Whether the square wave controller is suitable for high-speed motor

[John Sessions]

Compared with the square wave controller, FOC is technically advanced, but is it really suitable for the high-speed motor control application of UAV propeller?
Personally, I think FOC is more suitable for low-speed servo control to achieve accurate position and speed control. Small torque pulsation.
1. And for high-speed operation, whether to consider the problem that the maximum speed is limited by PWM switch frequency ~
2. What is the main consideration of adopting FOC scheme for UAV propeller control? Speed smoothness?
3. FOC is undoubtedly a better solution for low-speed work such as cradle head.
Hope everybody discusses!

[John Sessions]

The results of motor parameter identification are not accurate, and the identified inductors are all orders of magnitude e-12.I assigned 6uh to myself.Motor current loop runs smoothly.
The errors of the identified resistances are generally small, and the inductance values are generally less accurate.According to the parameter setting strategy of the current loop, the PID parameters of the current loop are calculated according to the value of resistance and inductance.

[Kantar Worldpanel]

The current chip function is still able to cope with the rotation speed of this motor, such as TI's instaSPIN FOC scheme, where tens of thousands of rotation motors are turned.
For example, 20K PWM switching frequency, 20K current loop, then according to the theoretical sampling law, can sample 10K current, that is, the electric frequency can reach 10K, if a 4-pole motor, can reach 60*10K/4 = 150,000 RPM.I'm not actually going to use a 20K current loop to pick up a 10K current, but I'm going to use a 1K current to pick up a 10,000-plus current.
The uav adopts the FOC scheme. One is to consider the small torque fluctuation of FOC, and the noise will be lower. The other is that the wave control efficiency of FOC will be higher.

[Larios]

Originally Posted by John Sessions

Compared with the square wave controller, FOC is technically advanced, but is it really suitable for the high-speed motor control application of UAV propeller?
Personally, I think FOC is more suitable for low-speed servo control to achieve accurate position and speed control. Small torque pulsation.
1. And for high-speed operation, whether to consider the problem that the maximum speed is limited by PWM switch frequency ~
2. What is the main consideration of adopting FOC scheme for UAV propeller control? Speed smoothness?
3. FOC is undoubtedly a better solution for low-speed work such as cradle head.
Hope everybody discusses!

If u are talking about field oriented commutation it is not best suited for high speed applications. Many of the new 32 bit f3 controllers like KISS series run a quasi sinus similar to FOC and at apprx 90% open up to traditional BLDC commutation schemes. FOC will be a bit more efficient dynamically but at WOT there wont be an incredible difference. To run FOC really well with a PM bldc machine it best to have some positional feedback like and encoder. A directional one is even better. One of the best most efficient proposed drives fro propulsion is the Halbach Machine which can run with a large air gap and iron less core. Done right it can be lighter make much more torque and do it more efficiently. The rotor can be aluminum and the the core can be air. It can run with either drive style but the most efficient setups will always have a drive specifically tuned to a motor. A custom drive is the ticket. I have a book I will forward you about the best aeronautic electric propulsion systems investigated and compared. I don't really consider the UAVS props speeds most run here as high speed when speaking of motor rpms. Do I think FOC would be worth the additional fee$ involved for better low speed performance that may not manifest itself tangibly to a UAV pilot? Absolutely not!

For others maybe it is.

Think about a slot less Halbach machine and regeneration of some power on descents with the "smoother" generator.