共查询到20条相似文献,搜索用时 31 毫秒
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矩阵变换器励磁控制的无刷双馈风力发电系统 总被引:4,自引:0,他引:4
应用在双馈风力发电系统中的功率变换器必须具有功率双向流动的能力, 交直交循环变流器和交交矩阵变换器都可满足功率的双向流动要求. 而矩阵变换器能同时提供正弦的输入电流和输出电压, 输入电流可调节为超前、滞后或同相于输入电压, 输出电压可实现幅值、频率和网侧功率因数的独立控制. 利用矩阵变换器, 通过控制无刷双馈电机控制绕组的电压幅值、频率, 为风力发电系统提供励磁. 压频比控制器采用模型参考模糊自适应控制策略, 对电机的转速和功率因数进行控制. 采用DSP,CPLD构建了基于四步换流方案的矩阵变换器实验励磁系统, 仿真和实验结果验证了系统设计的正确性、可行性和稳定性, 为矩阵式变换器的实际应用提供了实验基础. 相似文献
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A. BounouhAuthor Vitae H. CamonD. BélièresAuthor Vitae F. Blard F. ZiadéAuthor Vitae 《Computer Standards & Interfaces》2011,33(2):159-164
This work explores MEMS (Micro-Electro-Mechanical Systems) potentialities to fabricate AC voltage references through mechanical-electrical transduction that could be used for high precision electrical metrology and for applications in miniaturized instrumentation. AC voltage reference ranging from 5 V to 90 V have been designed and fabricated using the same Epitaxial Silicon On Insulator (SOI) surface micromachining process allowing an accurate control of both dimensions and material properties. The measured MEMS AC voltage reference values have been found in a good agreement with CoventorWare calculations. These tests structures have also been used to develop the read-out electronics to drive the MEMS. 相似文献
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A. El Fadili F. Giri A. El Magri L. Dugard F.Z. Chaoui 《Asian journal of control》2012,14(6):1470-1483
The problem of controlling induction motors, together with associated AC/DC rectifiers and DC/AC inverters, is addressed. The control objectives are threefold: (i) the motor speed should track any reference signal despite mechanical parameter uncertainties and variations; (ii) the DC Link voltage must be tightly regulated; and (iii) the power factor correction (PFC) w.r.t. the power supply net must be performed in a satisfactory way. First, a nonlinear model of the whole controlled system is developed within the Park coordinates. Then, a multi‐loop nonlinear adaptive controller is synthesized using the backstepping design technique. A formal analysis based on Lyapunov stability and average theory is carried out to exhibit the control system performances. In addition to closed‐loop global asymptotic stability, it is proven that all control objectives (motor speed tracking, rotor flux regulation, DC link voltage regulation and unitary power factor) are asymptotically achieved, up to small but unavoidable harmonic errors (ripples). 相似文献
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研究航空电源交流畸变系数检测问题,其核心在于从采样数据中准确获得交流基波分量.提出一种新算法,将交流基波分量计算问题转换为非线性连续优化问题,通过多维单纯形下降法同步优化幅值、频率和相位,最小化基波分量与采样信号的误差,从而获得接近真实的交流基波分量,并据此准确计算交流畸变系数.该方法已被应用于某大功率航空电源检测系统... 相似文献
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本文针对硅微机械结构振动幅度由于封装难以计算机视觉测量及电学测量中的精度受接口电路参数影响的问题,在对静电梳齿驱动、平板电容检测的硅微谐振结构进行建模分析后,提出基于单边带电压比的电学测量振动幅度的方法并分析了测量方法的原理。实验表明研制的某硅微机械谐振加速度计在受迫振动下的振动幅度为0.25um,频谱分析还表明存在上电噪声引起的振动幅度,该测试方法还能应用于硅微谐振结构的谐振频率测量,同时为高品质因数的硅微机械谐振结构的可静电自激驱动提供了依据。 相似文献
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This paper proposes a hybrid controller which is a combination sliding mode control and PI control techniques for AC grid integrated offshore wind farm (OSWF) with voltage source converter ‐ high voltage direct current system. The controller must be capable of controlling AC voltage, DC‐link voltage, reactive power and effective power transfer. To examine the FRT capability, a symmetrical fault is applied at onshore AC grid side and compared the performances of the studied system based on the hybrid and PI controllers. The dynamic modelling and linearized system by state‐space modelling for the studied system are explained in detail. The small signal stability analysis and controller stability are observed with the help of the eigenvalue analysis. The analysis of the studied system with a hybrid and conventional controllers are conducted in the software environment of the MATLAB/SIMULINK . The effect of parameter uncertainty on total system stability is examined with the help of eigenmatrix of the studied system. 相似文献
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The problem of controlling synchronous motors, driven through AC/DC rectifiers and DC/AC inverters is addressed. The control objectives are threefold: (i) forcing the motor speed to track a varying reference signal in presence of motor parameter uncertainties; (ii) regulating the DC Link voltage; (iii) assuring a satisfactory power factor correction (PFC) with respect to the power supply net. First, a nonlinear model of the whole controlled system is developed in the Park-coordinates. Then, a robust nonlinear controller is synthesized using the damping function version of the backstepping design technique. A formal analysis based on Lyapunov stability and average theory is developed to describe the control system performances. Despite parameter uncertainties, all control objectives are proved to be asymptotically achieved up to unavoidable but small harmonic errors (ripples). 相似文献
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Rachid Lajouad Abdelmounime El Magri Abderrahim El Fadili Fatima‐Zahra Chaoui Fouad Giri 《Asian journal of control》2015,17(4):1365-1376
This paper presents a theoretical framework for adaptive control of a wind energy conversion system (WECS), involving a squirrel cage induction generator (SIG) connected with an AC/DC/AC IGBT‐based PWM converter. A multi‐loop nonlinear controller is designed to meet two main control objectives, i.e., (i) speed reference optimization in order to extract a maximum wind energy whatever the wind speed, and (ii) power factor correction (PFC) to avoid net harmonic pollution. These objectives must be achieved despite the mechanical parameters uncertainty. First, a nonlinear model of the whole controlled system is developed within the Park coordinates. Then, a multi‐loop nonlinear controller is synthesized using the adaptive backstepping design. A formal analysis based on Lyapunov stability is carried out to describe the control system performances. In addition to closed‐loop global asymptotic stability, it is proven that all control objectives (induction generator speed tracking, rotor flux regulation, DC link voltage regulation and unitary power factor) are asymptotically achieved. 相似文献
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Corman T. Kalvesten E. Huiku M. Weckstrom K. Merilainen P.T. Stemme G. 《Journal of microelectromechanical systems》2000,9(4):509-516
A new silicon IR source and CO2-chamber system for measurement of CO2 concentration is presented. The micromachined IR-source, which consists of four groups of polysilicon filaments coated with silicon nitride suspended across a KOH-etched cavity, is used to generate two switched “sample” and “reference” beams. The electrically modulated sources present a modulation time of 10 ms and a power consumption of 1 W. The CO2 chambers, placed beneath the reference sources, are used to produce a reference beam for long term stability and compensation against cuvette window contamination. They consist of 1-mm-deep micromachined cavities in which CO2 is encapsulated during an overpressure anodic bonding procedure. Silicon dioxide is used as an antireflective coating to optimize the filter's optical characteristics. Numerical simulations of the filters are presented and show good agreement with the measurements. The IR sources and the CO2 filters are both fabricated at wafer level. Using the presented IR-sensor system, measurements with a 9-mm-wide test channel show high CO2-sensitivity for CO2 concentrations between 0 and 10% confirming that the stringent requirements for this respirator application can be fulfilled 相似文献
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A monolithically integrated surface micromachined touch mode capacitive pressure sensor 总被引:2,自引:0,他引:2
A monolithically integrated surface micromachined touch mode capacitive pressure sensor and its interface circuits are presented. The device includes the capacitance to voltage, and capacitance to frequency converters on the same chip. The sensor is fabricated using a surface micromachining technology, which is processed simultaneously with a conventional 2.0-μm double-poly, double-metal n-well CMOS process. The performance of the integrated sensor meets the design specifications of good linearity and good stability. Evaluation results on the completed ‘sensor and circuit' chip are presented. 相似文献
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配电变压器监控系统中的交流采样算法 总被引:2,自引:0,他引:2
交流采样是按一定规律对被测信号的瞬时值进行采样,再用一定的数值算法求得被测量的值。实践证明,采用交流采样方法进行数据采集,通过算法运算后获得的电压、电流、有功功率、功率因数等电力参数有较好的精确度和稳定性。 相似文献
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针对煤矿井下直流电机车变流系统中存在三相电压不平衡而使传统的PWM整流器的交流侧出现负序电流分量的问题,提出了一种在三相电压不平衡情况下抑制PWM整流器交流侧负序电流分量的控制策略;详细介绍了该控制策略的具体实现。仿真及现场实验结果表明,采用该控制策略后,PWM整流器的交流侧电流波形基本接近正弦波形,实现了单位功率因数运行。 相似文献
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胡春龙 《计算技术与自动化》2022,(4):27-32
针对整流器调制过程易产生谐波干扰和非线性等问题,提出了一种DSP控制下SPWM调制的优化设计方法,以TMS320F2812型DSP为主控制器,对交流电压电流调理电路、直流电压调理电路、负载电流调理电路进行了设计、分析与计算,在DSP定时器周期中断下对电压、电流信号进行采样,将采样值优化后作为调制波采样时刻值,带入比较寄存器关系式中来改变比较寄存器的值,从而改变脉冲信号的占空比,通过Modbus协议以MCGS触摸屏下发调制度M,改变SPWM波形,并对电压信号进行显示。对系统进行了仿真和实验,结果表明系统输出信号正常、可靠,具有较强的稳定性和抗扰性。 相似文献
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Nowadays the size of the use of electronic devices like laptops, cell phone chargers, electric vehicles and UPS is rapidly increasing. So AC–DC converters need to incorporate the power factor correction along with voltage regulation. There are many AC–DC converter control methods available, but these methods do not perform well. Therefore In this paper, a smooth transformation on switching will be characterized by a high power factor in a single phase AC–DC converter by the use of intrinsic power management strategy. The proposed AC–DC converter's circuit topology is obtained by integrating a boost and buck converter. The Boost Converter's switching frequency does power factor correction to get less current harmonics at the input line. In this single phase AC–DC converter, the buck-boost converter is an important component that increases system power quality based on advanced PWM technique. So in this work, the Intrinsic Power Management Strategy (IPMS) is proposed to enhance the control over the DC–DC converter performance during unstable or transient operation. Rather than making a quick Pulse Width Modulation (PWM) signal, the computerized signal processor just creates a moderate changing DC signal to decide the PWM ramp function. The power factor correction model has been created and simulated by utilizing MATLAB programming. The simulation model demonstrates that the power factor is improved and the converter has regulated DC output voltage. To validate this simulation, a 1000 W prototype converter has been developed to feed a DC motor and the analysis of the results are presented. 相似文献
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