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queries related to MSP430F6745 & its library functions

Other Parts Discussed in Thread: MSP430F6745, MSP430F6775, MSP430F67791

hello All,

one of my customer has the below queries related to MSP430F6745  & its library functions. Appriciate if anyone can help on this.

They are planning to use  MSP430F6745  for their panel meter  project which will works in 3Phase 4 wire,3phase 3wire and 1phase 2 wire system with  accuracy class 0.2 as per IEC62053.

 

 below  are the queries ,

1) Using TI library functions we are able to calculate some parameter like Voltage ,current ,power and energy ,apart from these parameter we want to measure and calculate the parameter like Demand,THD,Neutral current etc ..Detail list  mentioned in attached Annexture A-Parameter List.

 

can we measure and calculate the mentioned parameter simultaneously by using library function and our functions used,at the time of calculating the parameters simulteneously  from library function and our functions used, is there any chances to clash the program etc.??

 

2) Is library functions supports for 3phase 3wire and 1phase 2 wire also??

 

3) How we will achieve class 0.2 as per  IEC62053 using  MSP430F6745 ?? Becuase the input current measurement will be done on SD24 and Input voltage measurement will be done on ADC10 .

 

4) We have searched on the TI website for development board but we found that the development board is available for 128-pin LQFP package and we are thinking about the 100-pin LQFP package of  MSP430F6745.So is target board available for 100-pin LQFP package of  MSP430F6745???

 

5) We think that in reference design the cummulative energy is save in External EEPROM ,Can you pl tell us the timing of energy saving means after every 1min or 40 sec or 2 min etc??

 

6)Is it possible to save energy count at the time of power supply fail in flash memory ??

 

7) Is internal reference available for ADC10 ??

 

8) Also find the picture of our meter current connection.The current termination is pass thru CTs (5A CTs outside the meter) , Can we able to achieve class 0.2 in this case?

 

Awaiting your reply,

Regards

Mandar

  • We are working to loop in the correct people to help you on this one - sorry for the delay.
    -Katie
  • Mandar,

    • To meet Class 0.2% accuracy, a sigma delta converter should be used for both currents and voltages. As a result, if the customer also wants neutral current measurement, the MSP430F6775 should be used instead of the MSP430F6745 since it offers a sigma delta converter for every voltage and current.
    • As an example of a meter that uses the MSP430F67791(the MSP430F67791 is a different device variant than the MSP430F6775), you can refer to the following TI Design:
    www.ti.com/.../TIDM-THREEPHASEMETER-F6779
    Please refer to the software in the design guide from the above link.
    • The target board for the F6745/F6775 is for the 128-pin PEU package.
    • 1 phase 2-wire can be supported by easily changing the software settings for the number of phases.
    • In regard to THD, please refer to the below post:
    e2e.ti.com/.../436793
    • Neutral Current can be monitored by first enabling the NEUTRAL_MONITORING_SUPPORT macro in the software, connecting a current sensor to the neutral current inputs on the board, and properly configuring the neutral channel.


    Regards,
    JH