EPE Association: EPE 2018 - LS2d: Advanced Drive Control

EPE 2018 - LS2d: Advanced Drive Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2018 ECCE Europe - Conference > EPE 2018 - Topic 04: Electrical Machines and Drive Systems > EPE 2018 - LS2d: Advanced Drive Control

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   A Novel Control Strategy for Modular Multilevel-Based Drives Considering the System Operating Point
By Mauricio ESPINOZA [View]
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Abstract: Modular Multilevel Converters (MMC) are considered an attractive solution for high-power medium voltage drives. However, in drive applications, the influence of the loading conditions leads to more complex control systems than the required ones for constant frequency applications. To solve this issue, a novel control methodology for the MMC-based drive is presented in this paper. The proposed scheme defines the best control structure to balance the voltage of the converter capacitors considering the drive operating point (e.g. the loading conditions and the machine frequency). The design of the converter parameters considering the desired behaviour of the converter is also discussed in this paper. Experimental results with an 18-power cells MMC are used to validate the proposed control strategy.

   Dual Control Drives for Increased Capability
By Marc PETIT [View]
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Abstract: Deadbeat-direct torque and flux control (DB-DTFC) is a powerful control law for drives which allowsfor choosing the flux linkage at every switching period without affecting the torque. This independentmanipulation of torque and losses, i.e. flux linkage, allows for new capabilities such as dynamic lossminimization at every switching instant, signal injection without any additional torque ripple forparameter estimation or self-sensing, as well as closed-loop torque control with minimal parametersensitivity. Moreover, since DB-DTFC uses an inverse model solution based on flux linkages, itinherently utilizes the full inverter Volt-sec. hexagon without changing the control law at the inverterlimits. While these features cannot be achieved with conventional current vector control (CVC), thispaper explains how to increase the capability of drives by flexibly moving between CVC, and DB-DTFCto take advantage of their best properties. The focus of this paper is to enable seamless and dynamictransitions between the controls even under parameter uncertainties. While switching betweencontrollers can add additional features, the switching transients are undesirable. In order to makeswitching between controllers more attractive, this paper focuses on making the switching transient assmooth as possible and shows how to shape the transient so it becomes acceptable for the application.The key issue here is that different controllers have different parameter sensitivities, so when theparameters are not precisely estimated, the controller will need to switch from one trajectory to the other. Finally, this paper discusses potential use cases for this technology. In particular, a comparison of the operation at the voltage and current limits for DB-DTFC and CVC is shown, where some controllertrade-offs become very obvious and control switching becomes an attractive solution. The discussion inthis paper is supported by simulation and experimental results on an IPMSM, which are in goodagreement with each other and the underlying concepts.

   Torque Ripple Reduction Method with Minimized Current RMS Value for SRM Based on Mathematical Model of Magnetization Characteristic
By Takahiro KUMAGAI [View]
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Abstract: This paper proposes a torque ripple reduction method with minimum current RMS value for switched reluctance motors (SRM). In the proposed method, the current waveform to achieve constant torque is derived based on a mathematical model of magnetization characteristics. In particular, the current waveform is optimized in term of the reduction of the current RMS value and the satisfaction of the input voltage limitation. The algorithm for determining the torque command is introduced to derive current command which is possible to generate by the input voltage and lead to the design of the maximum torque per current RMS value without any complex and time-consuming computation process. A three-phase 18S/12P type SRM is used in simulation and experiment in order to validate the proposed method. As a result, the reduction of torque ripple by 65.8\% and the reduction of the current RMS value by 19.2\% are achieved by proposed method.

   Torque-Ripple Minimization for Permanent-Magnet Synchronous Motors Based on Harmonic Flux Estimation
By Mojgan NIKOUIE [View]
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Abstract: This paper presents a control algorithm to reduce the torque ripple in permanent-magnet synchronous motors. This control algorithm is based on the on-line estimation of harmonic flux linkage. Together with the on-line estimation of the flux linkage, a proportional--integral--resonant controller is introduced to suppress the torque ripple.

EPE 2018 - LS2d: Advanced Drive Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2018 ECCE Europe - Conference > EPE 2018 - Topic 04: Electrical Machines and Drive Systems > EPE 2018 - LS2d: Advanced Drive Control
	[return to parent folder]

	A Novel Control Strategy for Modular Multilevel-Based Drives Considering the System Operating Point By Mauricio ESPINOZA	[View] [Download]
Abstract: Modular Multilevel Converters (MMC) are considered an attractive solution for high-power medium voltage drives. However, in drive applications, the influence of the loading conditions leads to more complex control systems than the required ones for constant frequency applications. To solve this issue, a novel control methodology for the MMC-based drive is presented in this paper. The proposed scheme defines the best control structure to balance the voltage of the converter capacitors considering the drive operating point (e.g. the loading conditions and the machine frequency). The design of the converter parameters considering the desired behaviour of the converter is also discussed in this paper. Experimental results with an 18-power cells MMC are used to validate the proposed control strategy.

	Dual Control Drives for Increased Capability By Marc PETIT	[View] [Download]
Abstract: Deadbeat-direct torque and flux control (DB-DTFC) is a powerful control law for drives which allowsfor choosing the flux linkage at every switching period without affecting the torque. This independentmanipulation of torque and losses, i.e. flux linkage, allows for new capabilities such as dynamic lossminimization at every switching instant, signal injection without any additional torque ripple forparameter estimation or self-sensing, as well as closed-loop torque control with minimal parametersensitivity. Moreover, since DB-DTFC uses an inverse model solution based on flux linkages, itinherently utilizes the full inverter Volt-sec. hexagon without changing the control law at the inverterlimits. While these features cannot be achieved with conventional current vector control (CVC), thispaper explains how to increase the capability of drives by flexibly moving between CVC, and DB-DTFCto take advantage of their best properties. The focus of this paper is to enable seamless and dynamictransitions between the controls even under parameter uncertainties. While switching betweencontrollers can add additional features, the switching transients are undesirable. In order to makeswitching between controllers more attractive, this paper focuses on making the switching transient assmooth as possible and shows how to shape the transient so it becomes acceptable for the application.The key issue here is that different controllers have different parameter sensitivities, so when theparameters are not precisely estimated, the controller will need to switch from one trajectory to the other. Finally, this paper discusses potential use cases for this technology. In particular, a comparison of the operation at the voltage and current limits for DB-DTFC and CVC is shown, where some controllertrade-offs become very obvious and control switching becomes an attractive solution. The discussion inthis paper is supported by simulation and experimental results on an IPMSM, which are in goodagreement with each other and the underlying concepts.

	Torque Ripple Reduction Method with Minimized Current RMS Value for SRM Based on Mathematical Model of Magnetization Characteristic By Takahiro KUMAGAI	[View] [Download]
Abstract: This paper proposes a torque ripple reduction method with minimum current RMS value for switched reluctance motors (SRM). In the proposed method, the current waveform to achieve constant torque is derived based on a mathematical model of magnetization characteristics. In particular, the current waveform is optimized in term of the reduction of the current RMS value and the satisfaction of the input voltage limitation. The algorithm for determining the torque command is introduced to derive current command which is possible to generate by the input voltage and lead to the design of the maximum torque per current RMS value without any complex and time-consuming computation process. A three-phase 18S/12P type SRM is used in simulation and experiment in order to validate the proposed method. As a result, the reduction of torque ripple by 65.8\% and the reduction of the current RMS value by 19.2\% are achieved by proposed method.

	Torque-Ripple Minimization for Permanent-Magnet Synchronous Motors Based on Harmonic Flux Estimation By Mojgan NIKOUIE	[View] [Download]
Abstract: This paper presents a control algorithm to reduce the torque ripple in permanent-magnet synchronous motors. This control algorithm is based on the on-line estimation of harmonic flux linkage. Together with the on-line estimation of the flux linkage, a proportional--integral--resonant controller is introduced to suppress the torque ripple.