论文部分内容阅读
KK-20型缆索起重机,吊重量为20吨,采用直流发电机—电动机系统。提升和牵引发电机额定容量为320千瓦及300千瓦。按设计要求,其过流保护继电器应整定为额定电流的2倍和1.5倍,即达1000安培。如此大安培数的直流电流,由于条件所限,不大容易做到,有些单位采用直流电焊机等等,甚感不便。我们采用短路方法,比较简单。接线图如下:电动机不接他激,处于包闸(即短路状态)此时电动机的反电势不可能产生,所以回路电流仅取决于外加电压的大小。调节自耦变压器,使发
KK-20 cable crane, hanging capacity of 20 tons, using DC generator - motor system. The rated capacities for lifting and towing generators are 320 kW and 300 kW. According to design requirements, the overcurrent protection relay should be set to 2 times the rated current and 1.5 times, that is up to 1000 amps. Such a large amperage of DC current, due to limited conditions, not easy to do, and some units using DC welding, etc., very inconvenient. We use short-circuit method, relatively simple. The wiring diagram is as follows: The motor is not energized, in the brake (ie, short-circuit state) at this time the motor back EMF can not be generated, so the loop current depends only on the size of the applied voltage. Adjust autotransformer to make hair