电励磁双凸极发电机的三相整流换相过程分析

阐述了电励磁双凸极无刷直流发电机整流发电的工作原理，推导了电流换相时间、换相重叠角以及换相压降的解析公式，并分析了励磁电流、发电机转速以及负载性质对电流换相的影响。理论分析与实验结果表明：电励磁双凸极发电机整流发电时的换相过程由电机自感和互感引起；励磁电流大小会使工作模态发生变化；当负载和励磁电流不变时，换相时间受发电机转速影响，换相重叠角保持不变；负载为阻性与感性时，存在换相重叠，负载为容性轻载时，换相重叠现象不明显。

Analysis of Commutation in Three-phase Rectifier of Doubly Salient Electro-magnetic Generator

The working principle of doubly salient electro- magnetic generator(DSEG) was introduced. The formulas of commutation time, mean DC voltage loss and overlapping angle during commutation were deduced. The influences of some factors, such as exciting current, rotating speed and load characters, on commutation were analyzed. Theoretical analysis and experimental results show that the commutation of the current in DSEG results from self-inductance and mutual inductance. The exciting current can change working modes of rectifier. Commutation time is influenced by rotating speed and overlapping angle is kept unchanging when the load and exciting current unchanged. Commutation overlapping arises when the rectifier load is in resistance or resistance-inductance. While the load is in capacitance-resistance, commutation overlapping is not notable.