EPE Association: EPE 2020 - DS1f-2: Adjustable Speed Drives-2

EPE 2020 - DS1f-2: Adjustable Speed Drives-2
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 04: Electrical Machines and Drive Systems > EPE 2020 - DS1f-2: Adjustable Speed Drives-2

   [return to parent folder]

   Design of a circumscribing polygon wide bandgap based integrated modular motor drive topology with thermally decoupled windings and power converters
By Abdalla Hussein MOHAMED [View]
[Download]

Abstract: In this paper, the design of an integrated modular motor drive topology based on the circumscribing polygonof the outer surface of the conventional cylindrical housing is introduced from the mechanical andthe thermal point of view. The design of the shared machine and converter cooling system is optimizedfrom the thermal point of view using computational fluid dynamics (CFD) simulations. A wide bandgap,specifically Gallium Nitride (GaN), based half-bridge converter module is designed and implementedfor integration. For a case study of a machine of outer radius 75 mm, axial length 80 mm and six statormodules, the resulted surface area for each converter module is 80*87 mm2. The size of the convertermodule was reduced so as to exactly match the available surface around the machine. A method for thecalculation of the maximum power per module is introduced resulting in 1032W per module for the casestudy considered in the paper. A method for the DC-link capacitor design is introduced and the influenceof the stator phases connections on the DC-link current stress is explained. Experimental measurementsare done on one segment of the proposed integration topology.

   Effect of passive inverter output motor filters on drive systems
By Dr. Dennis KAMPEN [View]
[Download]

Abstract: The evaluation shows the effect of different on the market available inverter output filters onimportant drive system characteristics. Each filter is explained and the filter effect on motor insulation,inverter losses, cable losses, motor losses, audible noise, EMI, bearing currents and costs is compared.This paper offers a comprehensive overview and might help drive system designers in choosing themost suitable passive filter solution.

   Evaluation of Drive Topologies for Macro Scale Synchronous Electrostatic Machines
By Peter KILLEEN [View]
[Download]

Abstract: Macro scale electrostatic machines have promising characteristics for low speed direct drive applications. However, their medium voltage (7kV) and low current (inf.1A) characteristics provide a unique challenge for power electronics. Models for the semiconductors, electrostatic machine, and magnetic components were combined to perform a simulation-based comparison between the standard two-level voltage and current source inverter topologies. A low current 10 kV JFET super-cascode was modelled based off static and dynamic characterizations for the switch. Inductors were designed for the CSI dc-link and the VSI output filters and the improved generalized steinmetz equation algorithm modeled magnetic core loss. System losses and harmonic content, combined with implementation considerations, form a basis to compare the two inverter topologies. The comparison shows that the current source inverter is a better choice for a variable-speed drive with a wide operating range, especially at higher speeds. The voltage source inverter topology is speed limited due to the resonance between the inductive output-filter and capacitive machine. However, at low speeds, the VSI can provide high efficiency (~90\%) over a wide operating range, suitable for "position and hold" applications.

   Experimental tuning and design guidelines of a dynamically reconfigured weighting factor for the predictive torque control of an induction motor
By Ilker SAHIN [View]
[Download]

Abstract: In this study, an experimental approach for the weighting factor design of the predictive torque control of an induction motor (IM) is presented. The weighting factor is set to the value which yields a low total harmonic distortion (THD) figure in the phase currents. Then, this optimized value is dynamically adjusted with respect to the speed error term, which is defined as the magnitude of difference between the commanded speed and the actual speed. By doing so, superior transient performance is achieved without sacrificing steady-state THD values. The presented approach for dynamically adjusted weighting factor is tested on a two-pole, 500 W IM, driven by a two-level voltage source inverter (2L-VSI), via finite control set model predictive control (FCS-MPC). Experimental results show the effectiveness of the proposed method: by the adoption of dynamic lambda approach, speed reversal time from -3000 rpm to +3000 rpm is decreased by 38\% under the same controller structure and settings.

   Influence of system parameters in variable speed AC-induction motor drives on parasitic electric bearing currents
By Martin WEICKER [View]
[Download]

Abstract: High frequency bearing currents are a parasitic phenomenon that affects inverter-fed induction machines, causing damage and wear to the mechanical bearings, which might lead to unexpected failures, increase of the machine downtime and reduction of its lifespan. This paper describes how the bearing currents are affected by changes in the components of the electrical circuit that feeds the induction machine. The referred system consists of: Two-level voltage source inverter, different passive filters (a) common-mode ring filter, b) common-mode ring filter with small phase-to-ground capacitances, c) differential mode filter, d) dual-mode filter and e) du/dt-filter), different motor supply cables (shielded vs. unshielded cables with lengths_of_50_m, 150_m or 300_m) and the two different induction motors (rated power of 11_kW and 15_kW, respectively). So, in total sixty system arrangements were tested. The highest reduction of bearing currents was measured with the dual-mode filter in all cable configurations.

   Saliency Selection for Search-based AC Machine Low and Zero Speed Estimation Methods
By Kris SCICLUNA [View]
[Download]

Abstract: This paper presents the analysis and selection of a suitable injection angle to be used with continuous pulsating injection and search-based sensorless control. Pulsating injection offers the possibility of different injection orientations in the stationary reference frame. The injection results in High-Frequency current signatures, which vary in shape and magnitude due to the multiple saliency harmonics on the experimental Permanent Magnet Synchronous Machine. The analysis and selection process presented in this paper aims to reduce the implementation time for robust sensorless control. Experimental results are presented for different injection angles and iq-current operating points.

EPE 2020 - DS1f-2: Adjustable Speed Drives-2
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 04: Electrical Machines and Drive Systems > EPE 2020 - DS1f-2: Adjustable Speed Drives-2
	[return to parent folder]

	Design of a circumscribing polygon wide bandgap based integrated modular motor drive topology with thermally decoupled windings and power converters By Abdalla Hussein MOHAMED	[View] [Download]
Abstract: In this paper, the design of an integrated modular motor drive topology based on the circumscribing polygonof the outer surface of the conventional cylindrical housing is introduced from the mechanical andthe thermal point of view. The design of the shared machine and converter cooling system is optimizedfrom the thermal point of view using computational fluid dynamics (CFD) simulations. A wide bandgap,specifically Gallium Nitride (GaN), based half-bridge converter module is designed and implementedfor integration. For a case study of a machine of outer radius 75 mm, axial length 80 mm and six statormodules, the resulted surface area for each converter module is 80*87 mm2. The size of the convertermodule was reduced so as to exactly match the available surface around the machine. A method for thecalculation of the maximum power per module is introduced resulting in 1032W per module for the casestudy considered in the paper. A method for the DC-link capacitor design is introduced and the influenceof the stator phases connections on the DC-link current stress is explained. Experimental measurementsare done on one segment of the proposed integration topology.

	Effect of passive inverter output motor filters on drive systems By Dr. Dennis KAMPEN	[View] [Download]
Abstract: The evaluation shows the effect of different on the market available inverter output filters onimportant drive system characteristics. Each filter is explained and the filter effect on motor insulation,inverter losses, cable losses, motor losses, audible noise, EMI, bearing currents and costs is compared.This paper offers a comprehensive overview and might help drive system designers in choosing themost suitable passive filter solution.

	Evaluation of Drive Topologies for Macro Scale Synchronous Electrostatic Machines By Peter KILLEEN	[View] [Download]
Abstract: Macro scale electrostatic machines have promising characteristics for low speed direct drive applications. However, their medium voltage (7kV) and low current (inf.1A) characteristics provide a unique challenge for power electronics. Models for the semiconductors, electrostatic machine, and magnetic components were combined to perform a simulation-based comparison between the standard two-level voltage and current source inverter topologies. A low current 10 kV JFET super-cascode was modelled based off static and dynamic characterizations for the switch. Inductors were designed for the CSI dc-link and the VSI output filters and the improved generalized steinmetz equation algorithm modeled magnetic core loss. System losses and harmonic content, combined with implementation considerations, form a basis to compare the two inverter topologies. The comparison shows that the current source inverter is a better choice for a variable-speed drive with a wide operating range, especially at higher speeds. The voltage source inverter topology is speed limited due to the resonance between the inductive output-filter and capacitive machine. However, at low speeds, the VSI can provide high efficiency (~90\%) over a wide operating range, suitable for "position and hold" applications.

	Experimental tuning and design guidelines of a dynamically reconfigured weighting factor for the predictive torque control of an induction motor By Ilker SAHIN	[View] [Download]
Abstract: In this study, an experimental approach for the weighting factor design of the predictive torque control of an induction motor (IM) is presented. The weighting factor is set to the value which yields a low total harmonic distortion (THD) figure in the phase currents. Then, this optimized value is dynamically adjusted with respect to the speed error term, which is defined as the magnitude of difference between the commanded speed and the actual speed. By doing so, superior transient performance is achieved without sacrificing steady-state THD values. The presented approach for dynamically adjusted weighting factor is tested on a two-pole, 500 W IM, driven by a two-level voltage source inverter (2L-VSI), via finite control set model predictive control (FCS-MPC). Experimental results show the effectiveness of the proposed method: by the adoption of dynamic lambda approach, speed reversal time from -3000 rpm to +3000 rpm is decreased by 38\% under the same controller structure and settings.

	Influence of system parameters in variable speed AC-induction motor drives on parasitic electric bearing currents By Martin WEICKER	[View] [Download]
Abstract: High frequency bearing currents are a parasitic phenomenon that affects inverter-fed induction machines, causing damage and wear to the mechanical bearings, which might lead to unexpected failures, increase of the machine downtime and reduction of its lifespan. This paper describes how the bearing currents are affected by changes in the components of the electrical circuit that feeds the induction machine. The referred system consists of: Two-level voltage source inverter, different passive filters (a) common-mode ring filter, b) common-mode ring filter with small phase-to-ground capacitances, c) differential mode filter, d) dual-mode filter and e) du/dt-filter), different motor supply cables (shielded vs. unshielded cables with lengths_of_50_m, 150_m or 300_m) and the two different induction motors (rated power of 11_kW and 15_kW, respectively). So, in total sixty system arrangements were tested. The highest reduction of bearing currents was measured with the dual-mode filter in all cable configurations.

	Saliency Selection for Search-based AC Machine Low and Zero Speed Estimation Methods By Kris SCICLUNA	[View] [Download]
Abstract: This paper presents the analysis and selection of a suitable injection angle to be used with continuous pulsating injection and search-based sensorless control. Pulsating injection offers the possibility of different injection orientations in the stationary reference frame. The injection results in High-Frequency current signatures, which vary in shape and magnitude due to the multiple saliency harmonics on the experimental Permanent Magnet Synchronous Machine. The analysis and selection process presented in this paper aims to reduce the implementation time for robust sensorless control. Experimental results are presented for different injection angles and iq-current operating points.