【作者】 陈艳慧；

【导师】 刘开培；

【作者基本信息】 武汉大学 ， 电力电子与电力传动， 2004， 硕士

【摘要】 有源电力滤波器是一种新型的电力电子装置，可以有效的补偿电网谐波及无功电流，它具有实时性和准确性的工作特点。瞬时无功功率理论在有源电力滤波器中有着重要的应用，它在三相三线制电路中的应用已经比较成熟，但是在三相四线制电路中瞬时无功功率理论还存在诸多问题。本文针对三相四线制系统，从功率定义的角度讨论了几种不同的基于瞬时无功功率理论的功率定义方法及其补偿算法，并详细论述了p-q-r法在电力系统谐波检测中的应用。 本文首先在理论上分析比较了传统的瞬时无功功率理论和Nabae瞬时无功功率理论及其它们的补偿算法。得到这样的结论：当电压中无零序分量时，这两种补偿效果完全一致；当电压中含有零序分量时，两种方法补偿效果不一样，而且使用Nabae瞬时无功功率理论时不能将中线电流补偿到零。 本文还论述了p-q-r瞬时无功功率理论及其在谐波检测中的应用的局限性，并分析比较了p-q-r理论与传统瞬时无功功率理论的一致性。得到这样的结论：电压无畸变的情况下，p-q-r方法可以准确地检测出系统谐波电流，但在电压有畸变的情况下，由于p轴电压中含有高次分量，p、r轴电流同样均含有高次电流成分，因此不能准确检测出系统高次谐波；无论电压是否有畸变，p-q-r谐波检测与传统瞬时无功功率理论是等价的。 本文还讨论了重采样方法和均值滤波在p-q-r法中的应用。由于在p-q-r方法中电流和电压都要经过两次坐标变换，计算量较大。通过理论分析及仿真可以看到把p、q轴的电流只含有3的倍数次谐波，如果我们在有效信号不混叠的前提下进行重采样，同时采用合适的均值滤波器，不仅可以减小计算量，而且还可以有效减小滤波器的延迟时间。理论分析和仿真研究均证明了这种算法的正确性。 最后，本文用数据采集卡针对以上算法进行了实验，验证了以上方法的正确性。更多还原

【Abstract】 Active power filter is a new power electronic device which can effectively compensate harmonic and reactive current of network. It has many favorite work characteristic such as real-time and accuracy. Instantaneous reactive power theory has been widely used in active power filter, especially in three-phase three-line system. But there exits a lot of question when instantaneous reactive power theory is used in three-phase four-line system. This paper puts emphasis on three-phase four-line system. From the angle of power definition this paper brings forward several different power definitions based on instantaneous reactive power theory and their compensation algorithm. Beside this paper also discuss p-q-r theory and its application in harmonic detection in power system.Firstly, we discuss traditional instantaneous reactive power theory, Nabae instantaneous reactive power theory and their compensation methods. The conclusion is that when there isn’t 0 sequence voltage the two algorithms above is exactly the same when there exists 0 sequence voltage the two compensation methods is different from each other and the traditional theory can compensation neutral-line current. While Nabae theory cannot compensate neutral-line current to zero.Secondly, we discuss p-q-r instantaneous power reactive power theory and its limitation in harmonic detection. We can conclude that when the voltage is not distorted, p-q-r theory can detect harmonic of three-phase system accurately. But when the voltage is distorted, the voltage of p axle contain high-order voltage, the dc currents of p axle and q axle also contains high-order current, so high-order harmonic of three-phase can not be detected accurately. We also prove that p-q-r harmonic detection is equivalent with tradition power theory no matter whether the voltage is distorted.Thirdly, we still apply resample theory and main filter to p-q-r theory. In p-q-r theory, the voltages and currents must be transferred through twice coordinate conversions and calculation amount is very great. Through theory analysis and simulation we can see that the currents of p axle and q axle only contain 3k order harmonic (k is a integer). If we resample the currents of p axle and q axle with the premise that the effective signal is not overlapped and at same time adopt suitable main filter, then the calculation amount and the delay time of filter are both greatly reduced. Simulation proves this method correct.Lastly, we put those algorithms to tests using an A/D card and the results prove their correction.更多还原