• Journal of Power Electronics
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• v.11 no.6
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• pp.931-937
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• 2011

This paper presents a method for the performance improvement of a shunt active power filter (SAPF) using the indirect current control (ICC) scheme. Compared to the conventional direct current control (DCC) scheme, the ICC gives better performance with a lower number of sensors. A simplified and efficient control algorithm using a low cost Intel 80C196KC microcontroller is implemented using only two current sensors for the source current and one voltage sensor for the DC-link voltage of the SAPF circuit. The objective is to eliminate harmonics and to compensate the reactive power produced by non-linear loads such as an uncontrolled rectifier feeding an inductive load. The APF is realized using a three phase voltage source inverter (VSI) with a dc bus capacitor. Experimental results are presented to prove the better performance of the ICC method over the DCC one.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.800-802
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• 1993

This paper presents a new current control method of the six-pulse cycloconverter for a variable speed drive system of a large capacity ac mortor. It is necessary for a high performance control as a vector control that the output current scheme of the cycloconverter has a good charistic in transient state. A new proposed current control method is that the output current of the cycloconverter is followed after the current reference directly as fast as possible under any condition. Simulation resualts with the proposed new current control method are shown. As a result the validity of the proposed method is confirmed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.2
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• pp.301-307
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• 2009

In the paralleled converter module with peak current mode control, current imbalance appears when the voltage controllers with integral control of converter module are not exactly identical. In this paper, the voltage controller is designed to equal the current command of each converter module using the current command bus. The current balance controller is also proposed to balance the average currents of converter modules with imbalaced inductance. It is designed to have good transient response. Proposed method is implemented with the paralleled 2-module and 4-module boost converters with imbalanced inductance. Experimental results verify the performance of current share during both steady and transient states of converter.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.3
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• pp.258-265
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• 2011

This paper presents a variable frequency current control scheme for the air-pressure control of diaphragm. Differ from the conventional air-pressure control of diaphragm, the proposed method uses a single-phase inverter to control the phase current and frequency. The phase current is adjusted to keep the reference air-pressure of the diaphragm. And the current frequency is changed to reduce the mechanical vibration. In order to smooth change of the operation with a constant air-pressure, the frequency is changed according to the voltage reference from the current controller. When the phase current is satisfied to the constant air-pressure, the current frequency is increased to reduce the vibration of the diaphragm. When the reference voltage to keep the phase current is over than the set value, the current frequency is decreased to keep the air-pressure. The proposed control scheme is verified by the experimental test of a commercial diaphragm.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2040-2042
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• 1997

A voltage source PWM converter based on lossless resonator and a source current control system are proposed in this paper. It is proved that steady-state deviation reduces to zero from the transfer function of source current control system, owing to the lossless resonator. The system can be controlled by the feedback control only, because of no need to use a feedforward control in the proposed a source current control system. Therefore, as using lossless resonator, control system can be simply made up. Simulations are described in the case of difference between source current and source current reference.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.5
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• pp.283-294
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• 2004

This paper introduces the new Direct Torque Control(DTC) method based on the estimated torque in Switched Reluctance Motor(SRM) and applies the proposed DTC to SRM for the instantaneous torque ripple reduction. The nonlinear characteristics of SRM is considered in the calculation of the estimated torque and the theory is described in this paper. Current control is one of the kernel elements of torque controller and the performance of the current control should be high for this work. But the conventional PI current control has a weak point in SRM application because of motional EMF. Consequently, this paper makes up for the weakness of PI controller through present of new current controller, that is termed the non-interference current control. The ability of proposed torque and current controller is verified through simulation and experiment.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.3
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• pp.185-192
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• 1998

This paper presentsa new currnet control method ofthe six-pulse cycloconverter which is used as a variable speed drive system of a large capacity ac mortor. For a high performance control as a vector control, it is necessary that the output current control ofthe power converter has a good characteristic in transient state. A new proposed current control method is that the output current of a cycloconverter is followed after the current reference directly as fast as possible under any condition. Simultion results for the proposed new current control method are shown and its validity of the proposed method is confired.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.928-933
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• 1998

This paper presents a novel current control system to eliminate the steady state control error and to improve the transient characteristics for PWM AC-DC converter. A general mathematical model of the converter that is represented as a state-space model is first established. The state-space model is used for the simulation of PWM switching converter with the proposed current control system. The proposed sinusoidal tracking control system that does not require coordinate transformations using principle of the integral controller is described. It is proved that the steady state deviation reduces to zero through a transfer function of source current control system. Finally, it is seen that simulations agree with the experimental results in source current and reference of controlled ac current loop.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.1
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• pp.27-32
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• 2006

In this paper, a new scheme of current programmed control for three phase PWM AC-AC converter is presented. Compared to duty-ratio voltage control, current programmed control has several advantages such as reduction of system order, inherent current protection and robust output. By considering only the magnitude components, a similar scheme in the DC-DC converter can be extended to the three phase PWM AC-AC converter. The proposed current programmed control will be well adopted into various converter topologies though three phase PWM AC-AC boost converter is treated as an example. The converter analysis is carried out by applying the vector DQ transformation to obtain physical insight into the converter operation and to establish some important characteristic equations for control purpose. The experiment results show the validity of the proposed scheme.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1228-1233
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• 2013

In this paper, design of Wound Rotor Synchronous Motor(WRSM) for Integrated Starter and Generator(ISG) is performed based on Finite Element Analysis(FEA). WRSM can control not only magnitude and phase of armature current, but also field current. Thus, various control methods can be considered. Since driving characteristic of WRSM depends greatly on the control method, characteristic analysis accoding to possible driving current combination is reguired. Especially in high speed region, the control method that reduces unnecessary d-axis current by reducing field current is possible, which is similar to field weakening control. By the current combination reducing field and d-axis current, the design minimizing copper loss to increase efficiency on identical driving point is possible. In this paper, high efficient WRSM is designed applying the current combination which can minimize copper loss on each driving point.