• 대한전기학회논문지
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• 제39권3호
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• pp.254-262
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• 1990

In the active power filter, the PWM method for controlling the power converter plays an important role for the performance and the efficiency of the filter. In this paper, a new PWM method for the single phase current source type active power filter is presented, which is intended particularly for obtaining the maximum efficiency of the compensation. This method is basically based upon the optimized injection method, but in contrast to the existing method, this method adapts the optimized injection method by putting not only the pulse width, but also the pulse position into control variables. By doing this, when the number of pulses per one cycle is N, lower order harmonics up to the Nth order can be completely eliminated by the filter. So, this method is much more efficient than any other existing method. These characteristics are well verified by the computer simulations and the experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1051_1052
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• 2009

This paper deals with operational characteristic analysis of a single-phase PCS (Power Conditioning System) for PV (Photovoltaic) power generation system with AF (Active Filter) function. The theory of dq transformation has been applied to the control strategy of a single-phase PV power generation system to implement the AF function. Application of the virtual two-phase using phase-shift makes it possible to use the dq theory for the single-phase PV power generation system. The authors are sure that the proposed system is a very useful to compensate harmonics caused by nonlinear loads in a single-phase utility system. In this paper, not only a theoretical aspect of the single-phase PV-AF system is discussed, but also the DSP (Digital Signal Processor) based experiment results are presented to demonstrate the effectiveness of the single-phase PV-AF system.

• 대한전기학회논문지:전력기술부문A
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• 제52권2호
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• pp.90-98
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• 2003

Recently, the increasing application of electronic equipments and information devices has heightened the interest in power qualify. The term power quality is applied to a wide range of electromagnetic phenomena on the power system and is also concentrated by all areas such as utilities, their customers and suppliers of load equipments. In engineering terms, power Qualify is expressed by voltage qualify because the power supply system can only control the quality of the voltage. Therefore, the standards in power quality area are devoted to keep the supply voltage within allowable limits. This paper deals with single-phase unified power quality conditioner (UPQC), which ai s at the integration of series-active and shunt-active filter. The series filter il used to compensate for the voltage distortions and the shunt filter is used to provide reactive power and counteract the harmonic current injected by the load. Also, the voltage of the DC link capacitor is controlled to a desired value by the shunt active filter. The validity of the proposed UPQC is demonstrated using both the MATLAB/SIMULINK simulation and the experimental device with DSP (TMS320C32).

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1145-1147
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• 2004

This paper proposed a new control method for single-phase hybrid active power filter. The proposed algorithm can change single phase system into the orthogonal system which has two phases giving time-delay in regular single phas and making the imaginary second phase. It can make orthogonal system like as being used in $3{\phi}/2{\phi}$ transformation with two phases. It can do complex calculation which calculates intantaneous reactive power. Istead of existing method applying to intantaneous reactive power theory in fixed reference frame, this paper proposed the algorithm which has advantage over reducing harmonics using rotating reference frame. It verified the effectiveness the proposed method through simulation and experiment.

• 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.

• 전력전자학회논문지
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• 제10권3호
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• pp.296-301
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• 2005

본 논문은 고조파 검출방식의 하나인 순시무효전력을 이용한 검출방식을 단상용 능동전력필터에 적용할 수 있도록 하였다. 가상회로를 가정하여 단상시스템에도 $\alpha$-$\beta$변환 기법을 이용함으로서 순시무효전력 검출 방식이 용이하게 적용될 수 있도록 하였다. 그리고 고조파 보상 인버터는 멀티레벨 인버터를 사용하였으며 트랜스포머 없이 입력 전원에 연결되어 고조파를 보상할 수 있도록 하였다. 제안된 알고리즘은 시뮬레이션과 실험을 통하여 입증되었다.

• 전력전자학회논문지
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• 제17권2호
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• pp.158-165
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• 2012

In this paper, the test bed using three-phase PWM converter connected with single phase inverter in series is set up to configure an active AC electric load. Since the two topologies, three-phase PWM converter and single-phase inverter, can be operated bidirectionally, the system not only re-generates surplus power to grid but also prevents power dissipation. However, the construction of system has a drawback. That is, ripple components two times of inverter operation frequency occur at DC-Link due to cascade connection, it can be cause of three phase unbalance Since the operational characteristic of the active AC electric load, the power frequency entered into the electric load can be varied, and the ripple of DC-Link is changed as well. In this paper, the three-phase PWM converter using a variable notch filter is proposed, and the reduction of three-phase current unbalance is presented. the validity of the proposed PWM converter using a variable notch filter is verified by the simulation and experimental results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.504-506
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• 2005

This paper proposes a new neutral current reduction method using PQR instantaneous power theory on the active power filter, unbalanced nonlinear load condition in three-phase four-wire systems. For reduction of neutral line current, the single phase active power filter is used and its performance is same with the three-phase four-wire active power filter. For fully-digital implementation, ramp comparison PWM method was adopted. Simulation results verify good performance of the proposed current control strategy on the shunt APFs.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.132-133
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• 2014

This paper presents an algorithm for an active power filter which can be used in both single-phase and three-phase electric system. The proposed algorithm focuses on the extraction of harmonic component of load current in each phase and in order to verify the validity of the proposed algorithm while loads are nonlinear, simulations have been done by PLECS software and tested by typhoon-HIL which is real time emulator.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권5호
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• pp.238-245
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• 2003

In this paper, a single Phase voltage source voltage-controlled active power filter(APF) for power quality improvement was proposed. The proposed APF has the performance of harmonic suppression and unity power factor correction. The performance of harmonic suppression can be obtained by controlling the waveshape of the APF output voltage to be sine wave. And, unity power factor is controlled by the reactive power control loop of the APF output. Simulation and experimental results using diode rectifier showed that the voltage-controlled APF, unlike the current-controlled APF, can reduce the voltage harmonics as well as current harmonics. Also the results showed that the input dover factor and power quality were greatly improved.