STPMC1 datasheet(68/77 Pages) STMICROELECTRONICS

68 / 77 page

Energy calculation algorithm

STPMC1

68/77

Doc ID 15728 Rev 6

In case of shunt sensor (TCS = 1), an additional stage of internal digital differentiated

produces the value:

Equation 22

vd = dvu/dt = A ω cos (ω t) kDIF

The shunt preamplifier, AD converter and calibrator produce the value:

Equation 23

vs = i RS (AI/VREF) kI = i kS = C sin (ω t + ϕ)

The 2nd stage internal integrations produce the values:

Equation 24

vdi = ∫ vddt = A sin (ω t) kDIF kINT = A sin (ω t)

Equation 25

vsi = ∫ vsdt = - (C / ω) cos (ω t + ϕ) kINT

The frequency compensated values are:

Equation 26

Vdic = ω / kINT vdi = A ω sin (ω t) / kINT

Equation 27

vsic = ω / kINT vsi = - C cos (ω t + ϕ)

The 3rd stage internal integrations and DC cancellations produce the values:

Equation 28

vdiic = ∫ vdicdt = A cos (ω t) kDIF kINT = A cos (ω t)

Equation 29

vsiic = ∫ vsicdt = - (C / ω) sin (ω t + ϕ) kINT

10.1

Active energy calculation

The active power is computed as follows.

First, the voltage stream from the 1st stage (

Equation 13 or Equation 22) is multiplied to the

16-bit current from the 2nd stage (

Equation 16 or Equation 25) and current stream from the

1st stage (

Equation 14 or Equation 23) is multiplied to 16-bit voltage from the 2nd stage of

filter (

Equation 15 or Equation 24), yielding:

Equation 30

P1 = vu vii = - ABkINT sin (ω t) sin (ω t + ϕ) = - ABkINT[cos ϕ - cos (2 ω t + ϕ)] / 2

Equation 31

P2 = vui vi = ABkINT cos (ω t) cos (ω t + ϕ) = ABkINT [cos ϕ + cos (2 ω t + ϕ)] / 2

STPMC1 数据表(PDF) 68 Page - STMicroelectronics

STPMC1 数据表(HTML) 68 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77

数据表下载