共查询到19条相似文献,搜索用时 62 毫秒
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高电压等级电力系统中,大容量有源电力滤波器的谐波抑制性能主要受主电路开关器件耐压水平和工作频率的限制.提出一种由有源级联多电平逆变器和无源单调谐滤波器构成的混合型有源电力滤波器主电路拓扑结构以及该混合型装置主要参数的设计方法.由于无源滤波器的存在,稳态运行时,可以大幅降低有源部分的容量和耐压水平,同时分析了该混合型装置绝大多数基波电压由无源部分承担的原因.此外,有源部分级联结构的应用可以降低单个开关器件的耐压水平,获得较高的等效输出频率.对级联混合型有源电力滤波器主电路及其控制系统进行仿真,仿真结果验证了所提方案的特点以及良好的补偿效果. 相似文献
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并联混合型有源电力滤波器仿真分析 总被引:2,自引:0,他引:2
并联混合型有源电力滤波器能够很好地实现谐波抑制和无功补偿.给出了有源电力滤波器系统结构,建立了数学模型,还给出了主电路直流侧电容电压值和交流侧电感值的选取方法,利用 Matlab\Simulink \PSB构建了仿真模型,得到了仿真结果. 相似文献
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针对高压有源电力滤波器,为了采用级联结构时在相同的级联数目下可以获得更多的电平数,同时提高输出功率等级,并且考虑到开关频率和系统补偿特性关系,采用一种混合级联多电平拓扑结构。该有源电力滤波器由可以等效为电压源与电流源的两部分串联组成,电流源部分为传统的PWM变换器;电压源部分由3个H桥逆变器级联构成,其输出电压的基波分量可以抵消电网电压,因此电流源部分的PWM变换器交流侧承受的电压很低,有功损耗小,从而可以提高PWM变换器的开关频率,从而谐波抑制的效果更好。其控制策略简单,易于实现。作为高压大容量有源电力滤波器预研,在单相电网电压有效值220V条件下,通过MATLAB仿真和实验结果证明了该拓扑的有效性和实用性。 相似文献
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并联混合型有源电力滤波器能够很好地实现谐波抑制和无功补偿。给出了有源电力滤波器系统结构,建立了数学模型,还给出了主电路直流侧电容电压值和交流侧电感值的选取方法,利用 Matlab\Simulink \PSB构建了仿真模型,得到了仿真结果。 相似文献
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针对高压有源电力滤波器,为了减小有功损耗且提高补偿性能,提出一种改进型混合级联多电平拓扑结构,等效为电压源与电流源相串联。电压源由混合级联27电平变换器构成,其输出电压的基波分量与高压配电网电压相抵消,从而为电流源的运行提供了很低的电压环境。电流源由PWM变换器构成,其额定功率很小,IGBT开关频率较高,从而使得有源电力滤波器具有极好的补偿性能。有源电力滤波器的主要功率由开关频率50/60 Hz的方波变换器输出,从而使得有源电力滤波器的总损耗很小。理论分析与仿真结果证明了该新型拓扑结构的有效性。 相似文献
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This paper presents a characteristics comparison of a high‐frequency multilevel inverter connected with small‐ capacity filter inverters. In general, PWM inverters require a low‐pass filter in order to reduce switching harmonics. However, in the high‐frequency systems such as class D power amplifiers, the cutoff frequency of the low‐pass filter must be set at high frequency. Thus, harmonic distortion of the output voltage is enlarged to a harmful level. Increasing the number of output voltage levels is effective in reducing the harmonic distortion of the output voltage and the low‐pass filter size. The proposed systems consist of a five‐level inverter and several cascade‐connected low‐voltage full bridge inverters without any external DC power sources for filtering the output voltage. The five‐level inverter generates a stepwise waveform with five‐level voltage, and the low‐voltage filter inverter superimposes harmonic components to compensate for the voltage waveform distortion. Therefore, the proposed system can reduce its total switching loss and can increase the number of the output voltage levels. In this paper, the effectiveness of the proposed systems is verified through several experiments. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(3): 58–65, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20373 相似文献
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单独注入式APF直流侧电压的稳定控制 总被引:2,自引:1,他引:1
有源电力滤波器(APF)的直流侧电容电压不稳定直接影响滤波装置的补偿性能.通过对单独注入式.APF的直流侧电容电压升高机理进行分析,得出了APF的能量交换中有功功率与无功功率的流动造成直流侧电压的波动,同时当逆变器开关损耗及输出滤波器内阻损耗小于回灌到APF直流侧的有功功率时,直流侧电压也会抬升的结论.一方面在注入电路参数设计中考虑了实际应用中要注意电网电压的冲击等情况,以保证逆变器中功率器件的安全运行;另一方面提出对直流侧电容电压进行模糊控制的方法,通过检测滤波器支路的基波电流,控制APF产生与基波电流方向相同或相反的基波电压,来实现主动地控制APF从电网吸收或向电网释放有功功率,从而提高了电容电压稳定性. 相似文献
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This paper aims at the investigation of an active power filter (APF) comprised of a transformerless multilevel inverter (MLI) for power conditioning in three-phase three-wire distribution network. The inverter topologies used here are three, five, seven and nine-level. The system configuration mainly involves cascaded MLI structure of APF, generation of compensation filter currents based on instantaneous active and reactive current component (id–iq) method and dc-link voltage regulation using a PI controller. Not many papers focus on the regulation of dc-link capacitor voltage. Here we have proposed the implementation of bacterial foraging optimization (BFO) to extract the gains of PI controller. The proposed work provides improved dc-link voltage regulation, quick prevail over current harmonics and reduction of overall source current THD. Adequate MATLAB/Simulink simulation results are presented for the different cascaded MLIs discussed above. Additionally, the performance has been validated in real-time using Opal-RT Lab simulator considering three different conditions of supply i.e., balanced sinusoidal, balanced non-sinusoidal and unbalanced sinusoidal. 相似文献
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Yu‐Kang Lo Tian‐Fu Pan Jian‐Min Wang 《International Journal of Circuit Theory and Applications》2008,36(8):975-982
A new strategy for setting the DC voltage level of an active power filter is proposed in this letter. By determining the peak slope of the command for the compensating current within a defined load range, an optimal value for the DC voltage level can be determined based on the trade‐off between an undistorted input current and a minimum switching loss. Experimental results conform well with the theoretical analysis. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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为解决三桥臂电容中点式三相四线有源电力滤波器存在的上下桥臂直流侧电压不平衡的问题和启动过程中直流侧电压超调的问题,提出一种三闭环控制策略。通过分析直流侧电压对控制系统的影响,纹波产生的原因,提出直流侧电压的控制指标。在分析直流侧电压与能量交换的关系的基础上,提出一种直流侧电压均压控制方法。针对直流侧总电压在启动过程中的超调问题给出解决方案,给出一种软启方案控制超调,并在大负载和小负载两种情况提出不同控制方案。最后通过实验数据,对这些控制方案进行了验证。 相似文献