Application of motor soft starter in drainage system

Promulgator : TAIXIDate : 2018-05-10Views : 109

Power electronics, micro processing technology and modern control theory are used to design and produce new starting equipment with international advanced level. This product can effectively limit the starting current of AC asynchronous motor when starting. It can be widely used in fans, pumps, transport and compressors and so on. It is an ideal replacement product of traditional star / triangle conversion, autotransformer, magnetic control, and so on.

Startup mode

Using a Soft Starter connected to the power supply and the controlled motor, the starting angle of the inner thyristor is controlled, and the input voltage of the motor is increased from zero to the preset function relationship until the start end. The motor is given full voltage, that is, soft starting, and the starting torque of the Soft Starter Cabinet increases gradually during the soft starting process. The speed is increasing.

Working principle

Soft start (soft starter) is a kind of new motor control device which integrates soft starting, soft parking, light load energy saving and various protection functions. It is called Soft Starter. The soft starter uses a three-phase anti parallel thyristor as a voltage regulator and connects it to the power supply and the stator of the motor. This kind of circuit is a three-phase fully controlled bridge rectifier circuit. When the soft starter is used to start the motor, the output voltage of the thyristor is gradually increased and the motor is gradually accelerated until the thyristor is fully guided. The motor works on the mechanical characteristics of the rated voltage to achieve a smooth start, reduce the starting current and avoid starting a over current trip. When the motor reaches the rated number, the starting process is over, and the Soft Starter Cabinet automatically uses the bypass contactor to replace the completed task thyristor, providing the rated voltage for the normal operation of the motor in order to reduce the heat loss of the thyristor, prolong the service life of the soft starter, improve its working efficiency, and avoid the harmonic pollution in the power grid.  Soft Starter Cabinet also provide soft parking at the same time. On the contrary, the soft stop and soft start process, the voltage gradually decreases, the transfer number gradually drops to zero, avoiding the torque impact caused by free parking.