共查询到19条相似文献,搜索用时 203 毫秒
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通过分析滞环电流控制工作原理,建立了电感电流连续状态下滞环电流控制方式小信号模型。证明了滞环电流控制环在开关频率较高时带来的相位延迟较小,可等效为比例环节。将该结论应用于大信号分析,基于双Buck逆变器建立了半周期滞环电流控制单相逆变器的大信号模型,通过分析,进一步得出了单相逆变器外环补偿电路的设计准则,使其能很好地兼顾系统的动态及稳态性能。设计制作了一台115 V/400 Hz,2 kVA逆变器原理样机,实验结果验证了文中分析的正确性。 相似文献
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基于PWM开关模型,提出了单相高频环节逆变器尤其是后级单相逆变器建模方法。介绍了相关建模思想、建模流程及方法,并给出半桥双Buck逆变器建模结果验证,并将该方法推广至半桥逆变器。在此基础上,提取了半桥逆变器环路增益及输入阻抗模型,进而研究单相逆变器子系统及级联系统稳定性。最后指出目前该方法的局限性及未来有待完成的工作。 相似文献
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针对并网系统谐波预测问题,提出引入逆变器实际输出谐波电流建立谐波阻抗模型的方案。首先分析并网系统谐波谐振原理,对单相LCL型并网逆变器进行阻抗建模。为提高阻抗模型准确性,在分析逆变器低频特性的基础上,将单个逆变器并网谐波电流考虑到阻抗模型中,建立谐波阻抗模型,与电路模型仿真对比结果验证了模型的有效性。利用提出的谐波阻抗模型,对多逆变器并网系统进行谐波交互分析及谐波预测建模,以8个并网逆变器为例,分析谐振对并网谐波电流和公共接入点(PCC)处谐波电压的影响,谐波预测模型和电路模型对比仿真结果验证了该多逆变器谐波预测模型的有效性和准确性。 相似文献
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基于灰色模型的多电平逆变器的预测控制 总被引:1,自引:0,他引:1
建立多电平逆变器闭环控制的非线性动态行为模型,使用灰色系统理论的灰色模型GM(1,1)建模方法,对多电平逆变器输出信号测量值在线新陈代谢灰色滤波及单步预测,与逆变器的输入给定信号综合得到控制误差,实现多电平逆变器的PID预测控制。仿真与实验结果表明,基于灰色系统模型的多电平逆变器预测控制具有算法容易实现,鲁棒性好等特点,提高了系统的控制品质。 相似文献
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针对大容量三相三电平逆变器原理性仿真中一般没有考虑复合母排的分布式结构、逆变器交流输出铜排及电力电缆的传输线参数、负载感应电机的高频电路参数等,从而不能准确反应吸收电容、功率开关管、滤波器等器部件安装位置对全系统性能的影响,不能有效指导相关器部件设计的问题,结合仿真和实验提出一种三相三电平逆变器建模方法。通过建立电容母排、传输母排和IGBT母排的多端口电路模型,考虑逆变器柜内输出铜排与交流输出电力电缆传输线参数,提出一种三相感应电机的高频电路模型及其参数测量方法,在此基础上对三相三电平逆变器进行了全系统仿真建模和试验验证。利用三相三电平逆变器全系统仿真模型及建模方法,可指导复合母排、吸收电容、交流输出滤波器、熔断器等器部件的工程设计。 相似文献
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针对传统基于信号分析的中性点箝位(NPC)逆变器故障诊断方法存在频谱易泄露,及难以分析非稳态、非线性故障信号的问题,提出一种基于Prony算法的三电平逆变器开路故障诊断方法。首先,采用小波变换对原始测量信号去噪预处理,克服Prony法对噪声敏感的缺点。其次,通过Prony分析拟合逆变器的三相电流信号,提取其幅值、频率、相位、衰减因子四维故障特征。然后,应用支持向量机(SVM)对中性点箝位逆变器故障进行分类。最终,在仿真平台上验证文中所提算法,仿真结果表明,对中性点箝位逆变器开路时瞬变非线性电流信号可以有效的提取故障特征,实现单、双管的开路故障诊断。 相似文献
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故障诊断是实现电机容错控制的前提,为了提高电机系统的可靠性,针对无刷直流电机驱动系统中逆变器功率管的开路故障,采用小波变换对电机三相电流信号进行分析,为了能快速地提取故障信息,提出利用3层以上细节信号的乘积作为检测信号,根据乘积信号的小波变换能够准确找到故障点,以低频小波信号的能量值作为提取特征来识别发生故障的逆变器功率管。该方法故障识别可靠性高,信号特征提取算法简单。仿真及实验结果验证了所提方法的有效性和准确性。 相似文献
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Gabriel Garcerá Raúl González‐Medina Emilio Figueres Jesús Sandia 《International Journal of Circuit Theory and Applications》2012,40(8):793-813
In photovoltaic (PV) double‐stage grid‐connected inverters a high‐frequency DC–DC isolation and voltage step‐up stage is commonly used between the panel and the grid‐connected inverter. This paper is focused on the modeling and control design of DC–DC converters with Peak Current mode Control (PCC) and an external control loop of the PV panel voltage, which works following a voltage reference provided by a maximum power point tracking (MPPT) algorithm. In the proposed overall control structure the output voltage of the DC–DC converter is regulated by the grid‐connected inverter. Therefore, the inverter may be considered as a constant voltage load for the development of the small‐signal model of the DC–DC converter, whereas the PV panel is considered as a negative resistance. The sensitivity of the control loops to variations of the power extracted from the PV panel and of its voltage is studied. The theoretical analysis is corroborated by frequency response measurements on a 230 W experimental inverter working from a single PV panel. The inverter is based on a Flyback DC–DC converter operating in discontinuous conduction mode (DCM) followed by a PWM full‐bridge single‐phase inverter. The time response of the whole system (DC–DC + inverter) is also shown to validate the concept. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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目前高压直流输电系统逆变侧发生不对称故障时,采用最小关断角判别法判别换相失败,其研究仅考虑电压因素,预测效果不理想.针对此问题,通过对换相失败机理和影响因素的分析,认为直流电流上升与交流电压下降均会使关断角减小,将直流电流与交流电压解耦,得到一个仅含电压变化率的逆变侧关断角表达式作为判据.该判据可依据对直流线路和逆变侧... 相似文献
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Abhilash Tirupathi Kirubakaran Annamalai Somasekhar Veeramraju Tirumala 《International Journal of Circuit Theory and Applications》2020,48(10):1744-1765
Three-phase single DC-source based multilevel inverter topologies play a pivotal role in industrial applications due to the reduced number of components and higher efficiency. This paper emphasizes the inverter for medium-voltage applications that employ a conventional three-phase T-type structure (T-NPC). The primary circuit of the proposed configuration consists of a T-NPC structure connected to the half-bridge cells at the top and the bottom sides of each phase. The secondary circuit consists of DC-link capacitors whose voltage balancing is attained through a separate voltage balancing circuit (VBC). Using the proposed configuration, the number of components and independent DC supplies are reduced compared with the conventional topologies such as a neutral point clamped (NPC) inverter, a flying capacitor (FC) inverter, and a cascaded H-bridge (CHB) inverter for the same number of output voltage levels. Hence, the proposed topology results in the reduction of weight, volume, and power losses of the inverter. A sine-triangle comparison method is employed in the field programmable gate array (FPGA) platform to generate the firing pulses of the circuit switches. The effectiveness of the proposed topology is verified with simulation studies and is experimentally validated with a scaled-down prototype. 相似文献
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