【作者】 金超武；

【导师】 徐龙祥；

【作者基本信息】 南京航空航天大学 ， 机械设计及理论， 2011， 博士

【摘要】 作为21世纪先进航空发动机关键新技术之一的多电发动机具有普通发动机无法比拟的优点,而它的一个核心关键技术就是高温磁悬浮轴承技术。文中主要对高温磁悬浮轴承中的高温位移传感器和数字化电控系统这两项关键技术进行了研究。文中成功地研制了能工作在550℃环境下的差动变压器式位移传感器,对工作温度升高影响差动变压器式位移传感器性能的机理和特征以及所采用的温度补偿技术进行了研究,解决了由于温度升高带来的位移传感器灵敏度升高、温漂和时漂的技术难题,通过在高温下对差动变压器式位移传感器进行标定得到高温下位移传感器的各项性能,研究结果表明：环境温度从常温22℃升高到550℃时,降低初级线圈激励频率可使位移传感器灵敏度随温度的增幅降低,激励频率在10kHz时,位移传感器灵敏度的增幅为4.2%；当位移传感器灵敏度为20mV/μm时,不采用温度补偿技术时,位移传感器的最大温漂和时漂分别为344mV,17mV,采用温度补偿技术后,位移传感器的最大温漂和时漂分别为150mV,10mV,相当于被测物体只有7.5μm和0.5μm的位移；在550℃时,测量范围在-0.35mm～+0.35mm时,位移传感器的灵敏度为19.62mV/μm,线性度为0.74%,重复性为±0.97%,迟滞性±0.40%,截止频率为800Hz；将研制的高温位移传感器应用到单自由度高温磁悬浮轴承试验台上实现了被悬浮物体的稳定悬浮。针对高温磁悬浮轴承中被测物体被一层金属隔层完全封闭的应用场合,文中建立了带有金属隔层的差动变压器式位移传感器的数学模型,推导了金属隔层材料的磁性能与电性能对传感器性能影响的理论计算公式,采用MATLAB和ANSOFT分别对无和有金属隔层这两种情况下传感器的性能进行了仿真研究,并将有金属隔层的差动变压器式位移传感器应用到一个五自由度磁悬浮轴承试验台上进行了试验研究,研究结果表明：当传感器初级线圈激励频率为10kHz,在离差动变压器式位移传感器铁芯0.15mm处加入0.15mm厚的黄铜,位移传感器灵敏度下降了8.18%,但线性度提高了38.7%,同时位移传感器的截止频率降低了5%；在差动变压器式位移传感器与转子之间加入0.15mm厚的黄铜,五自由度磁悬浮轴承试验台仍然能实现磁悬浮转子的稳定悬浮和高速旋转,转速为30　000r/min。文中分析了用于磁悬浮轴承的位移传感器所产生的测量误差对磁悬浮轴承工作性能的影响机理及特征,推导了差动变压器式位移传感器和电涡流传感器的测量误差与传感器的结构参数,安装方式和安装位置之间的理论关系,该研究为高温磁悬浮轴承用位移传感器的设计和安装奠定了一定理论基础。针对磁悬浮轴承电控系统中的位移传感器处理电路,提出了用数字同步解调、Costas环和FFT变换法的思想，采用FPGA芯片以软件的形式实现了处理电路的硬件功能，运用MATLAB对三种信号处理方法进行了仿真研究并在位移传感器静态标定专用装置上进行了试验研究，得到三种处理方法下的差动变压器式位移传感器的各项性能，研究结果表明：在位移传感器性能、所占硬件资源和延时时间上，三种处理方法各有优缺点，可根据不同情况选择合适的处理方法。文中针对磁悬浮轴承电控系统中的控制器和功率放大器，研究了基于FPGA的数字控制器和功率放大器，采用MATLAB对控制器的PID算法和三电平开关功率放大器驱动信号产生部分进行了仿真研究，并对基于FPGA的功率放大器的各项性能进行了试验研究，最后将基于FPGA的控制器和三电平开关功率放大器应用到磁悬浮球系统中，实现了磁悬浮球的稳定悬浮。更多还原

【Abstract】 As one of the new critical technology of aero engine in the21stcentury, more-electric enginewith high temperature active magnetic bearings (HTAMB) as the key technology has incomparableadvantages over traditional engine. The high temperature displacement sensor and digital electroniccontrol system of HTAMB are mainly studied in this paper.A differential transformer displacement sensor (DTDS) which can works under550oC ismanufactured, and the influence of high operating temperature on the DTDS mechanism andcharacteristics and the following temperature compensation technology are mainly analyzed. Thetechnical problems of sensor sensitivity increase, temperature and time drift caused by thetemperature rise are solved, and the various performances of DTDS under high temperature can beobtained through detailed calibration. The results show that reducing incentive frequency helps todecrease the sensitivity growth of DTDS when the work temperature rise from environmentaltemperature to550oC, and the sensitivity growth is about4.2%when the excitation frequency is10kHz. With the sensor sensitivity20mV/μm, the sensor maximum temperature drift is344mV andtime drift is17mV without temperature compensation, while the temperature drift becomes150mVand time drift becomes10mV after adopting temperature compensation technology. When themeasurement range is-0.35~+0.35mm with the work temperature550oC, the DTDS has the followingcharacteristics: sensitivity19.62mV/μm, linearity0.74%, repeatability±0.40%, hysteresis±0.40%andcutoff frequency800Hz. Finally, this DTDS is successfully used in a single degree-of-freedom (DOF)HTAMB test bed.For some special HTAMB application occasions that demand the rotor isolated from externalenvironment, the mathematical model of DTDS with metal layers are established. And the theoreticalcalculation formulas concerning the impacts of metal layer magnetic and electric characteristics on theDTDS performances are deduced. The DTDS performance with and without metal layers areseparately simulated on the platform of MATLAB and ANSOFT. And then the DTDS with metallayers are applied to a five-DOF AMB test bed. The research results show that the sensor sensitivityhas decreased8.18%and cutoff frequency decreased5%, while the linearity increased38.7%. Despiteof those changes, the rotor can also be stably suspended and rotated at30000r/min in the five-DOFAMB system. The impacts of displacement sensor measurement errors on the AMB work performance arestudied in detail. The measurement errors for different sensor types, installation methods andassembly locations are theoretically deducted. This research provides a certain theoretical basis for theHTAMB displacement sensor design and installation.Aimed at the displacement sensor processing circuits in AMB electronic-controlled system, theDTDS processing circuits based on FPGA are studied. The digital synchronous demodulation, Costasring and FFT transform algorithm are separately applied to the processing circuits. Then the followingsimulations and experiments are carried out in MATLAB and special static calibration devicerespectively to obtain the various performance of DTDS adopting the above three processing methods.The results show that the different processing method has its own advantages and disadvantages onthe displacement sensor performance, occupied hardware resources and delay time. So it is advisableto choose appropriate treatment methods according to different situations.The controller and power amplifier based on FPGA in AMB system are also studied. Both thePID algorithm and drive signal of tri-level switch power amplifier are simulated using MATLAB.Then the relevant experiments are carried out to study the various performance of power amplifierbased on FPGA. Finally, they are applied to a magnetic levitation ball system. The experiment resultsshow that the new type controller and power amplifier can achieve ball stable levitation.更多还原