【作者】 戴卫力；

【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， 2008， 博士

【摘要】 本文对国内外航空起动/发电系统的历史、技术发展和研究现状进行了概括总结。在此基础上,选择12/8极电励磁双凸极电机作为起动/发电机,对航空起动/发电系统的起动控制和发电运行进行了研究,成功研制了18kW无刷直流起动/发电系统。同时,本文还对并列结构混合励磁双凸极发电机也进行了研究。文章研究了电励磁双凸极发电机的三种发电方式,建立了电励磁双凸极发电机的数学模型。利用实验和有限元仿真计算相结合的方法研究了发电机在不同发电方式下的基本特性。对不同发电方式下的电枢反应,换相重叠和外特性也进行了研究,给出了换相电感的组成和计算方法,推导了换相时间和换相重叠角的解析公式。随后,针对高、低压直流双输出发电系统进行了双输出发电调压的设计和研究,成功研制了18kW高、低压直流双输出发电系统。为了在保留电励磁双凸极发电机磁场调节方便的同时提高发电机的效率,文章又对并列结构的混合励磁双凸极发电机进行了研究。文中建立了相应的数学模型,运用实验和有限元仿真相结合的方式研究了混合励磁发电机的空载特性、外特性、调节特性和短路特性。分析了不同发电方式下发电机电枢反应与换相重叠的影响,揭示了并列结构混合励磁发电机具有三种工作模态,并求解了不同发电方式下三种工作模态的边界条件。给出了基于励磁电流双向对称的混合励磁发电机的设计原则,使电机励磁绕组用料最省,励磁时间常数和励磁功率最小。成功研制了一种能实现励磁电流双向控制的电压调节器,动态性能优越,响应快。文中还在分析涡轮喷气发动机起动要求的基础上,着重解决了电励磁双凸极电机起动发动机时的若干重要问题:通过采用双定子结构的双凸极电机,显著减小了电机电动时的转矩脉动和发电时的输出电压纹波;从理论和实验上解释了提前角度控制能提高电机输出转矩的内在机理,在此基础上提出了软件换相控制加硬件角度细分的提前角度控制实现方法,通过标准角度和提前角控制策略下机械特性的优化合成,确定了转速与提前角度值的关系表,建立了基于转速与时间的双重起动控制策略,保证了电机在低速和中、高速时的输出转矩和功率,很好地完成了发动机的冷开车和热开车试验。更多还原

【Abstract】 Starter-generator system for the aircraft engine is an important part in the electricity systems of the aircraft. Some starter-generator systems during different phases of the aircraft electric power development are introduced in this paper subseaquently, and their characters are analyzed. Next, doubly salient electro-magnetic machine (DSEM) was selected as the starter-generator and the basic theory of the starter-generator system were researched in this paper. Then, an 18kW brushless DC starter-generator system for the aircraft engine was made successfully.According to the different rectifiers, three generating modes were given in this paper firstly. Then, mathematical model of DSEM was built, and basic characteristic of the generator and short circuit malfunction in different generating modes were studied by experiments and finite element simulation. Subseaquently, armature action, commutation overlap and load character in different generating modes were analyzed and calculated by finite element analysis software ANSOFT. The calculation method of the commutation inductance and formulars about commutation time, overlap angle were deduced. Next, a dual output voltages regulated technology of the doubly salient electro-magnetic generator was studied, and the dual output voltage regulator was made in this paper successfully.In order to keep the advantage of DSEG and improve the system efficiency, Doubly Salient Hybrid Excitation Genenrator (DSHEG) was performed. The structure of DSHEG was illustrated and its mathematical model was built. Basic characteristic of the generator—output characteristic at no load and under load, the characteristic between the exciting current and the load, short circuit character were researched by experiments and Finite Element Analysis. Armature action and commutation influencing on the load character in different generating modes were researched. Then, three working stages of DSHEG were studied and the boundary conditions of three stages were solved in this paper. Next, the design principle of DSHEG based on bidirectional symetrical exciting current and a bidirectional excitation voltage regulator were performed. The voltage regulator makes the output voltage of the generator stable by adoptig bipolar pulse width modulation control strategy. In the end, the stable and the dynamic experimental results of the DSHEG show that the character of the DSHEG is better than DSEG.Some important problems about the starting control were solved in this paper based on the requirements of the starting engine. The ripple of the torque at motoring is reduced greatly by improving the structure of the machine. The motor starting control algorithms based on the speed and the time was peformed. Then, the truth that Advanced Angle Control Mode (AACM) can improve output torque and power got verified by theory analysis and experiments. The table about the advanced angle value and the rotor speed was built by optimizing tne mechanical character at standard angle control mode and AACM. According to the table, DSEM can work at the best condition all the time by changing control strategy at different speed. In the end, the starter-generator system was built, and the experiments of the starting and generating were fullfilled successfully.更多还原