Matrix converters are AC to AC power converter topology that can generate required amplitude and frequency AC sinusoidal wave form conventional AC source
based mainly on semiconductor switches with minimal requirement for passive components. It consist of nine bi-directional switches arranged in matrix manner such that any input phase can be directly connected to any output phase. In most of the cases a three input three output converter will consist of bidirectional switches arranged in 3 row and 3 column manner resembles to a matrix of nine bi-directional switches, hence the term ‘Matrix converter ’. The process of switching on and off the bidirectional switche made the variable frequency and amplitude signals at the output of the matrix converter.
The matrix converters are intensively researched area in the last decade. This
interest is reflected in the number of articles that are published in the field of matrix
converter. This interset is mainly due to the fact that a all-silicon converter that can
completely replace the conventional AC-DC-AC inverters. The matrix converter can
provide the amplitude and frequency conversion, bi-directional power flow and input displacement factor control without the presence of bulky life limitted capacitors and other passive elements.
Despite of advantage of matrix converters, they are not used commonly in most
of the industries. There are several reasons for the selection of conventional AC-DC-AC inverter over the matrix converter. Firstly, Even though the matrix converter topology was started in 1970 breaktrough in the field of the matrix converter happned in last decade.So still its considered as a new technology. Secondly, the number of the semiconductor switches in a matrix converter is greater than the number used in a DC-link converter. Therefore, the cost of implementation of a matrix converter is larger than a conventional dc-link converter of the same ratings.Finally, the amplitude of the output voltages generated by a matrix converter is limited to 0.866 of the input voltage amplitude for the most popular modulation methods. Therefore, electrical motors or any other standard device connected as load to a matrix converter do not operate at their nominal rated voltage.
Even though Matrix converter has some disadvantages its very attractive for
some application. Firstly, there are applications where energy storage elements like
capacitors and inductors are to be avoided. For example, the large electrolytic capacitors of a dc-link converter is one of the elements that decreases the reliability of the converter. Secondly, the cost of power semiconductors continues to fall and there is no evidence to suggest that this trend will change for the future. On the other hand, the real cost of energy storage elements is not falling. For this reason, matrix converters will became increasingly more cost competitive. Thirdly, a matrix converter is a very attractive solution when regeneration is required. The bidirectional power flow capability and input displacement factor control of matrix converters make them an ideal solution for same application. Finally, there are applications where the converter size, weight and performance is of major concern. The lack of bulky energy storage elements and the integration of semiconductors in power modules specifically designed for matrix converters mean that large power density factors are achievable employing matrix converters.
In this paper proposed a new multilevel modulation technique by cascading
the H-bridge inverter and rectifier. In indirect matrix converter inveter side and rectifier side are seperated and they are connected by fictious DC link. The MMMCs are similar to the cascaded H-bridge (CHB) converter in both structure and features such as modular design, good waveform quality, and allowing the use of low voltage power devices. Besides, they have inherent four quadrant operation capability and can be used iregenerative applications. Regarding modulation strategy, none of those for operating the CHB converter or the conventional MCs can be directly borrowed for the MMMCs.
This paper is dedicated to the design of indirect space vector based modulation techniques for the MMMCs.
based mainly on semiconductor switches with minimal requirement for passive components. It consist of nine bi-directional switches arranged in matrix manner such that any input phase can be directly connected to any output phase. In most of the cases a three input three output converter will consist of bidirectional switches arranged in 3 row and 3 column manner resembles to a matrix of nine bi-directional switches, hence the term ‘Matrix converter ’. The process of switching on and off the bidirectional switche made the variable frequency and amplitude signals at the output of the matrix converter.
The matrix converters are intensively researched area in the last decade. This
interest is reflected in the number of articles that are published in the field of matrix
converter. This interset is mainly due to the fact that a all-silicon converter that can
completely replace the conventional AC-DC-AC inverters. The matrix converter can
provide the amplitude and frequency conversion, bi-directional power flow and input displacement factor control without the presence of bulky life limitted capacitors and other passive elements.
Despite of advantage of matrix converters, they are not used commonly in most
of the industries. There are several reasons for the selection of conventional AC-DC-AC inverter over the matrix converter. Firstly, Even though the matrix converter topology was started in 1970 breaktrough in the field of the matrix converter happned in last decade.So still its considered as a new technology. Secondly, the number of the semiconductor switches in a matrix converter is greater than the number used in a DC-link converter. Therefore, the cost of implementation of a matrix converter is larger than a conventional dc-link converter of the same ratings.Finally, the amplitude of the output voltages generated by a matrix converter is limited to 0.866 of the input voltage amplitude for the most popular modulation methods. Therefore, electrical motors or any other standard device connected as load to a matrix converter do not operate at their nominal rated voltage.
Even though Matrix converter has some disadvantages its very attractive for
some application. Firstly, there are applications where energy storage elements like
capacitors and inductors are to be avoided. For example, the large electrolytic capacitors of a dc-link converter is one of the elements that decreases the reliability of the converter. Secondly, the cost of power semiconductors continues to fall and there is no evidence to suggest that this trend will change for the future. On the other hand, the real cost of energy storage elements is not falling. For this reason, matrix converters will became increasingly more cost competitive. Thirdly, a matrix converter is a very attractive solution when regeneration is required. The bidirectional power flow capability and input displacement factor control of matrix converters make them an ideal solution for same application. Finally, there are applications where the converter size, weight and performance is of major concern. The lack of bulky energy storage elements and the integration of semiconductors in power modules specifically designed for matrix converters mean that large power density factors are achievable employing matrix converters.
In this paper proposed a new multilevel modulation technique by cascading
the H-bridge inverter and rectifier. In indirect matrix converter inveter side and rectifier side are seperated and they are connected by fictious DC link. The MMMCs are similar to the cascaded H-bridge (CHB) converter in both structure and features such as modular design, good waveform quality, and allowing the use of low voltage power devices. Besides, they have inherent four quadrant operation capability and can be used iregenerative applications. Regarding modulation strategy, none of those for operating the CHB converter or the conventional MCs can be directly borrowed for the MMMCs.
This paper is dedicated to the design of indirect space vector based modulation techniques for the MMMCs.
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