What is good drone motor?

1. High power density

Power density describes the power per unit volume. High power density means that?the?#drone ?#motor ?can be made smaller and lighter?under the?#same ?#power .

Test Vidoe from Игорь Негода: https://www.youtube.com/watch?v=mkCXy90RE9g&t=332s

2.?Small structure size and lower weight

Test Vidoe from Игорь Негода: https://www.youtube.com/watch?v=mkCXy90RE9g&t=332s

3. High efficiency

The losses?of the?#uav ?motor consist of the following parts:

Copper loss:?this is the loss caused by resistance heating

Iron loss:?the?#magnetic ?field inside the motor induces current in the?#iron ?#core , and this part of the eddy current will cause additional heat.

Friction loss

After deducting these losses, the output power acting on the shaft end can be obtained.

Test Vidoe from Игорь Негода: https://www.youtube.com/watch?v=mkCXy90RE9g&t=332s

4. Fast dynamic response

Whether it is a current loop, a speed loop or a position loop, the desired?#signal ?can be reached faster, more stably, and more accurately?as we hope.

There are two main points to pay attention to, the response time (Response time) and the overshoot (Overshoot). The overshoot is considered acceptable within the range of 10%.

?Behind the good dynamic response is a deep understanding of the motor model. Simply relying on?#PID , the control effect is very limited, but the model-based control will?inevitably?encounter many problems.?

Test Vidoe from Игорь Негода: https://www.youtube.com/watch?v=mkCXy90RE9g&t=332s

5. High encoder precision

The accuracy of the?#encoder ?determines the accuracy limit what?the motor can control. However, the positioning accuracy requirements are not so high, such as hair dryers, washing machines, air conditioners, etc??for some small appliances.

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In these cases, the encoder can be used instead of the design observation Sensors are used to estimate the position of the motor. This kind of sensorless control is also a hot research direction at present.

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How to stabilize the high torque output under low speed and zero frequency conditions, there is no good solution yet.

Test Vidoe from Игорь Негода: https://www.youtube.com/watch?v=mkCXy90RE9g&t=332s

6. Low temperature rise

If the?#temperature ?resistance is higher, the price of raw materials will be much higher.

When the motor runs under rated conditions for a while, the temperature measured by the stator will soon approach 100 degrees Celsius.

The greater?current?means?the?higer?internal temperature. The high temperature of the?#winding ?will melt the insulation layer?to cause a short circuit.

For permanent magnets, high temperatures will demagnetize?them.

To?improve the adaptability of motors at high temperatures?and develop new material are two solutions.

Test Vidoe from Игорь Негода: https://www.youtube.com/watch?v=mkCXy90RE9g&t=332s

7. Wide speed range

The field-weakening control?#algorithms ?allows the motor to have the ability to exceed the rated speed. The wider the speed range, the applicability of the motor?is stronger

Test Vidoe from Игорь Негода: https://www.youtube.com/watch?v=mkCXy90RE9g&t=332s

8.?Long service life

9. Low torque ripple

Torque ripple?causes speed fluctuations, vibration and noise, and resonance when the frequency of the?#torque ?matches the frequency of the current.

The torque ripple mainly comes from the?#cogging ?torque and?#friction ?torque.

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The cogging torque is?generated by the interaction between the permanent magnet and the stator core when the permanent magnet motor winding is not energized.

After the stator and rotor are assembled, a certain amount of magnetic field energy is also stored in the air gap. Due to the interaction of the magnetic field,

the rotor will be attracted to a specific position when the winding is not powered.

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If you manually push the rotor to rotate, the rotor will automatically return to its original position after?a period of time.

Therefore, the cogging torque?also brings?a problem, certain difficulties to the starting of the motor.?Therefore, the low cogging torque is important indicator.

Test Vidoe from Игорь Негода: https://www.youtube.com/watch?v=mkCXy90RE9g&t=332s

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T-MOTOR Products recommendations document (remark: Borchure)

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