• 제목/요약/키워드: total harmonic distortion (THD)

검색결과 259건 처리시간 0.023초

Modified Finite Control Set-Model Predictive Controller (MFCS-MPC) for quasi Z-Source Inverters based on a Current Observer

  • Bakeer, Abualkasim;Ismeil, Mohamed A.;Orabi, Mohamed
    • Journal of Power Electronics
    • /
    • 제17권3호
    • /
    • pp.610-620
    • /
    • 2017
  • The Finite Control Set-Model Predictive Controller (FCS-MPC) for quasi Z-Source Inverters (qZSIs) is designed to reduce the number of sensors by proposing a current observer for the inductor current. Unlike the traditional FCS-MPC algorithm, the proposed model removes the inductor current sensor and observes the inductor current value based on the deposited prior optimized state as well as the capacitor voltage during this state. The proposed observer has been validated versus a typical MPC. Then, a comparative study between the proposed Modified Finite Control Set-Model Predictive Controller (MFCS-MPC) and a linear PID controller is provided under the same operating conditions. This study demonstrates that the dynamic response of the control objectives by MFCS-MPC is faster than that of the PID. On the other hand, the PID controller has a lower Total Harmonic Distortion (THD) when compared to the MFCS-MPC at the same average switching. Experimental results validate both methods using a DSP F28335.

단상 Three-level boost converter의 역률개선 (Power Factor Improvement of Single-Phase Three-level Boost Converter)

  • 서영조
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2000년도 전력전자학술대회 논문집
    • /
    • pp.384-387
    • /
    • 2000
  • In this paper Power factor correction circuit of single-phase three-level boost converter is proposed. The advantage of the proposed control scheme for three-level boost converter are low blocking voltage of each power device low THD(Total Harmonic Distortion) and high power factor. The control scheme is based on the current comparator capacitor compensator and region detector, In simulations the proposed system is validated.

  • PDF

불평형 전원전압 하에서 삼상 PWM 컨버터의 전류 보상 기법 (Current Compensation Method of a Three Phase PWM Converter under Unbalanced Source Voltages)

  • 박내춘;김상훈
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2012년도 추계학술대회 논문집
    • /
    • pp.109-110
    • /
    • 2012
  • 본 논문에서는 불평형 전원 전압 하에서 삼상 PWM 컨버터의 전류 보상 기법을 제안하였다. 전원 전압이 불평형인 경우 PLL(Phase Locked Loop)를 이용하여 추출한 위상각에는 왜곡 성분이 포함된다. 이러한 왜곡된 위상각으로 컨버터를 제어하는 경우 입력 전류에도 고조파가 포함되게 된다. 본 논문에서는 불평형 전원 전압 하에서도 입력 전류의 THD(Total Harmonic Distortion)를 IEEE Std. 519 규정인 5% 이내로 제한할 수 있도록 하는 전류 보상 기법을 제안하였다. 제안된 기법은 시뮬레이션을 통해 그 타당성을 검증하였다.

  • PDF

Comparative Analysis of LCL and LLCL Filters for Three-level PWM Converters

  • Alemi, Payam;Le, Quoc Anh;Lee, Dong-Choon
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2014년도 전력전자학술대회 논문집
    • /
    • pp.283-284
    • /
    • 2014
  • In this paper, a comparative analysis of LCL and LLCL filters connected to three-level T-type PWM converters is presented, in which the filter inductor sizes are investigated in view of total harmonic distortion (THD) in grid phase currents. The analysis results are verified by simulation and experiments.

  • PDF

2상 하이브리드 스테핑 모터의 벡터 제어 시 구동 장치에 따른 출력 성능 비교 분석 (Comparative Analysis of Output Performance According to Driving Circuits for Two-phase Hybrid Stepping Motors)

  • 정혜인;김상훈
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2020년도 전력전자학술대회
    • /
    • pp.437-438
    • /
    • 2020
  • 본 논문에서는 2상 하이브리드 스테핑 모터 구동을 위해 H-bridge 회로 또는 3상 인버터를 이용하는 경우의 출력 성능을 비교 검토하였다. 벡터 제어로 구동하는 경우 2상 하이브리드 스테핑 모터의 상전압, 상전류의 THD(Total Harmonic Distortion)과 출력 토크 리플을 분석하였으며, 이를 위해 Matlab/Simulink를 이용한 150W급 스테핑 모터의 시뮬레이션을 수행하였다.

  • PDF

A New Topology of Multilevel Voltage Source Inverter to Minimize the Number of Circuit Devices and Maximize the Number of Output Voltage Levels

  • Ajami, Ali;Mokhberdoran, Ataollah;Oskuee, Mohammad Reza Jannati
    • Journal of Electrical Engineering and Technology
    • /
    • 제8권6호
    • /
    • pp.1328-1336
    • /
    • 2013
  • Nowadays multilevel inverters are developing generally due to reduced voltage stress on power switches and low total harmonic distortion (THD) in output voltage. However, for increasing the output voltage levels the number of circuit devices are increased and it results in increasing the cost of converter. In this paper, a novel multilevel inverter is proposed. The suggested topology uses less number of power switches and related gate drive circuits to generate the same level in output voltage with comparison to traditional cascaded multilevel inverter. With the proposed topology all levels in output voltage can be realized. As an illustration, a symmetric 13-level and asymmetric 29-level proposed inverters have been simulated and implemented. The total peak inverse (PIV) and power losses of presented inverter are calculated and compared with conventional cascaded multilevel inverter. The presented analyses show that the power losses in the suggested multilevel inverter are less than the traditional inverters. Presented simulation and experimental results demonstrate the feasibility and applicability of the proposed inverter to obtain the maximum number of levels with less number of switches.

Comparative Analysis of Current Controls for Boost PFC Converter under Light Load

  • Juil Kim;Yeong-Jun Choi
    • 한국컴퓨터정보학회논문지
    • /
    • 제29권6호
    • /
    • pp.143-151
    • /
    • 2024
  • 본 논문은 부스트 PFC (Power Factor Correction) 컨버터의 경부하시, 컨버터의 인덕터 전류 왜곡을 수학적으로 분석하고 원인을 정의한다. 경부하시 평균 전류 모드제어에서 인덕터 전류가 불연속적으로 도통하게 되어 부정확한 인덕터 전류 평균값이 전류 제어에 반영된다. 예측 전류 모드제어에서는 인덕터 전류에 비해 전류 리플이 상대적으로 커져 전류 왜곡이 심해진다. 또한 모델 예측 전류제어의 경우 인덕터 전류의 첨두치 부근에서 스위치가 OFF된다. 인덕터 전류 왜곡은 total harmonic distortion 증가와 역률 감소를 유발하기 때문에 반드시 해결되어야 한다. 본 논문은 수학적 분석을 기반으로 부스트 PFC 컨버터의 경부하시 전류 왜곡을 완화할 수 있는 설계 절차를 선정한다. 마지막으로 hardware-in-the-loop simulation을 사용하여 경부하시 제어 방법들을 비교분석했다.

계통연계형 인버터의 왜곡된 계통전압에 의해 발생하는 전류고조파 저감방법 (Reduction Method of Harmonic Current by Distorted Grid Voltage in the Grid-connected Inverter)

  • 목형수;최규하;이정민;김상훈;지준근
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2007년도 추계학술대회 논문집
    • /
    • pp.108-111
    • /
    • 2007
  • Phase angle in grid-connected inverter is important information for current control. When different loads are connected to PCC(Point of Common Coupling) of grid, distorted grid voltage is taken place by load utility generating distorted current. Especially, in case the grid voltage is distorted by low order frequency such as $3^{rd}$, $5^{th}$ harmonic, phase angle of PLL output is distorted. This paper analyze problem of current THD(Total Harmonic Distortion) due to distorted phase angle by distorted grid voltage, and propose control method compensating this problem. Also, it‘s validity is verified by simulation and experiment.

  • PDF

비선형 부하의 고조파로 인한 배전계통의 영향 분석 (Analysis of Harmonic Effects due to Non-linear Load in Distribution Systems)

  • 이호림;김현수;여상민;김철환
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2009년도 제40회 하계학술대회
    • /
    • pp.2225_2226
    • /
    • 2009
  • An increasing of non-linear loads such as power electronic equipment in distribution systems is the reason for the greater concern about harmonics in recent time. A harmonic current and voltage in distribution systems can cause many problems such as malfunction of protective equipment. In this paper, Total Harmonic Distortion(THD) of voltage according to magnitudes and measurement locations of the non-linear loads was calculated and analyzed with Electro-Magnetic Transients Program(EMTP).

  • PDF

A Kalman Filter based Predictive Direct Power Control Scheme to Mitigate Source Voltage Distortions in PWM Rectifiers

  • Moon, Un-chul;Kim, Soo-eon;Chan, Roh;Kwak, Sangshin
    • Journal of Power Electronics
    • /
    • 제17권1호
    • /
    • pp.190-199
    • /
    • 2017
  • In this paper, a predictive direct power control (DPC) method based on a Kalman filter is presented for three-phase pulse-width modulation (PWM) rectifiers to improve the performance of rectifiers with source voltages that are distorted with harmonic components. This method can eliminate the most significant harmonic components of the source voltage using a Kalman filter algorithm. In the process of predicting the future real and reactive power to select an optimal voltage vector in the predictive DPC, the proposed method utilizes source voltages filtered by a Kalman filter, which can mitigate the adverse effects of distorted source voltages on control performance. As a result, the quality of the source currents synthesized using the PWM rectifier is improved, and the total harmonic distortion (THD) values are reduced, even under distorted source voltages.