MCP3909RD-3PH1 Microchip Technology, MCP3909RD-3PH1 Datasheet - Page 91

• Manufacturer Part Number: MCP3909RD-3PH1
• Description: REF DESIGN MCP3909 3PH ENGY MTR
• Manufacturer: Microchip Technology

Specifications of MCP3909RD-3PH1

• Main Purpose: Power Management, Energy/Power Meter
• Embedded: No
• Utilized Ic / Part: MCP3909, PIC18F2520, PIC18F4550
• Primary Attributes: 3-Ph, 220 VAC, In Case, LCD, USB, GUI
• Secondary Attributes: Opto-Isolated Interface for Safety
• Operating Voltage: 220 V
• Operating Current: 5 A
• Description/function: Energy Meter
• For Use With/related Products: MCP3909
• Lead Free Status / RoHS Status: Not applicable / Not applicable

C.7
C.8
C.9
© 2009 Microchip Technology Inc.
MEASURING SECONDARY PARAMETERS
APPARENT POWER OF EACH PHASE AND TOTAL APPARENT POWER
POWER FACTOR OF EACH PHASE AND TOTAL POWER FACTOR
The methods of measuring parameters such as RMS values of voltage and current,
active power, reactive power and frequency have been discussed in previous sections.
These are primary parameters that need to be calculated from the original data. There
are some other parameters called secondary parameter, such as power factor of each
phase, total reactive power, total active power, total power factor, harmonic
components and cumulative energy. They are obtained indirectly from primary param-
eters.
The measurement of secondary parameters is discussed in this section.
C.7.0.1
For 3-phase 4-wire systems, 3-phase total active power and recative power are the
sum of power of each phase, respectively, which can be expressed as:
EQUATION C-54:
EQUATION C-55:
Apparent power is defined as:
EQUATION C-56:
Power factor is defined as the ratio of active power to apparent power. The definition
can be represented as shown in Equation C-57:
EQUATION C-57:
TOTAL ACTIVE POWER AND TOTAL REACTIVE POWER
Q
P
Power Calculation Theory
PF
=
S
=
=
Q
P
=
A
A
----------------------- -
+
+
Q
P
P
Q
2
2
B
+
P
B
+
+
+
p
Q
2
P
Q
2
C
C
DS51723A-page 91