MCP3909RD-3PH3 Microchip Technology, MCP3909RD-3PH3 Datasheet - Page 29

• Manufacturer Part Number: MCP3909RD-3PH3
• Description: REF DESIGN FOR MCP3909 W/18F2520
• Manufacturer: Microchip Technology

Specifications of MCP3909RD-3PH3

• Main Purpose: Power Management, Energy/Power Meter
• Utilized Ic / Part: MCP3909, PIC18F2520, PIC18F4550
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

3.3
© 2009 Microchip Technology Inc.
CALCULATION() - CALCULATING ELECTRICAL PARAMETERS
All power parameters are calculated with the function Calculation(), which is executed
once every 3 cycles of the power grid. As shown in Figure 3-2, all calculations are
performed post DFT (direct fourier transform), in the frequency domain.
• RMS Voltage/current Of Each phase
• Phase Angle
• Measuring Line Frequency
• Active, Reactive, Apparent Power Of Each Phase
• Positive and Negative Active Power
• Positive/negative Reactive Power
• 4-quadrant Reactive Energy
• Total Active Power, Total Reactive Power, and Total Apparent Power
• Total Power Factor
• Voltage and Current Distortion Of Each Phase
• Voltage and Current Harmonic Contents Of Each Phase
FIGURE 3-2:
Note:
Algorithms for all calculations are shown in Appendix C. “Power
Calculation Theory”.
Calculation() Flow Chart.
phase sequence 1~3
sync. window process
sync. window process
Select sync. window
DTF transformation
DTF transformation
Voltage signal and
Current signal and
Calculate function
Calculate voltage
Calculate voltage
sine/cosine table
function and
RMS value
harmonic
loop
phase sequence 1~3
Calculate frequency,
Calculate combined
and compensation
Combined energy
Update loop array
power calculation
Calculate current
Calculate current
determine phase
pointer and data
End of function
Active/reactive
accumulation
RMS value
calculation
sequence
harmonic
power
length
end
Firmware
DS51723A-page 29