• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2002년도 추계학술대회 논문집
• /
• pp.199-202
• /
• 2002

This paper suggests the control algorithm of a 3-phase 3-wire series active power filters which have harmonic voltage source and harmonic current source This suggested control algorithm can compensate harmonics which are generated by nonlinear load such as diode or thyristor converter and reactive power in 3-phase 3-wire power distribution system This control algorithm extracts a compensation voltage reference from performance function without phase transformation Therefore this control algorithm is simpler than any other conventional control algorithm. 3-phase 3-wire series active power filter and hybrid active power filter is manufactured and experiments are carried out for harmonic voltage source and harmonic current source to verify the effectiveness of presented control algorithm Experimental results are presented in this Paper, as well.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제55권8호
• /
• pp.430-435
• /
• 2006

This paper presents a method about the efficiency analysis and the harmonic reduction of single phase NPC multi-level inverter with LC-trap filter and LCR output filter. The proposed LC-trap filter is comprised of a conventional LC output filter, by using LC-trap filter the need for high damping resistor and low LC cut-off frequency is eliminated. Also, low damping resistor is increased the efficiency of the output filter. Experimental verification of the proposed circuit is provided with single phase NPC multilevel inverter system and DSP controller.

• Journal of Power Electronics
• /
• 제18권5호
• /
• pp.1513-1522
• /
• 2018

This paper proposes a new islanding detection method for inverter-based distributed generators by continuously injecting a negligible amount of 2nd order harmonic current. The proposed method adopts a proportional resonant (PR) controller for the output current control of the inverter, and a PR filter to extract the 2nd order harmonic voltage at the point of common coupling (PCC). The islanding state can be detected by measuring the magnitude ratio of the 2nd order harmonic voltage to the fundamental voltage at the PCC by injecting a 2nd order harmonic current with a 0.8% magnitude. The proposed method provides accurate and fast detection under grid voltage unbalance and load unbalance. The operation of the proposed method has been verified through simulations and experiments with a 5kW hardware set-up, considering the islanding test circuit suggested in UL1741.

• Journal of Power Electronics
• /
• 제17권6호
• /
• pp.1637-1649
• /
• 2017

This paper describes an intensive analysis of a harmonic identification algorithm in non-ideal voltages source systems. The dq-axis Fourier with a positive sequence voltage detector (DQFP) is a novel harmonic identification algorithm for active power filters. A compensating current control system based on repetitive control is presented. A design and stability analysis of the proposed current control are also given. The aim of the paper is to achieve a robustness of the harmonic identification in a distorted and unbalanced voltage source. The proposed ideas are supported by a hardware in the loop technique based on a $eZdsp^{TM}$ F28335 and the Simulink program. The obtained results are presented to demonstrate the performance of the harmonic identification and the control strategy for the active power filter in non-ideal systems.

• 전기학회논문지P
• /
• 제62권1호
• /
• pp.12-17
• /
• 2013

Fault currents are expressed as a combination of harmonic components and exponentially decaying DC offset components, during the occurrence of fault in power system. The DC offset components are included, when the voltage phase angle of fault inception is closer to $0^{\circ}$ or $180^{\circ}$. The digital protection relay should be detected quickly and accurately during the faults, despite of the distortions of relaying signal by these components. It is very important to implement the robust protection algorithm, that is not affected by DC offset and harmonic components, because most relaying algorithms extract the fundamental frequency component from distorted relaying signal. So, In order to high performance in relaying, advanced DC offset removal filter is required. In this paper, a new DC offset removal filter, which is no need to preset a time constant of power system and accurately estimate the DC offset components with one cycle of data, is proposed, and compared with the other filter. In order to verify performance of the filter, we used collecting the current signals after synchronous machine modeling by ATPDraw5.7p4 software. The results of simulation, the proposed DC offset removal filter do not need any prior information, the phase delay and gain error were not occurred.

• 조명전기설비학회논문지
• /
• 제19권1호
• /
• pp.87-93
• /
• 2005

본 논문에서는 측정${\cdot}$분석을 수행한 인천국제공항 여객터미널의 전력계통에 고조파 저감을 위한 고조파필터를 설계하여 이를 적용하였다. 특히 고조파를 다량 발생시키는 기기들에 대하여 향후 대표스펙트럼 선정을 위하여 고조파 측정을 수행하였다. 또한 EDSA를 사용하여 Simulation을 수행하여 수동필터의 고조파 저감효과를 분석하였으며, 또한 APF(Active Power Filter)와 ZSF(Zero Sequence Filter)의 설계를 수행하였다.

• 전력전자학회논문지
• /
• 제11권4호
• /
• pp.313-320
• /
• 2006

본 논문에서는 단상 NPC 멀티레벨 인버터의 출력단 고조파 저감을 위한 LC 트랩 필터의 설계 방법을 제시하였고, 출력전압 THD와 출력전류 고조파 FFT 분석을 수행하였다. 제시된 LC 트랩 필터는 일반적인 LCR 필터와 종속 접속된 구조를 가지며, 스위칭 주파수에 동조되었다. 인버터 시스템은 고전력 응용에 적합한 NPC 멀티레벨 인버터를 사용하였으며, 제어기는 DSP(TMS320C31)을 사용하여 구성하였다. 제안된 시스템의 효용성은 시뮬레이션과 실험 결과를 통하여 증명하였다.

• 제어로봇시스템학회논문지
• /
• 제16권9호
• /
• pp.872-875
• /
• 2010

This paper describes new harmonic disturbance compensation based on a peak filter array for Hard Disk Drives. Unlike a conventional method, the proposed method does not require any sin/cos functions or tables and reduces effects of all harmonic disturbances within a nyquist frequency. Two factors are introduced to parameterize stability and a gain tune. In addition, it is verified that the order of the proposed filter is minimal. From 600 experimental results, 8.5% performance improvement is achieved.

• Journal of electromagnetic engineering and science
• /
• 제5권4호
• /
• pp.208-212
• /
• 2005

In this paper, we introduced a band-pass filter employed the PBG structure and the aperture on the ground together. The harmonics of band pass filter have been suppressed by employing the PBG structure and the bandwidth of it has been broadened by using the aperture on the ground. The designed PBG cells have three different sizes. The largest cells, the middle cells, and the smallest cells have suppressed the multiple of second harmonics, the multiple of third harmonics, and the multiple of fifth harmonics, respectively. The center frequency has been 2.18 GHz. The bandwidth has been increased from 230 MHz up to 310 MHz(80 MHz, about $35\%$) by the aperture and the ripple characteristics in passband have been improved and the harmonic frequencies have been suppressed about 30 dB by the PBG.

• Journal of Power Electronics
• /
• 제15권6호
• /
• pp.1619-1627
• /
• 2015

This paper presents a power system harmonic elimination using the mixed adaptive linear neural network and variable step-size leaky least mean square (ADALINE-VSSLLMS) control algorithm based active power filter (APF). The weight vector of ADALINE along with the variable step-size parameter and leakage coefficient of the VSSLLMS algorithm are automatically adjusted to eliminate harmonics from the distorted load current. For all iteration, the VSSLLMS algorithm selects a new rate of convergence for searching and runs the computations. The adopted shunt-hybrid APF (SHAPF) consists of an APF and a series of 7^th tuned passive filter connected to each phase. The performance of the proposed ADALINE-VSSLLMS control algorithm employed for SHAPF is analyzed through a simulation in a MATLAB/Simulink environment. Experimental results of a real-time prototype validate the efficacy of the proposed control algorithm.