ADE9078 Energy Readings

Question

I have some qusitoin about ADE9078 , I had desgin my pcb using ADE9078 and Its work well , I can read Voltage, current ,power, PF and other reading and it seem good I want to know to Ask about : 1- I face a problem in reading energy value , the energy reading it stat work and accumulating but then it reset to zero when the accumalation reatch to 10.45 each time , I do know the reson this is the rigister configuration I used configured the xGAIN registers, configured the ACCMODE register with 0x0000 (4-wire wye, 50Hz, Signed active and reactive power/energy accumulation mode), configured the VLEVEL register with 0x00117514 as suggested in page 56 of User Manual, configured the CONFIG0 register with 0x00000000 as we use a 1000:1 Current Transformer Additionally, as we need to read the energy register with reset, we followed what is stated at page 43 of User Manual: configured the EGY_TIME register with 0xF9F 1,configured the EP_CFG register with 0xE001 (RD_RST_EN=0, EGY_LD_ACCUM=0, EGY_TMR_MODE=0, EGY_PWR_EN=1, NOLOAD_TMR=111,PWR_SIGN_SEL=0) void ADE9000Class::ReadActiveEnergyValue(ActiveEnergyRegVlaue *Data) { int32_t temp_lowpacke; int32_t temp_highpacket; temp_lowpacke = int32_t (SPI_Read_32(ADDR_AWATTHR_LO))>>19; temp_highpacket = int32_t (SPI_Read_32(ADDR_AWATTHR_HI)) ; Data->totalActiveEnergy_A = (temp_highpacket << 13)|temp_lowpacke ; } this is code and Library which I used currently drive.google.com/.../view 2-I have a problem in Frequency value it's 51.4Hz and actual value is 50Hz it would be calibration issue or I need make some Calculatotion?? I have Some doubt becase I am use different Crystals value I use 12MHz , but the recomended 12.288MHz may this changing make the freq. reading wrong ? 3- can I read the line to line Voltage in ADE9078 ? an example can I read Vab =480V ? If I use the same wire configuration wye , what shoud be wire congiguration to have both reading line ot line voltage(Vab) and line to nutral voltage (Va) 4- Can I Read the Harmonics value when using ADE9078 ?

dave.smith · Accepted Answer

1 
 Setup for line cycle or sample base accumulation https://www.analog.com/media/en/technical-documentation/data-sheets/ade9078.pdf pg 42 
 EGY_LD_ACCUM=1, EGY_TMR_ MODE 0 or 1 depending on the accumulation you want to do. I would suggest line cycle accumulation EGY_TMR_ MODE=1 
 status0.0 EGYRDY will indicate when accumulation is done over x half linecycles. 
 
 select the correct zero cross to use for line cycle accumulation using ZX_LP_SEL

2. 
 Yes the crystal is the time base and it is for the entire part and 51.4 is about right 12.288/12*50 = 51.2Hz 
 Sample rate will be 3906.25sps I would suggest you change the crystal to 12.288 if possible. 
 if not any calculations using 4000Ksps you might want to replace with 3906.25 
 Phase angle measurements will also be impacted. also the cfden calculation 
 
 ANGLx_x 
 CLKIN/24 = 512 kSPS with 12Meg clk 12/24 =500Ksps

3. 
 Using the RMS for Phases to neutral and teh angle between phases you can calculate teh phase to phase voltage . 
 
 for example: 
 If 
 Phase A = 220 = a in diagram 
 Phase B = 220 =c in diagram 
 and the angle Phase A to B is 120 deg = B in diagram use the angle measurement for this but don't forget to correct for 12Mhz

Phase to Phase = = (a 2 + c 2 - 2ac&middot;cos(B))^.5 = 415.69219 phase to phase 
 
 https://www.calculator.net/triangle-calculator.html?vc=&vx=&vy=240&va=&vz=240&vb=120&angleunits=d&x=52&y=21 
 
 I would suggest 12.88Mhz clk to match datasheet performance 
 Dave)

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