What are the advantages and disadvantages of traditional asynchronous motor starting and dragging mode and inverter starting and dragging asynchronous motor mode?

1, it is best to use frequency converter for soft start, with minimum starting current, easy to realize stepless speed regulation, and save electricity when starting and running. This is a modern startup method. Disadvantages are complex maintenance, high technology content and large one-time investment.

2. The star triangle is second, the starting current is moderate, and the operation does not save electricity. This is a common method.

3. Direct startup is uneconomical without maintenance, but it needs certain conditions: 1. Because the direct starting current of the motor is five times the normal running current, the capacity of the transformer supplying power to the motor must be more than five times the capacity of the motor. If the transformer is small, the starting current will seriously reduce the voltage of the transformer, which will affect the use of others. The self-motor will prolong the starting time and make the motor burn out or fail to start. 2. The wire supplying power to this motor should not be too long, and the cross-sectional area of the conductor should not be too small. Otherwise, the voltage of the strong starting current conductor will drop seriously, which will prolong the starting time of the motor and make the motor burn out or fail to start. 3. Contactor, air switch, iron shell switch and other switches with energy storage function must be used for starting, but bakelite knife and other switches that are directly opened and closed by manpower cannot be used. If the speed is slow, it will easily lead to arc short circuit.