交直流混合微电网建模与变流器控制技术研究

发布时间：2018-03-05 04:26

本文选题：交直流混合微电网　切入点：光伏电池　出处：《山东大学》2014年硕士论文　论文类型：学位论文

【摘要】：微电网是包含有本地发电装置、储能装置和本地负荷,并具有一定的自我调节和控制能力的配电子网,交直流混合微电网结合了交流微电网和直流微电网的各自优点。相对于单纯的交流微电网和直流微电网,交直流混合微电网减少AC/DC和DC/AC损失；可以同时用于交流负荷和直流负荷,减少用户设备内的变频装置,降低设备的制造成本。目前国内对交直流混合微电网的研究仍处于探索阶段,不同运行模式下变流器的控制策略及其协调控制是微电网系统稳定运行的关键。本文主要研究基于主从控制的交直流混合微电网系统微源建模与变流器控制技术研究,主要工作如下：首先建立双向AC/DC变流器的数学模型,在此基础上研究分析双向AC/DC变流器在不同运行模式下采用的控制策略：PQ控制和Vf控制。分别对PQ与Vf控制方法中的电流内环、电压外环控制器进行相应设计,且控制器调制方法采用SVPWM实现。其次理论分析光伏电池工作原理及输出特性,建立光伏电池工程仿真模型,深入分析研究交直流母线侧光伏电池在并网模式下采用的MPPT控制策略与孤岛模式下采用的MPPT与限功率控制策略；分析蓄电池的工作原理与充放电特性并建立其仿真模型,深入研究蓄电池在不同运行模式下的控制策略：恒流充放电与电压闭环控制。分析仿真结果验证所建模型的正确性。最后在Matlab/Simulink仿真环境中搭建交直流混合微电网及其控制系统仿真模型,分析交直流混合微电网在并网模式下的6种工作状态与孤岛模式下的4种工作状态,改变微电源的外部环境或负载情况进行各工作状态间的切换,分析仿真结果验证系统协调控制的有效性。
[Abstract]:A microgrid is an electronic distribution network that includes local power generation devices, energy storage devices and local loads, and has a certain capacity for self-regulation and control. The AC / DC hybrid microgrid combines the advantages of AC microgrid and DC microgrid. Compared with the simple AC microgrid and DC microgrid, the AC / DC hybrid microgrid reduces the loss of AC/DC and DC/AC. It can be used to both AC load and DC load, reduce the frequency conversion device in the user's equipment, and reduce the manufacturing cost of the equipment. At present, the research on AC / DC hybrid microgrid is still in the exploratory stage in our country. The control strategy and coordinated control of converters in different operation modes are the key to the stable operation of microgrid systems. This paper mainly studies the micro-source modeling and converter control technology of AC / DC hybrid microgrid system based on master-slave control. The main work is as follows:. Firstly, the mathematical model of bidirectional AC/DC converter is established. On the basis of this, the control strategies adopted in different operation modes of bidirectional AC/DC converter are studied, namely, the control strategy: PQ control and VF control. The current inner loop of PQ and VF control methods are analyzed respectively. The voltage outer loop controller is designed and the modulation method of the controller is implemented by SVPWM. Secondly, the working principle and output characteristics of photovoltaic cells are analyzed theoretically, and the engineering simulation model of photovoltaic cells is established. The MPPT control strategy of AC / DC bus side photovoltaic cell in grid-connected mode and the MPPT and limited power control strategy in isolated island mode are deeply analyzed, and the working principle and charge-discharge characteristics of battery are analyzed and its simulation model is established. In this paper, the control strategies of battery in different operation modes, constant current charge and discharge and voltage closed loop control, are studied, and the simulation results verify the correctness of the model. Finally, the simulation model of AC / DC hybrid microgrid and its control system is built in the Matlab/Simulink simulation environment, and six working states of AC / DC hybrid microgrid in grid-connected mode and four working states in isolated island mode are analyzed. Changing the external environment or load of the micro-power supply to switch between different working states, the simulation results verify the effectiveness of the coordinated control of the system.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46

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