【作者】 王莉；

【导师】 严仰光；

【作者基本信息】 南京航空航天大学 ， 电力电子与电力传动， 2006， 博士

【摘要】 270V高压直流电源系统具有重量轻、效率高、容易实现不中断供电等优点,而受到新一代飞机设计者的青睐。电励磁双凸极电机结构和控制简单,便于实现发电机和整流设备的一体化集成,非常适合作为航空270V高压直流电源系统的主发电机,因此,开展电励磁双凸极无刷直流发电系统的研究具有重要的意义。本文以12/8极电励磁双凸极高压直流发电机为研究对象,采用简化等效磁路对其静态特性做了理论分析。然后,考虑了电机铁芯非线性饱和和电枢反应影响,应用二维有限元深入分析了样机在不同工作状况下的磁场分布情况、磁链、电感和空载电势,给出了该发电机各电感、磁链和空载电势随励磁电流、相电流变化规律。基于有限元计算所得到非线性磁链,开展了12/8极电励磁双凸极直流发电机非线性建模方法的研究。尝试采用自适应模糊神经网络、支持向量机和三次样条插值法分别建立了该发电机非线性模型,并通过实例对比分析了三种方法的建模精度、预测性能,总结了三种方法的优缺点,给出了选用原则。分别用三种建模方法求解了空载电压波形,并与实验测试结果比较,验证了建模方法的可行性和所建模型的有效性。分析了推导了12/8极电励磁双凸极无刷直流发电机12种工作模态下的电压方程。在Matlab平台上建立了电励磁双凸极无刷直流发电机非线性分析模型。仿真分析和实验相结合,系统地研究了电励磁双凸极直流发电机发电性能,给出了该直流发电机的磁链、电感、各电压波形、输出直流电压和电压纹波大小随励磁电流和负载电流变化的规律。针对270V直流开关电器高压、高空灭弧困难的问题,开展高压直流无弧开关技术研究,研制了直流机电混合式功率控制器,针对传统电路结构的不足,改进了主电路,给出了具有反流故障阻断功能的电路结构,实验表明:所研制的样机有效的结合了机械式开关的静态特性和固态开关的快速动作特性,可以实现快速无弧切换,并具有反流阻断功能。开展了电励磁双凸极无刷直流发电系统数字调压技术研究。针对电励磁双凸极无刷直流发电机非线性特性,研究了非线性PI励磁控制方法及设计方法,给出了一种易于工程实现的非线性PI励磁控制算法。并对算法作了改进,设计了具有负载电流前馈补偿控制的非线性PI励磁控制实时算法,实验结果表明:系统的动态特性得到了明显的提高,且具有较好的稳态性能。更多还原

【Abstract】 The 270V high voltage DC power system has the advantages of less weight, higher efficiency and easier to realize uninterrupted and is attractive for next generation airplanes. And the doubly salient electromagnetic brushless DC generator, with the characters of simple structure, flexible control, and easy to be integrated with, is the best choice for the power system mentioned. Therefore it is significant to research on the doubly salient electromagnetic brushless DC generator power system.The static character of the 12/8 pole doubly salient electromagnetic generator is researched based on the simplified equivalent magnetic circuit method. The magnetic field in different operational situations is analyzed employing the 2D finite element method, with flux linkage, inductance and no-load voltage calculated. The principle of the inductance and flux linkage vs. the magnetic current and phase current are given.The nonlinear modeling method for the 12/8 pole doubly salient electromagnetic DC generator is researched based on the nonlinear flux linkage calculated by the finite element method. The nonlinear models of the DC generator are built with three methods, named Adaptive-Network-Based Fuzzy Inference System, Support Vector Machine and Spline, respectively. The modeling precision and forecasting capabilities of these three methods are analyzed and compared. Both the advantages and disadvantages of the methods mentioned are summarized with the choice principle given. The non-load voltage waveforms and characters of the doubly salient electromagnetic brushless DC generator are analyzed, based on the three nonlinear models obtained, and compared with the test results. The validity and feasibility of the three modeling method are verified theoretically and experimentally.The 12 operation modes of the output full-bridge rectifier are analyzed with voltage equations built for every mode, respectively. The nonlinear MATLAB model of the DC generator is developed. The generator performances are evaluated based on both the simulation and experiment results. The properties of the flux linkage, inductance, voltage waveform, output DC voltage and the voltage ripple versus exciting and load current, are investigated.In order to solve the problem of the difficulty in breaking arc of 270V DC mechanical switch under high voltage and high altitude, a mechanical-electrical Hybrid DC Power Controller is developed. A new circuit topology with the inverse current protection function is proposed to overcome the shortage of the traditional circuit. It is proved by the experiment results that the 270V DC hybrid power controller effectively keeps the static state characters of the mechanical switch and the dynamic characters of the solid switch and can closes and breaks arc-less rapidly. The inverse current protection function is verified experimentally. The digital voltage regulation for the doubly salient electromagnetic brushless DC generator is researched. The nonlinear PI excitation control algorithm, with the nonlinear characteristics of the doubly salient electromagnetic brushless DC generator considered, is developed and design method given. To improve dynamic performances of the DC generator system furthermore, a real time nonlinear PI algorithm with load-current forward control is developed. Experimental results verified that the proposed algorithm offers not only faster dynamic response, but also less voltage surge during load switched on and off, over a wide load range.更多还原