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提出了一种单相并联混合型有源电力滤波器电路结构.该电路由有源滤波器与基波串联谐振支路并联再与无源滤波电路串联构成,用于抑制非线性整流负载产生的谐波电流流入电源侧.在该电路中,无源滤波器分担大部分抑制谐波和无功补偿的任务,减少了有源滤波器的容量;有源电力滤波器用于改善无源滤波器的滤波效果和抑制它与系统阻抗可能发生的谐振.理论分析和实验结果表明,该混合型有源滤波器充分发挥了无源滤波器和有源滤波器各自的优点,改善了无源滤波器的滤波性能,同时使有源滤波器不再承受基波电压,因此最大限度地减少了有源滤波器的容量,从而使有源电力滤波器能够应用于大功率场合. 相似文献
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提出了一种混合型有源电力滤波器电路结构。该电路由有源滤波器与基波串联谐振支路并联再与无源滤波电路串联构成,用于抑制非线性整流负载产生的谐波电流流入电源侧。在该电路中,无源滤波器分担大部分抑制谐波和无功补偿的任务,减少了有源滤波器的容量;有源电力滤波器用于改善无源滤波器的滤波效果。理论分析和实验结果表明,该混合型有源滤波器充分发挥了无源滤波器和有源滤波器各自的优点,改善了无源滤波器的滤波性能,同时使有源滤波器不再承受基波电压,因此最大限度地减少了有源滤波器的容量,使有源电力滤波器能够应用于大功率场合。 相似文献
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基于瞬时无功功率理论的串联混合型单相电力有源滤波器 总被引:51,自引:12,他引:51
本文介绍一种串联混合型单相电力有源滤波器。首先与无源滤波器及并联型有源滤波器对比,分析了其补偿原理和特点。随后,介绍了其主电路结构及各部分功能。在对三相电路瞬时无功功率理论的思想进行扩展的基础上,得到了单相电路谐波电流的瞬时检测方法。对实现这于检测方法的基于DSP微处理器的数字控制电路的结构和工作过程也作了简要介绍。仿真和实验结果表明,该检测方法是有效的基于此检测方法的串联混合型单相电力有源滤波器 相似文献
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为了同时适合电压型谐波源和电流型谐波源的滤波,同时具有传统有源滤波器的并联型结构,本文提出一种基于复合控制的通用型有源电力滤波器,其基本原理为:检测系统的谐波电流和谐波源两端的基波电压,将这两个信号进行放大和组合后作为参考信号,通过电力电子逆变器产生一个电压源,将该电压源与一个带有较小阻抗值的联接电抗相串联后并联在谐波源和电力系统两端。理论分析表明该有源电力滤波器对基波进行动态无功补偿,对谐波相当于串联一个谐波高阻抗和并联一个谐波低阻抗,兼具疏导和隔离谐波的作用,从而构成一种高性价比的有源电力滤波器。该滤波器结构简单,保护方便,滤波效果好,逆变器容量小,适合于两种类型的谐波源。实验结果证明了该原理的有效性。 相似文献
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Bert Renders Koen De Gussemé Wouter R. Ryckaert Lieven Vandevelde 《Electric Power Systems Research》2009
The steadily growing share of converter-connected distributed generators, combined with a large amount of nonlinear and unbalanced loads connected to the electric power system, has led to a degraded power quality. Both harmonic voltage and harmonic current distortion may cause many unfavourable effects on the power system. However, the converter-connected distributed generators can be redesigned to have a positive effect on the distortion of the grid voltage. Two different approaches can be discerned. At the one hand, distributed generation units can be controlled to synthesize a resistive load for harmonic voltage components. This approach is called harmonic voltage damping. At the other hand, if the polluting current of an adjacent nonlinear load is measured and added to the control loop, the converter-connected distributed generator is able to compensate all harmonic current components of the nonlinear load. This approach is referred to as harmonic current compensation. In this paper, a control strategy for a converter-connected distributed generator is extended with a harmonic voltage damping function and a harmonic current compensation function. Experimental tests show that the voltage distortion of the grid voltage can be significantly improved. 相似文献
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Tien-Ting Chang Hong-Chan Chang 《Power Delivery, IEEE Transactions on》2000,15(3):990-995
This paper presents a combined differential evolution/multiple gradient summation approach for reducing harmonic distortion with active power line conditioners (APLCs). The purpose of this approach is to minimize the total injection currents of APLC's while satisfying harmonic standards and practical constraints such as the individual harmonic voltage distortion, total harmonic voltage distortion limits, and the commercially available discrete sizes of the APLCS. The proposed approach was tested on an 18-bus radial distribution system. Results obtained show that the proposed approach can effectively solve the APLC installation problem 相似文献
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针对目前谐波电流造成特定线路各元件损耗难以明确其来源的问题,提出一种基于无功功率方向法来判别引起公共连接点(point of common coupling,PCC)处的主谐波电流来源方法。通常情况下,系统侧和用户侧谐波源流过特定线路各元件造成的损耗大小,可由两侧各自贡献的谐波电流大小区分,故以谐波电流指标为判别依据。以电网中谐波阻抗基本性质为基础,结合PCC处谐波电压和电流实测信息,利用基本电路原理和不等式约束条件,在谐波无功功率方向法的思路与判别条件下,推导得出了仅根据谐波电压和电流的相角差,就可直接判别主谐波电流来源的方法。最后,通过多种实际工程场景的实测数据,验证了该方法的有效性,使用中的便捷性反映了该方法在工程实用中的价值。 相似文献
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《International Journal of Electrical Power & Energy Systems》2012,40(1):36-47
This paper presents a probabilistic approach to design an optimal size of photovoltaic distributed generator (PV-DG) in a distribution system. A steady-state voltage stability index is applied to select PV-DG locations. The objective of the proposed technique is to minimize average system active power losses, while considering power quality constraints (i.e., voltage regulation, total harmonic voltage distortion, total demand distortion and harmonic currents). Monte Carlo simulation is applied to acquire solar radiations, ambient temperatures, load demands and substation voltages. The proposed technique is tested on an actual 51-bus medium voltage distribution system in Thailand. From simulations, there is a different solution between selecting the optimal size of PV-DG from with and without considering background harmonics. Also in realistic cases, PV-DGs may improve voltage regulation and decrease losses in distribution systems; however, increase total harmonic voltage distortion values. 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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《Electric Power Systems Research》1999,52(2):181-188
The active power line conditioner (APLC) is a type of active power filter that compensates the voltage waveform distortion caused by harmonics in power systems. This paper presents a new approach based on the authors’ previously presented two-level algorithm, optimal harmonic power flow (OHPF), to investigate the determination of locations and sizes of APLCs: the master level determines the compensator/tap settings and the new APLC locations/sizes; the slave level includes subproblems which involve cases of fundamental and harmonic frequencies separately. The objective is to minimize the new APLC injection currents, the voltage distortion, and the KW losses while satisfying the power flow equations, the harmonic power flow equations, the security constraints, and the harmonic standard. Test results for an 18-bus distribution system show the applicability of the proposed method. 相似文献
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为了提高功率因数校正(power factor correction,PFC)输出电压对负载变化的动态性能,在分析电压环对输入输出谐波影响的基础上,提出一种快速动态响应数字PFC算法。该算法通过增大电压环带宽来提高负载动态响应速度,采用矢量旋转方式产生谐波补偿量来抵消因电压环带宽增大引起的二次谐波。它无需增加外围硬件电路,通过与控制芯片相对应的图形化编程方式完成快速动态响应数字算法。实验结果表明当负载功率发生大范围变化时,所设计的系统具有快速动态响应能力,同时输入电流总谐波畸变率(total harmonic distortion,THD)小于10%,功率因数达到0.99。 相似文献
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针对传统的被动式光伏并网孤岛检测存在的检测死区问题,提出一种基于双向谐波电压变化量的光伏并网孤岛检测方法。通过分析孤岛前后谐波电压的变动及传统谐波电压检测法的失效机理,提出基于双向谐波电压的孤岛检测策略。利用加窗傅里叶变换同步计算光伏集中并网发电系统送出线路电流及所接母线电压的谐波,从而获得各次谐波功率;由并网运行时谐波功率的正负极性判断各次谐波源方向,并根据正、负最大谐波功率值选择系统侧、光伏侧谐波的特征频次;利用滑动加窗傅里叶变换分析这2个频次的母线谐波电压变化量,建立孤岛检测判据,若系统侧谐波电压减小量和光伏侧谐波电压增加量均满足判据,则发生孤岛。仿真结果验证了所提方法的有效性。该方法不影响并网逆变器输出的电能质量,且能在较严重背景谐波下有效检测孤岛,检测死区较小。 相似文献