Motor variable frequency starting cabinet

Abstract

The invention provides a motor variable frequency starting cabinet comprising multiple motors and a variable frequency starting circuit, a power supply circuit and a control loop. The variable frequency starting circuit is connected with the motors through a plurality of starting contactors. The two ends of the power supply circuit are respectively connected with the three phase wires of a three-phase power supply and the motors. A motor protector sleeves on the three power wires of the motors. The power supply of the control loop is taken from any two phases of fire wires or any one phase offire wire and a power supply neutral wire of the power supply line. Only one frequency converter is utilized to realize variable frequency starting of a plurality of devices so as to effectively reduce device investment and effectively reduce the area of the distribution room. The motors can be controlled to be started one by one in the use process, and the next motor is started only after normaloperation of the pervious motor so that locking can be technically implemented, the impact on the power transformer caused by multiple motors starting simultaneously can be avoided and the capacity ofthe power transformer can also be effectively reduced, and thus the basic electricity cost of the enterprise can be reduced and the purpose of energy conservation and consumption reduction can be achieved.

Description

technical field [0001] The invention relates to a motor frequency conversion starting cabinet. Background technique [0002] When the large-capacity motor is directly started, the current is particularly large, which is 4-7 times the rated current, and the voltage drop caused in the grid greatly affects the operation of other electrical equipment; , Y-△ (star-delta) step-down start and when the frequency converter starts a single motor, the structure is simple and the degree of automation is low; [0003] When the mechanical equipment in many factories is running, it is necessary to start the motor through a frequency converter. Generally, one motor is equipped with a frequency converter. Enterprises with a lot of equipment need to configure many frequency converters. The cost is too high, and the initial investment is large. It will greatly occupy the area of ​​the power distribution room of the enterprise. [0004] For example, the publication number is: CN104796044A, a ...

AI Technical Summary

Problems solved by technology

[0004] For example, the publication number is: CN104796044A, a system based on PLC to control a frequency converter to soft start multiple motors, can use one frequency converter to start multiple motors, can reduce the one-time investment cost, and the motor operation is stable and reliable, effectively reducing the Failure rate, easy maintenance, improved centralized management technology of the production line, one inverter can start multiple motors by connecting the motors in parallel to the inverter, but it needs PLC auxiliary control, which increases the cost of motor startup control

Images