绕线转子无刷双馈电机漏感计算

Calculation of Leakage Inductance for Wound-Rotor Brushless Doubly-Fed Machine

为准确计算和测定绕线转子无刷双馈电机漏感参数,该文根据绕组电流在电机内不同位置所建立漏磁场的不同特点,推导槽漏感、端部漏感、谐波漏感计算公式。求解槽漏感时建立单槽槽漏磁场能量模型,分区域分层计算该槽漏磁场能量,利用叠加定理求出槽内导体漏感,参考网络图论列写关联矩阵求出各相槽漏感。求解端部漏感时,引入气隙电流和镜像电流,在均匀介质中建立线圈端部漏感计算模型,采用离散化的毕奥-萨伐尔定律求解两线圈间端部漏磁链,列写关联矩阵求出各相端部漏感。求解谐波漏感时,由于气隙长度相等使得磁动势波形与磁通密度波形具有相似性,对两种极对数的磁场,分别利用总电感减去基波电感计算两线圈间的谐波互感,列写关联矩阵求出各相谐波漏感。根据该模型计算一台不等匝同心式绕线转子无刷双馈电机漏感参数,通过与堵转试验及传统方法所得数据对比,验证了该方法的准确性。

In order to accurately calculate and determine the leakage inductance parameters of the brushless doubly-fed machine, this paper deduces the calculation formulas of slot leakage inductance, end leakage inductance, and harmonic leakage inductance calculation method, according to the different feature of the leakage magnetic field established by the winding current in different positions in the motor. When solving the slot leakage inductance, a single-slot leakage magnetic field energy model was established, and the energy of the slot leakage magnetic field was calculated by region stratification. The conductor leakage inductance in the slot is calculated by using the superposition theorem. Refer to the network diagram, the correlation matrix was written to calculate the slot leakage of each phase. When solving the end leakage inductance, the air gap current and mirror current were introduced to establish the calculation model of the end leakage inductance in the homogeneous medium. The discretized Biot-Sarvart's law were used to obtain the leakage flux linkage between the ends of two coils, the correlation matrix were introduced to calculate the end leakage inductance of each phase. When solving the harmonic leakage inductance, the magnetic potential waveform and magnetic density waveform are similar due to the equal length of air gap. The total inductance minus the base wave inductance equals the harmonic mutual inductance between two coils in the magnetic field, so that the correlation matrix was written to calculate the harmonic leakage inductance of each phase. The stall test for a sampled concentric rotor winding BDFM of unequal turns motor is made to get the short-circuit reactance. The measured short-circuit reactance is in good agreement with the calculated one, which verifies the validity of the proposed methods.