【作者】 马健；

【导师】 李珍国；

【作者基本信息】 燕山大学 ， 电机与电器， 2011， 硕士

【摘要】 能源、环境是当今人类生存和发展所要解决的紧迫问题。风能资源的开发有着巨大的经济、社会、环保价值和发展前景,它在降低环境污染、调整能源结构以及解决偏远地区居民用电问题等方面起到了突出作用。开关磁阻发电机(Switched Reluctance Generator,简称SRG)具有结构简单、转动惯量小、启动转矩大、控制策略灵活、功率电路简单可靠等特点,在风力发电系统中具有广阔的应用前景。在不对称功率变换器驱动开关磁阻风力发电系统中,外界风速较低时,发电机运动电动势将小于发电电压,导致发电阶段相电流无法增加,降低电机能量转换效率。为了避免相电流减小,本文采用了可独立控制发电电压的变发电电压功率变换器(Variable Generation Voltage Converter,简称VGVC),通过控制功率变换器开关管的通断,调节发电电压,从而增加发电阶段相电流,提高电机利用率。典型的VGVC驱动开关磁阻风力发电控制系统采用角度位置控制,参考发电电压是由电机转速和励磁电压决定的。通过仿真和实验波形发现,发电电压还与关断电流和相电流最大值有关。为了简化控制系统,本文提出一种VGVC驱动开关磁阻风力发电系统的电流波形控制。该控制策略将转速对系统的影响转化为电流,通过对关断电流和相电流最大值控制,满足输出功率要求,提高能量转换效率。本文使用MATLAB仿真软件,对四相8/6极SRG风力发电系统进行了仿真研究,搭建了实验平台。仿真及实验结果表明,VGVC驱动开关磁阻风力发电系统的电流波形控制能够有效地改善相电流波形,提高转换效率,验证了该控制策略的正确性、有效性和可行性。更多还原

【Abstract】 Nowadays, energy and environment are pressing problems in survival and development of human. The development of wind energy resources exists a huge economic, social, environmental value and development prospects. It has a prominent role in reducing pollution, adjusting energy structure and solving electricity problems in remote areas. Switched reluctance generation (Switched Reluctance Generator, SRG for short) has many outstanding features such as: simple structure, small moment of inertia, huge starting-torque, a flexible control strategy, simple and reliable power circuit. Hence it has broad application prospects in the wind power generation system.When the wind speed is low, the back-EMF of the generator could be lower than the generation voltage. As a result, the phase current will not increase at the generation stage, therefore, energy conversion efficiency of the machine are reduced. Moreover, this paper presents a variable generation voltage converter (Variable Generation Voltage Converter, VGVC for short) topology which can control the generation voltage independently to avoid the phase current decreasing. It can regulate generation voltage increase the phase current in generation stage improve the motor efficiency by controlling power converter switch on-off.Conventional SR wind power generation control system with VGVC drive adopt the angle position control. Generation reference voltage is determined by motor speed and the excitation voltage. However, random changes of wind speed will result in failure of generator control system, and directly affect phase current in the stage of generation. It was found by simulation and part of the experiment: Phase current turn-off and the maximum current is closely linked to generation voltage. In order to overcome the above disadvantages, this paper presents a current-wave control of SR wind power generation system with VGVC drive. The control strategy turns speed into the current to impact on the system. It can meet output power requirements and optimize to efficiency by controlling turn-off and maximum phase current.The platform experiment of a four phase 8/6 SRG wind power generation system is built, the model is simulated by using MATLAB simulation software. The results of simulation and experiment present the current-wave control of SR wind power generation system with VGVC can improve the phase current waveform efficiently, increase conversion efficiency of the system and also verify the validity and feasibility of the control scheme.更多还原