永磁直驱风力发电系统并网控制策略研究

发布时间：2018-06-28 06:44

本文选题：永磁直驱型风力发电 + 最大风能跟踪　；参考：《辽宁科技大学》2014年硕士论文

【摘要】：随着煤、石油、天然气等化石燃料资源日趋枯竭，能源安全问题越来越受到世界各国的广泛关注。全球空气污染和温室效应的日趋严重，促使全球掀起了一股追求绿色电力的热潮。风能以其取之不尽、用之不竭、无污染的特点，越来越受到人们的广泛重视。近些年来，我国风力发电市场不断扩大，风电产业得到迅猛发展。在风力发电系统中，基于电力电子技术的功率变换器是主要的核心装置，通过控制变换器实现发电机与电网之间的柔性连接，，调节发电机转速，同时对风电系统稳定、高效的运行有重要意义。本文主要对永磁直驱式风力发电机系统的并网变流器进行研究。相对于双馈型风力发电系统，它省去了故障率较高的齿轮箱，从而降低了发电机组运行维护的成本，提高了系统的可靠性和整体的效率。直驱式风力发电系统还可以实现对电网有功、无功功率的灵活控制。同时发电机与电网之间的全功率变流减少了它们的相互影响，低电压穿越性能优良。第1部分，对比研究了直驱型风力发电系统两种常用的拓扑结构，对比了它们各自的优缺点。选择“不可控整流器+Boost升压斩波电路+PWM逆变器”作为自己的拓扑结构。同时，简单介绍了与机侧整流器相关的最大风能跟踪（MPPT）理论、贝茨理论以及与网侧逆变器相关的空间矢量脉冲宽度调制（SVPWM）。第2部分，根据直驱型风力发电系统机侧的拓扑结构，建立其数学模型。首先，研究了机侧最大风能跟踪点的获取方法和最大风能跟踪（MPPT）的控制算法；然后，根据升压斩波电路的控制方法，选择转速外环电流内环的双闭环控制作为本文直驱型风力发电系统机侧的控制策略；最后，做出了总的控制结构图。第3部分，根据直驱型风力发电系统网侧的拓扑结构，建立其在三相静止坐标系下的数学模型和两相旋转坐标系下的数学模型。首先，根据并网逆变器的逆变原理，选择电压外环电流内环的双闭环控制策略作为本文并网逆变器的控制策略。然后，对于电压外环控制，选择模糊控制改进其PI控制器，对于电流内环控制，选择直接电流控制和PR控制器，实现内环的控制目标。最后，做出了总的控制结构图。第4部分，在MATLAB/SIMULINK环境下，对永磁直驱风力发电系统的整流部分和逆变部分，分别进行了相关的建模和仿真。通过分析它们的仿真结果，验证了本文控制策略的正确性和有效性。
[Abstract]:With the depletion of fossil fuel resources, such as coal, oil and natural gas, energy security has attracted more and more attention all over the world. Global air pollution and Greenhouse Effect are becoming more and more serious. Wind energy has been paid more and more attention for its inexhaustible and pollution-free characteristics. In recent years, China's wind power market has been expanding, wind power industry has been rapid development. In wind power generation system, power converter based on power electronics technology is the main core device. Through the control converter, the flexible connection between generator and power grid can be realized, and the speed of generator can be adjusted. At the same time, it is stable to wind power system. Efficient operation is of great significance. In this paper, the grid-connected converter of permanent magnet direct drive wind turbine system is studied. Compared with the doubly-fed wind power system, it saves the gearbox with high failure rate, thus reduces the cost of operation and maintenance of the generator set, and improves the reliability and overall efficiency of the system. Direct drive wind power system can also realize the flexible control of active and reactive power. At the same time, the full power converter between the generator and the grid reduces their interaction, and the low voltage traversing performance is excellent. In the first part, two common topology structures of direct-drive wind power system are studied, and their advantages and disadvantages are compared. The uncontrollable rectifier boost chopping circuit PWM inverter is chosen as its own topology. At the same time, the maximum wind energy tracking (MPPT) theory, Bates theory and space vector pulse width modulation (SVPWM) are introduced. In the second part, according to the topology of direct drive wind power system, the mathematical model is established. Firstly, the acquisition method of maximum wind energy tracking point and the control algorithm of maximum wind energy tracking (MPPT) are studied, and then, according to the control method of boost chopper circuit, The double closed loop control of the outer loop current and inner loop is selected as the control strategy of the direct-drive wind power system in this paper. Finally, the overall control structure diagram is given. In the third part, according to the topology of the grid side of the direct-drive wind power system, the mathematical model in the three-phase stationary coordinate system and the two-phase rotating coordinate system is established. Firstly, according to the inverter principle of grid-connected inverter, the double-closed loop control strategy of voltage outer loop current inner loop is selected as the control strategy of grid-connected inverter in this paper. Then, for voltage outer loop control, fuzzy control is selected to improve its Pi controller, and for current inner loop control, direct current control and PR controller are selected to realize the control goal of inner loop. Finally, the overall control structure is given. In the fourth part, in the environment of MATLAB / Simulink, the rectifier part and the inverter part of the permanent magnet direct drive wind power generation system are modeled and simulated respectively. By analyzing their simulation results, the correctness and effectiveness of the control strategy are verified.
【学位授予单位】：辽宁科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

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