EPE Association: EPE 2011 - DS2f: Topic 05: Matrix Converters

EPE 2011 - DS2f: Topic 05: Matrix Converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2011 ECCE Europe - Conference > EPE 2011 - Topic 05: Hard Switching Inverters and Control > EPE 2011 - DS2f: Topic 05: Matrix Converters

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   A Simple Current Control Method with Instantaneous Reactive Power Minimization for Four-Leg Indirect Matrix Converters
By Marco RIVERA, Ivan CONTRERAS, Jose RODRIGUEZ, Ruben PEÑA, Patrick WHEELER [View]
[Download]

Abstract: While the known modulation and control techniques for four-leg matrix converters are based on pulse width modulation or three-dimensional space vector modulation, this paper presents a simple current control strategy based on prediction calculation to select the switching states of the converter. By using a predictive cost function, the optimal switching state to be applied to the next sampling time is selected. This is done in order to minimize the instantaneous reactive power on the input side and to obtain a positive dc-link voltage at any time, while maintaining a good tracking of the load currents to their respective references. The feasibility of the proposed strategy is verified by simulation results.

   A SINGLE LOOP VOLTAGE CONTROLLER BASED REPETITIVE CONTROL FOR A MATRIX CONVERTER
By Wesam ROHOUMA [View]
[Download]

Abstract: In this paper a repetitive control approach is proposed to regulate the output voltage of a four-leg matrix converter for an Aircraft Ground Power Supply application. The proposed controller reduces the tracking error and increases the stability of the converter compared to traditional approaches. Simulations and experimental results from a 7.5KW converter prototype are presented to verify the operation of the proposed controller.

   An Open-Circuit Faults Diagnosis Method for Matrix Converters based on DWT Analysis of Output Current
By Panagiotis POTAMIANOS, Epaminondas MITRONIKAS, Athanasios SAFACAS [View]
[Download]

Abstract: A novel diagnosis method is proposed in this work which is designed to detect open-circuit faults that occur in the matrix converter topology. In the potential application range of this type of converters, increased reliability and fault tolerance of the drive system is required through its remedial operation in cases of partial failures. All these requirements indicate that a monitoring system that is able to timely detect the various possible failures is necessary. In this paper, the output current of the matrix converter is monitored and analyzed using the discrete wavelet transform (DWT) in order to detect partial or total open-circuit failures of the converter’s bidirectional switches. The main advantage of the proposed method is that it is based on the output current measurement in contrast to the output voltage measurement that is required by previously proposed methods. Thus, the proposed method can be integrated without additional costs into motor current signature analysis (MCSA) systems that are used to detect faults in induction machines (IM). The choice of the mother wavelet which is used in the DWT analysis as well as the choice of the window function are evaluated in this work. The case of rapid changes of the output phase currents corresponding to the operating conditions are also examined.

   Calorimetric comparison of the use of silicon carbide diodes in a 100kW matrix converter for aerospace applications
By Lee EMPRINGHAM, Liliana DE LILLO, Pat WHEELER, Jon CLARE [View]
[Download]

Abstract: A 100kW matrix converter designed for aerospace applications using Silicon Carbide schottky barrier diodes and silicon IGBTs to construct the power circuit is presented. Calorimetric methods will be used to determine improvements in switching losses. The research aim is to increase switching frequencies in order to minimise passive component size.

   Control of a Brushless Doubly-Fed Induction Generator via a Matrix Converter
By Ruben PENA, Roberto CARDENAS, Andres MUÑOZ, Alvaro SUREDA, Jon CLARE, Pat WHEELER [View]
[Download]

Abstract: The Doubly-Fed Induction Generator (DFIG) is one of the most widely used generators for wind energy applications and more of 50\% of the installed Wind Energy Conversion Systems (WECS) are using this sort of variable speed technology. However, the machine requires brushes for the operation which increases the maintenance work. To overcome this drawback a Brushless Double Fed Induction Generator (BDFIG), composed of two cascaded doubly-fed machines with the rotor windings interconnected, could be used. In this work, the control of a BDFIG is presented using a matrix converter (MC). Matrix converters may be seen as suitable converter choice for this application instead of the standard back-to-back PWM voltage source converter topology. Results from an experimental rig are presented for operation of the BDFIG at variable speed with the machine driven by a commercial AC drive as a prime mover.

   Eliminating Current Sensors of Indirect Matrix Converter Using Neuro-Fuzzy Controller
By Alireza JAHANGIRI, Ahmad RADAN [View]
[Download]

Abstract: This paper describes non-linear average model of Indirect Matrix Converter (IMC) with an output LCfilter in stationary and rotating reference frames. The defects of pervious control strategies based onderived average model are discussed and a novel adaptive neuro-fuzzy controller is proposed. Eliminating output current sensors, good dynamic performance in any operating point without overshoot and balanced output voltages with slight distortion of line side currents are among the benefits of the proposed method. Theory analyses, the model validation and simulation results are presented to verify the effectiveness ofthis control method.

   Experimental Verification for a Matrix Converter with a V-connection Chopper
By Kazuhiro KOIWA, Jun-ichi ITOH [View]
[Download]

Abstract: This paper proposes a circuit topology for a matrix converter with a boost up function in the input side. The proposed circuit uses a V-connection AC chopper to achieve the boost-up function. The matrix converter and the V-connection AC chopper are independently controlled, where a virtual indirect control method is applied to the matrix converter, and the control of the V-connection AC chopper is an open-loop control with a damping. One problem of this system is the resonance happens between the input reactor and the filter capacitor. In order to suppress the resonance, the damping control is implemented in the AC chopper. In this paper, the operation of the proposed circuit along with the loss analysis is discussed in details. For the simulation and experiment results, the proposed circuit is confirmed obtaining the maximum efficiency of 95.1 \%, which is higher efficiency than that of a conventional back-to-back converter.

   Improved modulation of two-stage matrix converter for EMA in aircraft applications
By Kun XIAO, Lina WANG, Pat WHEELER [View]
[Download]

Abstract: This paper presents the improved modulation strategy of Two-Stage Matrix Converter (TSMC) for applications in aircraft Electro-Mechanical Actuator (EMA) system. In the modulation of rectifier stage, Phase Locked Loop (PLL) is employed to track the instantaneous value of both the angle and the frequency of the input voltage vector. The frequency is then taken into calculation to compensate the angle sample delay, as a result of the un-ignorable angle alternation in each Pulse Width Modula-tion (PWM) cycle at input frequency of 360~800Hz. The drawbacks of the sample delay are discussed, which lie in the incorrect input power factor control, fluctuation of voltage transfer ratio and possibil-ity of short circuit in inverter stage. In the modulation of inverter stage, a 4-time commutation PWM pattern is presented, which reduces the number of commutations from 6 to 4 in each PWM cycle. Therefore, increasing the PWM frequency by 50\% remains the same number of commutations thus the same switching loss per time interval. The sample delay and the output current harmonic could be re-duced thereafter at the increased PWM frequency. Simulation and experiment results verify the im-proved performance of the proposed modulation.

   Matrix Converter Systems Stability Analysis Taking into Account Switching Effects
By Stephen COX, Pericle ZANCHETTA [View]
[Download]

Abstract: AC/AC matrix converters have recently been applied for industrial, military and aerospace prototype systems. However, their dedicated input filters may lead to instability in operation. In this paper, simulations are presented of a model that accounts explicitly for the switching, and these simulations are compared with an averaged model. It is shown that this averaged model may significantly underestimate the instability threshold compared with the more detailed, switching model, which is instead recommended for determining the stability margin.

   Open-Circuited Switch Fault Detection for Fault Tolerant Matrix Converter Motor Drive Systems
By Sudarat KHWAN-ON, Liliana DE LILLO, Lee EMPRINGHAM, Patrick WHEELER [View]
[Download]

Abstract: This paper describes a high speed fault detection strategy to detect and identify open-circuit device failures in matrix converter motor drive systems. The proposed fault detection algorithm is based on analysis of the currents circulating through the drive system and the bidirectional switches gating signals. The presented technique described in this paper is used to identify not only a fault caused in a single device but also multiple device failures. Simulation and experimental results are presented to validate the effectiveness of the proposed fault detection technique.

   Performance Optimization of a Square wave operation in an Indirect Matrix Converter with a Reactor free DC Boost Converter
By Goh TECK CHIANG, Jun-ichi ITOH [View]
[Download]

Abstract: This paper discusses a modulation control for an indirect matrix converter connects with a reactor free boost converter for induction motor drives. The square wave modulation is proposed to apply with a four-step commutation pattern to improve the voltage transfer ratio of the indirect matrix converter from 0.866 to 0.97 (VTR= vout/vin). Furthermore, a feed-forward control is proposed to apply in the reactor free boost converter to reduce the ripple in the battery current which is caused by the fluctuations at the neutral point voltage. In the experiment results, the battery current is reduced by approximately 72 \% by the feed forward control. The loss analysis shows an efficiency of 94 \% for the proposed method.

   Poly-Phased Matrix Converter - A 27 input phases to 3 output phases experimental set-up running with hard and soft commutations
By Antoine BEGUIN, Alfred RUFER [View]
[Download]

Abstract: This paper presents an experimental set-up of a 27 phases input to 3 phases output Poly-Phased MatrixConverter (27x3 PPMC) realised for the real time experimentation of the dedicated control electronics.When the original converter system is dedicated to the frequency conversion from a fast rotatinggenerator directly coupled to the gas turbine for feeding into the 50 Hz grid with a power level up tothe 100 MW range, the power level of the experimental set-up is chosen at about 1 kW. Firstexperimentations are documented with a frequency adaptation from 100Hz to 50Hz. The poly-phasedsynchronous machine’s induced voltages are emulated with 27 linear power operational amplifiers,feeding the primary winding of small transformers. The secondary windings built the polygonalconnection of the stator of the machine, and are connected to the 27 inputs of the poly-phased matrix.The PPMC is run in mix mode operation, which is a mix of natural and forced commutations. Thispaper also presents the theory that goes along with the mix mode operation of the PPMC andinvestigates especially the losses in the RC snubber circuits.

EPE 2011 - DS2f: Topic 05: Matrix Converters
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2011 ECCE Europe - Conference > EPE 2011 - Topic 05: Hard Switching Inverters and Control > EPE 2011 - DS2f: Topic 05: Matrix Converters
	[return to parent folder]

	A Simple Current Control Method with Instantaneous Reactive Power Minimization for Four-Leg Indirect Matrix Converters By Marco RIVERA, Ivan CONTRERAS, Jose RODRIGUEZ, Ruben PEÑA, Patrick WHEELER	[View] [Download]
Abstract: While the known modulation and control techniques for four-leg matrix converters are based on pulse width modulation or three-dimensional space vector modulation, this paper presents a simple current control strategy based on prediction calculation to select the switching states of the converter. By using a predictive cost function, the optimal switching state to be applied to the next sampling time is selected. This is done in order to minimize the instantaneous reactive power on the input side and to obtain a positive dc-link voltage at any time, while maintaining a good tracking of the load currents to their respective references. The feasibility of the proposed strategy is verified by simulation results.

	A SINGLE LOOP VOLTAGE CONTROLLER BASED REPETITIVE CONTROL FOR A MATRIX CONVERTER By Wesam ROHOUMA	[View] [Download]
Abstract: In this paper a repetitive control approach is proposed to regulate the output voltage of a four-leg matrix converter for an Aircraft Ground Power Supply application. The proposed controller reduces the tracking error and increases the stability of the converter compared to traditional approaches. Simulations and experimental results from a 7.5KW converter prototype are presented to verify the operation of the proposed controller.

	An Open-Circuit Faults Diagnosis Method for Matrix Converters based on DWT Analysis of Output Current By Panagiotis POTAMIANOS, Epaminondas MITRONIKAS, Athanasios SAFACAS	[View] [Download]
Abstract: A novel diagnosis method is proposed in this work which is designed to detect open-circuit faults that occur in the matrix converter topology. In the potential application range of this type of converters, increased reliability and fault tolerance of the drive system is required through its remedial operation in cases of partial failures. All these requirements indicate that a monitoring system that is able to timely detect the various possible failures is necessary. In this paper, the output current of the matrix converter is monitored and analyzed using the discrete wavelet transform (DWT) in order to detect partial or total open-circuit failures of the converter’s bidirectional switches. The main advantage of the proposed method is that it is based on the output current measurement in contrast to the output voltage measurement that is required by previously proposed methods. Thus, the proposed method can be integrated without additional costs into motor current signature analysis (MCSA) systems that are used to detect faults in induction machines (IM). The choice of the mother wavelet which is used in the DWT analysis as well as the choice of the window function are evaluated in this work. The case of rapid changes of the output phase currents corresponding to the operating conditions are also examined.

	Calorimetric comparison of the use of silicon carbide diodes in a 100kW matrix converter for aerospace applications By Lee EMPRINGHAM, Liliana DE LILLO, Pat WHEELER, Jon CLARE	[View] [Download]
Abstract: A 100kW matrix converter designed for aerospace applications using Silicon Carbide schottky barrier diodes and silicon IGBTs to construct the power circuit is presented. Calorimetric methods will be used to determine improvements in switching losses. The research aim is to increase switching frequencies in order to minimise passive component size.

	Control of a Brushless Doubly-Fed Induction Generator via a Matrix Converter By Ruben PENA, Roberto CARDENAS, Andres MUÑOZ, Alvaro SUREDA, Jon CLARE, Pat WHEELER	[View] [Download]
Abstract: The Doubly-Fed Induction Generator (DFIG) is one of the most widely used generators for wind energy applications and more of 50\% of the installed Wind Energy Conversion Systems (WECS) are using this sort of variable speed technology. However, the machine requires brushes for the operation which increases the maintenance work. To overcome this drawback a Brushless Double Fed Induction Generator (BDFIG), composed of two cascaded doubly-fed machines with the rotor windings interconnected, could be used. In this work, the control of a BDFIG is presented using a matrix converter (MC). Matrix converters may be seen as suitable converter choice for this application instead of the standard back-to-back PWM voltage source converter topology. Results from an experimental rig are presented for operation of the BDFIG at variable speed with the machine driven by a commercial AC drive as a prime mover.

	Eliminating Current Sensors of Indirect Matrix Converter Using Neuro-Fuzzy Controller By Alireza JAHANGIRI, Ahmad RADAN	[View] [Download]
Abstract: This paper describes non-linear average model of Indirect Matrix Converter (IMC) with an output LCfilter in stationary and rotating reference frames. The defects of pervious control strategies based onderived average model are discussed and a novel adaptive neuro-fuzzy controller is proposed. Eliminating output current sensors, good dynamic performance in any operating point without overshoot and balanced output voltages with slight distortion of line side currents are among the benefits of the proposed method. Theory analyses, the model validation and simulation results are presented to verify the effectiveness ofthis control method.

	Experimental Verification for a Matrix Converter with a V-connection Chopper By Kazuhiro KOIWA, Jun-ichi ITOH	[View] [Download]
Abstract: This paper proposes a circuit topology for a matrix converter with a boost up function in the input side. The proposed circuit uses a V-connection AC chopper to achieve the boost-up function. The matrix converter and the V-connection AC chopper are independently controlled, where a virtual indirect control method is applied to the matrix converter, and the control of the V-connection AC chopper is an open-loop control with a damping. One problem of this system is the resonance happens between the input reactor and the filter capacitor. In order to suppress the resonance, the damping control is implemented in the AC chopper. In this paper, the operation of the proposed circuit along with the loss analysis is discussed in details. For the simulation and experiment results, the proposed circuit is confirmed obtaining the maximum efficiency of 95.1 \%, which is higher efficiency than that of a conventional back-to-back converter.

	Improved modulation of two-stage matrix converter for EMA in aircraft applications By Kun XIAO, Lina WANG, Pat WHEELER	[View] [Download]
Abstract: This paper presents the improved modulation strategy of Two-Stage Matrix Converter (TSMC) for applications in aircraft Electro-Mechanical Actuator (EMA) system. In the modulation of rectifier stage, Phase Locked Loop (PLL) is employed to track the instantaneous value of both the angle and the frequency of the input voltage vector. The frequency is then taken into calculation to compensate the angle sample delay, as a result of the un-ignorable angle alternation in each Pulse Width Modula-tion (PWM) cycle at input frequency of 360~800Hz. The drawbacks of the sample delay are discussed, which lie in the incorrect input power factor control, fluctuation of voltage transfer ratio and possibil-ity of short circuit in inverter stage. In the modulation of inverter stage, a 4-time commutation PWM pattern is presented, which reduces the number of commutations from 6 to 4 in each PWM cycle. Therefore, increasing the PWM frequency by 50\% remains the same number of commutations thus the same switching loss per time interval. The sample delay and the output current harmonic could be re-duced thereafter at the increased PWM frequency. Simulation and experiment results verify the im-proved performance of the proposed modulation.

	Matrix Converter Systems Stability Analysis Taking into Account Switching Effects By Stephen COX, Pericle ZANCHETTA	[View] [Download]
Abstract: AC/AC matrix converters have recently been applied for industrial, military and aerospace prototype systems. However, their dedicated input filters may lead to instability in operation. In this paper, simulations are presented of a model that accounts explicitly for the switching, and these simulations are compared with an averaged model. It is shown that this averaged model may significantly underestimate the instability threshold compared with the more detailed, switching model, which is instead recommended for determining the stability margin.

	Open-Circuited Switch Fault Detection for Fault Tolerant Matrix Converter Motor Drive Systems By Sudarat KHWAN-ON, Liliana DE LILLO, Lee EMPRINGHAM, Patrick WHEELER	[View] [Download]
Abstract: This paper describes a high speed fault detection strategy to detect and identify open-circuit device failures in matrix converter motor drive systems. The proposed fault detection algorithm is based on analysis of the currents circulating through the drive system and the bidirectional switches gating signals. The presented technique described in this paper is used to identify not only a fault caused in a single device but also multiple device failures. Simulation and experimental results are presented to validate the effectiveness of the proposed fault detection technique.

	Performance Optimization of a Square wave operation in an Indirect Matrix Converter with a Reactor free DC Boost Converter By Goh TECK CHIANG, Jun-ichi ITOH	[View] [Download]
Abstract: This paper discusses a modulation control for an indirect matrix converter connects with a reactor free boost converter for induction motor drives. The square wave modulation is proposed to apply with a four-step commutation pattern to improve the voltage transfer ratio of the indirect matrix converter from 0.866 to 0.97 (VTR= vout/vin). Furthermore, a feed-forward control is proposed to apply in the reactor free boost converter to reduce the ripple in the battery current which is caused by the fluctuations at the neutral point voltage. In the experiment results, the battery current is reduced by approximately 72 \% by the feed forward control. The loss analysis shows an efficiency of 94 \% for the proposed method.

	Poly-Phased Matrix Converter - A 27 input phases to 3 output phases experimental set-up running with hard and soft commutations By Antoine BEGUIN, Alfred RUFER	[View] [Download]
Abstract: This paper presents an experimental set-up of a 27 phases input to 3 phases output Poly-Phased MatrixConverter (27x3 PPMC) realised for the real time experimentation of the dedicated control electronics.When the original converter system is dedicated to the frequency conversion from a fast rotatinggenerator directly coupled to the gas turbine for feeding into the 50 Hz grid with a power level up tothe 100 MW range, the power level of the experimental set-up is chosen at about 1 kW. Firstexperimentations are documented with a frequency adaptation from 100Hz to 50Hz. The poly-phasedsynchronous machine’s induced voltages are emulated with 27 linear power operational amplifiers,feeding the primary winding of small transformers. The secondary windings built the polygonalconnection of the stator of the machine, and are connected to the 27 inputs of the poly-phased matrix.The PPMC is run in mix mode operation, which is a mix of natural and forced commutations. Thispaper also presents the theory that goes along with the mix mode operation of the PPMC andinvestigates especially the losses in the RC snubber circuits.