A novel approach for improving the spectral performance of sinusoidal Pulse Width Modulation (SPWM) inverter is presented. By varying the carrier frequency according to chaotic time-sequence, the discrete spectrum of ...A novel approach for improving the spectral performance of sinusoidal Pulse Width Modulation (SPWM) inverter is presented. By varying the carrier frequency according to chaotic time-sequence, the discrete spectrum of the output voltage is transformed into the continuous spectrum, which could reduce the acoustic noise concentrated at specific tones in an inverter-driven electric machine. Fourier analysis shows that the harmonic at the fixed frequency has been restrained effectively and the distribution of the spectrum is in a wider range. Besides, a novel variable is introduced for the evaluation of the output voltage spectrum in SPWM inverter. Simulations and experiments with DSP confirm the advantages of the novel approach. Experimental results show the annoying acoustic noise has been translated into some enjoyable sound like a fall or water flowing when this novel method is applied.展开更多
Based on the concepts of objective fact and subjective desire proposed in this paper, the problems that exist in the nodal injections-based and transaction-based transmission service allocation scheme are pointed out....Based on the concepts of objective fact and subjective desire proposed in this paper, the problems that exist in the nodal injections-based and transaction-based transmission service allocation scheme are pointed out. To get around the problems above, a novel transmission service allocation scheme is proposed which considers the power flow distribution and the transaction impact on the system simultaneously so that the issues of “Cross-subsidies” and “Counter flow” can be avoided. The principle of the scheme is illustrated using two simple networks with 7 cases. The results show that the proposed scheme can satisfy the properties necessary for the development and growth of the electricity market.展开更多
This paper proposes a gain scheduled control method for a doubly fed induction generator driven by a wind turbine. The purpose is to design a variable speed control system so as to extract the maximum power in the reg...This paper proposes a gain scheduled control method for a doubly fed induction generator driven by a wind turbine. The purpose is to design a variable speed control system so as to extract the maximum power in the region below the rated wind speed. Gain scheduled control approach is applied in order to achieve high performance over a wide range of wind speed. A double loop configuration is adopted. In the inner loop, the rotor speed is used as the scheduling parameter, while a function of wind and rotor speed is used as the scheduling parameter in the outer loop. It is verified in simulations that a high tracking performance has been achieved.展开更多
A noncontact user interface using image processing for people with neuromuscular diseases is presented in this paper. The user interface is composed of a Web camera and a PC, and allows users to manipulate the PC usin...A noncontact user interface using image processing for people with neuromuscular diseases is presented in this paper. The user interface is composed of a Web camera and a PC, and allows users to manipulate the PC using small movements of single finger. By using image processing techniques with the Web camera, the finger is appropriately detected from the images captured by it. Control boxes for pointing and text input functions are also made. To verify performances of the interface, some tasks are experimentally performed by three able-bodied subjects and a person suffering from spinal muscular atrophy. It was clear from the experimental results that all the subjects could smoothly nerforrn the t,~k~展开更多
This paper provides a first indication that this is true for a system comprised of a static structure described by hyperbolic partial differential equations and is subjected to an external random input force. The syst...This paper provides a first indication that this is true for a system comprised of a static structure described by hyperbolic partial differential equations and is subjected to an external random input force. The system deforms the randomness of an input force sequence in proportion to its algorithmic complexity. The authors demonstrate this by numerical analysis of a one-dimensional vibrating elastic solid （the system） on which we apply a maximally-random force sequence （input）. The level of complexity of the system is controlled via external parameters. The output response is the field of displacements observed at several positions on the body. The algorithmic complexity and stochasticity of the resulting output displacement sequence is measured and compared against the complexity of the system. The results show that the higher the system complexity, the more random-deficient the output sequence.展开更多
文摘A novel approach for improving the spectral performance of sinusoidal Pulse Width Modulation (SPWM) inverter is presented. By varying the carrier frequency according to chaotic time-sequence, the discrete spectrum of the output voltage is transformed into the continuous spectrum, which could reduce the acoustic noise concentrated at specific tones in an inverter-driven electric machine. Fourier analysis shows that the harmonic at the fixed frequency has been restrained effectively and the distribution of the spectrum is in a wider range. Besides, a novel variable is introduced for the evaluation of the output voltage spectrum in SPWM inverter. Simulations and experiments with DSP confirm the advantages of the novel approach. Experimental results show the annoying acoustic noise has been translated into some enjoyable sound like a fall or water flowing when this novel method is applied.
文摘Based on the concepts of objective fact and subjective desire proposed in this paper, the problems that exist in the nodal injections-based and transaction-based transmission service allocation scheme are pointed out. To get around the problems above, a novel transmission service allocation scheme is proposed which considers the power flow distribution and the transaction impact on the system simultaneously so that the issues of “Cross-subsidies” and “Counter flow” can be avoided. The principle of the scheme is illustrated using two simple networks with 7 cases. The results show that the proposed scheme can satisfy the properties necessary for the development and growth of the electricity market.
文摘This paper proposes a gain scheduled control method for a doubly fed induction generator driven by a wind turbine. The purpose is to design a variable speed control system so as to extract the maximum power in the region below the rated wind speed. Gain scheduled control approach is applied in order to achieve high performance over a wide range of wind speed. A double loop configuration is adopted. In the inner loop, the rotor speed is used as the scheduling parameter, while a function of wind and rotor speed is used as the scheduling parameter in the outer loop. It is verified in simulations that a high tracking performance has been achieved.
文摘A noncontact user interface using image processing for people with neuromuscular diseases is presented in this paper. The user interface is composed of a Web camera and a PC, and allows users to manipulate the PC using small movements of single finger. By using image processing techniques with the Web camera, the finger is appropriately detected from the images captured by it. Control boxes for pointing and text input functions are also made. To verify performances of the interface, some tasks are experimentally performed by three able-bodied subjects and a person suffering from spinal muscular atrophy. It was clear from the experimental results that all the subjects could smoothly nerforrn the t,~k~
文摘This paper provides a first indication that this is true for a system comprised of a static structure described by hyperbolic partial differential equations and is subjected to an external random input force. The system deforms the randomness of an input force sequence in proportion to its algorithmic complexity. The authors demonstrate this by numerical analysis of a one-dimensional vibrating elastic solid （the system） on which we apply a maximally-random force sequence （input）. The level of complexity of the system is controlled via external parameters. The output response is the field of displacements observed at several positions on the body. The algorithmic complexity and stochasticity of the resulting output displacement sequence is measured and compared against the complexity of the system. The results show that the higher the system complexity, the more random-deficient the output sequence.
