Capacitive power transfer(CPT)technology is a newly emerging research focus for EV charging applications.Due to the absence of eddy current loss and light weight of the capacitive coupling metal plates,CPT technology ...Capacitive power transfer(CPT)technology is a newly emerging research focus for EV charging applications.Due to the absence of eddy current loss and light weight of the capacitive coupling metal plates,CPT technology is considered to be a promising alternative to the inductive power transfer(IPT)technology.In this paper,the recent designs of large-gap CPT systems designed for EV charging applications are summarized.And a graphical method based on Smith chart is proposed to analyze the characteristics of the compensation designs.With the design objectives graphically represented,the Smith chart can be used to visually analyze the performance of a compensation design,which could be helpful in multi-objectives design of the CPT system.The graphic features of three major design objectives on the Smith chart are investigated.Several guidelines of a good compensation design are concluded.展开更多
A machine learning model, using the transformer architecture, is used to design a feedback compensator and prefilter for various simulated plants. The output of the transformer is a sequence of compensator and prefilt...A machine learning model, using the transformer architecture, is used to design a feedback compensator and prefilter for various simulated plants. The output of the transformer is a sequence of compensator and prefilter parameters. The compensator and prefilter are linear models, preserving the ability to analyze the system with linear control theory. The input to the network is a window of recent reference and output samples. The goal of the transformer is to minimize tracking error at each time step. The plants under consideration range from simple to challenging. The more difficult plants contain closely spaced, lightly damped, complex conjugate pairs of poles and zeros. Results are compared to PID controllers tuned for a similar crossover frequency and optimal phase margin. For simple plants, the transformer converges to solutions which overly rely on the prefilter, neglecting the maximization of negative feedback. For more complex plants, the transformer designs a compensator and prefilter with more desirable qualities. In all cases, the transformer can start with random model parameters and modify them to minimize tracking error on the step reference.展开更多
Continuous phase plate（CPP）,which has a function of beam shaping in laser systems,is one kind of important diffractive optics.Based on the Fourier transform of the Gerchberg-Saxton（G-S） algorithm for designing CPP...Continuous phase plate（CPP）,which has a function of beam shaping in laser systems,is one kind of important diffractive optics.Based on the Fourier transform of the Gerchberg-Saxton（G-S） algorithm for designing CPP,we proposed an optical diffraction method according to the real system conditions.A thin lens can complete the Fourier transform of the input signal and the inverse propagation of light can be implemented in a program.Using both of the two functions can realize the iteration process to calculate the near-field distribution of light and the far-field repeatedly,which is similar to the G-S algorithm.The results show that using the optical diffraction method can design a CPP for a complicated laser system,and make the CPP have abilities of beam shaping and phase compensation for the phase aberration of the system.The method can improve the adaptation of the phase plate in systems with phase aberrations.展开更多
A visible laser-based vibration compensation interferometer has recently been designed for the EAST tokamak and the bench test has been finished.The system was optimized for its installation on EAST.The value of the f...A visible laser-based vibration compensation interferometer has recently been designed for the EAST tokamak and the bench test has been finished.The system was optimized for its installation on EAST.The value of the final optical power before the detectors without plasma has been calculated from the component bench test result,which is quite close to the measured value.A nanometer level displacement（of the order of the laser＇s wavelength） has been clearly measured by a modulation of piezoelectric ceramic unit,proving the system＇s capability.展开更多
An X-band inverse class-F power amplifier is realized by a 1-mm Al Ga N/Ga N high electron mobility transistor（HEMT）.The intrinsic and parasitic components inside the transistor,especially output capacitor Cds,influ...An X-band inverse class-F power amplifier is realized by a 1-mm Al Ga N/Ga N high electron mobility transistor（HEMT）.The intrinsic and parasitic components inside the transistor,especially output capacitor Cds,influence the harmonic impedance heavily at the X-band,so compensation design is used for meeting the harmonic condition of inverse class-F on the current source plane.Experiment results show that,in the continuous-wave mode,the power amplifier achieves 61.7% power added efficiency（PAE）,which is 16.3% higher than the class-AB power amplifier realized by the same kind of HEMT.To the best of our knowledge,this is the first inverse class-F Ga N internally-matched power amplifier,and the PAE is quite high at the X-band.展开更多
A novel microstructure fiber （MF） structure is proposed for broadband dispersion compensation. Through manipulating the four air-hole parameters and the pitch, the broad band dispersion compensation MF can be effici...A novel microstructure fiber （MF） structure is proposed for broadband dispersion compensation. Through manipulating the four air-hole parameters and the pitch, the broad band dispersion compensation MF can be efficiently designed. The newly designed MF could compensate （to within 0.8%） the dispersion of 101 times of its length of standard single mode fiber over the entire 100-nm band centered on 1550 nm. The proposed design has been simulated through the finite difference beam propagation method, and the corresponding design procedures are also presented. OCIS codes： 060.2310, 060.2280.展开更多
This paper presents a robust adaptive state feedback control scheme for a class of parametric-strict-feedback nonlinear systems in the presence of time varying actuator failures. The designed adaptive controller compe...This paper presents a robust adaptive state feedback control scheme for a class of parametric-strict-feedback nonlinear systems in the presence of time varying actuator failures. The designed adaptive controller compensates a general class of actuator failures without any need for explicit fault detection. The parameters, times, and patterns of the considered failures are completely unknown. The proposed controller is constructed based on a backstepping design method. The global boundedness of all the closed-loop signals is guaranteed and the tracking error is proved to converge to a small neighborhood of the origin. The proposed approach is employed for a two-axis positioning stage system as well as an aircraft wing system. The simulation results show the correctness and effectiveness of the proposed robust adaptive actuator failure compensation approach.展开更多
We show a useful analytical method to design grating compensated dispersion-managed systems. Our method is in good agreement with the numerical results even in the presence of group delay ripples in the chirped fiber ...We show a useful analytical method to design grating compensated dispersion-managed systems. Our method is in good agreement with the numerical results even in the presence of group delay ripples in the chirped fiber gratings.展开更多
基金This work was supported by National Natural Science Foundation of China(51507168)International Science&Technology Cooperation Program of China(2016YFE0102200)Beijing information science and technology university 2017'training plan"project.
文摘Capacitive power transfer(CPT)technology is a newly emerging research focus for EV charging applications.Due to the absence of eddy current loss and light weight of the capacitive coupling metal plates,CPT technology is considered to be a promising alternative to the inductive power transfer(IPT)technology.In this paper,the recent designs of large-gap CPT systems designed for EV charging applications are summarized.And a graphical method based on Smith chart is proposed to analyze the characteristics of the compensation designs.With the design objectives graphically represented,the Smith chart can be used to visually analyze the performance of a compensation design,which could be helpful in multi-objectives design of the CPT system.The graphic features of three major design objectives on the Smith chart are investigated.Several guidelines of a good compensation design are concluded.
文摘A machine learning model, using the transformer architecture, is used to design a feedback compensator and prefilter for various simulated plants. The output of the transformer is a sequence of compensator and prefilter parameters. The compensator and prefilter are linear models, preserving the ability to analyze the system with linear control theory. The input to the network is a window of recent reference and output samples. The goal of the transformer is to minimize tracking error at each time step. The plants under consideration range from simple to challenging. The more difficult plants contain closely spaced, lightly damped, complex conjugate pairs of poles and zeros. Results are compared to PID controllers tuned for a similar crossover frequency and optimal phase margin. For simple plants, the transformer converges to solutions which overly rely on the prefilter, neglecting the maximization of negative feedback. For more complex plants, the transformer designs a compensator and prefilter with more desirable qualities. In all cases, the transformer can start with random model parameters and modify them to minimize tracking error on the step reference.
文摘Continuous phase plate（CPP）,which has a function of beam shaping in laser systems,is one kind of important diffractive optics.Based on the Fourier transform of the Gerchberg-Saxton（G-S） algorithm for designing CPP,we proposed an optical diffraction method according to the real system conditions.A thin lens can complete the Fourier transform of the input signal and the inverse propagation of light can be implemented in a program.Using both of the two functions can realize the iteration process to calculate the near-field distribution of light and the far-field repeatedly,which is similar to the G-S algorithm.The results show that using the optical diffraction method can design a CPP for a complicated laser system,and make the CPP have abilities of beam shaping and phase compensation for the phase aberration of the system.The method can improve the adaptation of the phase plate in systems with phase aberrations.
基金supported by the National Magnetic Confinement Fusion Program of China(Nos.2014GB106002,2014GB106003,2014GB106004)National Natural Science Foundation of China(Nos.11105184,11375237,11505238)
文摘A visible laser-based vibration compensation interferometer has recently been designed for the EAST tokamak and the bench test has been finished.The system was optimized for its installation on EAST.The value of the final optical power before the detectors without plasma has been calculated from the component bench test result,which is quite close to the measured value.A nanometer level displacement（of the order of the laser＇s wavelength） has been clearly measured by a modulation of piezoelectric ceramic unit,proving the system＇s capability.
基金Project supported by the National High Technology Research and Development Program of China(Grant No.2015AA016801)
文摘An X-band inverse class-F power amplifier is realized by a 1-mm Al Ga N/Ga N high electron mobility transistor（HEMT）.The intrinsic and parasitic components inside the transistor,especially output capacitor Cds,influence the harmonic impedance heavily at the X-band,so compensation design is used for meeting the harmonic condition of inverse class-F on the current source plane.Experiment results show that,in the continuous-wave mode,the power amplifier achieves 61.7% power added efficiency（PAE）,which is 16.3% higher than the class-AB power amplifier realized by the same kind of HEMT.To the best of our knowledge,this is the first inverse class-F Ga N internally-matched power amplifier,and the PAE is quite high at the X-band.
基金This work was supported by the National Basic Research Program of China (No. 2003CB314900) the Key Grant Project of Chinese Ministry of Education (No. 104046)
文摘A novel microstructure fiber （MF） structure is proposed for broadband dispersion compensation. Through manipulating the four air-hole parameters and the pitch, the broad band dispersion compensation MF can be efficiently designed. The newly designed MF could compensate （to within 0.8%） the dispersion of 101 times of its length of standard single mode fiber over the entire 100-nm band centered on 1550 nm. The proposed design has been simulated through the finite difference beam propagation method, and the corresponding design procedures are also presented. OCIS codes： 060.2310, 060.2280.
基金supported by Esfahan Regional Electric Company(EREC)
文摘This paper presents a robust adaptive state feedback control scheme for a class of parametric-strict-feedback nonlinear systems in the presence of time varying actuator failures. The designed adaptive controller compensates a general class of actuator failures without any need for explicit fault detection. The parameters, times, and patterns of the considered failures are completely unknown. The proposed controller is constructed based on a backstepping design method. The global boundedness of all the closed-loop signals is guaranteed and the tracking error is proved to converge to a small neighborhood of the origin. The proposed approach is employed for a two-axis positioning stage system as well as an aircraft wing system. The simulation results show the correctness and effectiveness of the proposed robust adaptive actuator failure compensation approach.
文摘We show a useful analytical method to design grating compensated dispersion-managed systems. Our method is in good agreement with the numerical results even in the presence of group delay ripples in the chirped fiber gratings.
