【作者】 吴勇；

【导师】 万淑芸；

【作者基本信息】 华中科技大学 ， 控制理论与控制工程， 2007， 博士

【摘要】 有源电力滤波技术是一项涉及电力电子、检测技术、控制理论、信号处理及计算机技术等多学科的研究领域。随着工业现代化发展,电力系统中非线性负载的大量增加,日趋严重的谐波污染对电能的生产、利用以及设备的使用造成了很大的危害。有源电力滤波器是目前用来治理谐波污染最具前景的方法之一,它包含了多门学科的理论与技术,成为研究与开发的热点。目前有源电力滤波的研究主要集中在以下几个方面:高精度实时谐波检测和信号处理、电流快速跟踪智能控制、高功率因数变流技术以及主电路拓扑结构和非线性参数设计等。瞬时无功功率理论是谐波检测中使用最广泛的方法,本文详细分析了基于瞬时无功功率理论的谐波实时检测性能,针对其在动态响应性能上存在的不足,研究一种基于超前网络补偿的谐波检测方法。理论分析和仿真实验结果都表明,采用校正检测系统频率响应零点的方法能有效改善瞬时无功功率理论谐波检测的动态响应性能。基于瞬时无功功率理论谐波检测仅限于三相电路,而且受电网电压影响,小波变换在信号处理方面具有特殊的应用价值。本文对小波变换用于谐波电流实时检测的原理、小波基的选择、检测精度和动态性能进行了深入的分析,指出小波变换实时算法中的边界扩展是影响其检测性能的主要原因。通过分析电流幅值和小波系数之间的关系,提出一种基于小波系数的谐波检测实时补偿方法,使检测性能得到明显提高。建立有源电力滤波器的数学模型,是实现其控制的理论基础。本文在导出数学模型基础上,推导出开关函数和交流输出电压的数学表达式及频谱特征。分别从满足不同性能指标的角度对有源电力滤波器主电路各项参数进行了分析,给出了它们的取值范围和设计原则。针对谐波电流具有时变和变化率高的特点,对谐波电流跟踪预测控制进行了研究。从预测控制的三个基本特征出发,对有源电力滤波器电流预测控制的结构、原理、控制规律等方面进行研究,分析了电流预测控制参数对系统稳定性和动态响应性能的影响。采用电流预测控制有效的提高了电流控制精度和动态性能,对预测控制在快速响应系统中的应用作了有益尝试。本文以TMS320F2812控制器为核心,建立了有源电力滤波器实验平台,在该平台上对谐波检测和电压、电流控制进行了实验。对实验结果进行分析,给出了实验结论。更多还原

【Abstract】 The technology of active power filter (APF) is a research field concerning power electronic, detecting technique, control theory, signal processing and computer science. With the increasing of nonlinear loads in power system, serious harmonic current pollution has threathen the running of power system and affected the use of electrical equipments. APF is one of the most prospect methods to suppress harmonic contamination. It contains several theories and technologies, becoming the research hotspot. Today, research on APF mainly concentrates on real time high precision harmonic detectiong and signal processing, current controlling, high power factor conversion technique, main circuit topology structure and nonlinear parameters design.The instantaneous reactive power theory is widely used in harmonic detecting, and its capability is analyzed in this paper. To solve the shortcoming of instantaneous reactive power theory in dynamic performance, a new harmonic detecting method based on lead network compensation is proposed. The method improves the capability of harmonic detecting by correcting its zeros in frequency response. The theoretical analysis and computer simulations show that the method can improve the dynamic performance.Instantanous reactive power theory based harmonic detecting is limited in three-phase circuit and is immune to the electric voltage. Wavelet transform, for its special application value in signal processing, is used in real time harmonic detecting. The principle, wavelet basis, precision and dynamic response of harmonic realtime detecting based on wavelet transform are analyzed. This method has low performance because of boundary extension in wavelet arithmetic. Through analyzing the relationship between amplitude of current and wavelet coefficients, a compensation method is proposed. This compensation method can markedly improve the performance of real time harmonic detecting based on wavelet transform.The accurate mathematics model of active power filter is the theory base for control realization. After establishing the mathematics model, the spectrum of switching function and ac side voltage are analyzed. Studies on main circuit of APF, the calculating methods for main parameters are deduced to meet the performance.Real time and accurate harmonic current control is the key of APF. A harmonic current control, based on predictive control, is presented in this paper. The principle, structure, character and control rule of APF with current predictive control are analyzed. Especially, the stability and dynamic response of control system are discussed and the effects of parameters for performance are analyzed. Predictive control improves the precision and dynamic performance of current control and a useful attempt is made for predictive control to be applied in fast respone system.The APF experimental platform based on TMS320F2812 is presented. Harmonic detecting and current controlling experiments are done on the platform. The results of experiment are analyzed and the conclusions are drawn.更多还原