【作者】 肖刚；

【导师】 杨顺昌；

【作者基本信息】 重庆大学 ， 电气工程， 2003， 硕士

【摘要】 交流励磁发电机的基本结构与绕线式异步电机相同，其定子侧接电网，转子上采用三相对称分布的励磁绕组，由变频器提供对称交流电励磁，且励磁电压的幅值大小、频率、相位、相序都可根据要求加以控制，从而可以控制发电机励磁磁场大小、相对于转子的位置和电机的转速，使得交流励磁发电机具有良好的稳定性及转速适应能力、独立的有功与无功调节能力和较强的进相运行能力，性能超越传统同步发电机和感应发电机，因而有着广阔的应用前景。本文论述了交流励磁发电机的运行原理及动态同步轴系下的励磁控制策略。在Saber仿真软件的平台下，建立了交流励磁发电机及其励磁控制器的仿真模型。由于交流励磁发电机既可能运行于励磁系统向电机转子方输入电功率，也可能运行于励磁系统将转子方输出的电功率回馈给电网，根据交流励磁发电机系统对励磁变频器功率双向流动及变频器输入和输出电流谐波含量少、谐波幅值小的要求，本文提出采用输入和输出性能优良的矩阵式交-交变频器作为励磁电源。从等效交-直-交变换的空间矢量调制方法出发，深入分析了矩阵式变频器的变换关系，导出了交-交直接变换控制规律和双空间矢量脉宽调制技术，阐述了矩阵式变频器的换流控制策略，分析了输入滤波器和过电压保护电路的设计方法，实现了矩阵式变频器的建模和运行分析。利用所建模型，对交流励磁发电机系统的稳态调节特性、暂态特性进行了仿真研究；仿真研究了发电机定、转子电流和感应电势及变频器输入电流波形，并作了相应的谐波分析；与交-直-交变频器和交-交变频器作励磁电源时发电机的运行特性进行了对比分析。本文所作的研究工作，为交流励磁发电机的励磁系统工程设计提供了一定的理论参考依据更多还原

【Abstract】 The structure of alternating current excitation generator (ACEG) is same as wound rotor induction machine. The stator of ACEG is connected to the grid and the three symmetrical excitation windings in the rotor are fed by converter. The magnitude and frequency and phase and phase sequence of excitation voltage can be controlled, so the magnitude and position of excitation MMF as well as the speed of rotor can be controlled. Therefore, ACEGs have superior performances by contrast with conventional synchronous generators and induction generators, such as upstanding stability, power generation of variable speed constant frequency (VSCF), adjusting active power and reactive power independently, and absorbing lag reactive power deeply. So there are good prospects for alternating current excitation generators.In this thesis, the operation principle of ACEG and the excitation control strategy based on dynamical synchronous reference frame are analyzed, the simulation models of the generator and excitation controller are established based on the Saber simulator. According to the requirement of ACEG , the converter should have regeneration capability, and the input and output currents of converter should be sinusoidal. Matrix AC-AC converter (MC) has good input and output performances. MC as the exciter is proposed in this thesis. According to the space vector modulation method of the equivalent structure of the AC-DC-AC transformation, the transformation relations of the matrix converter are deeply investigated. The AC-AC direct conversion control and the double-space-vector PWM scheme of the matrix converter are deduced, the four-step current commutation strategy of matrix converter is expatiated, the design method of input filter and over voltage protection circuit is analyzed, and the modeling and simulation of a three-phase matrix converter are implemented. The steady state and transient characteristics of the ACEG system are simulated, the harmonics of the EMF and stator current and rotor current as well as MC’s input current are researched. The operation characteristics of ACEG with MC as an exciter are compared to those of ACEG with AC-DC-AC converter and cycloconverter as an exciter.The results in this thesis will be helpful to the design of the ACEG excitation control system更多还原