Table of contents monday, September 9, 1: 30pm-4: 00pm modular Multi-Level Converters, hvdc, and dc grids I 3
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- Bu səhifədəki naviqasiya:
- PM Machines IV
- Energy Efficient Motor Drives
- Sensorless Drives II
- Silicon and WBG Devices
Nick Ilsoe Berg, Rasmus Koldborg Holm and Peter Omand Rasmussen, Aalborg University, Denmark This paper describes the design and development of an novel Magnetic Lead Screw based active suspension system for passenger vehicles, using a new MLS topology. The design is based on performance specifications found from ISO road profiles, with a maximum harvested energy approach. By integrating the PMSM motor with the MLS, it possible to construct a very compact design with an integrated air spring. The prototype is build and frictional losses and efficiency for the MLS damper unit are measured. Additional the stall force and stall torque are measured for the build prototype to validate the developed 3D FEM model. It was concluded that the MLS damper unit was capable of delivering a mean efficiency of up to 80% for a full up and down stroke (+/- 48 mm). 4:20PM A Simple Design Method for Surface-mounted PM machines for Traction Application [#673]
Surface-mounted permanent magnet motors with concentrated windings (CW-SPM) can have a wide constant power speed range if properly designed. This study introduces a design approach for CW-SPM machines for traction application, presenting the new parametric design plane x, b, where x accounts for the rotor on stator radius split and b summarizes the share between copper and iron in the stator. The proposed design method aims at covering the important area of design of PMSMs with flux weakening capability, with a simple methodology. Analytical and finite-element (FEA) models are used jointly. The design flowchart is illustrated and the output designs are validated by FEA. All presented results are obtained through open-source design resources available online. 4:45PM Design Optimization of Spoke-Type PM Motors for Formula E Racing Cars [#1283]
This paper presents the performance trade-offs in the design optimization of spoke-type permanent magnet (PM) motors for high speed and very high torque density traction motors. An example 18-slot 16-pole machine for a direct drive Formula E race car over the Le Mans driving cycle is considered. Both low speed and extended speed/field-weakening operations are evaluated using high fidelity finite element (FE) simulations, to simultaneously increase the torque density and decrease the power losses over the high energy- throughput zones of the machine torque-speed plane. The results of the design optimization process yielding 3,400 design candidates are utilized to quantify the performance trade-offs for increasing the power density in spoke-type PM motors. These trade-offs include the impacts on other performance metrics such as power losses, PM demagnetization, and torque ripple. The analysis is supplemented by multi-physics simulation of three counterpart optimized designs, and successful experimental verification of a prototype of one of those three designs which represents a record high power density motor in traction applications. PM Machines IV Wednesday, September 21, 3:30PM-5:10PM, Room: 101A, Chair: Leila Parsa, Radu Bojoi 3:30PM Tolerance Study to Forecast Performances of Permanent Magnet Synchronous Machines Using Segmented Stator for Mass Production [#1624] TaeSik Kim, Mazharul Chowdhury, Mohammad Islam, Abraham Gebregergis and Tomy Sebastian, Halla Mechatronics, United States This research provides a detailed analysis of build variations for mass produced permanent magnet synchronous motors on key performances such as torque ripple, and back-emf harmonics. The study defines the rule for worst case scenarios hence provide tolerance limits for each of the design parameters to be controlled to achieve certain performances under volume production. The research also sorts out the sources for each torque ripple order. A finite element based electromagnetic simulation is used for the tolerance study and effectively used for defining realistic limits for key design parameters. The motors were built and tested to verify the theories which showed strong correlation and justify the values of such study before launching volume production. 3:55PM Permanent Magnet Material and Pulsating Torque Minimization in Spoke Type Interior PM Machines [#146]
This paper proposes an alternative spoke type interior permanent magnet machine design to minimize the pulsating torque and decrease the use of permanent magnet materials. The proposed rotor design consists of a number of rotor lamination stacks with notches made on the surface and packed in the axial direction. Within each stack, the width of the permanent magnets (PMs) and the span of the notches are different from those in the other lamination stacks. The design has optimized and verified by 2D finite element and its performance was compared against the 2007 Camry motor model. The results demonstrate improvement in the pulsating torque and the PM material utilization of the proposed model. 4:20PM Mechanical Design Method for a High-Speed Surface Permanent Magnet Rotor [#1399]
Mechanical design of the rotor is an important part of the design process for high-speed electric machines. This paper proposes an analytical method for finding an approximate rotor length and diameter for a surface permanent magnet machine rotor early in the design process. Specifically, the method can be used to find approximate rotor length and diameter dimensions that will balance the need for acceptable factor of safety for rotor sleeve stress and the need for an acceptable separation margin between the operating and critical speeds. Analytical design results are compared to finite element analysis for both the mechanical stress and the natural frequency of the rotor. 4:45PM Analysis and Design of Triple-Rotor Axial-Flux Spoke-Array Vernier Permanent Magnet Machines [#928]
This paper presents a triple-rotor axial-flux spoke-array vernier permanent magnet (TR-AFSAVPM) machine to enhance the performance of vernier machines. By cooperating spoke-array rotor and coil-wounded winding, power factor and torque density of the proposed machines are much improved and their copper utilization is reduced as well comparing with conventional vernier machines. Firstly, the machine structure and operation principles are introduced. After that, analytical equations of the machine back-EMF and torque are derived to reveal its features. Based on both quasi-3D finite element analysis (FEA) and 3D-FEA, its high torque density performance is verified and a set of optimized machine sizing specifications is ultimately settled. A fractional slot axial-flux permanent magnet machine and an axial-flux surface vernier permanent magnet machine are designed to compare with the proposed machine. Analysis results show that the TR-AFSAVPM machine has high power factor, viz. 0.97 and high torque density, viz. 24.2kNm/m3. A prototype has been designed and is being manufactured to validate the results. Energy Efficient Motor Drives Wednesday, September 21, 3:30PM-5:10PM, Room: 101B, Chair: Francisco Canales, Dong Jiang 3:30PM Electrical Loss Minimization Technique for Wind Generators based on a Comprehensive Dynamic Modelling of Induction Machines [#136] Maria Carmela Di Piazza, Massimiliano Luna and Marcello Pucci, ISSIA-CNR, Italy This paper proposes a novel model-based electrical losses minimization technique (ELMT), whose main original contribution lies in the overall power losses function which has been derived from a comprehensive dynamic space-vector model of the IM including the iron losses, expressed in the rotor flux oriented reference frame. Such a losses formulation, obtained from the IM input-output power balance, reveals more general and accurate than the others in literature and consequently the expression of the optimal efficiency reference flux to be given to the FOC control system is more general and accurate too. The proposed ELMT has been integrated in an IM-based wind generation system including a previously developed GNG-based MPPT. Results show that the new formulation of the overall power losses of the IM permits an increase of the IM efficiency up to 4% with respect to the classic loss equation proposed in scientific literature. The integration of the proposed ELMT in a real wind generation system leads to an increase of the active power injected into the power grid ranging from 33% at high wind speeds up to 200% at low wind speeds. 3:55PM Maximum Efficiency Control Method in 7-phase BLDC Motor by Changing the Number of the Excited Phase Windings [#303]
This paper proposes a maximum efficiency control method in 7-phase brushless DC motors (7-phase BLDCMs) used for the ship propulsion system. In the same load condition, the electrical loss of the 7-phase BLDCM is dependent on the number of the excited windings and the instantaneous phase currents. Thus, it is necessary to determine the excitation number of the phase windings according to the load condition. The 2- and 4-phase excitation methods are proposed for the maximum efficiency operation. The phase excitation method of the minimum system loss according to the load condition can be obtained from the loss analysis. In addition, by using the loss analysis, the optimal speed which is the changing point of the phase excitation to select the optimal excitation methods (2-, 4- and 6 and 6-phase excitation) can be calculated and derived. The proposed method can be easily implemented by controlling the conductive angle of the phase current at the suitable phase windings. The maximum efficiency operation can be achieved by using the proposed excitation method and 6-phase excitation method. The usefulness of the proposed control algorithm is verified through simulation results. 4:20PM Control Strategy for Dual Three-Phase PMSMs With Minimum Losses in the Full Torque Operation Range Under Single Open-Phase Fault [#578]
Fault tolerance is an advantageous characteristic of multiphase machines when compared with three-phase ones. During open-phase fault, the current references need to be adapted to provide ripple-free torque. As a consequence of this modification, the post-fault phase currents might be larger than the rated current. Such situation leads to overheating, and to preserve the integrity of the system, some limits are set to the post-fault phase currents. Two main strategies have been proposed for the post-fault situation: maximum torque (MT) and minimum losses (ML). The MT strategy allows to obtain the widest torque operation range (TOR) in the post-fault situation but does not minimize the stator winding losses; conversely, the ML strategy provides the minimum stator winding losses for each torque value, at the expense of reducing the TOR. Thus, the solutions proposed so far do not achieve minimum stator winding losses in the entire (that of the MT strategy) TOR. This paper presents the full-range minimum losses (FRML) post-fault control strategy, which minimizes the losses in the whole TOR, for dual three-phase permanent-magnet synchronous machines with sinusoidally distributed windings under single open-phase fault. Experimental results are provided. 4:45PM A Multi-Pulse Front-End Rectifier System with Electronic Phase-Shifting for Harmonic Mitigation in Motor Drive Applications [#1158]
In this paper, an electronic phase-shifting strategy has been optimized for a multi-parallel configuration of line-commutated rectifiers with a common dc- bus voltage used in motor drive application. This feature makes the performance of the system independent of the load profile and maximizes its harmonic reduction ability. To further reduce the generated low order harmonics, a dc-link current modulation scheme and its phase shift values of multi-drive systems have been optimized. Analysis and simulations have been carried out to verify the proposed method. Sensorless Drives II Wednesday, September 21, 3:30PM-5:10PM, Room: 101CD, Chair: Fernando Briz, Giacomo Scelba 3:30PM A Robust Magnetic Polarity Self-Sensing Method for Start-Up of PM Synchronous Machine in Fan-Like System [#327] Wei Sun, Jian-Xin Shen, Meng-Jia Jin and He Hao, Zhejiang University, China In the field of permanent magnet synchronous motor (PMSM) self-sensing control, the initial rotor position estimation is always important, for which, the rotor magnetic polarity estimation is particularly a major task. This paper presents a robust rotor polarity estimation method based on the comprehensive utility of both magnetic saturation effect and rotor angular acceleration. The method can be used for the PMSM system for the fan or pump-like applications. In the method, pulsating-voltage-vector injection is used to track the d-axis and measure the incremental inductance variation of the estimated d-axis. The magnetic saturation effect is magnified by exciting a sinusoidal low-frequency d-axis current rather than the traditional DC current. The angular acceleration is then measured by exciting a positive ramp q-axis current. Both the incremental inductance variation and the angular acceleration contain the rotor polarity information. In this paper, these two methods are combined, as the latter method is to confirm the estimation of the former method. Thus, a robust self-sensing start-up is guaranteed. Experimental results validate the effectiveness of the proposed algorithm. 3:55PM Universal Sensorless Vector Control Applicable to Line-Start Permanent Magnet Synchronous Motors with Damper Winding [#1006]
This paper proposes an improved Universal Sensorless Vector (USV) control which can drive not only induction motor and damperless Permanent Magnet Synchronous Motor (PMSM) but also Line-Start PMSM with damper winding (LS-PMSM) by a unified control algorithm without a position/speed sensor. The reason why the step-out problem occurs when the conventional USV control is employed to operate the LS-PMSM is investigated and clarified. As a result, it is found that, by only adding a low pass filter to the load angle calculator to suppress the high-frequency vibration of the estimated load angle, the step-out problem is completely removed and the USV control becomes applicable to the LS-PMSM. The validity of the proposed method is demonstrated with experimental results on a 0.5-kW, 4-pole, 1500-r/min LS-PMSM. 4:20PM Improvement of Back-EMF Self-Sensing for Induction Machines when using Deadbeat-Direct Torque and Flux Control (DB-DTFC) [#662]
Back-EMF self-sensing is commonly used in induction machine (IM) drive systems for its maintenance cost and safety considerations. In recent years, deadbeat- direct torque and flux control (DB-DTFC) has been shown to be a highly effective method for induction machine control. It has advantages such as the fastest possible torque dynamics, dynamically loss manipulation capability independent of torque dynamics, and parameter insensitivity. This paper evaluates the synergy between back-EMF self-sensing technology and DB-DTFC for IM drive systems. In this paper, an observer-based closed-loop back-EMF tracking self-sensing control in an IM DB-DTFC drive system is presented. It includes a back-EMF state filter, back-EMF tracking observer, and cascaded motion observer. Back-EMF harmonic decoupling is explored to improve the low speed performance. The bandpass filter method (BPF) for back-EMF self-sensing is also presented. Finally, the closed loop system dynamic stiffness at very low speeds, with and without the BPF method, is experimentally evaluated. 4:45PM Sensorless Position Control of PMSM Operating at Low Switching Frequency for High Efficiency Climate Control Systems [#1578]
Low switching frequency operation is preferred to improve the system efficiency as well as for optimal use of inverter rating in variable speed drive systems. Low switching frequency operation presents stability and performance issues during transition from lower to higher speed operations using asynchronous to synchronous programmed pulse width modulation (PWM) operation of the inverter. The paper presents a sensorless vector control strategy for the permanent magnet synchronous motor (PMSM) drive operating at low switching frequency with programmed PWM methods. Specifically for the reduced switching frequency operation, the analysis, design and implementation of the key control subsystems consisting of the current controller, back EMF observer and position tracking controller in the drive system are developed and presented. Experimental results validate the design methodology, system performance including the efficiency improvement with the proposed control strategy. Silicon and WBG Devices Wednesday, September 21, 3:30PM-5:10PM, Room: 202C, Chair: Jerry Hudgins, Enrico Santi 3:30PM SuperJunction Cascode, a Configuration to Break the Silicon Switching Frequency Limit [#797] Juan Rodriguez, Jaume Roig, Alberto Rodriguez, Ignacio Castro, Diego G. Lamar and Filip Bauwens, Power Supply System Group, University of Oviedo, Spain; Power Technology Centre, ON Semiconductor, Belgium This paper evaluates the SuperJunction MOSFET in cascode configuration with a low-voltage silicon MOSFET. The structure combines the good switching performance provided by the cascode configuration with advantages of the silicon technology as the robustness, the maturity and the low-cost. The objective of this paper is to elucidate and to demonstrate the reduction of switching losses of SuperJunction MOSFETs in cascode configuration with respect to their standalone counterparts (directly driven). A detailed simulation analysis of power loss contributions is carried out under hard-switching operation. Eventually, experimental evidence is provided by using a boost converter (100 V-to-400 V) in continuous conduction mode for a wide range of switching frequency (100 kHz-to-400 kHz) and output power (180W-to-500W). 3:55PM Maximizing the Performance of 650 V p-GaN Gate HEMTs: Dynamic Ron Characterization and Gate-Drive Design Considerations [#538]
This paper presents a systematic characterization of a 650 V/13 A enhancement- mode GaN power transistor with p-GaN gate. Static and dynamic device characteristics are measured by taking into account of trapping induced effects such as current collapse and threshold voltage instability. Switching performance is evaluated up to 400 V, 10 A using a custom designed double- pulse test circuit. Optimal gate drive conditions are proposed to minimize the influence of adverse trapping effects on circuit performance while preventing the device from excessive gate stress. Moreover, gate drive circuit design and board layout considerations addressing the fast switching characteristics of GaN devices are also discussed. 4:20PM 15kV/40A FREEDM Super-Cascode: A Cost Effective SiC High Voltage and High Frequency Power Switch [#834]
High voltage wide bandgap (WBG) semiconductor devices like the 15kV SiC MOSFET have attracted great attentions because of its potential applications in high voltage and high frequency power converters. However, these devices are not commercially available at the moment and their high cost due to expensive material growth and fabrication may limit their widespread adoption in the future. In this paper, a 15kV/40A three terminal power switch, the FREEDM Super-Cascode, is reported for the first time which is based on series connection of 1.2kV SiC power devices. The design and operation principle of the FREEDM Super-Cascode are introduced and the performance including the static blocking capability, conduction characteristics over a wide range of temperatures, and dynamic switching performances are analyzed. In addition, the thermal resistance of the FREEDM Super-Cascode is measured and the power dissipation capability is projected. The FREEDM Super-Cascode costs only one third of the estimated high voltage SiC MOSFETs, and will facilitate early applications of SiC in very high voltage and high frequency power converters. 4:45PM A Study of Dynamic High Voltage Output Charge Measurement for 15 kV SiC MOSFET [#1599]
Newly developed 15 kV silicon carbide (SiC) power MOSFETs with fast switching capability enable the reduction of size, weight and complexity of medium voltage power converters. In medium voltage and high frequency applications, zero voltage switching (ZVS) is necessary since significant amount of energy is stored in MOSFETs parasitic output capacitors. Recovering these energy is important for high conversion efficiency while ZVS also reduces the dVdt significantly in these devices. To guarantee complete ZVS, it is crucial to accurately characterize the output charge of devices. In this paper, existing high voltage capacitance and output charge measurement techniques are reviewed. A dynamic half-bridge test method for 15kV SiC MOSFETs output charge measurement is thoroughly analyzed and experimentally verified up to 6 kV. Output capacitance model is then derived using the measured results. The test circuit not only reflects the realistic ZVS scenario, but also achieves high accuracy (less than 1 percent error) without resorting to special equipment or complex configuration which are usually necessary in high voltage test. System level design consideration, error analysis and accuracy certification for this high voltage tester is also given in the paper. Based on the test output charge, derived output capacitance model of 15 kV SiC MOSFETs module is presented. Yüklə 2,78 Mb. Dostları ilə paylaş:
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