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Search Results: 1 - 10 of 29346 matches for " Peak-Current Control "
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A Novel Over-Current Protection Technique Applied to Peak-Current Type DC-DC Converter  [PDF]
Yu Fang, Tengfei Wei, Liang He, Yong Xie, Yan Xing
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2010, DOI: 10.4236/jemaa.2010.26045
Abstract: The change of the over-current protection point of the power switches, caused by slope compensation, is analyzed in detail. It is discovered that the peak current protecting value increases as the duty cycle decreases. As a result, the safety operation of the switches is damaged greatly. A novel solution to improve over-current protection with constant peak current limitation is proposed by inducing synchronous slope compensation into the current limit function instead of the original constant voltage. The design principle and method of the protection circuit based on a UC3846 PWM controller for the interleaved dual-forward converter is presented. Experimental results are given to verify the analysis.
Design and Application of Wind Power Peak Control Technology  [PDF]
Songyi Zhu, Xinhua Deng, Shuguang Meng, Fuqiang Tang
Journal of Power and Energy Engineering (JPEE) , 2014, DOI: 10.4236/jpee.2014.29004

Wind power control technology is an important part of intelligent control in wind farms. By the automatic calculation and implementation of control strategy, problems such as imprecise of manual control scheduling, slow adjust rate, heavy workload, etc. have been solved. It can improve the capacity of wind power grid, and it also has the important meaning to the safe and stable operation of power grid. This paper introduces wind power control system from certain aspects such as control mode, control principle, and so on.

- , 2016, DOI: 10.12068/j.issn.1005-3026.2016.07.002
Abstract: 摘要 针对大功率无刷直流电机电流方波实现问题,提出一种在PWM_ON_PWM调制方式下的电流峰值控制策略,详细说明了该策略的控制原理,并给出了具体实施方案.该策略通过对非换相相电流的直接控制,提高了系统的反应速度,使得电机电流波形接近于理想方波,最终达到了减小电机转矩波动的目的.通过PLECS仿真工具,搭建无刷直流电机仿真模型,实现电流峰值控制方式的仿真.基于DSP控制芯片,搭建无刷直流电机电流峰值控制实验平台.仿真和实验结果显示,该控制策略不仅能实现方波控制,而且功率管开关频率可控.
Abstract:To realize the square-wave current of high-power brushless DC motor (BLDCM), a current peak control strategy using PWM_ON_PWM modulation mode was proposed and the control principle was described in detail. Then the concrete implementation plan was given. Through the direct control of the non-commutation phase current, the response speed of the system was improved and the desired square-wave current waveform was almost achieved, then the torque ripple of the motor was reduced finally. The simulation model of BLDCM was set up by PLECS to achieve the current peak control strategy. The experiment platform for current peak control of BLDCM was set up by DSP control chip. The simulation and experiment results showed that this control strategy can not only achieve the square-wave control, but also control the switching frequency of the power switching devices.
Bifurcation behaviours of peak current controlled PFC boost converter

Ren Hai-Peng,Liu Ding,
,刘 丁

中国物理 B , 2005,
Abstract: Bifurcation behaviours of the peak current controlled power-factor-correction (PFC) boost converter, including fast-scale instability and low-frequency bifurcation, are investigated in this paper. Conventionally, the PFC converter is analysed in continuous conduction mode (CCM). This prevents us from recognizing the overall dynamics of the converter. It has been pointed out that the discontinuous conduction mode (DCM) can occur in the PFC boost converter, especially in the light load condition. Therefore, the DCM model is employed to analyse the PFC converter to cover the possible DCM operation. By this way, the low-frequency bifurcation diagram is derived, which makes the route from period-double bifurcation to chaos clear. The bifurcation diagrams versus the load resistance and the output capacitance also indicate the stable operation boundary of the converter, which is useful for converter design.
Design of Broadband Vibration Absorber and Current Control Method

- , 2018, DOI: 10.16450/j.cnki.issn.1004-6801.2018.05.021
Abstract: 被动式吸振器(passive dynamic vibration absorber,简称PDVA)结构参数不可调,减振频带单一,不适用于宽频减振。为解决上述问题,首先,以磁流变弹性体(magnetorh eological elastomer,简称MRE)为刚度元件,设计一种刚度可调的自适应吸振器(adaptive dynamic vibration absorber,简称ADVA);其次,对弹性体原料组成及磁流变效应进行介绍和分析;然后,对受控系统增加吸振器,引起系统新的共振问题提出了吸振器工作过程中的电流控制方法以消除新增的共振现象;最后,进行了仿真及实验研究。结果表明,本设计可将减振频带拓宽至11.37 Hz,并且利用提出的电流控制方法可有效消除系统新增的共振峰。
Passive dynamic vibration absorber (PDVA), whose structural parameters can not be adjusted and vibration frequency band is single, is not suitable for broadband vibration. To solve the above problem, first, the magnetorheological elastomer (MRE) is used as the stiffness element to design an adaptive dynamic vibration absorber (ADVA). Second, the composition and MR effect of MRE are introduced and analyzed. Then, the current control method in the process of dynamic vibration absorber is proposed to eliminate the new resonance phenomenon which is caused by the addition of a vibration absorber to the controlled system. Finally, the simulation and experiment results show that the design can broaden the vibration frequency band to 11.37Hz. At the same time, the new resonant peak of the controlled system is eliminated effectively by the proposed control method.
A DBRTD with a High PVCR and a Peak Current Density at Room Temperature
Yili Chengrong,Xie Changqing,Wang Congshun,Liu Ming,Ye Tianchun,
Yili Chengrong
,Xie Changqing,Wang Congshun,Liu Ming,and Ye Tianchun

半导体学报 , 2005,
Abstract: AlAs/GaAs/In_0.1Ga_0.9As/GaAs/AlAs double-barrier resonant tunneling diodes(DBRTDs) grown on a semi-insulated GaAs substrate with molecular beam epitaxy is demonstrated.By sandwiching the In_0.1Ga_0.9As layer between GaAs layers,potential wells beside the two sides of barrier are deepened,resulting in an increase of the peak-to-valley current ratio (PVCR) and a peak current density.A special shape of collector is designed in order to reduce contact resistance and non-uniformity of the current;as a result the total current density in the device is increased.The use of thin barriers is also helpful for the improvement of the PVCR and the peak current density in DBRTDs.The devices exhibit a maximum PVCR of 13.98 and a peak current density of 89kA/cm~2 at room temperature.
A New Precision Peak Detector/Full-Wave Rectifier  [PDF]
Predrag B. Petrovi?
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.41009

A new precision peak detector/full-wave rectifier of input sinusoidal signals, based on usage of dual-output current conveyors, is presented in this paper. The circuit gives a DC output voltage that is the peak input voltage over a wide frequency range, with a very low ripple voltage and low harmonic distortion. The proposed circuits use an all-pass filter as a 90° phase shifter of the processed input signal. To verify the theoretical analysis, the circuit SPICE simulations results have also been included, showing good agreement with the theory. Inherently, the circuit is well suited for IC implementation.

A Gain Scheduled Method for Speed Control of Wind Driven Doubly Fed Induction Generator  [PDF]
Wei Wang, Kang-Zhi Liu, Tadanao Zanma
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.51B016
Abstract: 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.
Design of a Control Device for Synthetic Making Test Based on Pre-Arcing Current Detection and Phase Control  [PDF]
Zhengyang ZHOU, Minfu LIAO, Xingming FAN
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2009, DOI: 10.4236/jemaa.2009.14043
Abstract: The synthetic making test has been widely used in evaluating the break ability of high-voltage circuit breaker. However, the test research and application are still inadequate, especially in the condition of rated voltage. According to the realistic conditions of test stations in China, a control device based on pre-arcing current detection and phase control is proposed in this paper. A sample of the control device made up of DSP TMS320LF2407A is fabricated, in which the CPLD MAX7064 is used to transmit signals for EMC design. It can be applied in full voltage synthetic making test at a level of 126kV/63kA. The test results show that, it is accurate to control the making phase of the applied voltage, whether the closing is demanded at voltage peak or zero.
An Improved Non-isolated LED Converter with Power Factor Correction and Average Current Mode Control  [PDF]
Renbo Xu, Hongjian Li, Yongzhi Li, Changqian Zhang
Circuits and Systems (CS) , 2011, DOI: 10.4236/cs.2011.23034
Abstract: A new type of high power LED drivers is proposed by adopting an improved two-stages non-isolated configuration. In order to improve power factor and achieve accurate average current control under universal input voltages ranging from 100 Vrms to 240 Vrms, the power factor correction and average current mode control methods operating in continuous current conduction mode are designed and implemented. With the LUMILEDS emitter type LEDs, a laboratory prototype is built and measured. And from the measured results, it could be concluded that the proposed driver has many better performances such as high power factor, low current harmonic, accurate average current control and switch protection.
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