共查询到19条相似文献,搜索用时 312 毫秒
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在对电力系统有源无功与谐波补偿的原理进行理论分析的基础上,运用其有关分析结果讨论一种电力有源滤波器主电路及带有变结构非线性电流控制的双闭环控制系统的结构和工作原理,通过Pspice软件进行了仿真研究,仿真结果证实了该系统及控制方法的正确性与可行性。 相似文献
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大型同步发电机变结构励磁控制 总被引:6,自引:1,他引:5
本文提出了一种非线性变结构励磁控制器,它结合了非线性微分几何方法及变结构控制理论的优点,针对单机--无穷大系统进行静成及暂态稳定的仿真分析,并与非线性最优励磁控制方式比较,仿真结构表明,非线性变结构控制给邮较满意的动态响应特性和较好的鲁棒性。 相似文献
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提出一种基于准滑模变结构控制(QSMC)的有源电力滤波器的控制策略,用于减小常规滑模控制中存在的抖动问题。使用的方法是将系统的运动轨迹限制在理想滑动模态的某一领域 内,从而实现对滑模控制非线性部分进行处理,保证了在减小了系统的抖动的同时系统又具有较好的鲁棒性。同时分析了该装置的原理及控制方法,并对控制器的存在性,可达性及稳定性进行了分析。仿真结果证明了该控制算法简单,响应速度快,对外界噪声干扰和参数摄动具有鲁棒性等特点,对抖动也具有较好的抑制作用。 相似文献
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非线性有源天线阵相位噪声的计算及测试 总被引:1,自引:1,他引:0
为了将非线性有源天线阵应用到高性能雷达和通信系统中,必须尽可能地降低非线性有源天线阵的相位噪声。首先介绍了非线性有源天线阵的拓扑结构及相位噪声模型;然后根据该模型详细推导了非线性有源天线阵相位噪声的计算公式,并对整个阵列的相位噪声进行了计算机仿真;最后搭建了1×4单元非线性有源天线阵实验系统并对其相位噪声进行了测试,测试结果与计算机仿真结果吻合;最终得出了非线性有源天线阵低相位噪声信号的产生方法。 相似文献
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有源电力滤波器精确反馈线性化准滑模变结构控制 总被引:3,自引:0,他引:3
提出一种基于精确反馈线性化的有源电力滤波器(active power filter,APF)准滑模变结构复合控制策略,解决了传统有源电力滤波器滑模控制器设计结构复杂及抖振问题。根据三相有源电力滤波器在d-q坐标系下的仿射非线性模型,推导相应的坐标变换矩阵与状态反馈表达式,得到系统精确反馈线性化模型。针对此线性系统设计积分滑模函数,并证明等效控制的存在性与滑模控制的可达性。最终实现了准滑模变结构控制器设计,并给出参数选取范围。仿真与实验结果证明,该复合控制方法结合了精确反馈线性化控制与滑模控制的优点,具有较优的动态控制响应与稳态控制性能。 相似文献
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Po-Tai Cheng Bhattacharya S. Divan D.M. 《Industry Applications, IEEE Transactions on》1998,34(3):458-472
This paper presents a new control scheme for a hybrid parallel active filter (HPAF) system intended for high-power applications-up to 100 MW nonlinear loads-to meet IEEE 519 recommended harmonic standards. The active filter inverter is realized with small-rated (1%-2% of the load rating) square-wave inverters operating at the dominant harmonic frequencies. The proposed system achieves harmonic isolation at desired dominant harmonic frequencies, such as the fifth and seventh, even in the presence of supply voltage harmonic distortions. A novel method of active filter inverter DC-bus control, as proposed here, achieves power balancing by exchanging energy at the fundamental frequency and at the dominant harmonic frequency (such as the fifth). The proposed square-wave inverter-based HPAF system provides improved filtering characteristics as compared to the conventional passive filter and is expected to be cost effective for high-power nonlinear loads compared to the conventional passive filter or other active filtering solutions. The concept of harmonic isolation at dominant harmonic frequencies by square-wave inverters with the proposed control scheme is validated by simulation results 相似文献
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Bhattacharya S. Po-Tai Cheng Divan D.M. 《Industry Applications, IEEE Transactions on》1997,33(3):732-747
This paper presents a new control scheme for a parallel hybrid active filter system intended for harmonic compensation of large nonlinear loads up to 50 MVA, to meet IEEE 519 recommended harmonic standards. The active filter is small rated, 2%-3% of load kilovoltampere rating. The control scheme is based on the concept of synthesizing a dynamically variable inductance, and its usefulness is demonstrated for an active filtering application. A synchronous reference frame (SRF) controller implements the dynamically varying negative or positive inductance by generating active filter inverter voltage commands. This variable inductance controller parallel hybrid active filter system can selectively synthesize multiple “active inductances” at dominant harmonic frequencies without affecting passive filter impedances at all other frequencies. This controller also provides a “current limiting” function to prevent passive filter overloading under ambient harmonic loads and/or supply voltage distortions. Three implementation variations of a parallel hybrid active filter system are presented. This paper also proposes the use of power factor correction capacitors as low cost passive filters for a parallel hybrid active filter system, which are controlled to provide either single or multiple tuned harmonic sinks and to increase cost effectiveness for high power applications. Simulation results validate the proposed variable inductance controller operation for mistuned passive filters 相似文献
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A model at harmonic frequencies is developed for a static VAR compensator. The model consists of a harmonic voltage source in series with a variable source admittance. The model is shown to be useful in predicting resonance problems using digital simulation. Equations are also developed which show that a static VAR compensator can be described by a system of linear differential equations with periodic coefficients. 相似文献
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二极管钳位型多电平有源电力滤波器的仿真 总被引:1,自引:1,他引:0
由于功率器件耐压水平的限制,传统的2电平拓扑结构有源电力滤波器(APF)难以实现对高压非线性负载的谐波补偿.文中采用二极管钳位型多电平变换器,提出了其作为APF运行的方案.对该APF进行了理论分析,提出一种基于重复预测型观测器的无差拍控制方案.该方案采用重复预测型观测器,对指令谐波电流进行预测,可在相同的采样频率下提供更精确的谐波电流预测值,因而可以改善整个系统的控制效果.仿真结果表明该APF适用于高电压及大容量谐波补偿. 相似文献
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并联型有源电力滤波器控制方法与仿真 总被引:1,自引:0,他引:1
随着国家坚强智能电网的发展,智能型电力电子设备及技术在智能电网中大量使用。由于电力电子器件具有非线性特性,其使用给智能电网带来了谐波污染等问题。并联型有源电力滤波器采用了应用广泛的谐波抑制和无功补偿技术,它能对智能电网中的谐波和无功进行较好地动态补偿。分析了并联型有源电力滤波器的补偿原理,利用包含直流侧电压环控制的ip-iq法进行智能电网指令电流的检测和定时滞环电流跟踪控制方法对并联型有源电力滤波器进行电流跟踪控制,使用Matlab/Simulink搭建仿真模型,并从不同的控制角进行实例仿真。仿真结果和快速傅里叶分析表明,对于非线性负载晶闸管的不同触发角,定时滞环电流跟踪控制都能有效地实时跟踪控制,仿真模型系统能够实时检测出系统中所含指令运算电流,并进行有效补偿,达到了理想的效果。 相似文献
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分次补偿方式的并联型混合电力滤波器研制 总被引:5,自引:1,他引:5
介绍了由有源电力滤波器和无源滤波器并联构成混合滤波系统的工作原理,分析了有源和无源滤波器并联补偿谐波时谐波电流分配的问题,提出采用分次补偿的控制策略,并对系统控制策略的软件方法和控制电路的硬件实现进行了阐述。在此基础上研制了一台250kVA/380V并联混合型电力滤波器装置。该装置已应用于治理中频炉负载的工业现场。仿真和现场应用结果表明,采用该控制方法,可以在保证良好的补偿特性的同时,有效减少有源滤波器部分的容量,从而降低了整个装置的成本,更加适用于治理中大容量谐波负载的场合。 相似文献