EPE Association: EPE 2005 - Topic 04-3a - DS: Multilevel and matrix converters

EPE 2005 - Topic 04-3a - DS: Multilevel and matrix converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2005 - Conference > EPE 2005 - Topic 04: HARD SWITCHING CONVERTERS AND CONTROL > EPE 2005 - Topic 04-3a - DS: Multilevel and matrix converters

   [return to parent folder]

   A Comparison of the Reliability of a Matrix Converter and a Controlled Rectifier-Inverter
By CLARE Jon; WHITLEY Chris; BRADLEY Keith; GRAHAM Towers; WHEELER Patrick; DE LILO Lilliana; ATEN Martin [View]
[Download]

Abstract: This paper compares the calculated reliability of a Matrix Converter with a controlled rectifier/inverter topology for an aerospace motor drive application. These topologies are functionally equivalent in terms of input power quality and regenerative capabilities. The military handbook MIL-HDBK-217F guidelines have been used to predict reliability. Although the Matrix Converter has a higher number of semi-conductor switches, these switches are subjected to a lower voltage stress, which can shown to increase the device reliability. When this factor is taken into account it can be shown that the predicted reliability of the matrix converter is actually slightly better than the controlled rectifier-inverter solution

   A First Loss Evaluation using a vertical SiC-JFET and a Conventional Si-IGBT in the Bidirectional Matrix Converter Switch Topology
By LUTZ Josef; HOFMANN Wilfried; DOMES Daniel [View]
[Download]

Abstract: SiC (silicon carbide) is a material with outstanding properties for power semiconductor application. Beside research activities including different power semiconductor switch types, unipolar JFET devices for blocking voltage of more than 1200V are applicable as samples promising switching loss reduction above all. In this paper the switching behaviour of these SiC-JFETs is compared to this of a similar conventional Si-IGBT regarding the conditions of the bidirectional matrix converter switch topology. Statements concerning the on-state losses will also be discussed focusing the necessary reverse conducting capability of the JFET devices in the matrix converter switch topology.

   A Hybrid Multi-Converter System Combining Single-Phase Converters with Three-Phase Converters
By YOSHIDA Takatsugu; FUKUDA Shoji [View]
[Download]

Abstract: A new hybrid multilevel multi-converter system combining three single-phase GTO converters with a three-phase NPC IGBT converter is proposed. The GTO converters can adjust the output voltage, though they operate in square-wave switching to minimize the switching-related device losses. The IGBT converter not only cancels the harmonic voltages generated by the GTO converters but also controls the resultant output voltage. The system can accomplish a wider adjustable output voltage range compared with other hybrid systems. A control strategy in relation to a required reference voltage is proposed to obtain minimum harmonic distortion in the resultant output voltage. A 1.5kW prototype is built and experimental results verify the validity of the proposed system and control strategy. Comparative studies on hybrid converter system performance with a different number of GTO converters are also included.

   A Novel Control Strategy for High-Frequency Ac-link AC/AC Direct Converter based on Virtual Converter System
By ITOH Junichi ; ODAKA Akihiro; KONDO Seiji; MATSUMURA Daisuke; OHGUCHI Hideki [View]
[Download]

Abstract: This paper proposes a simple control strategy for a high-frequency ac-link ac/ac direct converter. The proposed control strategy is based on the virtual converter system that consists of a PWM rectifier part, a high-frequency ac-link part and an inverter part. The proposed method realizes wide control range, high performances and low snubber loss. The validity of the proposed method is confirmed through the simulation and experimental results.

   Analysis of Non-Idealities in Direct and Indirect Matrix Converters
By TUUSA Heikki; ESKOLA Matti; JUSSILA Matti [View]
[Download]

Abstract: This paper compares the voltage transfer characteristics of direct and indirect matrix converter topologies. Knowledge of the real voltage transfer capability of a converter is essential, especially in sensorless motor drives in low speed region. The comparison is based on the analysis of non-idealities caused by real semiconductor devices and safe commutation methods. The effects of on-state voltage losses and commutation methods are modelled with equations. The analysis is verified in measurements and simulations. The direct matrix converter follows the reference more accurately than the indirect matrix converter. Thus direct topology is also found to be a more suitable converter solution for sensorless motor drives if no compensation methods of voltage inaccuracies are used. The results show that analysis of voltage transfer inaccuracies in direct and indirect matrix converter topologies can be used as a basis to develop the compensation methods needed in high performance motor drives without speed sensors.

   Bidirectional switches for matrix converter in contactless energy transmission systems
By MECKE Rudolf [View]
[Download]

Abstract: For an increasing number of applications in mechanical engineering, production technology, transportation, process engineering and medical engineering there are promising application prospects for contactless inductive energy transmission systems in the power range of several kilowatts. In particular the dimensions of the primary and secondary system, the existence of ferrite cores on the primary or secondary side and the air gap length determine the transmission behaviour. The transferable electric power and the efficiency of contactless magnetic systems can be considerably increased by using higher transmission frequencies, greater than 100 kHz. At conventional systems the main losses of the complete system are caused by the primary inverter. Therefore novel power electronic topologies for direct energy conversion are necessary for this special application. The use of a matrix converter for contactless energy transmission reduces the number of energy conversion steps, avoids voluminous and expensive electrolytic DC link capacitors, increases the reliability especially at high temperatures, reduces conduction losses in power semiconductors and enables four-quadrant operation with sinusoidal line currents. The paper investigates special aspects of the matrix converter with high output frequencies in combination with contactless energy transmission, for instance commutation strategies, control concepts for three-phase line connection and sinusoidal line currents and the conduction and switching losses in the bidirectional power semiconductors.

   Development of High Bandwidth Multi-Phase Multilevel Power Supply for Electricity Supply Network Emulation
By ATKINSON David [View]
[Download]

Abstract: The increasing number of distributed power generation systems, and more specifically wind farms, has led to electricity network companies laying down specifications as to how these power sources interact with the grid. The system described here is intended to act as a controllable grid to aid in the testing of these and other systems. The system is based on a voltage source inverter followed by a low pass filter. In order to achieve accurate output voltage control, high bandwidth closed loop control is required. A multi-level inverter was used to exploit the higher switching speeds available with low voltage rating devices. Also the lower switching harmonics in multi-level inverter allows the filter cut-off frequency to be increased in order to achieve a higher bandwidth response. A unit was constructed with a nominal continuous rating of 7.5kW and experimental results are presented.

   Feedback Linearization Control with Average Current Sharing for Multiphase Synchronous Buck Converter
By GUERRERO Josep; CRUZ Juan; GARCIA DE VICUÑA Luis; MATAS Jose; ALENTORN Alberto; BERBEL Nestor [View]
[Download]

Abstract: This paper presents a novel control for a multiphase dc-dc converter, which provides tight output voltage regulation, fast transient response, and robustness against large-signal disturbances in the input-voltage and the load-current.

   Five-Level Inverter Having Only Double DC Power Supplies
By MORI Hideki; MATSUI Keiju; YAMAMOTO Isamu; YAMAGUCHI Satarou; UEDA Fukashi [View]
[Download]

Abstract: The five-level PWM inverter has many advantages such as ability to operate the ac motors or the power compensator with very large capacity in nearly sinusoidal current waveforms. For these reasons, these applications have just begun to study. However, this circuit must provide four dc power supplies for supplying the active power. In this paper, we propose a novel double power supply method, in which both power supplies are inter-connected by dc capacitors. The voltages of the inter-connected dc capacitor are controlled by a novel third order harmonic injection method, where the phase of modified third order harmonic signal having positive or negative polarity is controlled individually.

   High-voltage, high-frequency Marx-bank type pulse generator using integrated power semiconductor half-bridges
By TAVARES Pedro; REDONDO Luis; ELMANO Margato; SILVA Jose [View]
[Download]

Abstract: This paper discusses the operation of an all silicon-based solution for the conventional Marx generator circuit, which has been developed for high-frequency (kHz), high-voltage (kV) applications needing rectangular pulses. The conventional Marx generator, for high-voltage pulsed applications, uses passive power components (inductors or resistors), to supply the energy storage capacitors. This solution has the disadvantages of cost, size, power losses and limited frequency operation. In the proposed circuit, the bulky passive power elements are replaced by power semiconductor switches, increasing the performance of the classical circuit, strongly reducing costs, losses and increasing the pulse repetition frequency. Also, the proposed topology enables the use of typical half-bridge semiconductor structures, and ensures that the maximum voltage blocked by the semiconductors equals the power supply voltage (i.e. the voltage of each capacitor), even with mismatches in the synchronized switching, and in fault conditions. A laboratory prototype with five stages, 5 kW peak power, of the proposed silicon-based Marx generator circuit, was constructed using 1200 V IGBTs and diodes, operating with 1000 V d-c input voltage and 10 kHz frequency, giving 5 kV / 1 A pulses, with 10 microseconds width and 50 ns rise time.

   Joint use of mono-phase and three-phase inverters for improvement characteristics of multilevel frequency converters
By VORONTSOV Alexei; PRONIN Mikhail [View]
[Download]

Abstract: Control algorithms, correlation of factors of components and characteristics of multi-level frequency converters, which include in series connected mono-phase inverters in each leg of load and three-phase inverter are shown. Interchange of active power with mains is provided by transistor rectifier, which also a filter of mains currents and a compensator of reactive power.

   Novel Space Vector Based Hysteresis Current Control (HCC) Strategies for Matrix Converter
By WANG Xiao; TSENG King [View]
[Download]

Abstract: In this paper, two kinds of novel but simple control strategies for current controlled matrix converter are proposed and presented. One of the methods is based on three-level hysteresis comparator, and the other is based on four-level hysteresis comparator. The latter can result in a lower average switching frequency. Both controllers work with current components represented in stationary coordinate system. These two methods have all major advantages of both SVM and HCC control techniques, and can help to greatly reduce the system complexity compared to traditional SVM based matrix converter control system. Simulation results are presented to show the performance of both of these two HCC controllers for matrix converter.

   Real-Time Simulation of Matrix Converter Drives
By LIPO Thomas A.; DUFOUR Christian; WEI Lixiang [View]
[Download]

Abstract: This paper describes a real time simulator of matrix converter system. The simulated plant is a classical matrix converter with source, input filter and load. The simulator is based on the RT-LAB real time simulation platform, which enables easy model-to-target designs from Simulink models at time step below 10 microseconds. The simulator is designed to accept real IGBT/GTO/MOSFET firing pulses from high performance I/Os thus permitting matrix converter controller testing in hardware-in-the-loop (HIL) simulations. The matrix converter models use interpolation methods to obtain variable step-solver equivalent precision in the fixed time step scheme required by HIL applications. This paper highlights the special techniques necessary to simulate kHz-range inverters.

   Selection of Parameters for a Balancing Circuit of DC-DC and AC-AC Multicell Converters
By STALA Robert; PIROG Stanislaw [View]
[Download]

Abstract: The paper presents a dc/dc and ac/ac multicell converters with balancing circuit. The multicell converters use voltage sources of different values placed in every cell. Low capacitance capacitors may be used as the cells’ sources. But in that case an improper proportion of the source capacitors voltages can occur, which is very dangerous in multilevel converters. To eliminate this voltage unbalance the RLC series circuit (balancing cir-cuit) is connected to load in parallel. Phenomenon of stabilization of voltages on cells’ capacitors by balanc-ing current, mathematical description of the converter, energy transfer from source under unbalance state, sensibility of the system for balancing circuit parameters variation is presented. For three-cell dc/dc converter dynamical states and power losses in steady state versus parameters of the balancing circuit are analyzed. In ac/ac multicell converter the balancing circuit parameters determines the converter’s steady state. For three-cell ac/ac converter all quantities of the system that affect the proper proportion of cells’ voltages are presented.

   Space Vector Modulation Strategy For Conventional and Indirect Matrix Converters
By IGNEY Jens; BRAUN Michael [View]
[Download]

Abstract: This paper presents a modulation strategy for conventional matrix converters (CMC) and indirect matrix converters (IMC). The benefit of the strategy are the clarity of the space vector approach, the simplicity of the signal processing and a wide and analytically calculable control range. The control range nearly reaches the theoretical maximum of the CMC.

   Study of Multi-Pulse PWM for Multi-Level BTB for Distributed Generation System
By OONO Takanori ; KIMURA Noriyuki; MORIZANE Toshimitsu; TANIGUCHI Katsunori [View]
[Download]

Abstract: This paper describes about the multi-level BTB converter system installed in the power distribution system with the dispersed generation, such as solar power, wind power, or others. This type of generation is often installed at the end of the power distribution system. This makes the current flow in the power distribution system unexpected profile and sometimes cause too much high voltage. To avoid such phenomenon, installation of a power flow controller is one of the solutions. However smallness, lightness and low cost is indispensable. We propose to use the multi-level BTB converter system with the new PWM control as the power flow controller or STATCOM.

   Three-Level Voltage Source Converter controlled by means of Hysteresis-Band Current strategy, driving a Synchronous Machine
By LAFOZ Marcos [View]
[Download]

Abstract: This paper shows the development and experimental results of a Diode-Clamped Three-Level Converter driving a Synchronous Machine, connected to the network. A Double Hysteresis-Band Current Control strategy has been used to control the power converters and a Three-Level Converter Prototype has been developed in order to test this strategy. Constant switching frequency and easy control of DC capacitor voltage balance can be obtained by using this technique and experimental results have demonstrated.

EPE 2005 - Topic 04-3a - DS: Multilevel and matrix converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2005 - Conference > EPE 2005 - Topic 04: HARD SWITCHING CONVERTERS AND CONTROL > EPE 2005 - Topic 04-3a - DS: Multilevel and matrix converters
	[return to parent folder]

	A Comparison of the Reliability of a Matrix Converter and a Controlled Rectifier-Inverter By CLARE Jon; WHITLEY Chris; BRADLEY Keith; GRAHAM Towers; WHEELER Patrick; DE LILO Lilliana; ATEN Martin	[View] [Download]
Abstract: This paper compares the calculated reliability of a Matrix Converter with a controlled rectifier/inverter topology for an aerospace motor drive application. These topologies are functionally equivalent in terms of input power quality and regenerative capabilities. The military handbook MIL-HDBK-217F guidelines have been used to predict reliability. Although the Matrix Converter has a higher number of semi-conductor switches, these switches are subjected to a lower voltage stress, which can shown to increase the device reliability. When this factor is taken into account it can be shown that the predicted reliability of the matrix converter is actually slightly better than the controlled rectifier-inverter solution

	A First Loss Evaluation using a vertical SiC-JFET and a Conventional Si-IGBT in the Bidirectional Matrix Converter Switch Topology By LUTZ Josef; HOFMANN Wilfried; DOMES Daniel	[View] [Download]
Abstract: SiC (silicon carbide) is a material with outstanding properties for power semiconductor application. Beside research activities including different power semiconductor switch types, unipolar JFET devices for blocking voltage of more than 1200V are applicable as samples promising switching loss reduction above all. In this paper the switching behaviour of these SiC-JFETs is compared to this of a similar conventional Si-IGBT regarding the conditions of the bidirectional matrix converter switch topology. Statements concerning the on-state losses will also be discussed focusing the necessary reverse conducting capability of the JFET devices in the matrix converter switch topology.

	A Hybrid Multi-Converter System Combining Single-Phase Converters with Three-Phase Converters By YOSHIDA Takatsugu; FUKUDA Shoji	[View] [Download]
Abstract: A new hybrid multilevel multi-converter system combining three single-phase GTO converters with a three-phase NPC IGBT converter is proposed. The GTO converters can adjust the output voltage, though they operate in square-wave switching to minimize the switching-related device losses. The IGBT converter not only cancels the harmonic voltages generated by the GTO converters but also controls the resultant output voltage. The system can accomplish a wider adjustable output voltage range compared with other hybrid systems. A control strategy in relation to a required reference voltage is proposed to obtain minimum harmonic distortion in the resultant output voltage. A 1.5kW prototype is built and experimental results verify the validity of the proposed system and control strategy. Comparative studies on hybrid converter system performance with a different number of GTO converters are also included.

	A Novel Control Strategy for High-Frequency Ac-link AC/AC Direct Converter based on Virtual Converter System By ITOH Junichi ; ODAKA Akihiro; KONDO Seiji; MATSUMURA Daisuke; OHGUCHI Hideki	[View] [Download]
Abstract: This paper proposes a simple control strategy for a high-frequency ac-link ac/ac direct converter. The proposed control strategy is based on the virtual converter system that consists of a PWM rectifier part, a high-frequency ac-link part and an inverter part. The proposed method realizes wide control range, high performances and low snubber loss. The validity of the proposed method is confirmed through the simulation and experimental results.

	Analysis of Non-Idealities in Direct and Indirect Matrix Converters By TUUSA Heikki; ESKOLA Matti; JUSSILA Matti	[View] [Download]
Abstract: This paper compares the voltage transfer characteristics of direct and indirect matrix converter topologies. Knowledge of the real voltage transfer capability of a converter is essential, especially in sensorless motor drives in low speed region. The comparison is based on the analysis of non-idealities caused by real semiconductor devices and safe commutation methods. The effects of on-state voltage losses and commutation methods are modelled with equations. The analysis is verified in measurements and simulations. The direct matrix converter follows the reference more accurately than the indirect matrix converter. Thus direct topology is also found to be a more suitable converter solution for sensorless motor drives if no compensation methods of voltage inaccuracies are used. The results show that analysis of voltage transfer inaccuracies in direct and indirect matrix converter topologies can be used as a basis to develop the compensation methods needed in high performance motor drives without speed sensors.

	Bidirectional switches for matrix converter in contactless energy transmission systems By MECKE Rudolf	[View] [Download]
Abstract: For an increasing number of applications in mechanical engineering, production technology, transportation, process engineering and medical engineering there are promising application prospects for contactless inductive energy transmission systems in the power range of several kilowatts. In particular the dimensions of the primary and secondary system, the existence of ferrite cores on the primary or secondary side and the air gap length determine the transmission behaviour. The transferable electric power and the efficiency of contactless magnetic systems can be considerably increased by using higher transmission frequencies, greater than 100 kHz. At conventional systems the main losses of the complete system are caused by the primary inverter. Therefore novel power electronic topologies for direct energy conversion are necessary for this special application. The use of a matrix converter for contactless energy transmission reduces the number of energy conversion steps, avoids voluminous and expensive electrolytic DC link capacitors, increases the reliability especially at high temperatures, reduces conduction losses in power semiconductors and enables four-quadrant operation with sinusoidal line currents. The paper investigates special aspects of the matrix converter with high output frequencies in combination with contactless energy transmission, for instance commutation strategies, control concepts for three-phase line connection and sinusoidal line currents and the conduction and switching losses in the bidirectional power semiconductors.

	Development of High Bandwidth Multi-Phase Multilevel Power Supply for Electricity Supply Network Emulation By ATKINSON David	[View] [Download]
Abstract: The increasing number of distributed power generation systems, and more specifically wind farms, has led to electricity network companies laying down specifications as to how these power sources interact with the grid. The system described here is intended to act as a controllable grid to aid in the testing of these and other systems. The system is based on a voltage source inverter followed by a low pass filter. In order to achieve accurate output voltage control, high bandwidth closed loop control is required. A multi-level inverter was used to exploit the higher switching speeds available with low voltage rating devices. Also the lower switching harmonics in multi-level inverter allows the filter cut-off frequency to be increased in order to achieve a higher bandwidth response. A unit was constructed with a nominal continuous rating of 7.5kW and experimental results are presented.

	Feedback Linearization Control with Average Current Sharing for Multiphase Synchronous Buck Converter By GUERRERO Josep; CRUZ Juan; GARCIA DE VICUÑA Luis; MATAS Jose; ALENTORN Alberto; BERBEL Nestor	[View] [Download]
Abstract: This paper presents a novel control for a multiphase dc-dc converter, which provides tight output voltage regulation, fast transient response, and robustness against large-signal disturbances in the input-voltage and the load-current.

	Five-Level Inverter Having Only Double DC Power Supplies By MORI Hideki; MATSUI Keiju; YAMAMOTO Isamu; YAMAGUCHI Satarou; UEDA Fukashi	[View] [Download]
Abstract: The five-level PWM inverter has many advantages such as ability to operate the ac motors or the power compensator with very large capacity in nearly sinusoidal current waveforms. For these reasons, these applications have just begun to study. However, this circuit must provide four dc power supplies for supplying the active power. In this paper, we propose a novel double power supply method, in which both power supplies are inter-connected by dc capacitors. The voltages of the inter-connected dc capacitor are controlled by a novel third order harmonic injection method, where the phase of modified third order harmonic signal having positive or negative polarity is controlled individually.

	High-voltage, high-frequency Marx-bank type pulse generator using integrated power semiconductor half-bridges By TAVARES Pedro; REDONDO Luis; ELMANO Margato; SILVA Jose	[View] [Download]
Abstract: This paper discusses the operation of an all silicon-based solution for the conventional Marx generator circuit, which has been developed for high-frequency (kHz), high-voltage (kV) applications needing rectangular pulses. The conventional Marx generator, for high-voltage pulsed applications, uses passive power components (inductors or resistors), to supply the energy storage capacitors. This solution has the disadvantages of cost, size, power losses and limited frequency operation. In the proposed circuit, the bulky passive power elements are replaced by power semiconductor switches, increasing the performance of the classical circuit, strongly reducing costs, losses and increasing the pulse repetition frequency. Also, the proposed topology enables the use of typical half-bridge semiconductor structures, and ensures that the maximum voltage blocked by the semiconductors equals the power supply voltage (i.e. the voltage of each capacitor), even with mismatches in the synchronized switching, and in fault conditions. A laboratory prototype with five stages, 5 kW peak power, of the proposed silicon-based Marx generator circuit, was constructed using 1200 V IGBTs and diodes, operating with 1000 V d-c input voltage and 10 kHz frequency, giving 5 kV / 1 A pulses, with 10 microseconds width and 50 ns rise time.

	Joint use of mono-phase and three-phase inverters for improvement characteristics of multilevel frequency converters By VORONTSOV Alexei; PRONIN Mikhail	[View] [Download]
Abstract: Control algorithms, correlation of factors of components and characteristics of multi-level frequency converters, which include in series connected mono-phase inverters in each leg of load and three-phase inverter are shown. Interchange of active power with mains is provided by transistor rectifier, which also a filter of mains currents and a compensator of reactive power.

	Novel Space Vector Based Hysteresis Current Control (HCC) Strategies for Matrix Converter By WANG Xiao; TSENG King	[View] [Download]
Abstract: In this paper, two kinds of novel but simple control strategies for current controlled matrix converter are proposed and presented. One of the methods is based on three-level hysteresis comparator, and the other is based on four-level hysteresis comparator. The latter can result in a lower average switching frequency. Both controllers work with current components represented in stationary coordinate system. These two methods have all major advantages of both SVM and HCC control techniques, and can help to greatly reduce the system complexity compared to traditional SVM based matrix converter control system. Simulation results are presented to show the performance of both of these two HCC controllers for matrix converter.

	Real-Time Simulation of Matrix Converter Drives By LIPO Thomas A.; DUFOUR Christian; WEI Lixiang	[View] [Download]
Abstract: This paper describes a real time simulator of matrix converter system. The simulated plant is a classical matrix converter with source, input filter and load. The simulator is based on the RT-LAB real time simulation platform, which enables easy model-to-target designs from Simulink models at time step below 10 microseconds. The simulator is designed to accept real IGBT/GTO/MOSFET firing pulses from high performance I/Os thus permitting matrix converter controller testing in hardware-in-the-loop (HIL) simulations. The matrix converter models use interpolation methods to obtain variable step-solver equivalent precision in the fixed time step scheme required by HIL applications. This paper highlights the special techniques necessary to simulate kHz-range inverters.

	Selection of Parameters for a Balancing Circuit of DC-DC and AC-AC Multicell Converters By STALA Robert; PIROG Stanislaw	[View] [Download]
Abstract: The paper presents a dc/dc and ac/ac multicell converters with balancing circuit. The multicell converters use voltage sources of different values placed in every cell. Low capacitance capacitors may be used as the cells’ sources. But in that case an improper proportion of the source capacitors voltages can occur, which is very dangerous in multilevel converters. To eliminate this voltage unbalance the RLC series circuit (balancing cir-cuit) is connected to load in parallel. Phenomenon of stabilization of voltages on cells’ capacitors by balanc-ing current, mathematical description of the converter, energy transfer from source under unbalance state, sensibility of the system for balancing circuit parameters variation is presented. For three-cell dc/dc converter dynamical states and power losses in steady state versus parameters of the balancing circuit are analyzed. In ac/ac multicell converter the balancing circuit parameters determines the converter’s steady state. For three-cell ac/ac converter all quantities of the system that affect the proper proportion of cells’ voltages are presented.

	Space Vector Modulation Strategy For Conventional and Indirect Matrix Converters By IGNEY Jens; BRAUN Michael	[View] [Download]
Abstract: This paper presents a modulation strategy for conventional matrix converters (CMC) and indirect matrix converters (IMC). The benefit of the strategy are the clarity of the space vector approach, the simplicity of the signal processing and a wide and analytically calculable control range. The control range nearly reaches the theoretical maximum of the CMC.

	Study of Multi-Pulse PWM for Multi-Level BTB for Distributed Generation System By OONO Takanori ; KIMURA Noriyuki; MORIZANE Toshimitsu; TANIGUCHI Katsunori	[View] [Download]
Abstract: This paper describes about the multi-level BTB converter system installed in the power distribution system with the dispersed generation, such as solar power, wind power, or others. This type of generation is often installed at the end of the power distribution system. This makes the current flow in the power distribution system unexpected profile and sometimes cause too much high voltage. To avoid such phenomenon, installation of a power flow controller is one of the solutions. However smallness, lightness and low cost is indispensable. We propose to use the multi-level BTB converter system with the new PWM control as the power flow controller or STATCOM.

	Three-Level Voltage Source Converter controlled by means of Hysteresis-Band Current strategy, driving a Synchronous Machine By LAFOZ Marcos	[View] [Download]
Abstract: This paper shows the development and experimental results of a Diode-Clamped Three-Level Converter driving a Synchronous Machine, connected to the network. A Double Hysteresis-Band Current Control strategy has been used to control the power converters and a Three-Level Converter Prototype has been developed in order to test this strategy. Constant switching frequency and easy control of DC capacitor voltage balance can be obtained by using this technique and experimental results have demonstrated.