• Journal of Power Electronics
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• v.10 no.5
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• pp.477-484
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• 2010

A pulse width modulation-voltage source inverter (PWM-VSI) is used for variable speed permanent magnet synchronous motor (PMSM) drives. The PWM-VSI fed PMSM has two major disadvantages. Firstly, the PWM-VSI DC-link voltage limits the magnitude of the PMSM terminal voltage. As a result, the motor speed is restricted. Secondly, in a low speed range, the PWM-VSI modulation index declines. This is caused by a high DC-link voltage and a low terminal voltage ratio. As a result, the distortion of the voltage command and the stator current are increased. This paper proposes an optimal pulse amplitude modulation (PAM) control which can adjust the inverter DC-link voltage by using a buck-boost DC-DC converter. At a low speed range, the proposed system can reduce the distortion of the voltage command, which improves the stator current waveform. Also, the allowable speed range is extended. In order to verify the proposed method, experimental results are provided to confirm the simulation results.

• Journal of Power Electronics
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• v.12 no.1
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• pp.49-57
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• 2012

This paper presents performance evaluation of an Integrated Starter-Alternator (ISA) prototype with an Interior Permanent Magnet (IPM) synchronous machine under sensor-less operation. To attain a high starting torque at zero speed and in subsequent extremely low speed range, a hybrid signal injection method is proposed. At higher speed, an improved stator flux observer is used for the stator flux estimation. This observer is able to produce accurately-estimated stator flux linkage for high performance Direct Torque and Flux Control (DTFC) implementation. The sensor-less DTFC IPM synchronous machine drive takes full advantage of the capacity of the power converter and fulfills the control specifications for the ISA. The trajectory control algorithm responds rapidly and in a well behaved manner over a wide range of operating conditions. The experimental results verify the feasibility and advantages of the system.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.92-94
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• 1996

The switched reluctance motor(SRM) has a simple structure with a doubly-salient and is studied as a variable speed motor since it has a good performance in a wide range of speed and torque. This paper presents the control scheme in which ON/OFF angles are controlled by PI controller that compensates the error between the command and real speeds, and the speed response is improved by braking operation in motor decelerating.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.1201-1204
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• 2003

This paper described a replica-delay adaptive lock-acquisition scheme for high-speed DLLs. The proposed scheme provides the fast and correct locking cycle that is variable according to the magnitude of the arbitrary replica delay (fixed delay). The scheme guarantees the wide operation range and the fast lock-aquisition time. It has been confirmed by HSPICE simulations in a 0.35${\mu}{\textrm}{m}$ CMOS process.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.659-660
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• 2008

This paper presents a hybrid winding connection method for torque characteristics improving of a traction SRM. In order to get a high torque in wide speed range and torque ripple reduction, series and parallel winding connection are changed according to operating speed. From the analysis of torque character operation mode and efficiency, the proposed control scheme is verified.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.279-284
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• 1999

Although the switched reluctance motor (SRM) has a several advantages such as simple magnetic structure, robustness, wide range of speed characteristics and simple driving, it has a considerable inherent torque ripple and speed variation duet to the driving characteristics of pulse current waveform and the nonlinear inductance profile. The high torque ripple and speed variation inhibits wide application. The minimization of the torque ripple is very important in high performance servo drive applications, which require smooth operation with minimum torque pulsations. This paper presents the new SRM torque modeling technique for the control of instantaneous torque. The SRM is modeled by the database of torque profiles for every small variation in currents and rotor angles, which is inferred from the several measured data by the adaptive neuro-fuzzy inference technique. Simulation results demonstrating the effectiveness of proposed torque modeling technique are presented.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.7
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• pp.97-103
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• 2002

In this paper, a Logarithmic Video Amplifier(LVA) for radar system or satellite communications is described. The proposed LVA is composed of a input stage, amplification stage, and output stage. As well as a novel series-parallel architecture is proposed for the purpose of wide dynamic range and high speed operation, a newly developed input stage is designed in order to control the voltage level between LVA and detector diode. The LVA is fabricated with a 1.5um 2-poly 2-metal n-well Bi-CMOS technology, and the chip area is 1310 um x 1540 um. From the experimental results, it consumes 190 mW at 10V power supply, the chip has 60 dB dynamic range and 100ns falling time.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.338-343
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• 2010

Low cost motor drives are being sought for high volume energy efficient home appliances. Key to the realization of such low cost motor drives is to reduce the power electronic converter in terms of its components, particularly the active devices, finding the motor with least complexity for manufacturing and a controller that could extract the desired performance from the machine and converter combination. These and other factors such as self-starting, speed control over a wide range and most of all the crowning aspect of a four quadrant operation with bare minimum number of controllable switch (or switches) remain as formidable challenges for low cost motor drive realization. In this paper, a four quadrant switched reluctance motor (SRM) drive with only one controllable switch is realized by using a two-phase machine. The theory and operation of the proposed four-quadrant SRM drive with the proposed control algorithm for its realization are described. The motor drive is modeled, simulated and analyzed to verify its feasibility for self-starting, speed control and for four quadrant operation and the simulation results are presented. Experimental results confirm the validity of the proposed control algorithm for four quadrant control of the SRM drive. The focus of the paper is mainly directed toward the control algorithm for realizing the four-quadrant operation of the two-phase SRM drive with a single controllable switch converter.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.4
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• pp.291-296
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• 2015

This paper describes the design of a high-speed comparator for high-speed automatic test equipment (ATE). The normal comparator block, which compares the detected signal from the device under test (DUT) to the reference signal from an internal digital-to-analog converter (DAC), is composed of a rail-to-rail first pre-amplifier, a hysteresis amplifier, and a third pre-amplifier and latch for high-speed operation. The proposed continuous comparator handles high-frequency signals up to 800MHz and a wide range of input signals (0~5V). Also, to compare the differences of both common signals and differential signals between two DUTs, the proposed differential mode comparator exploits one differential difference amplifier (DDA) as a pre-amplifier in the comparator, while a conventional differential comparator uses three op-amps as a pre-amplifier. The chip was implemented with $0.18{\mu}m$ Bipolar CMOS DEMOS (BCDMOS) technology, can compare signal differences of 5mV, and operates in a frequency range up to 800MHz. The chip area is $0.514mm^2$.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.7
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• pp.565-571
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• 2005

We present a novel speed estimation of a Permanent Magnet Synchronous Motor(PMSM) based on Support Vector Regression(SVR). The proposed method can estimate wide speed range, including 0.33Hz with full load, accurately in the steady and transient states where motor parameters variations are known without parameter estimator. Moreover, the method does not need offline training previously but is trained on-line. The training starts with the PMSM operation simultaneously and estimates the speed in real time. The experimental results shows the validity and the usefulness of the proposed algorithm for the 0.4Kw PMSM DSP(TMS320VC33) drive system.