of the staircase shaped outputs.More recently, the Single Phase Matrix Converter (SPMC) has
emerged with other works on AC - AC, DC - DC, AC - DC and DC - AC operation. The new multiple converter for
single phase input using matrix topology using just a single control logic. It is very flexible, and it can be used as a
lot of converters. The MATLAB simulation of all above conversions are using bidirectional switch cell in matrix
arrangement by single logic unit and it improves the output waveform quality with high voltage gain. The Sinusoidal
Pulse Width Modulation (SPWM) method of control is used to simulation of converter is carried out in MATLAB.
KEYWORDS – Matrix Converter, Multilevel Matrix Converter, Chopper, Cycloconverter, rectifier, inverter, AC
voltage controller, Sinusoidal Pulse Width Modulation, MATLAB/SIMULINK.
I.
INTRODUCTION
Matrix Converters contain an array of bidirectional semiconductor switches and this array
allows connection of input lines to output lines. The Matrix Converter (MC) has several advantages over
traditional rectifier-inverter type power frequency conversions. It provides sinusoidal input and output
waveforms, with minimum higher order harmonics and no sub harmonics [1]. It does not have any dc-link
circuit and does not need any large energy storage elements. The main element in a Matrix Converter is the fully
controlled four-quadrant bidirectional switch, which allows high-frequency operation. It requires special
semiconductor switches and requires a bidirectional switch with capable of blocking voltage and conducting
current in both directions the energy flow can get from source to load and back, without need of bulky and
limited life time energy storage element. The Matrix Converter should be controlled using a specific and
appropriately timed sequence of the values of switching variables, which results in balanced output voltage
having the desired frequency and amplitude, whereas the input currents are balanced and in phase with respect to
the input voltages [2]. However, the maximum peak to peak output voltage cannot be greater than the minimum
voltage difference between the inputs. Regardless of the switching strategy, there is a physical limit on the
possible output voltage and the maximum voltage transfer ratio is 0.866 [6]. The control methods for Matrix
Converters must have the ability for independent control of the output voltages and input currents. Three types
of methods are commonly used:
1. Venturini method
2. PWM method
3. Space vector modulation
MULTILEVEL MATRIX CONVERTER
The Multilevel Matrix Converter (MMC) is an emerging topology that integrates the
multilevel concept into the Matrix Converter topology [5]. Usually the multilevel concept is viewed as a good
solution to high voltage and high power conversion. Having the ability to produce different output voltages
levels enabling the generation of stepped waveform with less harmonic distortion, which leads to lower dv/dt
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ISSN: 2393-994X
KARPAGAM JOURNAL OF ENGINEERING RESEARCH (KJER)
Volume No.: II, Special Issue on IEEE Sponsored International Conference on Intelligent Systems and Control (ISCO’15)
stresses and reduce voltage stress on power switches [7]. The Multilevel Matrix Converter is capable to produce
better output waveforms than conventional Matrix Converter. It have no need of energy storage element. Only
using matrix arrangement switching cell with single topology.
SINGLE PHASE MATRIX CONVERTER
The Single-phase Matrix Converter or SPMC was first implemented by Zuckerbeger. Now
presented a lot of possible application of it starts from conventional Matrix Converter application AC-AC
conventional and finished with DC solutions [9]. Aim of this paper is overview solution of existing SPMC
application possibilities. Describe switching strategies of each SPMC application solution. The SPMC operation
of universal power conversion. Thanks to absence of energy storage element, the instantaneous power on input
must be the same as the power on output side. Unfortunately reactive power input does not have to equal the
reactive power output [5]. The simple basic circuit diagram of Matrix Converter using AC or DC supply in
single matrix topologyis shown in Fig 1.
Fig. 1 Basic circuit of SPMC
It consists of four bidirectional switching arrangement of Matrix Converter.It comprises four
bidirectional power supplies are needed to supply the gate drive signals. Switches are (S1 a,S1b,S2a, S2b, S3a, S3b,
S4a, S4b,) are S1-S4 “a” or “b” current flow directions is “a” – forward direction, and “b”-opposite direction of
each switch. In this case, the Matrix Converter topology is used for universal power conversion such as AC/DC,
DC/AC, DC/DC, AC/AC without any change of topology [3]. The key element in a Matrix Converter is the
fully current at any one time. One possible disadvantage is that controlled four-quadrant bidirectional switch,
which allows each bidirectional switch cell requires an isolated power high-frequency operation.
BIDIRECTIONAL SWITCH
The main building block of the Matrix Converter is the bidirectional semiconductor switch. A
single device that can both conduct current in each direction and block voltage in both directions is currently not
commercially available. The Matrix Converter requires a bidirectional switch capable of blocking voltage and
conducting current in both directions, so discrete devices need to be used to construct suitable switch cells.
TWO ANTIPARALLEL IGBT’s
The two IGBT’s are connected in antiparallel bidirectional switch cell arrangement is shown in
Fig 2. The IGBT was used due to its high switching capabilities and high current carrying capacities. The reverse
voltage blocking and current conduction capability is enable for this arrangement. This arrangement leads to a
very compact converter with the potential for substantial improvements in efficiency.
Fig. 2 Two anti-paralleled IGBT’s
MULTIPLE CONVERTER FOR SPMC
The SPMC could be used to operate as a Cycloconverter, multilevel converter, act as three
phase inverter, AC voltage controller, DC chopper, rectifier and inverter. A new multiple converters using
matrix topology for all conversions using a single circuit is presented [6]. For different types of conversion
different circuits are used. But in certain applications like uninterruptable power supply which converts AC into
DC for charging the batteries using rectifiers and then converts the stored energy again into AC using inverter,
requires two conversion circuits. Also in traction different types of motors are employed such as DC series, DC
shunt and AC series which require conversion of supply. A number of conversion kits are required in
laboratories. This increases the total cost and also the space requirement. A recent technology known as Single
Phase Matrix Converter is capable of performing all these conversions.
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Volume No.: II, Special Issue on IEEE Sponsored International Conference on Intelligent Systems and Control (ISCO’15)
II. SIMULATION OF MULTILEVEL MATRIX CONVERTER
The Multilevel Matrix Converter it consists of four bidirectional semiconductor switches. It
has no energy storage elements. Having the ability to produce different output voltage levels enabling the
generation of stepped waveform with less harmonic distortion. The simulation model of Multilevel Matrix
Converter for simple topology is shown in Fig 3.
Fig. 3 Simulation model of MLMC
For an operation of MLMC it consists of four bidirectional switches then the sequence of
positive and negative cycle switching function with pulse generator input of Gate terminal can generate
multistepped staircase waveform. The suitable switching operation of MLMC is shown in table 1.
Table. 1 Conducting switches of MLMC
Converter
MLMC
Conducting switches
S1a, S1b
S4a, S4b
S3a, S3b
S2a, S2b
The switching table is presents number of conducting switches in Multilevel Matrix Converter.
The number of switches conduct at different firing pulses.The input pulses are given in IGBT Gate terminal in
the sequence of S1a, S4a, S3a and S2a. Then the output will be taken in different levels obtained from the
Multilevel Matrix Converter. The DC supply is input source and output of AC staircase waveform is taken.
Fig. 4 Output waveform of MLMC
The input from DC to staircase output waveform obtained using Multilevel Matrix Converter
with single logic control. From the output waveform five level stepped wave by using sequence of matrix switch
cell.
a.
MATRIX CONVERTER AS THREE PHASE INVERTER
In this type of conduction mode each switch conducts for 120°. At any instant of time only two
switches remains ON. In each leg S1a, S4a; S3a, S6a; and S5a, S2a are turned ON in the time of interval 120°.
From the Fig. 5 it is observed that two switches conduct at a time, one from the upper group and the other from
the lower group. At any time, two load terminals are connected to the DC supply and the third one remains open.
The resistive load is connected to the terminal. This mode of operation is to avoid the shoot through fault. In
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ISSN: 2393-994X
KARPAGAM JOURNAL OF ENGINEERING RESEARCH (KJER)
Volume No.: II, Special Issue on IEEE Sponsored International Conference on Intelligent Systems and Control (ISCO’15)
every step of 60° duration, only two switches are conducting. The six intervals of conducting pair of switches are
shown in table 2.
Table. 2 Conducting switch intervals for three phase inverter
Intervals
Conducting switches
I
S1a, S6a
II
S1a, S2a
III
S3a, S2a
IV
S3a, S4a
V
S5a, S4a
VI
S5a, S6a
The three phase inverter commutation is more reliable and possibility of two switches conducting
simultaneously. The Matrix Converter switching arrangement is bidirectional connection of each switch cell in
each leg. The simulation model of three phase inverter is shown in Fig 5.
Fig. 5 Simulation model of three phase inverter using MC
Fig. 6 Input and Output waveform of three phase inverter
From the output waveform Matrix Converter operation of three phase inverter should be obtained at
three different output voltages with high quality and high voltage gain.
b.
SPMC AS AN INVERTER
Inverter refers to the process of converting a DC voltage or current into AC voltage or current.
The inverter is used for various applications and this operation is more posssible for Single Phase Matrix
Converter with single logic control. For an inverter operation, the positive output switches S1a and S4a will
conduct while negative output switches S2a and S3a will conduct. The simulation diagram of inverter operation is
shows the Fig 3.From the simulation model of inverter the two switches S1a and S4aact as the same firing pulses
and another switching sequence of inverter the two switchesS2a and S3a conduct with same pulses.
469
ISSN: 2393-994X
KARPAGAM JOURNAL OF ENGINEERING RESEARCH (KJER)
Volume No.: II, Special Issue on IEEE Sponsored International Conference on Intelligent Systems and Control (ISCO’15)
Fig. 7 Input and Output waveform of Inverter
From the figure square wave should be obtained from inverter operation of Single Phase Matrix
Converter.
c.
SPMC AS CHOPPER
Chopper refers to the process of converting a fixed DC input voltage into variable DC output
voltage. The simulation model of Chopper is shows the Fig 3. For a Chopper operation the switches S1 a and S4a
will conduct. The switch S1a conduct as one firing pulse and switch S4a should be conduct as another firing
pulse.The simulation result of fixed DC input to variable DC output waveform is shown in Fig 8.
Fig. 8 Input and Output waveform of Chopper
d. SPMC AS RECTIFIER
Rectifier refers to the process of converting an AC voltage or current to DC voltage or
current.For a rectifier operation it consists of two types
 Half wave rectifier
 Full wave rectifier
i.
SPMC AS HALF WAVE RECTIFIER
For a half wave rectifier operation the positive output switches S1a and S4a will conduct only
and no negative switches conduct. The simulation diagram of half wave rectifier operation is shown in Fig 9.
Fig. 9 Simulation model of half wave rectifier
From the simulation model of rectifier the two switches S1a and S4a are conduct at same firing pulse.
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ISSN: 2393-994X
KARPAGAM JOURNAL OF ENGINEERING RESEARCH (KJER)
Volume No.: II, Special Issue on IEEE Sponsored International Conference on Intelligent Systems and Control (ISCO’15)
Fig. 10 Input and Output waveform of half wave rectifier
Form the output waveform of rectifier performed in half wave rectifier operation by using Single Phase
Matrix Converter.
ii.
SPMC AS FULL WAVE RECTIFIER
The simulation model of full wave rectifier is shows the Fig 9. For a full wave rectifier
operation the positive output switches S1a and S4a will conduct while negative switches S3b and S2b will
conduct.
Fig. 11 Input and Output waveform of full wave rectifier
From the output waveform the full wave rectifier operation is obtained by using Single Phase Matrix
Converter.
e.
SPMC AS CYCLO-CONVERTER
Cycloconverter refers to the process of AC to AC power conversion. The input power at one
frequency to output power at different frequency with one stage conversion. The simulation model of
Cycloconverter is shows the Fig 9.For a Cycloconverter operation the positive input cycle if the output is
positive switches S1a and S4a will conduct while in the negative input cycle if the output is positive switches S3b
and S2b will conduct. The negative half output of Cycloconverter is obtained by conduction of switches S2 a and
S3a and the switches S4b and S1b will conduct.Shows the simulation result fixed frequency to variable frequency
waveform is shown in Fig 12.
Fig. 12 Input and Output waveform of Cycloconverter
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f.
SPMC AS AC VOLTAGE CONTROLLER
AC voltage controller refers to the process of fixed alternating voltage directly to variable
alternating voltage without change in supply frequency. It is also called as a light dimmer controller or phase
controller. The load voltage is can be controlled by controlling the firing angle of the switches. The AC voltage
controller is used for domestic and industrial heating, speed control of motor, ac magnet controls and using
various applications. The simulation model of AC voltage controller is shows the Fig 9.For an operation of AC
voltage controller the bidirectional switch cell sequence of S1 a, S4a, S2b, S3b will conduct while the switching
sequence of S1b, S4b, S2a, S3a will conduct. The simulation result of fixed AC input and variable AC output
waveform of without change in supply frequency is shown in Fig 13.
Fig. 13 Input and Output waveform of AC voltage controller
SWITCHING TABLE
Following Table 3 summarize the different switching combinations for various operations of
Single Phase Matrix Controller.
Table. 3 Switching status for Different Converter operation
Converter
Conducting Switches
Inverter
S1a, S4a
S2a, S3a
S1a, S4a
(Rectifier)
Half wave rectifier
Full wave rectifier
S1a, S4a
S2b, S3b
Chopper (First Quadrant
operation)
Cycloconverter
S1a, S4a
S1a, S4a
S2b, S3b
S2a, S3a
S1b, S4b
S1a, S2b, S3b, S4a
S1b, S2a, S3a, S4b
AC voltage controller
From the switching table different converter operation by using different switching
combination of four bidirectional Single Phase Matrix Converter switches. It performed as various functions and
produce different outputs with single logic control unit.
II. SINUSOIDAL PULSE WIDTH MODULATION
A very popular method of controlling the voltage and frequency is by sinusoidal pulse width
modulation (which is also called as Sub harmonic pulse width modulation). In this method, a high-frequency
triangle carrier wave is compared with a three-phase sinusoidal waveform, the power devices in each phase are
switched on at the intersection of sine and triangle waves. The amplitude and frequency of the output voltage are
varied respectively, by varying the amplitude and frequency of the reference sine waves. The ratio of the
frequency of the sine wave to the frequency of the carrier wave is called modulation index.The carrier and
reference wave are mixed in a comparator. When sinusoidal wave has magnitude higher than the triangular
472
ISSN: 2393-994X
KARPAGAM JOURNAL OF ENGINEERING RESEARCH (KJER)
Volume No.: II, Special Issue on IEEE Sponsored International Conference on Intelligent Systems and Control (ISCO’15)
wave, the comparator output is high, otherwise it is low. The comparator output is processed in a trigger pulse
generator in such a manner that the output voltage wave of the rectifier has a pulse width agreement with the
comparator output pulse width.
Reference Signals
They are sinusoidal signals shifted between them of 120° and are characterized by the amplitude A r and
its frequency f.
The Carrier Wave
The carrier triangular wave is characterized by the amplitude Ap and the frequency fp, fp=1/tp. The
intersections between the reference voltage standards and the carrying wave give the time of opening and closing
of the switches.
Fig. 14 Sinusoidal PWM pulse generation
SIMULATION OF MLMC WITH SPWM
The simulation of Multilevel Matrix Converter with four bidirectional switches using Sinusoidal
Pulse Width Modulation method. It is used to give the input of smooth pulses for the Gate terminal of IGBT
switches. The resistive load is connected to the output terminal and fixed DC voltage is given to the input terminal.
The simulation model of MLMC with SPMC is shown in Fig 15.
Fig. 15 Simulation model of MLMC with SPWM
The subsystem of MLMC with including various components like taking sine wave, repeating sequence,
signal comparator using relational operator, the input and output data type conversion of double and Boolean type
with transport delay. The corresponding delay time is to mention in some milliseconds or it high frequency signal is
to give Gate terminal of IGBT.
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ISSN: 2393-994X
KARPAGAM JOURNAL OF ENGINEERING RESEARCH (KJER)
Volume No.: II, Special Issue on IEEE Sponsored International Conference on Intelligent Systems and Control (ISCO’15)
Fig. 16 Input and Output waveform of MLMC using SPWM
From the Multilevel Matrix Converter output voltage waveform of stepped wave by using SPWM method
with quality output voltage.
IV.
CONCLUSION
In this paper, a concept of Matrix Converter and implementation of Multilevel Matrix
Converter using single stage unit. Which is easy to obtained multilevel staircase output waveform from input
DC, and also performs a three phase inverter operation. The multi concept of Single Phase Matrix Converter can
be conceived design and realized by suitable switching schemes, where IGBT’s are used for the main power
switching device, arrangement of antiparallel switch cell. From results obtained it has been shown that the
SPMC can have either AC or DC supply input and synthesized AC or DC output, which can offer bi-directional
energy flow and avoid bulky energy storage elements. The switching signals were applied at the appropriate
switches using sinusoidal pulse width modulation. Moreover, a SPWM scheme has lower switching loss and
better reliability. The output waveform has been synthesized using pulse width modulation. The simulation
results are helpful to implement in hardware for the future purpose of industrial applications.
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