【作者】 朱良合；

【导师】 邹云屏；

【作者基本信息】 华中科技大学 ， 电力电子与电力传传， 2011， 硕士

【摘要】 随着越来越多的非线性负荷投入电网应用,三相四线制配电网系统谐波治理问题开始引起了人们的关注。由于三相四线制三电平有源滤波器可以有效滤除三相四线制电网负载谐波电流分量,且具有响应速度快、动态连续实时补偿的特点,故本文以三线四线制三电平三桥臂电容中分型APF的谐波补偿作为研究内容,深入研究APF系统的数学模型、电流环控制器设计和调制策略设计。本文建立了三相静止a - b - c坐标系下APF变换器表示为等效受控电压源和受控电流源时系统的数学模型,分析了直流侧电容电压平衡和不平衡两种情况下数学模型的异同点,从线性方程解空间的角度揭示系统调制策略灵活设计的原因。本文分析了一拍滞后实施对传统无差拍控制的影响,并在传统无差拍控制原理的基础上提出一种改进型无差拍控制,在系统模型参数精确的情况下,改进型无差拍控制将完全消除电压控制量一拍滞后实施的影响。本文分析了系统调制策略关于负载谐波电流补偿、中点电位控制、开关损耗控制的调制目标,并建立调制目标的精确数学表达式。在三相静止a - b - c坐标系下提出一种基于调制目标函数的优化调制策略。该调制策略最大程度地实现了负载谐波电流补偿、中点电位控制和开关损耗减小,可以作为实用的调制策略。本文搭建了基于浮点型DSP TMS320F28335的APF实验样机,完成了对所提改进无差拍控制和新型调制策略的实验验证。实验结果表明改进无差拍控制器较好地计算出合适的电压控制量,新型调制策略能同时完成电压控制量输出、中点电位平衡、开关损耗减小的调制目标,从而证明改进无差拍和新型调制策略的正确性和可行性。更多还原

【Abstract】 Due to more and more single phase non-linear loads being put into use, people begin to pay attentions to harmonic problem in three-phase four-wire system. The 3-phase 4-wire tri-level three-leg neutral-point split APF not only can effectively compensate the harmonic current in loads, but also has the characteristics of fast response and dynamic continuous real-time compensation, so this article mainly focuses on harmonic suppression technology of 3-phase 4-wire tri-level three-leg neutral-point split APF, mathematical models, the current loop controller design and modulation strategies design are studied in detail.In this thesis the system mathematical model is established in the a-b-c coordinate when APF converter is expressed as the equivalent of controlled APF converter voltage source and controlled current source, and analyze the similarities and differences between the mathematical models as the DC bus voltage under balanced and unbalanced , reveal the reason why modulation strategy can be designed flexibly from solution space of linear equationsIn this thesis the traditional deadbeat control affected by one-beat-delay implementation is analyzed in detail. Based on the principle of the traditional deadbeat control, a improved deadbeat control is proposed. If the precise model parameters have been given, the improved deadbeat control will completely eliminate the affect of voltage reference by one-beat-delay implementation.In this thesis the objectives of system modulation strategy with respect to load harmonic current compensation, mid-point potential control and switching power losses decrease, are analyzed in detail. The precise mathematical expressions about the objectives of system modulation strategy are also given, and then a optimal modulation strategy in the a-b-c coordinate is proposed based on functions of the objectives of system modulation strategy. The optimal modulation strategy furthest realize the load harmonic current compensation, the mid-point potential control and the switching power losses decrease, so it can be used as an practical modulation strategy.In this thesis an prototype of APF on floating-point DSP TMS320F28335 is established to verify the improved deadbeat control and the new modulation strategy. The results show that the deadbeat controller can well calculate the appropriate amount of voltage control, the new modulation strategy can also realize the objectives about load harmonic current compensation, mid-point potential control and switching power losses decrease, which verify that the improved deadbeat and anew modulation strategy are correct and feasible.更多还原