并网直驱式永磁同步风力发电最大功率跟踪控制策略

发布时间：2018-03-21 17:29

本文选题：直驱式风力发电　切入点：直流降压-升压变换器　出处：《西华大学》2014年硕士论文　论文类型：学位论文

【摘要】：直驱式永磁同步发电系统因噪声低、系统损耗低、可靠性高、系统运行效率高等优点,已成为大功率变速恒频风力发电领域的重要发展方向。而被动整流器+DC-DC电路+PWM(Pulse Width Modulate)逆变器的拓扑结构是其主要拓扑结构之一,该结构简单、可靠性高、控制算法复杂程度适中,具有较高的实用价值。本文以此结构为研究平台,着重研究在并网情况下如何实现最大功率跟踪控制,分别研究采用机侧变流器控制发电机定子电流和采用网侧变流器控制并网功率实现最大功率跟踪控制,并给出了控制策略。首先,研究了并网型直驱式永磁同步发电系统的工作原理及各组成部分的功能。详细分析了风力机的特性,建立了永磁同步发电机的数学模型,并对全功率变流器的控制结构作了简要介绍。其次,研究了全功率变流器的数学模型。针对机侧变换器,详细分析了三相桥式不控整流电路和Buck-Boost(降压—升压)电路输入电流、电压及输出电流、电压的变化情况；建立了并网逆变器在三相静止坐标系下的数学模型,根据坐标变换推导出并网逆变器在两相同步旋转坐标系下的数学模型。第三,针对采用机侧变换器实现最大功率点跟踪的控制方案,研究了机侧最大功率跟踪控制策略,包括最大功率跟踪控制和并网控制。简要分析了最大功率点跟踪的基本原理,研究了基于最佳电流的最大功率跟踪控制方法；研究了网侧PWM逆变器的直接电流解耦控制策略,对电流内环与电压外环分别建立了传递函数,并给出了控制结构中PI控制器参数的整定方法。第四,针对采用网侧逆变器实现最大功率点跟踪的控制方案,研究了网侧最大功率跟踪控制策略。详细分析了网侧最大功率点跟踪控制原理,以并网功率参考值为输入量,研究了网侧PWM逆变器的直接功率解耦控制策略；与机侧最大功率跟踪控制系统相比,该控制系统省去了电压内环,结构简单,更容易实现。最后,通过Matlab/Simulink建立并网直驱式永磁同步发电系统的仿真平台,分别建立了机侧最大功率跟踪控制系统和网侧最大功率跟踪控制系统,验证了上述两种控制系统的正确性和有效性,仿真结果表明,在最大功率跟踪的效率及跟踪速度方面具有相同的性能,但是网侧最大功率跟踪控制中直流母线电压更稳定,波动更小
[Abstract]:The direct-drive PMSG system has the advantages of low noise, low system loss, high reliability and high operating efficiency. It has become an important development direction in the field of high power variable speed constant frequency wind power generation, and the topology of passive rectifier DC-DC circuit PWM(Pulse Width modulator is one of its main topologies, which is simple and reliable. The control algorithm is of moderate complexity and has high practical value. Based on this structure, this paper focuses on how to realize the maximum power tracking control under the condition of grid-connected. The control of generator stator current by machine side converter and the control of grid-connected power by grid-side converter are studied respectively, and the control strategy is given. First of all, the working principle and the functions of each component of the grid-connected direct-drive PMSG system are studied. The characteristics of the wind turbine are analyzed in detail, and the mathematical model of the PMSG is established. The control structure of full power converter is introduced briefly. Secondly, the mathematical model of full power converter is studied. The variation of input current, voltage, output current and voltage of three-phase bridge type uncontrolled rectifier circuit and Buck-Boost-boost circuit are analyzed in detail. The mathematical model of grid-connected inverter in three-phase stationary coordinate system is established, and the mathematical model of grid-connected inverter in two-phase synchronous rotating coordinate system is derived according to coordinate transformation. Thirdly, aiming at the control scheme of maximum power point tracking using machine side converter, the control strategy of machine side maximum power tracking is studied. The basic principle of maximum power point tracking is briefly analyzed, the maximum power tracking control method based on optimal current is studied, and the direct current decoupling control strategy of grid-side PWM inverter is studied. The transfer function is established for the inner current loop and the voltage outer loop, and the tuning method of Pi controller parameters in the control structure is given. Fourthly, aiming at the control scheme of maximum power point tracking using grid-side inverter, the control strategy of maximum power tracking is studied. The principle of maximum power point tracking is analyzed in detail, and the reference value of grid-connected power is taken as input. The direct power decoupling control strategy of the grid-side PWM inverter is studied. Compared with the maximum power tracking control system on the machine side, the control system saves the voltage inner loop, and is simpler in structure and easier to realize. Finally, the simulation platform of grid-connected direct-drive PMSG system is established by Matlab/Simulink, and the maximum power tracking control system on the machine side and the maximum power tracking control system on the grid-side are established, respectively. The correctness and effectiveness of the two control systems are verified. The simulation results show that the efficiency and tracking speed of the maximum power tracking are the same, but the DC bus voltage is more stable in the maximum power tracking control on the grid side. Less volatility.
【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

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