미상 레이더의 Wobble 및 Sinusoidal PRI 식별 알고리즘

이용식(Yongsik Lee),임중수(Joongsoo Lim),임재성(Jaesung Lim) 한국전자파학회 2015 한국전자파학회논문지 Vol.26 No.12

미상의 레이더에서 방사하는 전자파를 수신하여 신호를 처리한 후, 레이더의 변조방식을 식별하는 일은 전자전에서 매우 핵심 과제이다. 본 논문에서는 최근 전자전 보호능력이 우수한 Wobble PRI 방식과 Sinusoidal PRI 변조방식을 자동식별하는 알고리즘을 DTOA(Difference Time Of Arrival)을 적용하여 개발하였다. 안테나로 입력되는 레이더 펄스의 PRI를 산출하고, 산출된 PRI의 각 값으로부터 시간차의 특성을 산출하여 알고리즘을 개발하였다. 알고리즘을 프로그래밍한 후 각각 40개의 표본 PRI데이터를 입력하여 처리한 결과, 모두 정확히 PRI 변조방식을 식별하였다. 개발된 알고리즘은 향후 ESM장비 또는 ELINT 장비에 적용 가능할 것으로 판단한다. In this paper, we propose an algorithm to identify Wobble PRI and Sinusoidal PRI among Radar pulses. We applied not only the DTOA(Difference Time Of Arrival) concept of radar pulse signals incoming to antennas but also a rising and falling cub characteristic of those PRIs. After making a program by such algorithm, we input each 40 data to Wobble PRI"s and Sinusoidal PRI"s identification programs and in result, those programs fully processed the data the according to expectations. In the future, those programs can be applied to the ESM, ELINT system.

The effect of two temperatures on a FG nanobeam induced by a sinusoidal pulse heating

Zenkour, Ashraf M.,Abouelregal, Ahmed E. Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.51 No.2

The present investigation is concerned with the effect of two temperatures on functionally graded (FG) nanobeams subjected to sinusoidal pulse heating sources. Material properties of the nanobeam are assumed to be graded in the thickness direction according to a novel exponential distribution law in terms of the volume fractions of the metal and ceramic constituents. The upper surface of the FG nanobeam is fully ceramic whereas the lower surface is fully metal. The generalized two-temperature nonlocal theory of thermoelasticity in the context of Lord and Shulman's (LS) model is used to solve this problem. The governing equations are solved in the Laplace transformation domain. The inversion of the Laplace transformation is computed numerically using a method based on Fourier series expansion technique. Some comparisons have been shown to estimate the effects of the nonlocal parameter, the temperature discrepancy and the pulse width of the sinusoidal pulse. Additional results across the thickness of the nanobeam are presented graphically.

The effect of two temperatures on a FG nanobeam induced by a sinusoidal pulse heating

Ashraf M. Zenkour,Ahmed E. Abouelregal 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.51 No.2

The present investigation is concerned with the effect of two temperatures on functionally graded (FG) nanobeams subjected to sinusoidal pulse heating sources. Material properties of the nanobeam are assumed to be graded in the thickness direction according to a novel exponential distribution law in terms of the volume fractions of the metal and ceramic constituents. The upper surface of the FG nanobeam is fully ceramic whereas the lower surface is fully metal. The generalized two-temperature nonlocal theoryof thermoelasticity in the context of Lord and Shulman's (LS) model is used to solve this problem. The governing equations are solved in the Laplace transformation domain. The inversion of the Laplace transformation is computed numerically using a method based on Fourier series expansion technique. Somecomparisons have been shown to estimate the effects of the nonlocal parameter, the temperature discrepancy and the pulse width of the sinusoidal pulse. Additional results across the thickness of the nanobeam are presented graphically.

3레벨 4레그 PWM 컨버터의 커먼 모드 전압 저감

지승준(Seung-Jun Chee),고상기(Sanggi Ko),김현식(Hyeon-Sik Kim),설승기(Seung-Ki Sul) 전력전자학회 2014 전력전자학회 논문지 Vol.19 No.6

This paper presents a carrier-based pulse-width modulation(PWM) method for reducing the common-mode voltage of a three-level four-leg converter. The idea of the proposed PWM method is intuitive and easy to be implemented in digital signal processor-based converter control systems. On the basis of the analysis of space-vector PWM(SVPWM) and sinusoidal PWM(SPWM) switching patterns, the fourth leg pole voltage of the three-phase converter called “f leg pole voltage” is manipulated to reduce the common-mode voltage. To synthesize f leg pole voltage for the suppression of the common-mode voltage, positive and negative pole voltage references of f leg are calculated. An offset voltage is also deduced to prevent the distortion of a, b, and c phase voltages. The feasibility of the proposed PWM method is verified by simulation and experimental results. The common-mode voltage of the proposed PWM method in peak-to-peak value is 33% in comparison with that of the conventional SVPWM method. The transition number of the common-mode voltage is also reduced to 25%.

Comparison of different applied voltage waveforms on CO2 reforming of CH4 in an atmospheric plasma system

Duc Ba Nguyen,이원규 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.1

Sinusoidal and pulse waveforms of applied voltage were employed for CO2 reforming of CH4 to syngas inan atmospheric dielectric barrier discharge reactor. The discharge power of a pulse waveform was higher than that ofsinusoidal waveform at the same applied voltage. The plasma reaction by a pulse waveform enhanced the conversion ofCO2 and CH4 and the selectivity of H2 and CO. It was confirmed that CO2 reforming of CH4 can be improved by theadaption of pulse-type power supply in a dielectric barrier discharge reactor immersed in an electrically insulating oilbath.

A single‑phase, nine‑level switched‑capacitor‑based inverter

Desmond O. Obe,Chinedu T. Obe,Chikodili H. Ugwuishiwu,Pauline I. Obe,Agozie H. Eneh,Charles I. Odeh,Emeka S. Obe 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.5

The conventional topological approach to eliminate the multiple-input DC voltage requirement in multilevel inverter configurations for synthesizing high-output voltage levels is to deploy split capacitor banks at the input terminal. This method stipulates a less expensive, light weight, and reduced size inverter system. However, the excessive demand for several capacitor banks and the complex voltage balancing strategy associated with this conceptual approach poses numerous limitations in their deployment. In view of these drawbacks, this study proposes a self-balanced, single-phase, nine-level switched-capacitor-based inverter topology consisting of a single-input DC voltage, an auxiliary circuit, and an H-bridge circuit unit. A commensurate single carrier-based sinusoidal pulse-width modulation scheme is developed for the proposed power circuit control, enabling the synthesis of a nine-level output voltage waveform whose amplitude is four times the input voltage value. Detailed power circuit operations and switching functions are adequately provided in the proposed topology. A comparison between the proposed inverter and its recent counterparts in terms of component count, cost involvement, and output voltage-boosting ability is duly carried out using Python data visualization. Results reveal that the proposed inverter competes well in these three criteria. For varying R–L load values, the inverter has the capability of high active and reactive power delivery. Its dynamic response for step changes in the modulation index under these power-mode operations is presented in this paper. For high active power-mode operation, efficiencies of 98.27% and 98.92% under light- and heavy-load conditions, respectively, are obtained on a 3-kW-rated inverter prototype.

Decoupled SVPWM for Five-Phase Permanent Magnet Machines with Trapezoidal Back-EMF

Lin, Zhipeng,Liu, Guohai,Zhao, Wenxiang,Chen, Qian The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

This paper presents a novel space vector pulse-width modulation (SVPWM) to synthesize an arbitrary non-sinusoidal phase voltage. The key of the proposed method is that the switching vectors used to comprise the reference vectors in the ${\alpha}_1-{\beta}_1$ frame and the ${\alpha}_3-{\beta}_3$ frame are decoupled. In the ${\alpha}_1-{\beta}_1$ frame, the reference vector is comprised by near two large vectors. The corresponding vector comprised by the two vectors in the ${\alpha}_3-{\beta}_3$ frame is considered as a disturbance, which is restrained by close-loop control. In the ${\alpha}_3-{\beta}_3$ frame, there are two methods to comprise the reference vector. Method I is a near two middle vectors method. Method II uses near four vectors (two middle and two little vectors). The proposed SVPWM using decoupled switching vectors can guarantee a maximum modulation index in the ${\alpha}_1-{\beta}_1$ frame. The effectiveness of the proposed method is verified by simulated and experimental results under various operation conditions.

Decoupled SVPWM for Five-Phase Permanent Magnet Machines with Trapezoidal Back-EMF

Zhipeng Lin,Guohai Liu,Wenxiang Zhao,Qian Chen 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

This paper presents a novel space vector pulse-width modulation (SVPWM) to synthesize an arbitrary non-sinusoidal phase voltage. The key of the proposed method is that the switching vectors used to comprise the reference vectors in the α₁-β₁ frame and the α₃-β₃ frame are decoupled. In the α₁-β₁ frame, the reference vector is comprised by near two large vectors. The corresponding vector comprised by the two vectors in the α₃-β₃ frame is considered as a disturbance, which is restrained by close-loop control. In the α₃-β₃ frame, there are two methods to comprise the reference vector. Method I is a near two middle vectors method. Method II uses near four vectors (two middle and two little vectors). The proposed SVPWM using decoupled switching vectors can guarantee a maximum modulation index in the α₁-β₁ frame. The effectiveness of the proposed method is verified by simulated and experimental results under various operation conditions.

Sinusoidal, Pulse, Triangular Oscillator Using Second Generation Current Conveyor

Choi, Jin-Ho The Korea Institute of Information and Commucation 2010 Journal of information and communication convergen Vol.8 No.5

This paper describes the sinusoidal, pulse, triangular oscillator using second generation current conveyor. To obtain the sinusoidal waveform the circuit blocks are constructed by using all pass filter and integrator. The pulse and the triangular waveforms are obtained from the output of sinusoidal oscillator. The peak-to-peak voltages of sinusoidal and triangular waveforms can be easily controlled by the dc offset voltage. Also the output frequency of the oscillator can be controlled by varying passive elements. The designed circuit is verified by HSPICE simulation.

Current Control for an AFE Rectifier Using Space Vector PWM

Cheol-Hwan Jeon,Jae-Jung Hur,Kyoung-Kuk Yoon,Heui-Han Yoo,Sung-Hwan Kim 해양환경안전학회 2019 海洋環境安全學會誌 Vol.25 No.4

해양산업분야에서는 극심한 대기오염으로 인하여 전기추진선박에 대한 관심이 높아지고 있다. 이로 인해 선내 전력품질의 저하를 개선하기 위한 연구가 활발히 진행되고 있다. 기존 DFE 정류기의 입력전류 고조파 함유량을 완화시키기 위해 수동형필터, 노치필터, 능동형필터 등을 이용한 다양한 방법이 등장하였다. 그 중에서도 능동필터의 일종인 AFE(Active Front End) 정류장치가 우수한 기술로써 평가받고 있다. 본 논문에서는 공간벡터변조에 의한 AFE정류장치의 전류제어방식을 제안하였다. 기존의 히스테리시스 방식, 삼각파 변조 방식 및 공간벡터변조방식을 PSIM을 사용해 시뮬레이션을 수행하여 비교, 분석하였고, 그 결과 공간벡터변조방식이 구조가 간단하고 성능이 가장 우수함을 확인하였다. Electric propulsion ships are gaining widespread interest in the marine industry owing to extreme air pollution concerns. Consequently, several studies are actively being conducted for improving the power quality. Various methods have been developed that incorporate passive filters, notch filters, and active filters for reducing the harmonic content in the input current of a conventional diode front end rectifier. Among such filters, the active front end (AFE) rectifier is considered as an excellent technology. In this paper, current control for an AFE rectifier employing space vector PWM (Pulse Width Modulation) is proposed. Conventional current control methods for the AFE rectifier, hysteresis, SPWM (Sinusoidal Pulse Width Modulation), and SVPWM (Space Vector Pulse Width Modulation) were simulated by employing the PSIM software tool for analysis and comparisons. The results corroborate that SVPWM has the simplest structure and provides the best performance.