High voltage motor:
The voltage of the high voltage motor is above 1000V. Commonly used are 6300V and 10000V. The motor power is proportional to the product of voltage and current. Therefore, if the power of the low-voltage motor is increased to a certain extent (such as 300KW/380V), the current is limited by the allowable capacity of the wire, or the cost is too high. A high power output needs to be achieved by increasing the voltage.
The advantages are: high power, strong impact resistance; small current.
The disadvantage is that the cost of the winding is relatively high, and the cost of the related insulating material will also become higher; the requirements for the use environment are far higher than the requirements of the low-voltage motor for the environment; the insulation treatment process is difficult and the labor cost is high. The motor has a long manufacturing cycle; the inertia is large, and it is difficult to start and brake.
The control device is determined according to the actual method: the motor capacity is much smaller than the power supply capacity and can be directly started under 1000 KW, and the inrush current is 3-6 times of the rated value. In order to prevent the inrush current from being too large, the starting mode for reducing the starting current must be considered for large motors: a series of reactance starting, variable frequency starting, and hydraulic coupling starting. There are complex and simple, and the price varies greatly. Due to the high voltage and large current surge, the motor must meet the overvoltage requirements and the insulation level must be high enough.
Low voltage motor:
The utility model has the advantages of simple structure, reliable operation, high frequency, convenient manufacture and maintenance, and good working characteristics. The low-voltage motor is divided into two types: AC asynchronous motor and DC motor.
AC
Asynchronous Motors are divided into three-phase and single-phase: three-phase asynchronous motors are mainly used for electric drag with large equipment load.
DC motors are mainly used for kiln body DC drive.
Winding type: stator, rotor, iron core, end difference, junction box, collector ring, fan or string frequency sensitive device.
Working principle: When the three-phase symmetrical stator winding of the AC asynchronous motor is passed into the symmetrical three-phase
AC Motor, or a synchronous number of revolutions n is generated, the motor is just connected to the power source when the motor is turned on. When the rotation has not started, the stationary rotor rotates in the direction of the magnetic field rotation under the action of the torque, and the rotor always follows the rotating magnetic field n2.
The main types, uses and characteristics of three-phase asynchronous motors:
Type: squirrel cage asynchronous motor: use and characteristics Most of the equipment uses this motor, easy to maintain;
Wound-type asynchronous motor: use and characteristics, driving, stacker and reclaimer walking, clinker clinker crushing, etc., starting torque is large;
Frequency conversion high-speed asynchronous motor: use and characteristics, stacking, reclaimer walking, belt conveyor, belt scale, classifier and other high speed, set at a certain speed, and energy saving;
Torque asynchronous motor: the side reclaimer cable coil is dragged, featuring constant torque load characteristics;
Electromagnetic brake asynchronous motor: mainly used for rotary dragging of stacking and reclaiming machines in a circular yard.
February 07, 2023
