【作者】 刘彬；

【导师】 曲延滨；

【作者基本信息】 哈尔滨工业大学 ， 电气工程， 2012， 硕士

【摘要】 由于不可再生能源的日益枯竭，可再生能源的利用和开发得到了全世界范围内的重视，目前发展较快的是风力发电技术。直驱永磁风力发电系统采用变速恒频风力发电技术，能够实现最大功率追踪，而且不需要齿轮箱，可靠性高，维护成本低，对电网影响小，低电压运行能力强，引起了广泛的关注。本文对直驱永磁风力发电系统的变流器控制策略和永磁同步发电机的无速度传感器控制方法进行了研究，主要研究内容如下：首先分析了直驱永磁风力发电系统的整体结构和主要组成部分，然后对系统各个主要部分进行了数学建模，分别建立了风力机、传动轴、永磁同步发电机、PWM变流器的数学模型。对背靠背PWM变流器的控制策略进行了分析和研究，主要分为发电机侧PWM变流器控制和电网侧PWM变流器控制，利用永磁同步发电机在两相旋转坐标系下的数学模型，采用磁场定向的原理，分析了永磁同步发电机的矢量控制原理，采用叶尖速比法实现最大功率追踪，建立了转速外环、电流内环的双闭环控制策略，并对控制策略的有效性进行了仿真分析。利用PWM变流器的数学模型和电网电压矢量定向的原理，建立电网侧PWM变流器直流母线电压外环，电流内环的双闭环控制策略，并对控制策略的有效性进行了仿真分析。分析了滑模变结构控制理论的基本原理，基本性质和设计过程，以发电机输出功率快速跟踪给定功率为控制目标，设计了滑模功率控制器，建立了发电机侧变流器功率外环，电流内环的双闭环控制策略，仿真结果表明输出功率能够快速跟踪最大功率，无静差，在风速变化时，发电机输出功率响应快，波动小。为了克服光电编码器的缺点和不足，研究了直驱永磁风力发电机的无传感器控制方法，采用滑模观测器来实现对转子转速和位置的估计，首先建立了传统滑模观测器方程，针对存在的抖振问题进行了分析，采用改进型饱和函数削弱了抖振强度。为了实现对高频抖振噪声更好的抑制，设计了随参考电角速度变化的开关增益自适应规律，构建了扩展的滑模观测器方程，得到了反电势和电角速度的自适应规律。最后对直驱永磁风力发电系统的无传感器控制性能进行了仿真分析，仿真结果表明所设计的自适应滑模观测器可以实现转子转速和位置角的准确估计，而且对发电机定子参数变化具有较强的鲁棒性。更多还原

【Abstract】 With the non-renewable energy resource exhausting, the use and development ofrenewable energy get the worldwide attention, wind power technique develops fasterthan the others at present. Direct-driven permanent magnet wind power system is a vscfwind power system, it can realize the maximum power tracking and work without gearbox, so its maintenance cost is small, and it also has small effects on power grids andstrong low voltage operation ability, so it has got great public attention. In this paper,the control strategy of converter system for direct-driven permanent magnet wind powergeneration system and sensorless control method of the permanent magnet synchronousgenerator is studied, the main research contents are as follows:First the overall structure and the main components of the direct-driven permanentmagnet wind power system is analysed, and then mathematical model of the main partsconsist of wind turbine, transmission shaft, the permanent magnet synchronousgenerator and the PWM converter is built.The control strategy of back to back PWM converter is studied, it mainly dividesinto the control of the generator side converter and the power grid side converter. Thenuse mathematical model of the permanent magnet synchronous generator in two phaserotation coordinate and the field-oriented principle to analyse vector control theory ofthe permanent magnet synchronous generator, choose tip speed ratio as the maximumpower tracking method, last the double closed loop control strategy is set up, the outerring is speed and inner ring is current, the simulation results verify the effectiveness ofthe control strategy. Use mathematical model of the PWM converter connected to thepower grid and voltage vectordirectional principle to set up the double closed loopcontrol strategy of the power grid side converter, the outer ring is voltage and inner ringis current, the simulation results verify the effectiveness of the control strategy.The basic principles, the basic properties and the design method of the slidingmode variable structure control theory is analysed. The control goal is that the outputpower of generator fastly track the reference power, then the double closed loop controlstrategy is set up, the outer ring is power and inner ring is current, The simulationresults show that the output power of generator can fast track the maximum power, theerror is zero when the wind speed change, the response of the output power is fast andthe fluctuation of the output power is small.In order to overcome shortcomings and the insufficiency of the photoelectricencoder, sensorless control method of direct-driven permanent magnet wind powergeneration system is studied. Use the sliding mode observer to achieve the rotor speedand position estimation, first the traditional sliding mode observer equation is set up,then the existing chattering problem is analyzed, use modified saturation function to weaken the chattering strength. In order to better restrain the strength of the highfrequency chattering noise, the adaptive law of switch gain following the referencevalue of the angular velocity is designed and the expansion equation of the sliding modeobserver is built, then the adaptive law of the back emf and the electricity angularvelocity is designed. Last the sensorless control performance of direct-driven permanentmagnet for wind power system is simulated, the simulation results show that theproposed adaptive sliding mode observer can realize the rotor speed and positionaccurate estimation, and has strong robustness against the parameters change ofgenerator stator.更多还原