Getting zeros for voltage values when used through COM interface in Python

[Dilan]

Hi,

I recently started to use the COM interface with Python and I’m simulating a 10 bus network as the initial step. I’m obtaining 0 values for all node voltages in this simulation.
I used the “CalcVoltageBases" and “set defaultbasefreq=50” commands as mentioned in another post and still getting the same results.
Also I get non zero voltage values when a similar code is used in Matlab .

Please find the code below. Highly appreciate if you can point out the problem in the attached code.

Thanks.

import numpy as np
import win32com.client
v=0.4
busnumber=10

loaddata=np.matrix([  [1,0,0] ,                                
                     [2,1000,100],
                     [3,1000,100],
                     [4,1000,100],
                     [5,5000,100],
                     [6,1000,100],
                     [7,1000,100],
                     [8,1000,100],
                     [9,1000,100],
                     [10,1000,100]])

linedata=np.matrix([[1,1,2,1,1],    
            [2,2,3,1,1],
            [3,3,4,1,1],
            [4,4,5,1,1],
            [5,5,6,1,1],
            [6,6,7,1,1],
            [7,5,8,1,1],
            [8,8,9,1,1],
            [9,9, 10,1,1]])

DSSObj = win32com.client.Dispatch("OpenDSSEngine.DSS")
Start=DSSObj.Start(0) 
DSSText = DSSObj.Text
DSSText.Command = "clear"
DSSText.Command ="New Circuit.Simple"  
DSSText.Command = "set defaultbasefreq=50 "
DSSText.Command ="Edit Vsource.Source BasekV="+str(v)+" pu=1.00 ISC3=3000 ISC1=2500"    
DSSText.Command ="New Line.1 Bus1=SourceBus Bus2=2 R1=1 X1=1 R0=1 X0=1 C1=0 C0=0  Length=1"  

for i in range(1,busnumber-1):

    DSSText.Command ="New Line."+str(int(linedata[i,0]))+ " Bus1="+str(int(linedata[i,1]))+ " Bus2="+str(int(linedata[i,2])) +" R1="+str((linedata[i,3]))+ " X1="+str((linedata[i,4]))+ " R0="+str((linedata[i,3]))+" X0="+str((linedata[i,4]))+ " C1=0 C0=0 Length=1"

for i in range(1,busnumber):

    DSSText.Command ="New Load."+ str(int(loaddata[i,0]))+ " Bus1="+ str(int(loaddata[i,0])) +" kV=0.4"+ " kW="+ str(loaddata[i,1]/1000)+ " kVar=" +str(loaddata[i,2]/1000)

DSSText.Command ="CalcVoltageBases"
DSSCircuit = DSSObj.ActiveCircuit
DSSSolution = DSSCircuit.Solution

DSSSolution.Solve
DSSLines = DSSCircuit.Lines
DSSBus= DSSCircuit.ActiveBus
VMSi=DSSCircuit.AllNodeVmagPUByPhase(2)

MyLineLosses = DSSCircuit.LineLosses
print(DSSCircuit.AllNodeVmagByPhase(3))
DSSObj.ClearAll()

[Roger Dugan]

Try

DSSText.Command ="Show Isolated"

To make sure you have everything connected

[Dilan]

Hi Roger,

Thank you very much for the quick response.

It looks like every thing is connected from the following ISOLATED CIRCUIT ELEMENT REPORT.

Please let me know if you notice a problem in the code.

ISOLATED CIRCUIT ELEMENT REPORT


***  THE FOLLOWING BUSES HAVE NO CONNECTION TO THE SOURCE ***


***********  THE FOLLOWING SUB NETWORKS ARE ISOLATED ************


***********  THE FOLLOWING ENABLED ELEMENTS ARE ISOLATED ************


***  THE FOLLOWING BUSES ARE NOT CONNECTED TO ANY POWER DELIVERY ELEMENT ***


***********  CONNECTED CIRCUIT ELEMENT TREE ************

(Lexical Level) Element name

(0) Vsource.source
(1) Line.1
[SHUNT], Load.2
(2) Line.2
[SHUNT], Load.3
(3) Line.3
[SHUNT], Load.4
(4) Line.4
[SHUNT], Load.5
(5) Line.7
[SHUNT], Load.8
(6) Line.8
[SHUNT], Load.9
(7) Line.9
[SHUNT], Load.10
(5) Line.5
[SHUNT], Load.6
(6) Line.6
[SHUNT], Load.7

[Dilan]

Hi Roger,

Thank you very much for the quick response.

It looks like every thing is connected from the following ISOLATED CIRCUIT ELEMENT REPORT.

Please let me know if you notice a problem in the code.

ISOLATED CIRCUIT ELEMENT REPORT


***  THE FOLLOWING BUSES HAVE NO CONNECTION TO THE SOURCE ***


***********  THE FOLLOWING SUB NETWORKS ARE ISOLATED ************


***********  THE FOLLOWING ENABLED ELEMENTS ARE ISOLATED ************


***  THE FOLLOWING BUSES ARE NOT CONNECTED TO ANY POWER DELIVERY ELEMENT ***


***********  CONNECTED CIRCUIT ELEMENT TREE ************

(Lexical Level) Element name

(0) Vsource.source
(1) Line.1
[SHUNT], Load.2
(2) Line.2
[SHUNT], Load.3
(3) Line.3
[SHUNT], Load.4
(4) Line.4
[SHUNT], Load.5
(5) Line.7
[SHUNT], Load.8
(6) Line.8
[SHUNT], Load.9
(7) Line.9
[SHUNT], Load.10
(5) Line.5
[SHUNT], Load.6
(6) Line.6
[SHUNT], Load.7

[Roger Dugan]

Try moving

Set DefaultBaseFrequency=50

to right after the Clear command. I suspect the circuit got defined with a source for 60 Hz.

[Dilan]

That solved the problem.

Thank you very much for the support.