26 results on '"Sul, Seung-Ki"'
Search Results
2. High-Fidelity Induction Motor Simulation Model Based on Finite Element Analysis.
- Author
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Lee, Joon-Hee, Kwon, Yong-Cheol, and Sul, Seung-Ki
- Subjects
FINITE element method ,INDUCTION machinery ,SIMULATION methods & models ,INDUCTION motors - Abstract
This article proposes a new high-fidelity simulation model of an induction motor (IM) based on finite-element analysis (FEA). The proposed model enables fast and accurate IM simulation with the inverter circuit model and control algorithm. That is, the proposed model can represent non-ideal features of IM, such as magnetic saturation, spatial harmonics, skew, and saturation-induced saliency in high accuracy. To construct the proposed model, a dq equivalent circuit of the squirrel cage rotor is introduced. Based on this, the static FEA is conducted which can accelerate the model construction compared to the conventional time-stepping FEA technique. Then, a flux-based IM model is established, which has advantages on speed, accuracy, and memory size in the simulation. To verify the effectiveness of the proposed model, the models are constructed for two commercial IMs used for the industrial drive. IM control algorithms are tested in various operating conditions on the proposed model. The results are compared with the time-stepping FEA and the experiment for the verification of the proposed model. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
3. MTPA Tracking Control of Sensorless IPMSM Based on Square-Wave Voltage Signal Injection.
- Author
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Yoo, Jiwon, Kim, Hyeon-Sik, and Sul, Seung-Ki
- Subjects
SQUARE waves ,SYNCHRONOUS electric motors ,VOLTAGE ,POSITION sensors ,ELECTROSTATIC induction ,SENSOR placement ,ELECTRIC inductance ,TORQUE control - Abstract
This article proposes an online maximum torque-per-Ampere (MTPA) control of an interior permanent-magnet synchronous motor (IPMSM) based on the square-wave voltage signal injection. Because the proposed method does not rely on a position sensor, it is applicable to sensorless IPMSMs. The proposed algorithm consists of a dynamic inductance estimator, frequency-adaptive flux observer, and an MTPA tracking controller. The proposed inductance estimation utilizes the pulsating square-wave voltage injection, which can maximize the injection frequency, and the dynamic performance can be preserved during the signal injection. Through the online flux and inductance estimation, the magnetic saturation of the IPMSM and the temperature variation can be fully considered in the MTPA control. The conventional rotor position estimator is replaced with the MTPA tracking controller, which does not rely on offline commissioning parameters. The proposed algorithm can operate under both the torque control and speed control mode, and accurate torque control on MTPA curve can be achieved. The simulation and experimental results demonstrate that the proposed method accurately tracks the MTPA point up to 200% of the rated torque in the mid- and high-speed region. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
4. Dynamic Overmodulation Scheme for Improved Current Regulation in PMSM Drives.
- Author
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Yoo, Jiwon and Sul, Seung-Ki
- Subjects
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PERMANENT magnet motors - Abstract
The overmodulation scheme plays an essential role in the dynamic performance of the current regulation under voltage limitation. This article analyses how the nonlinearity of the voltage hexagon affects dynamic overmodulation. Most dynamic overmodulation schemes had considered the voltage hexagon as the limit of the output voltage to maximize the voltage utilization. However, these schemes do not show uniform dynamic performance according to the rotor position on the voltage hexagon. To overcome this limitation, this article proposes an overmodulation scheme that is robust against the rotor position variation. The computer simulation and experimental results verify that the proposed method has the consistent performance regardless of the rotor position with less d-axis current overshoot keeping the fast dynamics. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
5. Design of Frequency-Adaptive Flux Observer in PMSM Drives Robust to Discretization Error.
- Author
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Yoo, Jiwon, Kim, Hyeon-Sik, and Sul, Seung-Ki
- Subjects
EULER method ,SYNCHRONOUS electric motors ,APPROXIMATION error ,COORDINATE transformations ,INTEGRATORS ,STATORS - Abstract
This article analyzes the effect of discretization in the frequency-adaptive flux observer (FAO). Although FAO has structural simplicity and ease of implementation, the discrete-time FAO has phase and gain errors in fundamental flux estimation. As a result, the estimated flux might be erroneous, especially in the high-speed region. For accurate flux estimation, this article analyzes how the voltage synthesis in the pulsewidth-modulation affects the stator flux. Through the analysis, the backward Euler method is selected for the primitive stator flux estimation. To mitigate the FAO's discretization error, the proposed FAO utilizes the integrators constructed at the rotor reference frame (RRF). Since the discretization error comes from the approximation error of the continuous-time integrator at the operating frequency, the proposed FAO conducts the fundamental flux extraction at the RRF, where the operating frequency components are treated as a dc signal. Thanks to the coordinate transformation, the FAO can be discretized with no error while keeping the structure of double integrators. The proposed method is verified through the computer simulation and experimental test. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. Novel rotor-flux observer using observer characteristic function in complex vector space for field-oriented induction motor drives
- Author
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Kim, Jang-Hwan, Choi, Jong-Woo, and Sul, Seung-Ki
- Subjects
Induction electric motors -- Equipment and supplies ,Rotors ,Mensuration -- Evaluation ,Mensuration -- Usage ,Business ,Computers ,Electronics ,Electronics and electrical industries - Abstract
This paper proposes a new strategy to estimate the rotor flux of an induction machine. The electrical model of the induction machine presents the basic idea based on an observer structure, which is composed of a voltage model and a current model. However, the former has the defects of sensitivity to machine parameters in the low-speed range, and the latter also has defects that are sensitive to the machine parameters in wide-speed range. In spite of these shortcomings, the closed-loop flux observer based on two models has been a prevalent estimation method for direct field-oriented control. In this paper, a generalized analysis method called the 'observer characteristic function method' is proposed to analyze all kinds of the linear flux observers in an unified form. By the observer characteristic function being utilized, the estimated rotor-flux error involved in the classical methods can be easily clarified. Moreover, the novel rotor-flux observer based on this analysis is also presented. The proposed flux observer is robust to the offset voltage and to parameter variation. The effectiveness of the novel flux observer has been verified by the numerical analysis and experimental results. Index Terms--Field-oriented control, flux observer, induction machines, observer characteristic function.
- Published
- 2002
7. Identification of IPMSM Flux-Linkage Map for High-Accuracy Simulation of IPMSM Drives.
- Author
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Lee, Joohyun, Kwon, Yong-Cheol, and Sul, Seung-Ki
- Subjects
DISCRETE Fourier transforms ,SYNCHRONOUS electric motors ,ELECTROMOTIVE force ,PARAMETER identification - Abstract
This article proposes a precise identification scheme of an interior permanent-magnet synchronous motor (IPMSM) flux linkage through experimental tests considering motor nonlinearities, such as the magnetic saturation and spatial harmonics. In the proposed scheme, the flux linkage is identified based on the voltage equation of IPMSM. The fundamental and harmonic electromotive force in the rotor reference frame is obtained in real time by applying a discrete Fourier transform with the phase compensation of the time delay due to digital control and pulsewidth modulation. The effect of the inverter nonlinearity is compensated using an experimentally obtained lookup table. Based on the identified flux-linkage map, a flux-based IPMSM model that accurately simulates motor behavior can be constructed. The effectiveness of the proposed flux-linkage identification scheme is verified through the comparison of simulation and experimental results. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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8. DC Bus Voltage Regulation Strategy in Maritime DC Power System for Minimized Converter Loss.
- Author
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Yun, Jonghun, Son, Young-Kwang, Cho, Hyung-June, and Sul, Seung-Ki
- Subjects
PERMANENT magnet generators ,SYNCHRONOUS generators ,VOLTAGE ,VARIABLE speed drives ,PULSE width modulation - Abstract
In a maritime dc power system, the rectified dc-bus voltage of a permanent magnet synchronous generator is generally regulated by the pulsewidth modulation (PWM) operation of an active ac/dc converter. This article proposes a dc bus voltage regulation strategy exploiting the six-step operation. Under the six-step operation, the switching loss of the converter can be significantly reduced, compared to the PWM operation. Moreover, due to the higher modulation index and the less flux-weakening current of the six-step operation, the conduction loss can also be reduced. By employing diode rectification mode at light load, the conduction loss induced by the non-negligible ripple current of the six-step operation could be minimized. This article implements a controller for the proposed dc bus voltage regulation strategy and verifies its validity with simulation and experimental setup. According to the simulation and the experimental test, the converter efficiency at the rated load is enhanced by 0.6% and 0.4%, and the converter loss is reduced by up to 70% and 19%, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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9. Torque Ripple-Minimizing Control of IPMSM With Optimized Current Trajectory.
- Author
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Cho, Hyung-June, Kwon, Yong-Cheol, and Sul, Seung-Ki
- Subjects
TORQUE control ,TORQUE ,MAGNETIC hysteresis ,PERMANENT magnets - Abstract
In an interior permanent-magnet synchronous machine (IPMSM) for higher torque density, there would be undesirable torque ripples due to spatial harmonics. This article analyzes the torque ripple based on the actual torque map, which is more practical and accurate than the torque model-based analyses. Based on the analysis, a torque ripple-minimizing scheme is proposed for practical IPMSMs. In addition, an experimental identification method of torque map is proposed. The identified torque map is used not only for the proposed torque ripple-minimizing method, but also for the torque reconstruction in experiments. Simulation and experimental results are provided to verify the proposed method. It is confirmed that the harmonic torque ripple under target has been reduced by over 90%. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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10. Signal-Injection Sensorless Control With Tilted Current Reference for Heavily Saturated IPMSMs.
- Author
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Lee, Joohyun, Kwon, Yong-Cheol, and Sul, Seung-Ki
- Subjects
SYNCHRONOUS electric motors ,ELECTRIC inductance ,TORQUE control - Abstract
This article proposes a compensation method for position estimation error under high-frequency signal-injection sensorless control (SISC), especially for heavily saturated interior permanent-magnet synchronous motors (IPMSMs). In the proposed method, the current reference is tilted so that the controller sees more desirable side of the inductance of IPMSM under control. With the proposed method, the position error can be fully compensated and the torque under SISC is limited not by the inductance characteristics of motor but current limit of the inverter and motor itself. Simulations and experiments are performed to verify the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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11. Non-Invasive Magnet Temperature Estimation of IPMSM Based on High-Frequency Inductance With a Pulsating High-Frequency Voltage Signal Injection.
- Author
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Jung, Hyun-Sam, Park, Donghoon, Kim, Hwigon, Sul, Seung-Ki, and Berry, Daniel J.
- Subjects
PERMANENT magnet motors ,ELECTRIC inductance ,TEMPERATURE sensors ,MAGNETIC torque ,ROTORS - Abstract
In this paper, a method to estimate the temperature of a permanent magnet of a traction motor for automotive applications is derived by analyzing the high-frequency inductance of an interior permanent-magnet synchronous motor. The derived method exploits the high-frequency inductance as an indicator of the magnet temperature, and it does not require a temperature sensor not only on the rotor side but also on the stator side. Hence, the method is truly noninvasive. The proposed method has been verified in a small-scale experimental setup. The performance of the method has been evaluated at various torques, speeds, and magnet temperatures ranging from −24 to 82 °C. Through testing at various operating conditions, it has been confirmed that the maximum error is less than 2.9 °C even when the speed and torque vary. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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12. Analysis on Position Estimation Error in Position-Sensorless Operation of IPMSM Using Pulsating Square Wave Signal Injection.
- Author
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Hwang, Chae-Eun, Lee, Younggi, and Sul, Seung-Ki
- Subjects
SQUARE waves ,ELECTRIC inverters ,ELECTRIC inductance ,SWITCHING circuits - Abstract
In this paper, the theoretical analysis of the position estimation error in position-sensorless operation using pulsating square wave signal injection is presented. The purpose of this paper is to analyze the phenomenon that the position estimation performance varies depending on the injection frequency. Mathematical derivation supported by simulation and experimental results shows that, in no-load condition, the voltage distortion induces position estimation error with 3rd-order harmonics if the frequency of the injected square wave is the same to the switching frequency. While, if the frequency is a half of the switching frequency or heavier load condition in either injection frequency, the effect of nonideal characteristics of inverter disappears and there is no 3rd harmonics in the position estimation error. Therefore, only the effect of cross-coupling inductance is reflected in the estimation error. As the result, the position estimation error appears in the form of 6th-order harmonics due to the spatial harmonics of inductances, and the error is relatively small compared with the switching frequency injection case. The theoretical analysis was verified by simulation and experimental results. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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13. Model-Based Sensorless Control of an IPMSM With Enhanced Robustness Against Load Disturbances Based on Position and Speed Estimator Using a Speed Error.
- Author
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Lee, Younggi and Sul, Seung-Ki
- Subjects
- *
DETECTORS , *ROBUST control , *ELECTRICAL load , *ELECTRIC potential , *ERRORS - Abstract
In this paper, new model-based sensorless control methods are proposed that include independent estimations of position and speed errors, and compatible position and speed estimators. Using the proposed position estimator, a unity transfer function can be achieved from the actual position to the estimated position, eliminating the effects of load disturbances. This implies that the position error would ideally be zero, even in a transient state. In addition, the effects of parameter and voltage synthesis errors on the steady-state position error are analyzed. Experimental results verify both the analysis and the effectiveness of the proposed methods under severe load disturbances such as speed transient (20 000 r/min/s) and load torque transient (10 p.u./s). With the proposed methods, position estimation errors are significantly reduced by more than 50% during speed and load torque transients at identical dominant-pole placements, verifying the enhanced tracking capability and robustness of the proposed methods against external load disturbances. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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14. Reduction of Injection Voltage in Signal Injection Sensorless Drives Using a Capacitor-Integrated Inverter.
- Author
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Kwon, Yong-Cheol and Sul, Seung-Ki
- Subjects
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ELECTRIC potential , *VOLTAGE control , *CAPACITORS , *POWER capacitors , *ELECTRIC inverters - Abstract
In signal injection sensorless drives, the injection voltage cannot be reduced under a certain value. The lower limit of the injection voltage is mainly enforced by the inverter nonlinearity that causes distortion of the injection voltage and degradation of the position estimation performance. After analyzing the inverter nonlinearity during the voltage injection, it is revealed that parasitic capacitances of insulated-gate bipolar transistors have positive effects on inverter output linearity and sensorless control. Based on this analysis, this paper proposes a method to reduce the injection voltage by connecting additional capacitors to the output terminals of the inverter. Simulation and experimental results are provided to verify the effectiveness of the proposed idea. In the experiments, using the capacitor-integrated inverter, it is shown that the injection voltage can be reduced by more than half without degrading the position estimation performance. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
15. Vector Control of Double-Delta Sourced Winding for a Dual-Winding Induction Machine.
- Author
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Park, Yongsoon, Yoo, Jeong-Mock, and Sul, Seung-Ki
- Subjects
INDUCTION machinery ,VECTOR control ,WINDING machines - Abstract
Ripple currents can be mitigated in motor drives by applying double-delta sourced winding (DDSW), which uses a multilevel operation approach with two-level converters. In practice, a dual-winding induction machine (DWIM) has been considered for this application due to its inherent compatibility with DDSW. The modeling of a DDSW-based DWIM is discussed for vector control, and a decoupling method between converters is proposed to improve the dynamic response of the current regulation. In addition, torque control is discussed for a situation in which one of the converters is dropped out. The effectiveness of the proposed methods is assessed via experiments under low switching frequencies because DDSW is appropriate for high-power applications, where multiple windings are essential. It was confirmed that the total harmonic distortion of the converter currents was decreased by 67.7% when an 11-kW DWIM was driven on the basis of DDSW. Furthermore, the bandwidth of the current regulation could be increased by 113.7% owing to the proposed decoupling method. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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16. Design, Modeling, and Control of an IPMSM With an Asymmetric Rotor and Search Coils for Absolute Position Sensorless Drive.
- Author
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Kwon, Yong-Cheol, Sul, Seung-Ki, Baloch, Noor Aamir, Morimoto, Shinya, and Ohto, Motomichi
- Subjects
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PERMANENT magnet motors , *FINITE element method , *ALGORITHMS , *ROTORS , *ROTATING machinery - Abstract
In this paper, a design methodology and control algorithms of an interior permanent-magnet synchronous machines (IPMSM) for absolute position sensorless drive are proposed. In conventional research on absolute position sensorless control, initial motion of the rotor was inevitable, which was not preferred in many applications. In order to eliminate the initial motion, an IPMSM with an asymmetric rotor and search coils is devised. In the proposed IPMSM, the information of the absolute position is included in the voltage signals at the search coils. By measuring and analyzing the search coil voltages, the absolute position can be estimated without any initial motion of the rotor. Overall performances of the proposed motor are evaluated through rigorous finite element analyses and experimental tests. [ABSTRACT FROM PUBLISHER]
- Published
- 2016
- Full Text
- View/download PDF
17. Improved Design of IPMSM for Sensorless Drive With Absolute Rotor Position Estimation Capability.
- Author
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Kwon, Yong-Cheol, Sul, Seung-Ki, Baloch, Noor Aamir, Murakami, Sohji, and Morimoto, Shinya
- Subjects
- *
PERMANENT magnet motors , *SYNCHRONOUS electric motor design & construction , *SENSORLESS control systems , *ELECTRIC potential , *FINITE element method - Abstract
In this paper, two designs of interior permanent-magnet synchronous machine (IPMSM) for sensorless drive with absolute rotor position estimation capability are proposed. A conventional IPMSM design proposed for the same purpose had a demerit that for the absolute position estimation, the rotor should initially stroke for 100 degrees in the worst case. Using the proposed IPMSMs featuring asymmetric winding and asymmetric rotor geometry, the initial stroke of the rotor can be reduced to 30 degrees. Moreover, basic characteristics of the motor such as torque ripples and harmonics of electromotive force (EMF) are conspicuously improved. The proposed designs are evaluated by rigorous finite-element analyses and experimental tests. An analytical model of the proposed motors considering their asymmetric structures is also developed and provided in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
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18. Suppression of Injection Voltage Disturbance for High-Frequency Square-Wave Injection Sensorless Drive With Regulation of Induced High-Frequency Current Ripple.
- Author
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Kim, Dongouk, Kwon, Yong-Cheol, Sul, Seung-Ki, Kim, Jang-Hwan, and Yu, Rae-Sung
- Subjects
ELECTRIC inverters ,SQUARE waves ,ELECTROMAGNETIC waves ,SQUARE-wave generators ,SAMPLING errors - Abstract
In the square-wave voltage signal injection sensorless drive of the interior permanent-magnet synchronous machine, the injection voltage can be distorted by the inverter nonlinearity effects especially when the injection voltage is low. If that happens, a high-frequency (HF) current signal which contains the rotor position information could be also distorted, which directly leads to an error in the position estimation. This paper analyzes the effects of the inverter nonlinearity on injection voltage, on induced current ripple, and on the position estimation performance in sequence and proposes a voltage injection method to minimize the impact of the inverter nonlinearity by the regulation of the HF current ripple. By simulations and experiments, the performance of the proposed method has been verified. The experimental results show 19.7% reduction of position estimation error under 15% of rated voltage signal injection without increasing the current ripple at a certain operating condition. Moreover, the performance of position estimation is kept uniform regardless of the loading condition. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
19. Sensorless Control of Synchronous Machine With an Inverter Integrated Rotor.
- Author
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Choe, Sehwa, Jung, Eunsoo, and Sul, Seung-Ki
- Subjects
ELECTRIC inverters ,MACHINERY ,POWER transmission ,ELECTRIC motors ,ELECTRIC power - Abstract
This paper proposes a new sensorless method for a synchronous machine with an inverter integrated rotor (SMIIR). The SMIIR is a newly developed machine based on the wound rotor synchronous machine (WRSM) but has no brushes and slip-rings. The conventional high-frequency signal injection sensorless methods are based on a physical magnetic saliency. Therefore, the conventional methods cannot be applied to the SMIIR since it has no adequate physical magnetic saliency. The proposed sensorless method suggests a virtual resistance saliency created by the rotor-side inverter, of which the saliency ratio and axes can be arbitrarily set. Based on this virtual saliency, the rotor position information can be included in the relationship between the high-frequency stator voltage and stator current independent of the machine parameters or operating conditions. Because the SMIIR inherently injects a high-frequency voltage for the power transfer, there is no need to inject additional voltage for the proposed high-frequency sensorless control. The initial $d$-axis detection algorithm using the rotor-side inverter without magnetic saturation is also proposed. The feasibility of the proposed sensorless method was verified by the experimental results of the prototype SMIIR. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
20. Implementation and Sensorless Vector-Control Design and Tuning Strategy for SMPM Machines in Fan-Type Applications.
- Author
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Kshirsagar, Parag, Burgos, Rolando P., Jang, Jihoon, Lidozzi, Alessandro, Wang, Fei, Boroyevich, Dushan, and Sul, Seung-Ki
- Subjects
SENSORLESS control systems ,VECTOR control ,ROTORS ,SYNCHRONIZATION ,PERMANENT magnet motors ,ELECTRIC drives ,SIMULATION methods & models - Abstract
This paper presents a complete design methodology for the sensorless vector control of permanent-magnet synchronous machine (PMSM) motor drives in fan-type applications. The proposed strategy is built over a linear asymptotic state observer used to estimate the PMSM back EMF and a novel tracking controller based on a phase-locked loop system, which, by synchronizing the estimated and actual d-q frames, estimates the rotor speed and position. This paper presents the complete derivation of all associated control loops, namely, state observer; tracking controller; d-q-axis current regulator; speed controller; an antisaturation control loop, which provides inherent operation in the flux-weakening region; and all corresponding antiwindup loops. Detailed design rules are provided for each of these loops, respectively verified through time-domain simulations, frequency-response analysis, and experimental results using a three-phase 7.5-kW PMSM motor drive, validating both the design methodology and the expected performance attained by the proposed control strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
21. Control of a Synchronous Motor With an Inverter Integrated Rotor.
- Author
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Jung, Eunsoo, Kim, Sungmin, Ha, Jung-Ik, and Sul, Seung-Ki
- Subjects
SENSORLESS control systems ,SYNCHRONOUS electric motors ,ELECTRIC inverters ,ROTORS ,MATHEMATICAL variables ,ALTERNATING current machinery - Abstract
In this paper, a synchronous motor with an inverter integrated rotor (SMIIR) is introduced, and its control scheme is proposed. This presents a new breed of synchronous motor in that it integrates an inverter inside the rotor. The basic operational principle and control strategies are discussed. Given these new strategies, the SMIIR can be considered as a synchronous motor which changes its field according to the harmonic voltage of the stator inverter. The feasibility of the proposed structure of the drive system and its operation principle are evaluated through experimental results. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
22. PWM Switching Frequency Signal Injection Sensorless Method in IPMSM.
- Author
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Kim, Sungmin, Ha, Jung-Ik, and Sul, Seung-Ki
- Subjects
PULSE width modulation ,SIGNAL detection ,SENSORLESS control systems ,PERMANENT magnet motors ,PERFORMANCE evaluation ,ROTORS ,SWITCHING circuits - Abstract
The rotor position of an interior permanent-magnet synchronous machine (IPMSM) can be estimated without a position sensor by signal injection sensorless control at standstill and/or in very low speed rotating condition. In the signal injection sensorless control, however, the fundamental control performance is limited by the frequency of the injected signal, and no negligible acoustic noise is generated. If the frequency of the injected voltage signal would increase to pulsewidth modulation (PWM) switching frequency and if the switching frequency is near or above audible range, the dynamics of the sensorless control can be improved, and the acoustic noise can be remarkably reduced or totally eliminated. This paper describes how to extract the rotor position information of IPMSM using the voltage signal injection whose frequency is the same as the PWM switching frequency. Compared to the conventional heterodyning process, the proposed method is simple to implement and appropriate for PWM switching frequency signal injection. The high-frequency voltage signal can be injected in the stationary reference frame or in the estimated rotor reference frame. In this paper, the 5- and 16-kHz signal injections are proposed, implemented, and compared. The experimental results confirm the effectiveness of the proposed method. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
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23. A Nine-Phase Permanent-Magnet Motor Drive System for an Ultrahigh-Speed Elevator.
- Author
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Jung, Eunsoo, Yoo, Hyunjae, Sul, Seung-Ki, Choi, Hong-Soon, and Choi, Yun-Young
- Subjects
ELEVATORS ,PERMANENT magnet motors ,SYNCHRONOUS electric motors ,ELECTRIC inverters ,MATHEMATICAL models ,CONTROL theory (Engineering) ,ELECTRIC fault location - Abstract
This paper presents a nine-phase permanent-magnet synchronous motor (PMSM) drive system based on multiple three-phase voltage source inverters. The nine-phase PMSM was developed as a traction motor for an ultrahigh-speed elevator. The mathematical model of the motor was simplified through symmetry of the system. Using the simplified model, the drive system can be controlled by the well-known d-q control theory. The feasibility and validity of the drive system were experimentally demonstrated at the world's tallest elevator test tower. Moreover, an additional experiment was performed to ensure the fault-tolerance capability of the system. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
24. High-Bandwidth Sensorless Algorithm for AC Machines Based on Square-Wave-Type Voltage Injection.
- Author
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Yoon, Young-Doo, Sul, Seung-Ki, Morimoto, Shinya, and Ide, Kozo
- Subjects
- *
BANDWIDTHS , *ALGORITHMS , *ALTERNATING currents , *BANDPASS filters , *OBSERVABILITY (Control theory) , *ELECTRIC machinery rotors , *PERFORMANCE evaluation , *SIGNAL processing - Abstract
This paper describes a new control algorithm which can enhance the dynamics of a sensorless control system and gives a precise sensorless control performance. Instead of the conventional sinusoidal-type voltage injection, a square-wave-type voltage injection incorporated with the associated signal processing method is proposed in this paper. As a result, the error signal can be calculated without low-pass filters and time delays, and the position estimation performance can be enhanced. Using the proposed method, the performance of the sensorless control can be enhanced; the bandwidth of the current controller was enhanced up to 250 Hz, and that of the speed controller was up to 50 Hz. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
25. A Protection Scheme Against Voltage Sags for Electrolytic Capacitorless AC Drives.
- Author
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Lee, Wook-Jin, Sul, Seung-Ki, and Shim, Young-Seok
- Subjects
- *
SEMICONDUCTOR switches , *ELECTROLYTIC capacitors , *CASCADE converters , *ELECTRIC inductance , *ELECTRIC potential , *PERMANENT magnets , *ROTORS - Abstract
This paper presents a protection strategy for the semiconductor switches in an electrolytic capacitorless converter. The proposed protection strategy is capable of protecting the semiconductor switches from overvoltage breakdown caused by the regenerative energy flowing from the load to the grid after the source lines are disconnected by the grid interruption. The energy stored in the machine inductance also may result in excessive dc-bus overvoltage due to the small dc capacitance in the electrolytic capacitorless converter. According to the proposed algorithm, the energy in the q-axis inductance is transferred to the d-axis inductance in the rotor reference frame while the dc-bus voltage is maintained within an allowable range by the proposed dc-bus voltage regulation during the grid (or source) interruption. The proposed protection strategy was verified by the experiments with an elevator system with a 10.8-kW 380-V interior permanent magnet (1PM) hoist machine. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
26. Sensorless Drive of Surface-Mounted Permanent-Magnet Motor by High-Frequency Signal Injection Based on Magnetic Saliency.
- Author
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Jang, Ji-Hoon, Sul, Seung-Ki, Ha, Jung-Ik, Ide, Kozo, and Sawamura, Mitsujiro
- Subjects
- *
MOTORS , *MACHINERY , *ELECTRIC impedance , *ROTORS , *ROTATIONAL motion - Abstract
Proposes a sensorless control scheme of a surface-mounted permanent-magnet motor using high-frequency voltage signal injection method based on the high-frequency impedance difference. Relationship between the high-frequency voltages and high-frequency currents; Types of the conventional sensorless control schemes of the permanent-magnet motor; Calculation of input signal to rotor position estimator.
- Published
- 2003
- Full Text
- View/download PDF
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