How can a validate the BLDC Motor Model

Hello everyone,

In these days i'm modelling a BLDC Motor with simulink. I want to validate my model with real time test data

In my test case, I have an ESC , BLDC Motor and Microcontroller for getting PWM signal.

ESC have a connection from battery and have another connection for getting PWM from the Microcontroller. And also have ESC-Motor connection for three phase

My input is PWM and my measured outputs are RPM and Thrust.

During the test, I increase the PWM step by step and measure the rpm and thrust and save them to Excel.

I have all BLDC motor parameters and i modeled a PWM source, an inverter and BLDC Motor

But in my model my input PWM is not constant. I want to create a model that PWM is constant.

For example i want to input 1450 PWM and scope the RPM & Thrust and do it for each pwm and save it. After that i want to compare the simulation results and test result.

What should i do ?

Best Regards

Emin

[Mr. Pavl M.]

What do you mean by Thrust?

Which

What is ESC in your case?

Can you hire me?

[Muhammed Emin Yavuzaslan]

Hi Sir @Pavl M.

1 - Thrust is refers to the force exerted in a specific direction with propeller or force produced by a motor to propeller. Also I have a propeller model too.

2 - Static Thrust

3- ESC is electronic speed controller

Thanks for replying my question but i didnt understand what do you mean by " hire me ". I'm Sorry

Best Regards

Emin

[Sabin]

PWM stands for Pulse Width Modulation, PWM signal is a pulse not a constant value. Can you explain what do you mean by 1450 PWM?

[Mr. Pavl M.]

Answer:

It is in fact, indeed today, possible to create model with variable pulse width, DC = duty cycle and amplitude are the main parameters of PWM waveform, which is usually measured as a ratio and low(off) to high(on) value height. DC=low_part_time_frame/TotalCycleTimeFrame.

By 1450 you might mean amplitude in ... , or period in ms (if so than find your Toff and Ton required for PWM), or frequency in Hertz of PWM in %, which convertible to DC:

Period=1/Frequency

Period=Ton+Toff

DutyCycle=Ton*Frequency*100=(1/Frequency - Toff)*Frequency*100=100*(1 - Toff*Frequency).

Answer 1

[Sabin]

PWM is a pulse and therefore not constant. For three-phase systems modulation waveform is also not going to be a constant value but a sinusoidal or pseudo-sinusoidal signal. What can be constant is the frequency or amplitude of the modulation waveform.

Check out this page for more information about Space Vector Modulation (SVM) for Motor Control:

https://mathworks.com/discovery/space-vector-modulation.html

For running several simulations and then compare the results you can use the Simulation Data Inspector:

https://mathworks.com/help/simulink/slref/simulationdatainspector.html