潮流能并网逆变器控制技术研究

发布时间：2018-12-12 05:57

【摘要】：随着新能源的不断发展,作为其中一个热门分支的海洋潮流能的开发利用也日益受到重视。随着研究的不断深入以及开发规模规模的逐渐扩大,潮流能并网发电技术也得到了快速发展。在这种背景下,在查阅了大量的文献基础之上,本文对潮流能发电系统中的并网逆变技术进行了研究。对比几种常见的逆变器拓扑结构形式,结合实际情况以及潮流能发电的特点,选取适合本文的拓扑结构并建立abc静止坐标系以及dq旋转坐标系下的状态和电路开关模型。为之后逆变器并网控制技术研究提供数学理论依据。在潮流发电系统当中,电力变换装置的结构选择直接会影响到系统的性能以及效率。本文采用的是一种双PWM变流器的两级式的变速恒频直驱式的潮流发电拓扑结构,该方式具有网侧和机侧功率因数高,注入电网电流谐波小的特点。机侧整流器应用一种变步长的MPPT算法,具有对水流速度变化跟踪快,不易引起最大功率点震荡的特点。网侧逆变器采用带电网电压前馈的电压电流双环的直接电流控制方式,具有系统调节速度快,控制简单,功率因数高的特点。文章对逆变器电压外环和电流内环进行了设计,电流内环设计为典型二阶系统,而电压外环则被设计为典型II型系统。并且分析了电网电压前馈的作用,同时应用了一种SPLL方式以保证并网电流与电网电压相位一致,使逆变器以高功率因数并网运行。在对控制策略进行了理论研究的基础之上,文章对采用该控制策略的样机进行了设计,包括直流滤波电容、三相桥臂器件选取、交流侧滤波器的设计和以ARM为核心的系统控制电路以及IGBT驱动的设计。文章还应用MATLAB/Simulink平台搭建了逆变器的仿真模型,并对软件锁相环和并网控制策略进行了仿真研究,为实际实验样机的设计调试提供可行性验证。最后,对试验样机进行了调试,以验证所采用的控制策略的正确性和可行性。
[Abstract]:With the development of new energy, the exploitation and utilization of ocean tidal energy, which is one of the most popular branches, has been paid more and more attention. With the deepening of the research and the expansion of the scale of development, the technology of grid-connected power flow has been developed rapidly. In this context, on the basis of a large number of references, the grid-connected inverter technology in power flow power generation system is studied in this paper. Compared with several common inverter topology forms, combined with the actual situation and the characteristics of power flow generation, select the topology suitable for this paper, and establish the state and circuit switch models under abc static coordinate system and dq rotation coordinate system. It provides the mathematical theory basis for the later research of grid-connected control technology of inverter. In the power generation system, the structure selection of the power conversion device will directly affect the performance and efficiency of the system. In this paper, a two-stage power flow topology with variable speed and constant frequency direct-drive is used in a double PWM converter, which has the characteristics of high power factor on the grid side and high power factor on the machine side, and low harmonic current in the injected power network. The machine side rectifier uses a variable step size MPPT algorithm, which has the characteristics of fast tracking of the change of flow velocity and difficulty of causing the maximum power point oscillation. The grid-side inverter adopts the direct current control mode with voltage and current double loop with grid voltage feedforward, which has the characteristics of fast system regulation, simple control and high power factor. In this paper, the voltage outer loop and the current inner loop of the inverter are designed. The current inner loop is a typical second order system, while the voltage outer loop is a typical II type system. The function of grid voltage feedforward is analyzed, and a SPLL method is applied to ensure that the phase of grid-connected current is the same as that of grid voltage, so that the inverter can run with high power factor. Based on the theoretical study of the control strategy, the paper designs the prototype of the control strategy, including DC filter capacitance, three-phase bridge arm device selection. The design of AC side filter, the system control circuit with ARM as the core and the design of IGBT driver. The simulation model of inverter is built by using MATLAB/Simulink platform, and the software phase-locked loop and grid-connected control strategy are simulated, which provides feasibility verification for the design and debugging of the actual experimental prototype. Finally, the test prototype is debugged to verify the correctness and feasibility of the proposed control strategy.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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