Active damping(AD)strategy is an economical and efficient method to solve the resonant problem of the permanent magnet synchronous motor(PMSM)drive system with inductor-capacitor(LC)sine wave filter.In this article,th...Active damping(AD)strategy is an economical and efficient method to solve the resonant problem of the permanent magnet synchronous motor(PMSM)drive system with inductor-capacitor(LC)sine wave filter.In this article,the AD methods used in PMSM drive system are classified as inherent damping(ID),state variable feedback,and digital filter.Based on this,the purpose of this article is to provide an overview and analysis of the AD methods on PMSM drive system in recent years,and to comprehensively review,compare,and summarize the stability,dynamic performance,robustness,and algorithm complexity.Furthermore,a new expansion of AD method based on capacitor current feedback with high-pass filter(HPF-CCF)is studied to ensure the effectiveness when the resonant frequency is around sixth of the sampling frequency.The simulation and experimental results validate the effectiveness of theoretical analysis.展开更多
Sinusoid curve fit is a very useful method in precise measurement, based on the modeling measurement. There are many valuable uses. But, what′s the specifications of the sinusoid curve fit software, and how to eval...Sinusoid curve fit is a very useful method in precise measurement, based on the modeling measurement. There are many valuable uses. But, what′s the specifications of the sinusoid curve fit software, and how to evaluate the uncertainty of it are still unknown yet, because they involve manifold factors and are complicated. Every one using the sinusoid curve fit software wants to know it. In this paper, the basic process and the uses of sinusoid curve fit are described, and some specifications and evaluation methods are introduced. One evaluation example of sinusoid curve fit software is discussed, the results and the specification are good.展开更多
A watt-class backward wave oscillator is proposed, using the concise sine waveguide slow-wave structure combined with a pencil electron beam to operate at 220 GHz. Firstly, the dispersion curve of the sine waveguide i...A watt-class backward wave oscillator is proposed, using the concise sine waveguide slow-wave structure combined with a pencil electron beam to operate at 220 GHz. Firstly, the dispersion curve of the sine waveguide is calculated, then, the oscillation frequency and operating voltage of the device are predicted and the circuit transmission loss is calculated. Finally, the particle-in-cell simulation method is used to forecast its radiation performance. The results show that this novel backward wave oscillator can produce over 1-W continuous wave power output in a frequency range from 210 GHz to 230 GHz. Therefore, it will be considered as a very promising high-power millimeter-wave to terahertz-wave radiation source.展开更多
GHz single-photon detector(SPD)is a crucial part in the practical high speed quantum key distribution(QKD)system.However,any imperfections in a practical QKD system may be exploited by an eavesdropper(Eve)to collect i...GHz single-photon detector(SPD)is a crucial part in the practical high speed quantum key distribution(QKD)system.However,any imperfections in a practical QKD system may be exploited by an eavesdropper(Eve)to collect information about the key without being discovered.The sine wave gating SPD(SG-SPD)based on InGaAs/InP avalanche photodiode,one kind of practical high speed SPD,may also contain loopholes.In this paper,we study the principle and characteristic of the SG-SPD and find out the filtering loophole of the SG-SPD for the first time.What is more,the proof-of-principle experiment shows that Eve could blind and control Bob's SG-SPD by exploiting this loophole.We believe that giving enough attention to this loophole can improve the practical security of the existing QKD system.GHz single-photon detector(SPD)is a crucial part in the practical high speed quantum key distribution(QKD)system.However,any imperfections in a practical QKD system may be exploited by an eavesdropper(Eve)to collect information about the key without being discovered.The sine wave gating SPD(SG-SPD)based on InGaAs/InP avalanche photodiode,one kind of practical high speed SPD,may also contain loopholes.In this paper,we study the principle and characteristic of the SG-SPD and find out the filtering loophole of the SG-SPD for the first time.What is more,the proof-of-principle experiment shows that Eve could blind and control Bob's SG-SPD by exploiting this loophole.We believe that giving enough attention to this loophole can improve the practical security of the existing QKD system.展开更多
The new three phase VFVA sine wave generator is presented in this paper. A new sampling holding three phase VFVA sine wave generator’s principle, circuit and experimentation waveform are introduced. The principle of ...The new three phase VFVA sine wave generator is presented in this paper. A new sampling holding three phase VFVA sine wave generator’s principle, circuit and experimentation waveform are introduced. The principle of this sampling holding circuit is simple and the realization of har’dware circuit is easy. Here we describe the three phase reference sine wave which is produced by this generator’s circuit and is required by PWM inverter is described in this paper, and also introduced the speed control and harmonir analysis of PWM inverter variable frequency.展开更多
Methods The method of longitudinal injection to an ultra-low emittance storage ring by a sine wave kicker is investigated in this paper.Beam dynamics of the injected and stored beams are both studied.With a third-harm...Methods The method of longitudinal injection to an ultra-low emittance storage ring by a sine wave kicker is investigated in this paper.Beam dynamics of the injected and stored beams are both studied.With a third-harmonic kicker,the emittance and the orbit of the stored beam can be well preserved and the injection efficiency can reach 100%.展开更多
Target detection is one of the key technology of precision chemical application.Previously the digital coding modulation technique was commonly used to emit and receive the optical signal in the target detection syste...Target detection is one of the key technology of precision chemical application.Previously the digital coding modulation technique was commonly used to emit and receive the optical signal in the target detection systems previously in China.It was difficult to adjust the output power,and the anti-interference ability was weak in these systems.In order to resolve these problems,the target detection method based on analog sine-wave modulation was studied.The spectral detecting system was set up in the aspects of working principle,electric circuit,and optical path.Lab testing was performed.The results showed that the reflected signal from the target varied inversely with detection distances.It indicated that it was feasible to establish the target detection system using analog sine-wave modulation technology.Furthermore,quantitative measurement of the reflected optical signal for near-infrared and visible light could be achieved by using this system.The research laid the foundation for the future development of the corresponding instrument.展开更多
A unique high efficiency photovoltaic(PV)system is presented. It uses partial sine wave tracking for a pulse-width modulation(PWM) boost converter as well as a full-bridge inverter. The boost converter and full-bridge...A unique high efficiency photovoltaic(PV)system is presented. It uses partial sine wave tracking for a pulse-width modulation(PWM) boost converter as well as a full-bridge inverter. The boost converter and full-bridge inverter are connected via a compact intermediate film capacitor(i.e. non-smoothing DC link stage). PWM switching is activated by a dual mode control technique. In the proposed topology, simultaneous switching of both power conversion stages is avoided and therefore this increases the power conversion efficiency. The distinctive operating principles of these two power processing stages are discussed and analyzed with the experimental results for single-phase loading of the PV system.展开更多
Exact solutions with three-wave form including three solitary wave, breather-type two-solitary wave, doubly breather-type of solitary wave, double-periodic kind of solitary wave are obtained using bilinear form and ex...Exact solutions with three-wave form including three solitary wave, breather-type two-solitary wave, doubly breather-type of solitary wave, double-periodic kind of solitary wave are obtained using bilinear form and extended threewave approach with the aid of Maple. It is important that completed elastic collision, non-completed elastic collision,and fusion of three waves are investigated, respectively.展开更多
By using the function transformation and proper Sub-ODE, exact travelling wave solutions of the m-KdV-Sine-Gordon and the m-KdV-Sinh-Gordon equation are obtained, from which exact travelling wave solutions of the m-Kd...By using the function transformation and proper Sub-ODE, exact travelling wave solutions of the m-KdV-Sine-Gordon and the m-KdV-Sinh-Gordon equation are obtained, from which exact travelling wave solutions of the m-KdV equation, the Sine-Gordon equation and the Sinh-Gordon equation are derived.展开更多
基金supported in part by the National Natural Science Foundational of China under Grants 62373363 and 52007190
文摘Active damping(AD)strategy is an economical and efficient method to solve the resonant problem of the permanent magnet synchronous motor(PMSM)drive system with inductor-capacitor(LC)sine wave filter.In this article,the AD methods used in PMSM drive system are classified as inherent damping(ID),state variable feedback,and digital filter.Based on this,the purpose of this article is to provide an overview and analysis of the AD methods on PMSM drive system in recent years,and to comprehensively review,compare,and summarize the stability,dynamic performance,robustness,and algorithm complexity.Furthermore,a new expansion of AD method based on capacitor current feedback with high-pass filter(HPF-CCF)is studied to ensure the effectiveness when the resonant frequency is around sixth of the sampling frequency.The simulation and experimental results validate the effectiveness of theoretical analysis.
文摘Sinusoid curve fit is a very useful method in precise measurement, based on the modeling measurement. There are many valuable uses. But, what′s the specifications of the sinusoid curve fit software, and how to evaluate the uncertainty of it are still unknown yet, because they involve manifold factors and are complicated. Every one using the sinusoid curve fit software wants to know it. In this paper, the basic process and the uses of sinusoid curve fit are described, and some specifications and evaluation methods are introduced. One evaluation example of sinusoid curve fit software is discussed, the results and the specification are good.
基金Project supported by the National Natural Science Foundation for Distinguished Young Scholars of China (Grant No. 61125103)the National Natural Science Foundation of China (Grant Nos. 60971038 and 60971031)the Fundamental Research Funds for the Central Universities,China (Grant No. ZYGX2009Z003)
文摘A watt-class backward wave oscillator is proposed, using the concise sine waveguide slow-wave structure combined with a pencil electron beam to operate at 220 GHz. Firstly, the dispersion curve of the sine waveguide is calculated, then, the oscillation frequency and operating voltage of the device are predicted and the circuit transmission loss is calculated. Finally, the particle-in-cell simulation method is used to forecast its radiation performance. The results show that this novel backward wave oscillator can produce over 1-W continuous wave power output in a frequency range from 210 GHz to 230 GHz. Therefore, it will be considered as a very promising high-power millimeter-wave to terahertz-wave radiation source.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61605248 and 61505261)
文摘GHz single-photon detector(SPD)is a crucial part in the practical high speed quantum key distribution(QKD)system.However,any imperfections in a practical QKD system may be exploited by an eavesdropper(Eve)to collect information about the key without being discovered.The sine wave gating SPD(SG-SPD)based on InGaAs/InP avalanche photodiode,one kind of practical high speed SPD,may also contain loopholes.In this paper,we study the principle and characteristic of the SG-SPD and find out the filtering loophole of the SG-SPD for the first time.What is more,the proof-of-principle experiment shows that Eve could blind and control Bob's SG-SPD by exploiting this loophole.We believe that giving enough attention to this loophole can improve the practical security of the existing QKD system.GHz single-photon detector(SPD)is a crucial part in the practical high speed quantum key distribution(QKD)system.However,any imperfections in a practical QKD system may be exploited by an eavesdropper(Eve)to collect information about the key without being discovered.The sine wave gating SPD(SG-SPD)based on InGaAs/InP avalanche photodiode,one kind of practical high speed SPD,may also contain loopholes.In this paper,we study the principle and characteristic of the SG-SPD and find out the filtering loophole of the SG-SPD for the first time.What is more,the proof-of-principle experiment shows that Eve could blind and control Bob's SG-SPD by exploiting this loophole.We believe that giving enough attention to this loophole can improve the practical security of the existing QKD system.
文摘The new three phase VFVA sine wave generator is presented in this paper. A new sampling holding three phase VFVA sine wave generator’s principle, circuit and experimentation waveform are introduced. The principle of this sampling holding circuit is simple and the realization of har’dware circuit is easy. Here we describe the three phase reference sine wave which is produced by this generator’s circuit and is required by PWM inverter is described in this paper, and also introduced the speed control and harmonir analysis of PWM inverter variable frequency.
基金This work was supported by National Key Research and Development Program of China(2016YFA0402001).
文摘Methods The method of longitudinal injection to an ultra-low emittance storage ring by a sine wave kicker is investigated in this paper.Beam dynamics of the injected and stored beams are both studied.With a third-harmonic kicker,the emittance and the orbit of the stored beam can be well preserved and the injection efficiency can reach 100%.
基金Supported by the National“863”Project of China(2010AA10A301)National Technology Support Project for the 12th Five-year Plan(2011BAD20B07)
文摘Target detection is one of the key technology of precision chemical application.Previously the digital coding modulation technique was commonly used to emit and receive the optical signal in the target detection systems previously in China.It was difficult to adjust the output power,and the anti-interference ability was weak in these systems.In order to resolve these problems,the target detection method based on analog sine-wave modulation was studied.The spectral detecting system was set up in the aspects of working principle,electric circuit,and optical path.Lab testing was performed.The results showed that the reflected signal from the target varied inversely with detection distances.It indicated that it was feasible to establish the target detection system using analog sine-wave modulation technology.Furthermore,quantitative measurement of the reflected optical signal for near-infrared and visible light could be achieved by using this system.The research laid the foundation for the future development of the corresponding instrument.
文摘A unique high efficiency photovoltaic(PV)system is presented. It uses partial sine wave tracking for a pulse-width modulation(PWM) boost converter as well as a full-bridge inverter. The boost converter and full-bridge inverter are connected via a compact intermediate film capacitor(i.e. non-smoothing DC link stage). PWM switching is activated by a dual mode control technique. In the proposed topology, simultaneous switching of both power conversion stages is avoided and therefore this increases the power conversion efficiency. The distinctive operating principles of these two power processing stages are discussed and analyzed with the experimental results for single-phase loading of the PV system.
基金Supported by National Natural Science Foundation of China under Grant No.11361048Sichuan Educational Science Foundation under Grant No.12ZB069
文摘Exact solutions with three-wave form including three solitary wave, breather-type two-solitary wave, doubly breather-type of solitary wave, double-periodic kind of solitary wave are obtained using bilinear form and extended threewave approach with the aid of Maple. It is important that completed elastic collision, non-completed elastic collision,and fusion of three waves are investigated, respectively.
基金Supported by the National Science Foundation of Education Department of Henan Province（2011B110013）
Acknowledgement The authors would like to express their sincere thanks to Professor Wang Mingliang for his enthusiastic help and encouragement.
文摘By using the function transformation and proper Sub-ODE, exact travelling wave solutions of the m-KdV-Sine-Gordon and the m-KdV-Sinh-Gordon equation are obtained, from which exact travelling wave solutions of the m-KdV equation, the Sine-Gordon equation and the Sinh-Gordon equation are derived.
