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MSP430F67791A: MSP430F67791A 2nd harmonics

SHOBHENDRA KUMAR

Prodigy 20 points

Part Number: MSP430F67791A

Dear Sir/Madam,

we are using MSP430F67791A device in our High End Numerical Relay, in this product we need to detect 2nd HARMONIC in all 4 current channel. and need to give ALARM based on this 2nd HARMONIC

hereby we request you to guide us on HOW TO DETECT THE 2nd HARMONIC , we have connected 4 current ct inputs to SD0N0, SD0P0, SD1N0, SD1P0, SD2N0, SD2P0, SD030, SD3P0,

We will be awaiting for your reply shortly

rgds

shobhendra

over 4 years ago

0 Gary Gao over 4 years ago

TI__Mastermind 39840 points

Hi shobhendra

You can refer to this application note Total Harmonic Distortion Measurement For Energy Monitoring (Rev. A)

0 SHOBHENDRA KUMAR over 4 years ago

Prodigy 20 points

Gary Gao

can u help us to calculate 2nd Harmonics by individually in all 4 current channel.

0 Gary Gao over 4 years ago in reply to SHOBHENDRA KUMAR

TI__Mastermind 39840 points

I think 2nd Harmonics frequency is known right? You can use FIR filter to filter other frequency signals first and do FFT to find the maximum value that should be the 2nd Harmonics.

0 SHOBHENDRA KUMAR over 4 years ago in reply to Gary Gao

Prodigy 20 points

Is there any supporting file (library) for calculating FIR Filter and FFT algorithm.?

As we have 3 phase current sensing ADC, we would like to calculate individual phase 2ND harmonics with MSP430F67791A, is it possible to calculate in same controller.?

0 Gary Gao over 4 years ago in reply to SHOBHENDRA KUMAR

TI__Mastermind 39840 points

Yes, we have DSP lib to do this with MPY32 hardware accelerators

https://dev.ti.com/tirex/explore/node?node=APFYDDVAZQjSJ7vLKa8XPg__IOGqZri__LATEST

0 SHOBHENDRA KUMAR over 4 years ago in reply to Gary Gao

Prodigy 20 points

Which particular library of dsp will help to calculate 2nd harmonics for individual phase signal.?

0 Gary Gao over 4 years ago in reply to SHOBHENDRA KUMAR

TI__Mastermind 39840 points

The FIR and FFT part will be help to calculate the 2nd harmonics

0 Raushan Mishra over 4 years ago

Prodigy 50 points

Which library to refer for calculating phase angel of analog signal.?

0 Gary Gao over 4 years ago in reply to Raushan Mishra

TI__Mastermind 39840 points

Hi

To calculate the phase angel you can refer to TI design I have mentioned before link section 3.2.3.1.3.

0 Raushan Mishra over 4 years ago in reply to Gary Gao

Prodigy 50 points

From continuous raw adc samples can you please explain how to detect 2nd harmonics.

0 Raushan Mishra over 4 years ago in reply to Gary Gao

Prodigy 50 points

This MPY32 hardware accelerator is it a add on additional hardware required for MSP430F67791A to calculate harmonics.?

0 Gary Gao over 4 years ago in reply to Raushan Mishra

TI__Mastermind 39840 points

Hi Raushan

Sorry missing this information. Yes MPY32 can be used to calculate harmonics.

0 Raushan Mishra over 4 years ago in reply to Gary Gao

Prodigy 50 points

Hi Gary Gao,

I am using CCS IDE and after adding "QmathLib.h" file , getting error as attached in png file.

Please let me know how to resolve it.

Where can i get supporting c file for same?

0 Gary Gao over 4 years ago in reply to Raushan Mishra

TI__Mastermind 39840 points

Please check if the CCS configuration below

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