EPE Association: EPE 2013 - LS2d: Converter Control, Current/Voltage Control

EPE 2013 - LS2d: Converter Control, Current/Voltage Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 06: Modulation strategies and specific control methods for static converters > EPE 2013 - LS2d: Converter Control, Current/Voltage Control

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   Arm-current-based control of Modular Multilevel Converters
By Hans-Peter NEE, Lennart ANGQUIST, Staffan NORRGA, Antonios ANTONOPOULOS [View]
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Abstract: Inner control of a Modular Multilevel Converter (M2C) based on direct tolerance-band modulation of the arm currents has been studied. This approach is attractive because it allows low switching frequency, directly provides the desired arm-current waveform and enables fast protective actions at the same time as the complexity of the over-all control system is reduced. Issues related to common-mode voltage are discussed and supporting PSCAD simulations are presented together with some results from experiments with a reduced-power prototype converter.

   Control Strategy with Variable Commutation Instants for MPC Based on Two Flying Capacitors Connected in Parallel
By Eduard SOLANO, Ana LLOR, Guillaume GATEAU, Thierry MEYNARD, Maurice FADEL [View]
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Abstract: In this work we propose a control strategy based on Model Predictive Control (MPC) with variable commutation instants at constant frequency. Two stages are used by association of a reduced cost function and a state machine which selects the optimum state. The strategy is applied to flying capacitor converters connected in parallel, which requires the development of strategies capable to control the external and internal variables of the converter.

   Open-circuit Fault Detection and Isolation for Modular Multilevel Converter Based on Sliding Mode Observer
By Shuai SHAO, Pat WHEELER, Jon CLARE, Alan WATSON [View]
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Abstract: This paper presents a fault detection and isolation (FDI) method for a Modular Multilevel Converter(MMC). This method can locate an open-circuit faulty device accurately and quickly. Based on a slidingmode observer (SMO) and a switching model of a half bridge, the approach is to assume the location ofthe fault, modify the observer equation and then compare the measured and observed states to verify, orotherwise, the assumption for possible fault locations. This technique requires no additional measurementelements and can easily be implemented in a microcontroller. The operation and robustness of theproposed method are confirmed using simulation results.

   Tolerance Band Modulation Methods for Modular Multilevel Converters
By Arman HASSANPOOR CHALESHTARI, Kalle ILVES, staffan NORRGA, Lennart ANGQUIST, Hans-Peter NEE [View]
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Abstract: Modular multilevel converters (M2C) are increasingly used in high voltage direct current (HVDC) systems. The efficiency of M2Cs is highly related to the modulation method which determines the switching frequency and capacitor voltage ripple in the converter station. A new approach to modulation of M2C is presented in this paper. Tolerance-band methods are employed to obtain switching instants, and also cell selection. The proposed methods overcome the modulation problem for converters with few numbers of cells and also reduce the sorting efforts for cell balancing purposes while maintaining the cell-capacitor voltage limits. The evaluation is done by time-domain simulation by which the performance of each method is studied in both steady-state and transient cases. It is observed that using tolerance band methods not only reduces the switching frequency but also allows for handling severe fault cases in a grid connected system. Use of this method can reduce the switching losses and also allow for reduction of the cell capacitor size.

EPE 2013 - LS2d: Converter Control, Current/Voltage Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 06: Modulation strategies and specific control methods for static converters > EPE 2013 - LS2d: Converter Control, Current/Voltage Control
	[return to parent folder]

	Arm-current-based control of Modular Multilevel Converters By Hans-Peter NEE, Lennart ANGQUIST, Staffan NORRGA, Antonios ANTONOPOULOS	[View] [Download]
Abstract: Inner control of a Modular Multilevel Converter (M2C) based on direct tolerance-band modulation of the arm currents has been studied. This approach is attractive because it allows low switching frequency, directly provides the desired arm-current waveform and enables fast protective actions at the same time as the complexity of the over-all control system is reduced. Issues related to common-mode voltage are discussed and supporting PSCAD simulations are presented together with some results from experiments with a reduced-power prototype converter.

	Control Strategy with Variable Commutation Instants for MPC Based on Two Flying Capacitors Connected in Parallel By Eduard SOLANO, Ana LLOR, Guillaume GATEAU, Thierry MEYNARD, Maurice FADEL	[View] [Download]
Abstract: In this work we propose a control strategy based on Model Predictive Control (MPC) with variable commutation instants at constant frequency. Two stages are used by association of a reduced cost function and a state machine which selects the optimum state. The strategy is applied to flying capacitor converters connected in parallel, which requires the development of strategies capable to control the external and internal variables of the converter.

	Open-circuit Fault Detection and Isolation for Modular Multilevel Converter Based on Sliding Mode Observer By Shuai SHAO, Pat WHEELER, Jon CLARE, Alan WATSON	[View] [Download]
Abstract: This paper presents a fault detection and isolation (FDI) method for a Modular Multilevel Converter(MMC). This method can locate an open-circuit faulty device accurately and quickly. Based on a slidingmode observer (SMO) and a switching model of a half bridge, the approach is to assume the location ofthe fault, modify the observer equation and then compare the measured and observed states to verify, orotherwise, the assumption for possible fault locations. This technique requires no additional measurementelements and can easily be implemented in a microcontroller. The operation and robustness of theproposed method are confirmed using simulation results.

	Tolerance Band Modulation Methods for Modular Multilevel Converters By Arman HASSANPOOR CHALESHTARI, Kalle ILVES, staffan NORRGA, Lennart ANGQUIST, Hans-Peter NEE	[View] [Download]
Abstract: Modular multilevel converters (M2C) are increasingly used in high voltage direct current (HVDC) systems. The efficiency of M2Cs is highly related to the modulation method which determines the switching frequency and capacitor voltage ripple in the converter station. A new approach to modulation of M2C is presented in this paper. Tolerance-band methods are employed to obtain switching instants, and also cell selection. The proposed methods overcome the modulation problem for converters with few numbers of cells and also reduce the sorting efforts for cell balancing purposes while maintaining the cell-capacitor voltage limits. The evaluation is done by time-domain simulation by which the performance of each method is studied in both steady-state and transient cases. It is observed that using tolerance band methods not only reduces the switching frequency but also allows for handling severe fault cases in a grid connected system. Use of this method can reduce the switching losses and also allow for reduction of the cell capacitor size.