防爆电机负载启动方式选择

Mode Selection of Start for Explosion-proof Motor

当一台电机用一个变压器供电时,为节约费用,变压器不能选得太大。因此,选择合理的启动方式,对减小变压器容量及启动的安全性尤为重要。以锅炉鼓风机负载用电机为例进行了启动方式选择的计算分析,结果表明:直接启动不利于防爆安全;星-角启动不适用于鼓风机类负载;得出了自耦变压器启动k=1.25比较合适的结论。同时,提出了降低风轮转速和降低进风量两种措施,以减小引风机用防爆电机启动时间长带来的危害及满足节能的需要。

Usually, the bigger of the size of the transformer is, the more operational cost of motor-driving system will be, if a transformer as the supply power energizes a motor. Wherefore, it is very important of the appropriate starting mode to decrease the transformer capacity and ensure the security of starting. Take a motor with a boiler blower as an example. By calculation and analysis on the starting mode, it is proven that it is not applicable of line start for explosion protection security; it is not applicable of stardelta starting to blower-group load; and it is appropriate of the compensator starting with k=1.25. Meanwhile, by the provisions of depressing the revolution of the wind wheel and air input, it can reduce the risk caused by long starting time of explosion-proof motor and meet the requirement of save energy.