改进型单位功率因数法的有源电力滤波器研究

发布时间：2018-07-30 08:40

【摘要】：随着技术的进步,越来越多的先进设备投入电力系统中使用。这些设备多数是非线性设备并产生了谐波电流,因此有必要采取有效措施治理电力系统谐波。治理谐波电流的方法较多,装设有源电力滤波器(APF)是一种较为理想的方法,并在实际中广泛应用。研究的方面主要有谐波电流检测、变流器控制和直流侧电压控制。本文研究APF的谐波电流检测中的单位功率因数法,并根据实际应用的要求提出了改进方法。本文根据研究的现状选择并联型APF作为研究对象,对比了用于该类型APF的几种常用的谐波电流检测方法的优缺点。根据比较的结果,单位功率因数法被选定为谐波电流检测方法,但是该方法非常容易受到电网畸变电压的影响,对此本文提出了改进方法,采用自适应滤波器消除电网谐波电压,将电压滤波后再计算基波电流。滤波器采用LMS算法,为了减小稳态误差提出了新的变步长算法,新算法利用相对误差信号作为参考信号计算步长因子,用于改善稳态误差并实时调整步长因子。对新的变步长算法通过Matlab软件搭建了仿真模型,针对新方法与传统方法的性能参数进行了比较,仿真结果充分显示了新方法消除谐波电压具有较好的效果,比传统方法要好很多。在此基础上,对APF系统进行了仿真,仿真结果显示出在电网电压畸变的条件下,改进方法能够实现对谐波电流的补偿作用。在仿真的基础上,利用数字信号处理器(DSP)搭建了硬件实验装置,完成了对并联型APF的软件与硬件设计。硬件设计主要涉及主电路、驱动电路、采样电路和保护电路等方面,并对一些主要电气元件进行了选型。软件设计主要涉及主程序流程和谐波检测部分程序流程。
[Abstract]:With the development of technology, more and more advanced equipments are used in power system. Most of these equipments are nonlinear and produce harmonic current, so it is necessary to take effective measures to control the harmonic of power system. There are many methods to control harmonic current. (APF) with source power filter is an ideal method, and it is widely used in practice. The main research areas are harmonic current detection, converter control and DC side voltage control. In this paper, the unit power factor method for harmonic current detection in APF is studied, and an improved method is proposed according to the requirements of practical application. In this paper, parallel APF is selected as the research object according to the present situation of the research, and the advantages and disadvantages of several common harmonic current detection methods for this type of APF are compared. According to the comparison results, the unit power factor method is selected as the harmonic current detection method, but the method is very vulnerable to the influence of the power grid distortion voltage. In this paper, an improved method is proposed. The harmonic voltage is eliminated by adaptive filter and the fundamental current is calculated after filtering the voltage. In order to reduce the steady-state error, a new variable step size algorithm is proposed. The new algorithm uses the relative error signal as the reference signal to calculate the step size factor, which is used to improve the steady-state error and adjust the step factor in real time. The simulation model of the new variable step size algorithm is built by Matlab software. The performance parameters of the new method and the traditional method are compared. The simulation results show that the new method has a good effect on eliminating harmonic voltage. It is much better than the traditional method. On this basis, the APF system is simulated. The simulation results show that the improved method can compensate the harmonic current under the condition of voltage distortion. On the basis of simulation, the hardware experiment device is built by using digital signal processor (DSP), and the software and hardware design of parallel APF is completed. The hardware design mainly involves the main circuit, drive circuit, sampling circuit and protection circuit, and some main electrical components are selected. Software design mainly involves the main program flow and harmonic detection part of the program flow.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713.8;TM761

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