`
table:
Example 1:Read a phase voltage UAN,read the data stored in the address 243 colimn to read the
data,that is,the communication read out value Val_t=3800,read PU=100,Ue=400,so Val_s=
Val_t*PU/Ue=3800*100/400=950V.
Example 2:Read a phase voltage UAN,read the data stored in the address 243 colimn to read the
data,that is,the communication read out value Val_t=3800,read address 13-14 voltage facto
Ratio=0.25,则 Val_s=Val_t*Ratio=3800*0.25=950V.
7.5.2Active power,resctive,apparent power and electric energy
The series of measured values are read out by the 0X03 command of the MODBUS-RUT communication
protocol,and each item occupies two word.The correspongence between the communication value and
the actual one-time side value is as follows:Val_s=Val_t / 100;Val_t=the first word×65536+the
second word。
Example 1: read A phase active power Pa,the data is stored at address 253-254:the read value of
address 253 communication is 1,and the readout value of address 154 is 26000.Read PU=100,
PI=1000,Ue=400,so Val_t=1×65536+26000=91536,so Val_s =Val_t*PI*PU/Ue/10=2288400W.
Example 2: read A phase active power Pa,the data is stored at address 253-254:the read value
of address 253 communication is 1,and the readout value of address 154 is 26000.Read address power
and electric energy coefficient of 18-19 Ratio=25,so Val_t=1×65536+26000=91536,so Val_s =
Val_t*Ratio=2288400W.
7.5.3Voltage wave peak coefficient,telephoe wave form factor,current K coefficient,voltage
wave peak value,current/voltage positive sequence negative sequence,zero sequence
component and unbalancedness.
This series measuring value is read out by Modbus-RTU protocol 0×03 command,each item occupy
one word.Relation between communication value and actual value is shown as below table:
VoltageUan、Ubn、Ucn、Uab、Ubc、Uca
Power factor PF
A
、PF
B
、PF
C
、PF
总
Val_s=Val_t * PI * PU / Ue / 10
Val_s=Val_t * PI * PU / Ue/10