TIDM-HV-1PH-DCAC: TIDM-HV-1PH-DCAC

Ramesh Muruganantham

Part Number: TIDM-HV-1PH-DCAC
Other Parts Discussed in Thread: CONTROLSUITE, POWERSUITE

Hello

I am trying to play around this eval board Voltage Source Inverter Reference Design. I was using build1 for AC output 60 HZ. I tried to change the switching frequency to 25 Khz (instead of 20 KHZ). It stopped working. The gate pulse itself is not generated. What is the reason?

Regards,

Ramesh

over 8 years ago

0 Manish Bhardwaj over 8 years ago

TI__Mastermind 43730 points

Ramesh,

If you revert back to 20 kHz do you see the PWM pulses?

Also , what version of software did you use, the one in controlSUITE or the DIGITAL POWER SDK

-Manish

0 Ramesh Muruganantham over 8 years ago in reply to Manish Bhardwaj

Expert 1410 points

Hi Manish,
I could see the pwm pulse if I revert back to 20 Khz and I can see the pulse upto 24 Khz( But I can see the sine wave is not stable at this frequency). At 25 Khz the pulses are not seen.

I used the version from Digital Power SDK

Regards
Ramesh

0 Manish Bhardwaj over 8 years ago in reply to Ramesh Muruganantham

TI__Mastermind 43730 points

Just one more question,

are you using the F28377D version or the F28004x version of the code?

-Manish

0 Manish Bhardwaj over 8 years ago in reply to Manish Bhardwaj

TI__Mastermind 43730 points

I just tried the F28004x version of the SW and i saw PWM pulses coming out at 20, 25 and 27kHz,

Can you further elaborate on the issue? Are you probing the PWM pins?

Also did you change the frequency through the CFG page?

Make sure while probing you do not have HV on the board.

0 Ramesh Muruganantham over 8 years ago in reply to Manish Bhardwaj

Expert 1410 points

I was using F28377D version. I am probing the gate pulses of IGBT. I changed the frequency through CFG page. I switched of the bus voltage (or keep around 20 voltage ) while probing.

Regards,
Ramesh

0 Manish Bhardwaj over 8 years ago in reply to Ramesh Muruganantham

TI__Mastermind 43730 points

Are you using the ADC option or the SDFM option from the CFG page??

I see that for SDFM i am unable ot generate PWM pulses, but for ADC i can.

0 Manish Bhardwaj over 8 years ago in reply to Manish Bhardwaj

TI__Mastermind 43730 points

The issue with SDFM occurs because of the SDFM OSR takes a long time,

please refer to section www.ti.com/.../tiduay6c.pdf fig 11,

the EPWM11 is used to issue the ISR in case of SDFM,

When PWM frequency exceeds the SDFM OSR x3 window, the value for triggering the ISR is greater than the PWM period and hence no ISR is triggered.

Hence the behavior of the code is expected.

1. YOu can reduce the OSR (however currently we do not support this option in powerSUITE GUI)
2. You can use the ADC

0 Ramesh Muruganantham over 8 years ago in reply to Manish Bhardwaj

Expert 1410 points

Thanks Manish. Currently I am traveling. I will check this next week and get back.

Regards,
Ramesh

0 Ramesh Muruganantham over 8 years ago in reply to Ramesh Muruganantham

Expert 1410 points

I was using SDFM only

0 Ramesh Muruganantham over 8 years ago in reply to Ramesh Muruganantham

Expert 1410 points

Dear Manish,

I changed to ADC and it is working for 25 Khz. Thanks

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TIDM-HV-1PH-DCAC: TIDM-HV-1PH-DCAC