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Significant phase delay of the phase current occurs when the single phase PM brushless DC motor operates at high speed, which will cause out-of-phase of the current and back-emf waveform and hence generate a negative torque. Two commutation strategies that are phase commutation advancing technique and conducting pulse-width control can be employed to solve this problem. In this paper, the selection...
Before, the methode of simulating the high-frequency contents of inverter-fed traction motor and the winding inter-turn voltage distribution has been the equivalent circuit model. The main simulating tool has been MATLAB. But now another method may be better than this one. Based on electromagnetic field theories, this paper researches the effect of steep-fronted voltage wave-shapes infringing on a...
In this paper, a three-phase voltage transients emulator is proposed using a non-external power supply topology with a feedback control loop per phase. The development process in control design, simulate and experimental result of a 3.6kW three-phase voltage emulator will be shown. The possible voltage transients to emulate are: Sags, Swells and Flickers. According to electrical standard such as:...
With the advancement of technology and incorporation of sophisticated systems in the aircrafts, the modern aircrafts are highly dependent on the reliable electrical power systems. Prognostic and Health Management (PHM) is the evolving field for fault diagnosis, failure prevention and cost cutting maintenance. In this paper, a real-time frequency estimation algorithm based on 3-line Discrete Fourier...
The polynomial time frequency transforms have become a useful tool to analyze polynomial-phase signals for their time-varying characteristics. To minimize the required computational complexity to deal with high order polynomial-phase signals, efficient fast algorithms are extremely important for any practical applications. Based on radix-3 decomposition techniques, this paper presents fast algorithms...
A new modular multilevel converter (MMC) based static synchronous compensator (STATCOM) is proposed and hereafter called M-STATCOM. The new shunt compensator, features with the characteristics such as high modularity, availability, low generation of harmonics, etc., is well suitable for medium- or high-voltage utility grid without line-frequency transformers. M-STATCOM can not only be controlled in...
With the increasing application of Induction Heating (IH) systems in various industries such as metallurgy, concerns about the harmonic effects and power quality of the power grid have been involved in the problems facing network operation engineers. This paper presents two methods to improve the power quality of three phase current source induction system. The two methods are active and passive solutions...
Particle Impact Noise Detection is one of the most important methods in detecting remainders within space relays, and effective activation of the remainders is vital for the detection. In this paper, the electrostatic adherence and contact electrification of remainders were analyzed using the principles of electrostatics and kinetics. The strained condition of electrostatic adherent remainders was...
This paper presents a single-path pipelined hardware structure for DFT computation based on the radix-22 FFT algorithm. The proposed structure requires log4N −1 complex multipliers, log2N complex adder/subtracters and 2(N −1) complex data stores. Compared with previously reported single-path pipelined structures, the number of add/subtracters is reduced by 50 percents. A realization of the delay and...
The suppression effect of Bacillus amyloliquefacien Ba33 against TMV and PVY by biological detect through necrotic lesions host and RNA detect through RT-PCR was studied. The result showed that the suppression ratio of necrotic lesions against TMV and PVY was 95.25% and 99.22% respectively. And Ba33 could suppression RNA replication of TMV and PVY in Nicotiana tabacum var. NC89 leaves from 24 to 84h...
To ensure the lunar lander landing safely, and execute the expected scientific experiments smoothly, a new terrain simulation method is proposed in this paper, which can build a terrain model of Sinus Iridum with a high resolution of better than 1 meter. The terrain surface trend is fitted from a low-resolution terrain with genetic programming (GP) and genetic algorithm (GA). A high resolution terrain...
An on-line gait synthesis scheme for a bipedal walking robot is proposed. To realize efficient and human-like gait, MTi sensors were mounted on the lower limb of human subject to acquire kinematics information that can be integrated to the angular changes of hip and knee joints during walking. The time series angles were normalized and then sampled by cubic spline interpolation. By employing discrete-time...
In order to select the new type electrostatic sprayer for tea pest control, The performance of different sprayers were compared and the deposition of droplets in tea plants and the losses on the ground were determined. Results indicated that, the spray liquid discharge from the nozzle of electrostatic sprayer 3WBJ-16DZ that operated at 0.5Mpa was 1290mL/min, followed by the electric sprayer WS-18D,...
This article is based on the needs of photovoltaic solar energy generation. A new type of multilevel DC chopper with a small bulk is researched. We analyzed three-level Boost circuit, found a kind of power supply module and gave a new family of multilevel converter topology. Four-level Boost circuit has been detailed analysis. Theoretically we analyzed its work and the four levels appear rear the...
In this paper, a coupled-inductor Sepic-type power factor corrector (PFC) with soft-switching is proposed to drive high brightness LED panel. The two inductors in the Sepic-type PFC are magnetically coupled to lower volume. A soft-switching cell composed of an active switch, a resonant inductor and a resonant capacitor is embedded into the PFC to obtain zero-voltage switching (ZVS) feature so as to...
Spatial patterns of Bemisia tabaci adults in different growing periods of tobacco (Zhongyan-100) were studied based on the analysis of geostatistics to lay the theoretical foundation for sampling, monitoring and integrated control of B. tabaci. From tobacco transplantation to June 5th, the spatial pattern of B. tabaci adult was random. From June 12th to Sep. 18th, the semivariogram curves of B. tabaci...
This paper presents a predictive proportional integral control for digital DC-DC converter. The predictive controller predicts the output voltage of the next switching cycle by estimating the charge of the inductor and diode current charging the output capacitor. The controller also features an upper bound and a lower bound to limit the overshoot and undershoot of the output voltage respectively....
Recently, DC-DC boost converters are usually required in many applications which has low output voltage, such as renewable energy sources. The interleaved boost converters consists of several identical boost converters connected in parallel and controlled by the interleaved method which has the same switching frequency and phase shift. The advantages of interleaved boost converters include increased...
The paper presents a novel ZVS buck converter topology. The proposed topology solves narrow duty cycle and hard switching problems of conventional buck converter in lower output voltage and higher output current. At the same times, the voltage stresses across main switches are also clamped at input voltage. In the topology, an adjustable inductor and a resonant capacitor are used to reduce charge...
This paper proposes a multi-objective reinforcement learning algorithm (MORLA) and uses simultaneous perturbation stochastic approximation (SPSA) to improve the convergence of it. Usually, reinforcement learning (RL) is used to design neurocontroller for control system with single objective. When facing multi-objective system, it is necessary to design the neurocontroller according to the personal...
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