Why do rare earth permanent magnet motors save energy?

The energy-saving advantages of rare earth permanent magnet motors are as follows:

In the past few years, the high profile in the motor industry has been the permanent magnet motor, and its popularity has shown an increasing trend. The reason why permanent magnet motors have attracted so much attention is inseparable from the strong support of relevant national policies. High-efficiency and ultra-efficient motor products represented by high-efficiency permanent magnet motors can be quickly popularized, helping to save energy, reduce emissions, and keep the green mountains and green waters. Energy conservation and environmental protection must be the future development trend, especially in the motor industry. The energy-saving characteristics of permanent magnet motors show their advantages. Its energy-saving rate can be higher than 20%. The energy-saving advantages of rare earth permanent magnet motors are as follows:

Six major energy-saving advantages of rare earth permanent magnet motors:

1. Permanent magnet motors save 20-40% more energy than ordinary motors. The energy saving rate varies depending on the specific equipment working conditions.

2. The permanent magnet synchronous motor reaches the first level of energy efficiency, with an energy efficiency of more than 95%; the ordinary three-phase asynchronous motor has a third level of energy efficiency, with an energy efficiency of only about 90%.

3. The rotor of the permanent magnet synchronous motor has rare earth permanent magnet steel, which does not require the stator to provide induction power and has less loss than ordinary motors;

4. The stator lead-out wire of the permanent magnet synchronous motor is star-shaped (Y) connected, which can keep the power constant and the current small; most ordinary motors use the △ connection method;

5. During the operation of the permanent magnet synchronous motor, the energy efficiency value can remain unchanged when the load changes. The energy efficiency value of the ordinary asynchronous motor will change when the load changes. The energy efficiency of the ordinary asynchronous motor reaches three-quarters of the load. The value remains unchanged, and its energy efficiency value will plummet when the load is less than 70%.

6. The no-load current of a permanent magnet synchronous motor is small, only reaching one-tenth of the rated current, while the current of an ordinary asynchronous motor reaches one-third when no load.

Three major components of rare earth permanent magnet motor:

1. The rare earth permanent magnet motor uses high-performance permanent magnets, which eliminates the need for current excitation in the stator or rotor part of the motor, thus eliminating the copper loss (winding heating loss) in this part;

   2. Using a brushless structure, there is no mechanical loss of the carbon brush structure, but the brushless motor achieves commutation through an electronic commutation structure. There is a loss of some electronic components here, which is compared with the saved mechanical loss. The value is small, so the loss in the commutation part is smaller than the loss in the brushed motor;

3. Using high-performance rare earth permanent magnets, under the same rated power and rated speed, the motor can be made smaller, saving motor silicon steel sheets and reducing part of the iron loss. Low-power motors using rare earth permanent magnet motors can achieve an efficiency close to 90%, while ordinary motors are only about 75%.