Bidirectional silicon controlled rectifier adjusting type liquid resistance starter

Abstract

The invention, which relates to the field of the electrical technology, provides a bidirectional silicon controlled rectifier adjusting type liquid resistance starter. Bidirectional silicon controlled rectifiers are connected in parallel to liquid resistors of a motor; and the conduction angles of the bidirectional silicon controlled rectifiers are controlled by a control unit. The control unit is composed of a time setting adjusting unit, an adjusting signal unit, and a synchronous triggering unit. According to preset starting time, the time setting adjusting unit outputs an adjusting signal with the current of 4 to 20mA after operation by using each second as the step length; on the basis of the adjusting signal, the trigger unit sends a trigger command out in real time when a synchronous signal is valid, the conduction angles of the bidirectional silicon controlled rectifiers are gradually increased until full conduction is realized, thereby completing the reduction process of the equivalent resistance to zero. According to the invention, no mechanical moving component is used; the size is reduced; and no noise is caused. The box body of the liquid resistor liquid can be processed into one in a sealed mode, so that the steam generated by starting of the liquid resistors and the number of times for liquid adding can be reduced and thus the maintenance workload and the production cost can be substantially reduced. The control circuits are reduced; and the operation becomes simple.

Description

technical field [0001] The invention relates to the field of electrical technology, in particular to a bidirectional thyristor adjustable liquid resistance starter. Background technique [0002] For a long time, the traditional method has been adopted for the stepless adjustment of liquid resistance, that is, the motor drives the screw through the small belt pulley, the belt, and the large belt pulley, and the nut on the screw rod drives the lifting frame and the moving plate to move downward, changing the movement of the moving plate. , The distance between the static plates, in order to achieve the purpose of adjusting the liquid resistance. However, the screw drive device takes up a lot of space in the cabinet and is heavy. It has mechanical moving parts and needs to be driven by a motor. It is noisy during operation and the screw needs to be lubricated and maintained for a long time. Water vapor will be generated during the starting process, which will have a certain im...

AI Technical Summary

Problems solved by technology

However, the screw drive device takes up a lot of space in the cabinet and is heavy. It has mechanical moving parts and needs to be driven by a motor. It is noisy during operation and the screw needs long-term lubrication and maintenance.

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