BL6502A

BL6502A

BL6502A

BL6502A

http://www.belling.com.cn

- 6 -

3/15/2007

Total 14 Pages

Single Phase Energy Meter IC

Single Phase Energy Meter IC

Single Phase Energy Meter IC

Single Phase Energy Meter IC

with Integrated Oscillator

with Integrated Oscillator

with Integrated Oscillator

with Integrated Oscillator

Notes:

1) CF is not synchronous to F1 or F2 frequency outputs.

2) Sample tested during initial release and after any redesign or process change that may affect this

parameter.

THEORY OF OPERATION

Principle of Energy Measure

In energy measure, the power information varying with time is calculated by a direct

multiplication of the voltage signal and the current signal. Assume that the current signal and the

voltage signal are cosine functions; Umax, Imax are the peak values of the voltage signal and the

current signal; ωis the angle frequency of the input signals; the phase difference between the

current signal and the voltage signal is expressed asφ. Then the power is given as follows:

)

cos(

)

cos(

)

(

max

max

ϕ

+

×

=

wt

I

wt

U

t

p

If φ=0:

)]

2

cos(

1

[

2

)

(

max

max

wt

I

U

t

p

+

=

If φ≠0:

[

]

[

]

)

2

cos(

2

)

cos(

2

)

sin(

)

2

sin(

)

cos(

)

2

cos(

2

)

cos(

2

)

sin(

)

2

sin(

2

)

cos(

)]

2

cos(

1

[

2

)

sin(

)

sin(

)

cos(

)

cos(

]

)

2

cos(

1

[

2

)

sin(

)

sin(

)

cos(

)

cos(

)

cos(

)

cos(

)

cos(

)

(

max

max

max

max

max

max

max

max

max

max

max

max

max

max

max

max

max

max

max

max

max

Φ

+

+

Φ

=

Φ

+

Φ

+

Φ

=

Φ

+

Φ

+

=

Φ

+

Φ

+

=

Φ

+

Φ

×

=

Φ

+

×

=

t

I

U

I

U

t

t

I

U

I

U

t

I

U

t

I

U

t

t

I

U

t

I

U

t

I

t

I

t

U

t

I

t

U

t

p

ω

ω

ω

ω

ω

ω

ω

ω

ω

ω

ω

ω

ω

P(t) is called as the instantaneous power signal. The ideal p(t) consists of the dc component and ac

component whose frequency is 2ω. The dc component is called as the average active power, that

is:

)

cos(

2

max

max

ϕ

I

U

P

=

The average active power is related to the cosine value of the phase difference between the voltage

signal and the current signal. This cosine value is called as Power Factor (PF) of the two channel

signals.