三相四线制三电平三桥臂APF控制策略研究

发布时间：2018-04-14 07:42

本文选题：有源电力滤波器 + 稳压控制　；参考：《安徽大学》2017年硕士论文

【摘要】：当今社会的发展离不开电能。随着近代社会突飞猛进的发展,大量的电力电子产品被人们使用。这给人们带来了便利,同时也给电力系统注入了大量的谐波、无功及零序电流。这些谐波、无功及零序电流不仅影响输电线路的使用寿命,同时影响周围用电设备的使用寿命,造成不必要的损失。因此,提高电能质量具有十分重要的意义。传统的无源滤波器只能对某些特定次谐波进行补偿,并不能满足需求,而有源电力滤波器(Active Power Filter,APF)具有良好的动态跟踪补偿性能,能够治理负载电流畸变,补偿基波正序无功分量以及补偿基波负序零序分量。本文主要研究对象为三相四线制三电平三桥臂APF,简单介绍了无功功率理论及谐波电流的几种检测方法。选用二极管钳位型三电平APF拓扑结构,介绍了 APF的工作原理,对二极管钳位型三电平APF逆变电路几种工作状态进行分析并建立对应abc三相坐标系下时域模型;为了便于控制器的设计进行d-q旋转坐标变换并采用前馈解耦控制,通过内环电流控制及外环电压控制实现对APF控制系统的设计,并对电流控制系统及电压控制系统PI调节器参数进行优化。单独分析了直流侧中性点电压不平衡原因,给出了完整的系统控制框图,为了抑制中性点电压偏移,采用SVPWM算法控制。分析了系统在含有零序电流及不含有零序电流两种情况下27个空间矢量对中性点电压的影响以及采取的相应控制措施,并对SVPWM算法进行简化处理。最后,对APF直流侧电容及交流侧LCL滤波器参数进行优化设计,并通过MATLAB搭建仿真模型,通过仿真波形的准确结果验证设计电路的可行性;搭建实验平台,测量相关参数及波形,验证文中给出的相关控制策略的有效性。
[Abstract]:The development of today's society can not do without electric energy.With the rapid development of modern society, a large number of power electronics products are used by people.This not only brings convenience to people, but also injects a lot of harmonics, reactive power and zero sequence current into power system.These harmonics, reactive power and zero-sequence currents not only affect the service life of transmission lines, but also affect the service life of the surrounding electrical equipment, resulting in unnecessary losses.Therefore, it is of great significance to improve the power quality.The traditional passive filter can only compensate some special subharmonics, but it can not meet the demand. The active Power filter (APF) has good dynamic tracking compensation performance and can eliminate the load current distortion.Compensates the fundamental wave positive sequence reactive power component and compensates the fundamental wave negative sequence zero sequence component.This paper mainly focuses on three-phase four-wire three-level three-level three-level three-bridge arm APF.The reactive power theory and several detection methods of harmonic current are briefly introduced.The three-level APF topology of diode clamping type is selected and the working principle of APF is introduced. Several working states of diode clamped three-level APF inverter circuit are analyzed and the time-domain model corresponding to abc three-phase coordinate system is established.In order to design the controller with d-q rotation coordinate transformation and feedforward decoupling control, the APF control system is designed by internal loop current control and outer loop voltage control.The Pi regulator parameters of current control system and voltage control system are optimized.The reason of voltage imbalance in DC neutral point is analyzed separately, and a complete system control block diagram is given. In order to suppress the voltage offset of neutral point, SVPWM algorithm is used to control it.The influence of 27 space vectors on the neutral voltage and the corresponding control measures are analyzed in the case of zero sequence current and zero sequence current, and the SVPWM algorithm is simplified.Finally, the APF DC side capacitance and AC side LCL filter parameters are optimized, and the simulation model is built by MATLAB. The feasibility of the design circuit is verified by the accurate results of the simulation waveform, and the experimental platform is built to measure the relevant parameters and waveforms.The effectiveness of the proposed control strategy is verified.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM761

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