ESC Commutation, Noise and Max. Speed Problem

[VinsmokeSanji]

Hello Sir or Madam,

We have designed an ESC according to STEVAL-ESC002V1 and used ST's 6Step_Library. In our application, There are commutation, noise and maximum speed problem.

• MCU and gate driver is STSPIN32F0A
• MOSFET is STL220N6F7
• Switching frequency is 32kHz
• Zero crossing timer frequency is 250kHz
• Motor parameters:
  • 14 pole pairs
  • Max. 5300 rpm at no load (We can rotate only at 5200 rpm)
• using OPEN_LOOP, COMPLEMENTARY_DRIVE, ST_PWM_INTERFACE, SENSE_COMPARATORS, FAST_DEMAG macros

What can be the problem or is there another library that we can use for our application?

[Cristiana SCARAMEL]

Hi @Yasin Türk​ and welcome to the ST Community.

Are you using the STSW-ESC002V1 package? It is the reference firmware for the STEVAl-ESC002V1.

You can find more details on the dedicated user manuals: UM2518 for the board and UM2530 for the firmware.

Let me know if these info can help you.

[VinsmokeSanji]

Hi @Cristiana SCARAMEL​ 

Yes I am using STSW-ESC002V1 package. I've looked at those user manuals and choosed macros accordinh to UM2530. In UM2736 at chapter 4.5., there is a sense comparators algorithm. We use this algorithm for our application. Is this algorithm applicable for low inductance bldc motors like drone motors?

[Cristiana SCARAMEL]

Hi @Yasin Türk,

​the firmware you mentioned is designed for drone propellers. It is able to reach higher rpm than the sensorless technique based on ADC.

Did the shared information help you solve your initial problem?

If so please, please click on the "Select as Best" label in the proper answer.

[VinsmokeSanji]

We are using this firmware in our project. And there is still noise and maximum speed problem. So, why does not our drone motor reach higher speed? What can be the problem?

[Cristiana SCARAMEL]

Hi @Yasin Türk​,

concerning to the maximum speed, I suggest to check the supply voltage. A supply voltage even slightly lower than the nominal one of the motor can justify the difference in the maximum speed reached.

About the noise please provide a detailed description of what you mean. Some oscilloscope waveforms could be help (e.g. one motor phase and respective Op Amp signals).

[VinsmokeSanji]

Hi Cristiana,

Based on our observations, supply voltage does not change. At the same environmental aspects, Air 40A ESC's noise is 86 dB and our ESC's noise is 92 dB. You can find motor phase and current signals files attached.

[Cristiana SCARAMEL]

Hi @Yasin Türk​,

please provide the above requested waveforms: one motor phase and respective Op Amp signals in the same screenshoot.

[VinsmokeSanji]

Hi Cristiana,

I am sorry about the late response. I added one motor phase and respective op-amp signals. Opbemf1 and Opbemf2 are signals at low speed. Opbemf3 and Opbemf4 are signals at maximum speed. Opbemf5 is also signal at maximum speed but voltage resolution is at 5V.