• Journal of Power Electronics
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• v.10 no.1
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• pp.43-50
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• 2010

This paper proposes a new harmonic elimination PWM (HEPWM) scheme for voltage source inverters (VSI) based on the curve fittings of certain polynomials functions. The resulting equations to calculate the switching angle of the HEPWM require only the addition and multiplication processes; therefore any number of harmonics to be eliminated and the fundamental amplitude of the pole switching waveform (NP1) can be controlled on-line. An extensive angle error analysis is carried out to determine the accuracy of the algorithm in comparison to the exact solution. To verify the workability of the technique, an experimental single phase VSI is constructed. The algorithm is implemented on a VSI using a 16-bit microprocessor. The results obtained from the test rig are compared to the theoretical prediction and the results of the MATLAB simulations.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2704-2707
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• 1999

This paper presents a simple high power audio class amplifier which is controlled by a new current control switching method. Although this class D amplifier has an only one current control loop with the proposed switching method, a good performance can be obtained. And a novel switching strategy for driving stereo signal amplifier circuit with three phase full bridge is discussed also. With the simulation and experimental results, usefulness of the proposed amplifier is confirmed.

• Proceedings of the KIEE Conference
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• 2003.07e
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• pp.79-82
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• 2003

The switching-mode power converter has been widely used because of its features of high efficiency and small weight and size. In the switching-mode power converter, the output voltage is generally controlled by varying the duty ratio of main switch. When a converter operates in steady state, duty ratio of the converter is kept constant. So the power of switching noise is concentrated in specific frequencies. The more white noise is injected, the more conducted EMI is reduced. But output-voltage is not sufficiently regulated. This is the reason why carrier frequency selection topology is proposed. In the case of carrier frequency selection, output-voltage of steady state and transient state is fully regulated. Spectrum analysis is performed on the Phase current and the CM noise voltage. The former is measured with Current Probe and the latter is achieved with LISN, which are connected to the spectrum analyzer respectively.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.44.2-44
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• 2001

This paper presents a new concept for controlling of under actuated robot manipulators with avoiding obstacles using switching computed torque method (SCTM). One fundamental approach of this algorithm is to use the partly stable controllers (PSCs) in order to fulfill the ultimate control objective. Here, we use genetic algorithms (GA)in order to employ the optimum control action for a given time frame with the available set of elemental controllers, depending on which links/variables are controlled, i.e. the selection of optimum switching sequence of the control actions. The proposed approach models links of the robot using evolving ellipses and then introduces a penalty scheme for the objective function of GA when it detects collisions. An under actuated robot manipulator, which has three detrees-of-freedom is taken into consideration so as to illustrate the design procedure. Simulation results show the e.ectiveness of the proposed method.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.4
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• pp.317-324
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• 2004

The ink jet printer media advance system is required to be exactly driven to the target position via tracking the reference velocity profile to obtain the high quality print image. A single gain PID controller is not sufficient to fulfill the control objectives, the exact velocity tracking and the accurate positioning, at the same time. A dual PID controller and its switching strategy are presented in this paper to achieve the control objectives. The media advance system is controlled by two separate PID controllers, one of which is for velocity control, and the other is for position control. A PID controller controls the velocity of the media advance system until it reaches the predetermined switching position. When the media advance system passes the predetermined position, the controller is switched to the other PID controller which is more profitable for exact positioning. The switching position is determined by the estimated stop distance. The simulation and experimental results are presented to show the validity and effectiveness of the proposed controller.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.6
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• pp.546-550
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• 2013

We propose a novel negative differential resistance (NDR) device with ultra-high peak-to-valley current ratio (PVCR) by combining pn junction diode with depletion mode nanowire (NW) transistor, which suppress the valley current with transistor off-leakage level. Band-to-band tunneling (BTBT) Esaki diode with degenerately doped pn junction can provide multiple switching behavior having multi-peak and valley currents. These multiple NDR characteristics can be controlled by doping concentration of tunnel diode and threshold voltage of NW transistor. By designing our NDR device, PVCR can be over $10^4$ at low operation voltage of 0.5 V in a single peak and valley current.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.3
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• pp.305-311
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• 2014

In this paper, a new switching pattern is presented for multilevel inverters. With changing off-angel of each switch, the on time interval of all switches will approximately be equal and then the lifetime of inverter will increase, also using this method can reduce electrical stress on switches in higher levels of inverter. Switching angels as for desired modulation index are calculated using genetic algorithm whereas selective harmonics are controlled within the allowable range. The computed angels are simulated in Matlab/Simulink for respective circuits to validate the results.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.4
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• pp.347-355
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• 2002

Obstacle avoidance of underactuated robot manipulators using switching computed torque method (SCTM) is presented. One fundamental feature of this novel method is to use partly stable controllers (PSCs) in order to fulfill the ultimate control objective. Here, we use genetic algorithms (GAs) to acquire the optimum switching sequence of the control actions for a given time frame with the available set of elemental controllers, depending on which links/variables are controlled. The effectiveness of the concept is illustrated by taking a three-degrees-of-freedom (DOF) manipulator and showing enhanced performance of the proposed control methodology.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.4
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• pp.658-666
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• 1987

In this paper, a new mehtod of reducing harmonics that involved in input AC line currents or in output DC voltage of the converter system is presented. which is due mainly to the quipment of 2-3 switching taps on interphase reactor. In case that the 3 tap method is applicable to conventional 12 pulse converter, it could not bring to an effect of reducing harmonics under firing angle 15\ulcorner To solve these problems, 24 pulse or 36 pulse converter is controlled by microprocessor. The former is performed in 2 tap method when \ulcorneris less than 15\ulcorner the latter in 3 tap method when it is more then 15\ulcorner Therefore the originality of this paper liea in microprocessor based equipment of the 2-3 switching taps on interphase reactor. I applied this method to the 12 pulse converter, and proved validity of that theoretically and experimentally.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.163-166
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• 2001

Software controlled traffic management becomes more difficult with increasing switch size, because a huge number of connections are multiplexed in a high speed switching system and each ATM connections does not have a fixed bandwidth It is based on high-speed WDM(wavelength division multiplexed) links that can multiplex a huge number of connections on a statistical basis, and a self-load balancing technique. the Proposed switching system is scalable, and achieves the non-blocking capability without the use of complicated software control, using instead a hardware self-load balancing mechanism