STEVAL-IPE008V1 STMicroelectronics, STEVAL-IPE008V1 Datasheet - Page 46

• Manufacturer Part Number: STEVAL-IPE008V1
• Description: BOARD EVAL STPM01/STR715FR0
• Manufacturer: STMicroelectronics
• Type: Other Power Managementr

Specifications of STEVAL-IPE008V1

• Main Purpose: Power Management, Energy/Power Meter
• Embedded: Yes, MCU, ARM7
• Utilized Ic / Part: STPM01, STR715FR0
• Primary Attributes: 3-Ph Energy Meter (or Single Phase)
• Secondary Attributes: Measures Active, Reactive, Apparent Power
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: STPM01, STR715FR0
• Other names: 497-6412; STEVAL-IPE008V1

Theory of operation
46/60
Equation 6
dv/dt → v(t) = V
i(t) →
[see
Now four signals are available. Combining (pairing) them by means of two multiplying stages
two results are obtained:
Equation 7
[see
Equation 8
[see
After these two operations, another stage performs the subtraction between the results p2
and p1 and a division by 2, obtaining the active power:
Equation 9
[see
In this way, the AC part V•I•cos(2
power.
In the case of current sensors like “Rogowski coils”, which provide the rate of the
instantaneous current signal (di/dt), the initial voltage signal differentiated stage will be
switched off. In this case the signals coming from the A/D conversion and their consequent
integrations will be:
Equation 10
v(t) = V•sin
I
p
p
p
i
/
) t (
/
′
) t (
1
2
) t (
) t (
) t (
=
=
Figure 28
Figure 28
Figure 28
Figure 28
=
=
∫
=
di
p (
i
) t (
dt
dv
v
dt
/
) t (
) t (
2
⋅
) t (
ω
⋅
dt
=
⋅
∫
t
i
) t (
2
−
i
−
) t (
- 8]
- 9]
- 10]
- 11]
=
I
p
/
⋅
⋅
=
−
sin
1
⋅
ω
(
dt
ω
)) t
V
I
⋅
ω
cos(
⋅
=
⋅ ⋅
I
t; [see
cos(
=
−
2
cos
V
V
ω
⋅
ω
⋅ ⋅
t
I
I
ϕ
Figure 28
t
⋅
+
Doc ID 10853 Rev 7
2
2
cos
+
cos
−
ϕ
ω
ϕ
)
V
)
t +
ϕ
ϕ
⋅ ⋅
I
−
ϕ
cos(
)/2 has been then removed from the instantaneous
- 7]
V
⋅ ⋅
2
I
2
cos(
ω
t
2
+
2
ϕ
ω
)
t
+
ϕ
)
STPM01