共查询到19条相似文献,搜索用时 187 毫秒
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研究一种单相光伏并网发电控制仿真系统。利用Matlab2008b/Simulink,采用boost电路和逆变电路两级式结构,其中采用电导增量法的最大功率跟踪功能在boost电路中实现,并网控制通过采集电网电压参数和逆变输出电流电压参数在逆变电路中通过PI调节实现。通过光伏阵列通用模型验证最大功率跟踪模块的正确性,通过并网实验验证并网跟踪性能。基本实现了光伏阵列最大功率点的快速、准确跟踪功能和逆变输出电流电压与电网电压的同频同相,保证了输出电流为正弦波形且纹波较少,能够快速跟踪电网电压的变化。证明此系统在实际中是可行的。 相似文献
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针对目前光伏系统最大功率点跟踪方法普遍须要同时采集光伏电池输出电压信号和输出电流信号这一情况,文章提出了一种只须要检测光伏电池输出电压的控制方法,该方法采用占空比扰动法的工作模式,去掉了电流采样电路,简化了系统结构,并在saber环境下进行了仿真试验。最后通过对仿真结果的分析,证明了提出的光伏系统最大功率点跟踪方法的可行性和准确性。 相似文献
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阐述了多支路型光伏并网逆变器的基本原理和研制的关键技术.通过对光伏并网逆变器最大功率点跟踪、并网控制技术和孤岛效应等问题的分析,提出了相应的解决方案:采取最大功率跟踪方法,系统能在光强变化时,迅速、准确地跟踪太阳能电池阵列的最大功率点;以多输入支路的独立最大功率跟踪策略,解决了由于太阳能电池阵列参数不一致造成的输出功率降低的问题;在并网逆变技术上采用电流超前跟踪,简单实现了输出功率因数为1,有效地提高了输出电能质量. 相似文献
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为实现电网电压不平衡时对T型三电平光伏并网系统输出功率和电流质量的控制,以达到入网功率平稳或电流正弦为控制目标,结合光伏阵列输出功率前馈,在两相静止坐标系下提出一种直流母线电压外环PI控制、并网电流内环有限集模型预测控制的控制策略,并在电压外环中引入2倍频陷波器以获得平滑的入网功率参考值。仿真结果表明:当电网电压不对称时,采用所提控制策略能够实现对入网有功、无功功率2倍频脉动及负序电流的分别抑制或协调控制,且并网电流谐波畸变小、入网电能质量高,同时实现T型三电平逆变器的中点电位平衡。 相似文献
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针对传统的Z源逆变电路控制方式中需要独立分析升压电路控制因子和并网电路控制因子的问题,先在典型的Z源全桥逆变电路的拓扑结构中实现单桥臂上下管的直通相位控制方式下的开关时序,进而分析了Z源逆变电路的5种模态的工作原理,提出了一种适用于单相光伏逆变系统的Z源逆变电路直通控制方式,就是利用能量传递和傅里叶算法在直通零矢量和输出逆变电压之间建立直接联系。以一台3kW光伏并网逆变样机的测试结果表明,样机PV电压稳定,并网电压电流相位在50%输出功率下基本一致,其谐波含量和功率因数符合要求;同时,还具备一定的过压、欠压动态保护特性,反应时间迅速。结果表明,Z源逆变电路及其直通控制策略在光伏并网系统中的应用效果较好。 相似文献
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A novel topology of the bidirectional energy storage photovoltaic grid-connected inverter was proposed to reduce the negative impact of the photovoltaic grid-connected system on the grid caused by environmental instability. Using the proposed Inverter as a UPS power supply in case of a grid failure, storage electrical energy and regulating the energy delivered to the grid for reducing the pressure on the grid. A new artificial fish-swarm algorithm and variable step voltage perturbation method were presented to track the maximum power point of the solar panels. Analysis was done to reduce the output ripple of the inverter and sinusoidal pulse width modulation (SPWM) was selected to control the inverter. Model simulation was performed using PSpice software to obtain the volt-ampere characteristic curve of the solar panel output. The solar array simulator was used to verify the effect of maximum power point tracking at different light intensities. The study concludes that the maximum power point tracking (MPPT) efficiency of the bidirectional energy storage photovoltaic grid-connected inverter designed was as high as 99.9%. The distortion rate of the grid-connected current waveform was within 2% and the DC current component was less than 0.5%. The output voltage and power were in full compliance with the grid connection standard. 相似文献
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针对相同滤波效果下采用L型滤波器的单相光伏并网逆变器的PI控制需要较大的电感值以及存在高损耗、电流内环响应速度降低和成本较高的不足,提出了采用基于LCL滤波的电容电流反馈和电网电压前馈的准PR控制策略,以增加系统阻尼、抑制振荡、提高系统稳定性能,并通过Matalab/Simulink软件搭建仿真模型进行了验证。结果表明,经LCL滤波后,在准PR控制策略下,加入电容电流反馈和电网电压前馈后,获得的入网电流畸变率更小,实现了入网电流的无静差跟踪,抑制了电网电压的扰动,且系统输出的波形满足入网要求。 相似文献
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This paper presents a control for a three phase five-level neutral clamped inverter (NPC) for grid connected PV system. The maximum power point tracking (MPPT) is capable of extracting maximum power from the PV array connected to each DC link voltage level. The MPPT algorithm is solved by fuzzy logic controller. The fuzzy MPPT is integrated with the inverter so that a DC–DC converter is not needed and the output shows accurate and fast response. A digital PI current control algorithm is used to remain the current injected into the grid sinusoidal and to achieve high dynamic performance with low total harmonic distortion (THD). The validity of the system is verified through MATLAB/Simulink and the results are compared with three phase three-level grid connected NPC inverter in terms of THD. 相似文献
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The overall efficiency of photovoltaic (PV) systems connected to the grid depends on the efficiency of direct current (DC) of the solar modules to alternate current (AC) inverter conversion. The requirements for inverter connection include: maximum power point, high efficiency, control power injected into the grid, high power factor and low total harmonic distortion of the currents injected into the grid. An approach to power factor control and reactive power regulation for PV systems connected to the grid using field programmable gate array (FPGA) is proposed. According to the grid demands; both the injected active and reactive powers are controlled.In this paper, a new digital control strategy for a single-phase inverter is carried out. This control strategy is based on the phase shift between the inverter output voltage and the grid voltage, and the digital sinusoidal pulse width modulation (DSPWM) patterns, in order to control the power factor for a wide range of the inverter output current and consequently the control and the regulation of the reactive power will be achieved. The advantage of the proposed control strategy is its implementation around simple digital circuits.In this work, a simulation study of this strategy has been realized using Matlab/Simulink and PSIM. In order to validate its performance, this control has been implemented in a FPGA. Experimental tests have been carried out demonstrating the viability of this control in order to control the power factor and the injected power into the grid. 相似文献
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基于模糊PI控制的海上风电柔性直流输电整流器研究 总被引:1,自引:0,他引:1
为提高海上风电柔性直流输电电压等级,抑制直流侧电压跌落和闪变,将三相电压源变流器用于送端整流器。采用多个功率单元级联的拓扑结构,电流内环采用PI解耦控制、电压外环模糊PI调节双闭环控制方式。分析了变流器数学模型,建立了MATLAB/Simulink仿真模型,实现了电压级联输出.在线PI参数整定。仿真结果验证了该系统在海上风电柔性直流输电应用中的有效性。 相似文献