Design and Application of a Single Phase Multilevel Inverter Suitable for using as a Voltage Harmonic Source

Ersoy Beser,Birol Arifoglu,Sabri Camur,Esra Kandemir Beser 전력전자학회 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.2

This paper presents a single phase multilevel inverter for using as a voltage harmonic source. First, a single phase multilevel inverter system is presented and the structural parts of the inverter are described. In order to obtain multilevel output voltage waveforms, a switching strategy based on calculating switching angles is explained and an improved formula for determining switching angles is given. Simulation and experimental results of multilevel voltage waveforms are given for 15, 31 and 127 levels. The proposed topology does not only produce output voltages with low THD values. It also produces the required harmonic components on the output voltage. For this purpose, equations for switching angles are constituted and the switching functions are obtained. These angles control the output voltage as well as provide the required specific harmonics. The proposed inverter structure is simulated for various functions with the required harmonic components. The THD values of the output voltage waves are calculated. The simulated functions are also realized by the proposed inverter structure. By using a harmonic analyzer, the harmonic spectrums, which belong to the output voltage forms, are found and the THD values are measured. Simulation and experimental results are given for the specific functions. The proposed topology produces perfectly suitable results for obtaining the specific harmonic components. Therefore, it is possible to use the structure as a voltage harmonic source in various applications.

Method Based on Sparse Signal Decomposition for Harmonic and Inter-harmonic Analysis of Power System

Chen, Lei,Zheng, Dezhong,Chen, Shuang,Han, Baoru The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

Harmonic/inter-harmonic detection and analysis is an important issue in power system signal processing. This paper proposes a fast algorithm based on matching pursuit (MP) sparse signal decomposition, which can be employed to extract the harmonic or inter-harmonic components of a distorted electric voltage/current signal. In the MP iterations, the method extracts harmonic/inter-harmonic components in order according to the spectrum peak. The Fast Fourier Transform (FFT) and nonlinear optimization techniques are used in the decomposition to realize fast and accurate estimation of the parameters. First, the frequency estimation value corresponding to the maxim spectrum peak in the present residual is obtained, and the phase corresponding to this frequency is searched in discrete sinusoids dictionary. Then the frequency and phase estimations are taken as initial values of the unknown parameters for Nelder-Mead to acquire the optimized parameters. Finally, the duration time of the disturbance is determined by comparing the inner products, and the amplitude is achieved according to the matching expression of the harmonic or inter-harmonic. Simulations and actual signal tests are performed to illustrate the effectiveness and feasibility of the proposed method.

Method Based on Sparse Signal Decomposition for Harmonic and Inter-harmonic Analysis of Power System

Lei Chen,Dezhong Zheng,Shuang Chen,Baoru Han 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

Harmonic/inter-harmonic detection and analysis is an important issue in power system signal processing. This paper proposes a fast algorithm based on matching pursuit (MP) sparse signal decomposition, which can be employed to extract the harmonic or inter-harmonic components of a distorted electric voltage/current signal. In the MP iterations, the method extracts harmonic/interharmonic components in order according to the spectrum peak. The Fast Fourier Transform (FFT) and nonlinear optimization techniques are used in the decomposition to realize fast and accurate estimation of the parameters. First, the frequency estimation value corresponding to the maxim spectrum peak in the present residual is obtained, and the phase corresponding to this frequency is searched in discrete sinusoids dictionary. Then the frequency and phase estimations are taken as initial values of the unknown parameters for Nelder-Mead to acquire the optimized parameters. Finally, the duration time of the disturbance is determined by comparing the inner products, and the amplitude is achieved according to the matching expression of the harmonic or inter-harmonic. Simulations and actual signal tests are performed to illustrate the effectiveness and feasibility of the proposed method.

Study of Harmonic Suppression of Ship Electric Propulsion Systems

Yifei Wang,Youxin Yuan,Jing Chen 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

This paper studies the harmonic characteristics of ship electric propulsion systems and their treatment methods. It also adopts effective measures to suppress and prevent ship power systems from affecting ship operation due to the serious damage caused by harmonics. Firstly, the harmonic characteristics of a ship electric propulsion system are reviewed and discussed. Secondly, aiming at problems such as resonant frequency and filter characteristics variations, resonance point migration, and unstable filtering performances in conventional passive filters, a method for fully tuning of a passive dynamic tunable filter (PDTF) is proposed to realize harmonic suppression. Thirdly, to address the problems of the uncontrollable inductance L of traditional air gap iron core reactors and the harmonics of power electronic impedance converters (PEICs), this paper proposes an electromagnetic coupling reactor with impedance transformation and harmonic suppression characteristics (ECRITHS), with the internal filter (IF) designed to suppress the harmonics generated by PEICs. The ECRITHS is characterized by both harmonic suppression and impedance change. Fourthly, the ECRITHS is investigated. This investigation includes the harmonic suppression characteristics and impedance transformation characteristics of the ECRITHS at the fundamental frequency, which shows the good performance of the ECRITHS. Simulation and experimental evaluations of the PDTF are carried out. Multiple PDTFs can be configured to realize multi-order simultaneous dynamic filtering, and can effectively eliminate the current harmonics of ship electric propulsion systems. This is done to reduce the total harmonic distortion (THD) of the supply currents to well below the 5% limit imposed by the IEEE-519 standard. The PDTF also can eliminate harmonic currents in different geographic places by using a low voltage distribution system. Finally, a detailed discussion is presented, with challenges and future implications discussed. The research results are intended to effectively eliminate the harmonics of ship electric power propulsion systems and to improve the power quality of ship power systems. This is of theoretical and practical significance for improving the power quality and power savings of ship power systems.

Study of Harmonic Suppression of Ship Electric Propulsion Systems

Wang, Yifei,Yuan, Youxin,Chen, Jing The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

This paper studies the harmonic characteristics of ship electric propulsion systems and their treatment methods. It also adopts effective measures to suppress and prevent ship power systems from affecting ship operation due to the serious damage caused by harmonics. Firstly, the harmonic characteristics of a ship electric propulsion system are reviewed and discussed. Secondly, aiming at problems such as resonant frequency and filter characteristics variations, resonance point migration, and unstable filtering performances in conventional passive filters, a method for fully tuning of a passive dynamic tunable filter (PDTF) is proposed to realize harmonic suppression. Thirdly, to address the problems of the uncontrollable inductance L of traditional air gap iron core reactors and the harmonics of power electronic impedance converters (PEICs), this paper proposes an electromagnetic coupling reactor with impedance transformation and harmonic suppression characteristics (ECRITHS), with the internal filter (IF) designed to suppress the harmonics generated by PEICs. The ECRITHS is characterized by both harmonic suppression and impedance change. Fourthly, the ECRITHS is investigated. This investigation includes the harmonic suppression characteristics and impedance transformation characteristics of the ECRITHS at the fundamental frequency, which shows the good performance of the ECRITHS. Simulation and experimental evaluations of the PDTF are carried out. Multiple PDTFs can be configured to realize multi-order simultaneous dynamic filtering, and can effectively eliminate the current harmonics of ship electric propulsion systems. This is done to reduce the total harmonic distortion (THD) of the supply currents to well below the 5% limit imposed by the IEEE-519 standard. The PDTF also can eliminate harmonic currents in different geographic places by using a low voltage distribution system. Finally, a detailed discussion is presented, with challenges and future implications discussed. The research results are intended to effectively eliminate the harmonics of ship electric power propulsion systems and to improve the power quality of ship power systems. This is of theoretical and practical significance for improving the power quality and power savings of ship power systems.

Design and Application of a Single Phase Multilevel Inverter Suitable for using as a Voltage Harmonic Source

Beser, Ersoy,Arifoglu, Birol,Camur, Sabri,Beser, Esra Kandemir The Korean Institute of Power Electronics 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.2

This paper presents a single phase multilevel inverter for using as a voltage harmonic source. First, a single phase multilevel inverter system is presented and the structural parts of the inverter are described. In order to obtain multilevel output voltage waveforms, a switching strategy based on calculating switching angles is explained and an improved formula for determining switching angles is given. Simulation and experimental results of multilevel voltage waveforms are given for 15, 31 and 127 levels. The proposed topology does not only produce output voltages with low THD values. It also produces the required harmonic components on the output voltage. For this purpose, equations for switching angles are constituted and the switching functions are obtained. These angles control the output voltage as well as provide the required specific harmonics. The proposed inverter structure is simulated for various functions with the required harmonic components. The THD values of the output voltage waves are calculated. The simulated functions are also realized by the proposed inverter structure. By using a harmonic analyzer, the harmonic spectrums, which belong to the output voltage forms, are found and the THD values are measured. Simulation and experimental results are given for the specific functions. The proposed topology produces perfectly suitable results for obtaining the specific harmonic components. Therefore, it is possible to use the structure as a voltage harmonic source in various applications.

교육용 건물의 GHP 냉/난방 부하의 고조파 특성에 관한 연구

김경철(Kyung-Chul Kim),오경훈(Kyung-Hoon Oh),이규진(Kyu-Jin Lee) 한국조명·전기설비학회 2009 조명·전기설비학회논문지 Vol.23 No.4

GHP(Gas Heating Pump) 시스템은 가스 엔진으로 구동되는 압축기로 구성되는 효율적인 냉/난방기이고, 학교나 사무용 빌딩에 널리 쓰이고 있다. GHP는 느린 응답, 큰 시정수와 시간에 따라 변하는 시스템으로 제어하기가 어렵다. 이들 비선형 부하는 고조파 전류를 발생시키고, 전력계통의 정현파 전압을 왜곡시킨다. 고조파 측정 결과로 고조파는 시간에 따라 변하는 특성이 관측되었다. 시간에 따라 변하는 고조파를 해결하기 위해서 쓰이는 가장 보편적인 방법은 누적확률을 사용하는 것이다. 본 논문에서는 GHP부하의 고조파 특성, IEC 61000-3-2에 의한 고조파 평가와 사례연구 시스템의 고조파 시뮬레이션 및 고조파 필터 적용을 심도있게 다루고자 하였다. The GHP(Gas Heat Pump) is an efficient cooling/heating system in which a compressor is driven by a gas engine and is brodening its application to the facilities such as schools and office buildings. It is difficult to control the GHP system because of slow response, big time constant and timevariant system. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probability approach is the most commonly used method to solve time varying harmonics. This paper provides an in depth analysis on harmonics field measurement of the GHP loads, harmonic assessment by IEC 61000-3-2, and harmonic simulation and harmonic filter application using EDSA program for the case study system.

저압 전기설비에서 고조파 양상의 분석에 관한 연구

노인곤 ( In Gon Ro ),황순구 ( Soon Gu Hwang ),우인성 ( In Sung Woo ),황명환 ( Myung Whan Hwang ) 한국안전학회(구 한국산업안전학회) 2013 한국안전학회지 Vol.28 No.8

This study, as a basic research on how to lower the harmonic current spreading to the power source system, presents the theoreticalanalysis of harmonics current generating at the source part of electric facility. For the analysis, the harmonics current influencing on thesource as well as its sub-parts was analyzed and the standards of harmonic current controll a few of developed countries were multiplechecked and investigated. Besides, to analyze the harmonic current appearing at the various power sources of electric facilities with poweranalyzer, 15 electricity accommodators and the wave-types according to the loading system were chosen and measured, respectively. Also,the harmonics current depending upon power-loading style was investigated after the level of harmonic current was rated. From the results, itwas checked that the total harmonic distortion (THD) lowers down to 9.3 percent due to the reduction of current harmonic by installing aseries reactor on the streetlamp and that the series reactor is effective for the reduction of current harmonic.

시간에 따라 변하는 전기로 부하의 고조파 측정, 평가 및 시뮬레이션에 관한 연구

김경철,진성은,이주홍,전영수,Kim, Kyung-Chul,Jin, Seong-Eun,Lee, Joo-Hong,Jeon, Young-Soo 한국조명전기설비학회 2006 조명·전기설비학회논문지 Vol.20 No.5

규모가 큰 제철소는 전기로와 같은 비선형 부하를 가지고 있다. 고조파 측정 결과로 고조파는 시간에 따라 변하는 특성이 관측되었다. 순시치 측정에 의한 고조파 평가는 측정 순간에 따라 고조파가 다를 수 있으므로 모호한 결과를 초래할 수 있다. 시간에 따라 변하는 고조파를 해결하기 위해 쓰이는 가장 보편적인 방법은 누적확률을 사용하는 것이다. 고조파 시뮬레이션은 사례연구 시스템의 전압 및 전류 왜곡을 평가하기 위해 이용되었다. 본 논문에서는 전기로 부하의 고조파 현장 측정, 국제 고조파 관리 기준인 IEC 61000-3-6과 IEEE Std. 519에 의한 고조파 평가, 시간에 따라 변하는 고조파의 시뮬레이션을 심도 있게 다루고자 한다. 고조파 해석 프로그램인 EDSA는 사례 연구에 시뮬레이션 도구로 사용되었다. Large steel industries have nonlinear loads such as electric arc furnaces. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. Direct application of the harmonic assessment to the snapshot measurements would result in ambiguous conclusions depending on which instant is sampled. A cumulative probablistic approach is the most commonly used method to solve time-varying harmonics. Harmonic simulations are performed to evaluate the harmonic voltage and current distortions throughout the system. This paper provides an in depth analysis on harmonics field measurement of the electric arc furnace loads, harmonics assessment by the international harmonic standards IEC 61000-3-6 and IEEE Std. 519 and harmonic simulation for the time-varying harmonics. The EDSA program was used as a simulation tool for the case study.

Optimal pulse pattern with negative pulses and third harmonic mixed injection

Qinqing Zhang,Wenxiang Song,Tianqing Shui,Hongzhang Lyu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.3

Adding negative pulses into a neutral-point clamped three-level inverter is an optimal pulse pattern (OPP) that can help restrain the neutral-point (NP) voltage fluctuation. However, this method can also cause the current harmonic distortion to be increased so that it becomes difficult to quantify the negative pulse width. Third harmonic injection can suppress neutralpoint potential fluctuation without increasing the switching frequency and it can also be automatically eliminated. Based on current harmonic minimization pulse width modulation (CHMPWM), a new optimal pulse pattern containing negative pulses and third harmonics is presented, which can inhibit NP voltage. Regarding the re-expression of the fundamental voltage expression, the optimal third harmonic content can be determined by constructing the analytical relationship between the fundamental voltage and the neutral-point current under the harmonic voltage. Combining this with a fitness function, sequence quadratic programming (SQP) is utilized to solve the new switching angles, which means that the CHMPWM is injected by negative pulses and third harmonics. Through simulations and experiments on a three-level inverter with a resistance-inductance load, it is verified that the proposed method can effectively suppress the voltage fluctuation at the neutral-point of the DC bus while taking the current harmonic distortion rate into account.