交错磁极无刷直流起动发电机电磁性能分析

发布时间：2018-07-17 01:41

【摘要】：皮带传动一体化起动发电机(Belt-driven Starter Generator,BSG)起停系统可减少发动机怠速运行时间进而降低油耗和尾气排放。交错磁极无刷直流起动发电机是一种电动势为梯形波、转子侧有永磁体、定子侧有直流励磁绕组的混合励磁电机,具有气隙磁密调节范围大、功率密度高、转矩密度高、控制简单等优点,适用于高起动转矩和宽转速范围高效恒压发电要求的BSG起停系统。目前,该结构电机的相关研究较少且不够深入,为此本文对其电磁性能进行了如下研究。首先,采用有限元方法分析了电励磁磁场与永磁磁场的耦合关系以及负载时电枢磁场对以上两种磁场的影响,并基于磁场分析结果采用路计算方法推导了每极磁通的计算公式,分析了换相和电动势波形为非理想梯形波对电磁转矩的影响,用一台2kW样机实验验证了每极磁通和电磁转矩计算公式的准确性。其次,采用场路结合的方法分析了每极合成气隙磁密和单极侧气隙磁密的分布特点,并针对单极侧气隙磁密分布不对称的特点提出一种低成本的六霍尔传感器转子位置检测方法,该方法对六个霍尔传感器的输出信号进行了分组和逻辑运算,得到逻辑运算后的信号与传统无刷直流电动机霍尔信号特征一样。实验表明了关于单极侧气隙磁密分布特点分析的正确性和所提六霍尔传感器转子位置检测方法的适用性。最后,基于相绕组电压推导了母线电压与母线电流、励磁电流的关系式。不可控整流时电枢电流有换流过程,使相电流平均值与母线电流平均值不相等,对电枢电流换流过程及其对母线电压的影响进行分析,得到计入换流影响的母线电压表达式,实验验证了该母线电压计算公式的准确性。
[Abstract]:The Belt-driven Starter Generator (BSG) starting and stopping system can reduce the engine idle running time and reduce the fuel consumption and exhaust emissions. The staggered pole brushless DC starting generator is a hybrid excitation motor with a trapezoid wave, a permanent magnet on the rotor side, and a DC excitation winding on the stator side. It has the advantages of large air gap magnetic density adjustment range, high power density, high torque density, simple control and so on. It is suitable for BSG starting and stopping system with high starting torque and high speed constant voltage power generation requirements. At present, the related research of the structure motor is less and not deep enough. The finite element method is used to analyze the coupling relationship between the magnetic field and the permanent magnetic field, and the influence of the armature magnetic field on the two kinds of magnetic fields when the load is loaded. Based on the result of the magnetic field analysis, the calculation formula of each pole magnetic flux is derived. The influence of the commutation and EMF wave on the electromagnetic torque is analyzed. The accuracy of the calculation formula for each pole flux and electromagnetic torque is verified by the experiment of the platform 2kW prototype. Secondly, the distribution characteristics of the magnetic density and the air gap magnetic density in each polar air gap are analyzed by the method of field circuit combination, and a low cost six Holzer sensor rotor position detection is proposed in view of the asymmetry of the magnetic density distribution of the air gap in the unipolar side air gap. The method is used to group and logic the output signals of six Holzer sensors. The signal after the logic operation is the same as that of the traditional brushless DC motor Holzer signal. The experiment shows the correctness of the analysis of the magnetic density distribution characteristics of the air gap in the monopole side and the detection method of the rotor position of the six Holzer sensor. Finally, based on the phase winding voltage, the relationship between the bus voltage and the busbar current and the excitation current is derived. The armature current has a commutation process when the uncontrollable rectifier is controlled. The average value of the phase current is not equal to the average of the busbar current, and the influence of the armature current exchange process and the voltage of the bus is analyzed, and the influence of the commutation is taken into account. The bus voltage formula is used to verify the accuracy of the bus voltage calculation formula.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.631

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