• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.268-270
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• 1995

This paper proposes a novel PWM technique for a three phase current fad type converters. A minor loop compensation method is introduced to compensate leading current and to minimize input line current (Iu) distortion resulting from the resonance between AC filter capacitor and source inductance of power system. This PWM converter has excellent characterics as next. The control system is simply designed, and the operation with unity power factor can be easily obtained by automatic compensating the leading current of the filter circuit. Also. the three phase sinusoidal input current can be obtained.

• Journal of electromagnetic engineering and science
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• 제2권2호
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• pp.100-104
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• 2002

A proper equivalent circuit model for coupling iris has been derived in order to compensate the length of cavity in a $TE_{011}$TEX> mode cylindrical cavity filter. A method to resolve the difference in bandwidth and feature or ripple systematically has been proposed. This method can be applied to other types of waveguide cavity filter.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.189-191
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• 2005

This paper proposes an implementation of a line- voltage sensorless three-phase active power filter. The line synchronization for an active power filter does not require any additional hardware. It can be properly operated under various line-voltage variation. Current compensation is done in the time domain allowing fast time response. All control functions are implemented in software using a single-chip microcontroller, thus simplifying the control circuit. It is shown via experimental results that the proposed controller gives good performance for the line-voltage sensorless active power filter.

• Journal of Power Electronics
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• 제15권3호
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• pp.819-829
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• 2015

This paper presents a shunt active power filter (SAPF) for compensating inter-harmonics and harmonics when inter-harmonics content is evident in the grid. The principle of inter-harmonics generation in the grid was analyzed, and the inter-harmonics effect on repetitive controllers was discussed in terms of control performance. Traditional repetitive controllers are not applicable in inter-harmonic compensation. Moreover, the effect of an ideal controller on harmonics signals was analyzed on the basis of the internal model principle. The repetitive controller was improved in the form of a basis function according to theoretical analysis. The finite-dimensional repetitive controller, which is also called the multiple-period repetitive controller, was designed for the control of multiple periodic signals. A selective harmonic compensation system was developed with SAPF. This system can be used to compensate harmonics and inter-harmonics in the grid. Finally, system control performance was verified by simulation and experimental results.

• Journal of Power Electronics
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• 제16권5호
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• pp.1928-1938
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• 2016

The three-phase four-wire shunt active power filter (APF) is an effective method to solve the harmonic problem in three-phase four-wire power systems. In addition, it has two possible topologies, a four-leg inverter and a three-leg inverter with a split-capacitor. There are some studies investigating DC-link voltage control in three-phase four-wire APFs. However, when compared to the four-leg inverter topology, maintaining the balance between the DC-link upper and lower capacitor voltages becomes a unique problem in the three-leg inverter with a split-capacitor topology, and previous studies seldom pay attention to this fact. In this paper, the influence of the balance between the two DC-link voltages on the compensation performance, and the influence of the voltage balance controller on the compensation performance, are analyzed. To achieve the balance between the two DC-link capacitor voltages, and to avoid the adverse effect the voltage balance controller has on the APF compensation performance, a new DC-link voltage balance control strategy for the three-phase four-wire split-capacitor APF is proposed. Representative simulation and experimental results are presented to verify the analysis and the proposed DC-link voltage balance control strategy.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.119-122
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• 2000

This paper presents a new compensation method of series active power filter. The proposed method applied in the three-phase three-wire system can generate harmonic compensation voltage in front of the harmonic source. Futhermore it is also expended to three-phase four-wire system considering zero-sequence voltage. The compensation principle is described in detail. Experimental result show the validity of the proposed method in the three-phase three-wire system

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.133-136
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• 2000

Current Source Inverter(CSI) operated in square wave mode is more efficient than the PWM CSI because of increased cost greater complexity of control algorithm, and substantial switching losses EMI. But the square wave output current of CSI rich in low order harmonics produce motor torque ripples. Therefore in this paper describes the active power filters for square wave current compensation of current source induction motor. Also extended current synchronous detection(ECSD) as compensation algorithm is proposed. To confirm the validity o proposed system some simulation results are presented and discussed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.468-469
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• 2010

DSTATCOM(Distribution STATic COMpensator) is one of the custom power devices, and protects a distribution line from unbalanced and harmonic current caused by non-linear and unbalanced loads. Conventional researches use a LPF(Low Pass Filter) to eliminate ripple component at the calculation of compensation current. This paper proposes a calculation of compensation current using phase shift that can be a counterproposal of conventional methods using LPF.

• 한국멀티미디어학회논문지
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• 제24권12호
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• pp.1589-1597
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• 2021

Due to the low output rate and time delay of vehicle's navigation results, the electro-optical tracking system(EOTS) cannot estimate accurate target positions. If an inertial measurement unit(IMU) is additionally mounted into the EOTS and inertial navigation system(INS) is constructed, the high navigation output rate can be obtained. And the time-delay can be compensated by using the augmented Kalman filter. An accurate initial attitude is required in order to have accurate navigation outputs. In this paper, an attitude determination algorithm is proposed using the augmented Kalman filter in order to compensate measurement delay of the EOTS and have accurate initial attitude. The proposed initial attitude determination algorithm consists of an augmented Kalman filter, an INS, and an integrated Kalman filter. The augmented Kalman filter compensates the time-delay of the vehicle's navigation results and the integrated Kalman filter estimates the navigation error of the INS. In order to evaluate performance of the proposed algorithm, vehicle's navigation outputs and IMU measurements were generated using sensors' model-based measurement generator and initial attitude estimation errors of the proposed algorithm and the conventional algorithm without the augmented Kalman filter were compared for the generated measurements. The evaluation results show that the proposed algorithm has better accuracy.

• 전기학회논문지
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• 제57권8호
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• pp.1377-1382
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• 2008

DSTATCOM(distribution static compensator) is one of the custom power devices, and protects a distribution line from unbalanced and harmonic current caused by non-linear and unbalanced loads. Researches about DSTATCOM are mainly divided two parts, one is the calculation of compensation current and the other part is the current control. Conventional researches use a LPF(low pass filter) to eliminate ripple component at the calculation of compensation current. But this method has a problem that LPF's characteristics restrict the compensation performance of instantaneous active and reactive power. This paper proposes a calculation of compensation current using state observer that can be a counterproposal of conventional methods using LPF. Improved performance of instantaneous active and reactive power compensation was shown by experiments.