Permanent Magnet Motor Assembly is rotor has rare earth permanent magnets, which does not require induction electricity from the stator; permanent magnet motors use star connection Y, asynchronous motors above 4kw are △ connection, and Y connection has a smaller current than △ connection; permanent The magneto uses different materials and has a high insulation level. Under the premise of keeping the power constant, the frame size can be reduced, the copper consumption is reduced, the permanent magnet motor has good control performance, and the starting torque can be adjusted to meet the high torque starting, Thereby reducing the motor model and avoiding the situation of large horse-drawn carts.
When the asynchronous motor is started, the current is 6-7 times the rated current, which is not good for the life of the motor. In order to achieve the required torque, there is even an increase in the motor model, and the motor is operating at low load and the efficiency is reduced. When the intelligent industrial motor starts, the current is gradually increased and will not exceed the rated current, the torque can also reach the rated torque, there is no current impact, the service life is extended, and the motor is working at a reasonable load. The energy-saving principle shows that the permanent magnet synchronous motor speed control is precise. It has greater advantages on occasions with high-speed requirements.
Since there is no need to absorb reactive current from the grid, there is neither copper loss nor iron loss on the rotor, so the synchronous motor can maintain a power factor close to 1 in a wide load range, and the efficiency of the machine is 8 higher than that of an asynchronous motor of the same capacity. %, the energy index (ηXcosΦ) increases by about 18%. From the actual use, the no-load current of the permanent magnet motor is only about 1/3 of that of the asynchronous motor, reducing consumption; when the dragging equipment reaches a constant flow and pressure, the automatic control system will automatically adjust, and the current will decrease or In a reactive state; the energy efficiency value of the permanent magnet motor can remain unchanged when the load changes during the operation process, and the energy efficiency value of the asynchronous motor will change when the load changes; the energy efficiency of the asynchronous motor when the load reaches three-quarters The value remains the same. When the load is less than 70%, its energy efficiency value will drop linearly.