ADE9078 datasheet(39/108 Pages) AD

39 / 108 page

ADE9078

Data Sheet

Rev. 0 | Page 38 of 107

Then, each bit in the xWATTOS register can correct an error of

0.05% at 10,000:1. Note that in most applications, the total

active power performance with small inputs is sufficient with

xWATTOS at zero.

Table 15 shows the settling times for total active power for a

50 Hz signal.

Table 15. Total Active Power Settling Time

Total Active Power Settling Time (sec)

Configuration

FS = 99%

FS = 99.90%

Integrator On, HPF On,

and LPF2 On

0.85

1.2

Integrator Off, HPF On,

and LPF2 On

0.85

1.2

Integrator Off, HPF On,

and LPF2 Off

0.06

0.66

Total Reactive Power

Total reactive power includes reactive power on the fundamental

and on the harmonics. The current channel, AI_PCF, is shifted

by 90° at the fundamental and at all harmonics. Then, this signal is

multiplied by the voltage waveform, AV_PCF. Then the result is

low-pass filtered, unless DISRPLPF = 1. Finally the APGAIN is

applied to perform a gain correction and the AVAROS value is

applied to correct the VAR offset. Note that, in most applications,

the total reactive power performance with small inputs is

sufficient with AVAROS at zero.

Figure 57 shows how the total reactive power calculation is

performed.

APGAIN

AVAROS

AVAR

LPF2

DISRPLPF

AI_PCF

AV_PCF

ENERGY/

POWER/

CF ACCUMULATION

90 DEGREE

PHASE SHIFT

Figure 57. Total Reactive Power (AVAR) Calculation

The total reactive power at a power factor of 0 has a similar ripple

to the total active power at a power factor of 1 (see Figure 56).

The resulting AVAR signal has an update rate of 4 kSPS and a

bandwidth of 1.6 kHz, as given in Table 1.

Phase B and Phase C have similar datapaths to those described

for AVAR to calculate BVAR and CVAR, with individual gain

and phase coefficients, BPGAIN and BVAROS, and CPGAIN

and CVAROS.

XVAROS has the same scaling as xVAR (see the Total Active

Power section to understand how to calculate this register value).

It is possible to disable total reactive power by setting the

VAR_DIS register. Note that the run register must be set to 0

before changing the VAR_DIS setting and must then be set to 1

again.

Table 16 shows the settling times for total reactive power for a

50 Hz signal.

Table 16. Total Reactive Power Settling Time

Total Reactive Power Settling Time (sec)

Configuration

FS = 99%

FS = 99.90%

Integrator On, HPF

On, and LPF2 On

0.85

1.19

Integrator Off, HPF

On, and LPF2 On

0.85

1.19

Integrator Off, HPF

On, and LPF2 Off

0.02

0.07

Total Apparent Power

Apparent power is generated by multiplying the current rms

measurement, xIRMS by the corresponding voltage rms, xVRMS

and then applying a gain correction, APGAIN. The result is stored

in the AVA register. Note that the offset of the total apparent

power calculation is performed by calibrating the AIRMS and

AVRMS measurements, using the AIRMSOS and AVRMSOS

registers (see the Filter-Based Total RMS section for more

information on the rms calculation).

The resulting AVA signal has an update rate of 4 kSPS and a

bandwidth of 1.6 kHz, as given in Table 1.

Phase B and Phase C have similar datapaths to those described

for AVA to calculate BVA and CVA, with individual gain

coefficients, BPGAIN and CPGAIN.

In some applications, if a tamper is detected on the voltage channel

inputs, it is desirable to accumulate the apparent energy assuming

that the voltage were at a nominal level. The ADE9078 offers a

240 V rms. If the VNOMx_EN bits in the CONFIG0 register

are set, VNOM is multiplied by xIRMS when calculating xVA.

Table 17 shows the settling times for total apparent power for a

50 Hz signal.

Table 17. Total Apparent Power Settling Time

Configuration

Total Apparent Power Settling Time,

FS = 99% (sec)

Integrator On, HPF On,

and LPF2 On

1.09

Integrator Off, HPF On,

and LPF2 Off

0.96

AIRMSOS

APGAIN

AIRMSOS

AIRMS

AVA

AVRMS

VNOM

LPF2

AI_PCF

215

LPF2

AI_PCF

ENERGY/

POWER/

CF ACCUMULATION

Figure 58. Total Apparent Power (AVA) Calculation

ADE9078 数据表(PDF) 39 Page - Analog Devices

ADE9078 数据表(HTML) 39 Page - Analog Devices

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 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载

链接网址

ADE9078 数据表(PDF) 39 Page - Analog Devices

ADE9078 数据表(HTML) 39 Page - Analog Devices

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 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表 下载

链接网址

数据表下载