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How to Island two Sources using openDSS?

Beginners
2019-05-15
2019-05-17
  • Gunasekaran Madhu

    Question:
    Actually my system having one 250KVA voltage source connected to a 250KVA transformer through 33kv source bus (SB1) and the secondary of the transformer TR1 is connected to 415V substation bus (Sub1). In the substation bus the feeders (F1 to F5) are connected as a ring network. Each feeder is loaded by 40KVA at a distance of 20meters between them. Then Feeder F3 is connected to F6 at a distance of 2meters. feeder F6 is connected to another Substation bus (Sub2) through F7,F8,F9 each at a distance of 10meters length and each are loaded with 20KVA. The Sub2 is connected to a 100KVA transformer TR2. thee other end of TR2 is connected to another Source bus (SB2) where the 100KVA Generator is connected. There was lines connecting each feeders namely L1 to L11. In this L7 is connecting F3 and F6.

    **Problem Statement: **
    while commenting the line L7, I cant find any of the power is shared by Generator.
    can you help me to find island power delivered by generator as well as the voltage source.

    **My Script **
    clear
    Set DefaultBaseFrequency=50
    New object= circuit.practice2
    Edit Vsource.Source Basekv=33 MVA=0.25 bus1=SourceBus pu=1

    !New Isource.Source1 bus1=Sourcebus1 phases=3 amps=1.05

    !250KVA TR1- Transformer
    New Transformer.TR1 Buses=[SourceBus, Sub_Bus] conns=[Delta Wye] kVs=[33 0.415] kVAs=[250 250]

    !100KVA TR2- Transformer
    New Transformer.TR2 Buses=[SourceBus1, Sub_Bus1] conns=[Delta Wye] kVs=[33 0.415] kVAs=[100 100]

    New Linecode.3_5AlC R1=0.15 X1=0.087 R0=0.15 X0=0.087 C1=1.34e6 C0=1.34e6 Units=km

    !defining lines
    New Line.LINE1 Bus1=Sub_Bus Bus2=LoadBus1 Linecode=3_5AlC Length=20 Units=M
    New Line.LINE2 Bus1=LoadBus1 Bus2=LoadBus2 Linecode=3_5AlC Length=20 Units=M
    New Line.LINE3 Bus1=LoadBus2 Bus2=LoadBus3 Linecode=3_5AlC Length=20 Units=M
    New Line.LINE4 Bus1=LoadBus3 Bus2=LoadBus4 Linecode=3_5AlC Length=20 Units=M
    New Line.LINE5 Bus1=LoadBus4 Bus2=LoadBus5 Linecode=3_5AlC Length=20 Units=M
    New Line.LINE6 Bus1=LoadBus5 Bus2=Sub_Bus Linecode=3_5AlC Length=20 Units=M

    !line to be opened
    New Line.LINE7 Bus1=LoadBus3 Bus2=Sub_Bus1 Linecode=3_5AlC Length=2 Units=M
    !Open Object=Line.LINE7 terminal=1

    New Line.LINE8 Bus1=Sub_Bus1 Bus2=LoadBus6 Linecode=3_5AlC Length=10 Units=M
    New Line.LINE9 Bus1=LoadBus6 Bus2=LoadBus7 Linecode=3_5AlC Length=10 Units=M
    New Line.LINE10 Bus1=LoadBus7 Bus2=LoadBus8 Linecode=3_5AlC Length=10 Units=M
    New Line.LINE11 Bus1=LoadBus8 Bus2=Sub_Bus2 Linecode=3_5AlC Length=10 Units=M

    !defining loads
    New Load.LOAD1 Bus1=LoadBus1 kV=.415 kVA=40 PF=.98
    New Load.LOAD2 Bus1=LoadBus2 kV=.415 kVA=40 PF=.98
    New Load.LOAD3 Bus1=LoadBus3 kV=.415 kVA=40 PF=.98
    New Load.LOAD4 Bus1=LoadBus4 kV=.415 kVA=40 PF=.98
    New Load.LOAD5 Bus1=LoadBus5 kV=.415 kVA=40 PF=.98

    New Load.LOAD6 Bus1=LoadBus6 kV=.415 kVA=20 PF=.98
    New Load.LOAD7 Bus1=LoadBus7 kV=.415 kVA=20 PF=.98
    New Load.LOAD8 Bus1=LoadBus8 kV=.415 kVA=20 PF=.98

    New Generator.DG1 Bus1=SourceBus1 kV=33 kW=98 PF=1 Model=3

    Set voltagebases=[33 .415]
    Calcvoltagebases
    solve

     
    • Davis Montenegro

      Hello,

      Islanding is possible in OpenDSS but you have to be careful. In the power flow problem formulation inside OpenDSS the DER is declared as a negative load, which is very convenient for many purposes but for islanding is a problem. You see, as a negative load there is no enough power injection to sustain a zone that's isolated from the main substation, we have discussed this topic several times in this forum and published a large amount of papers talking about it. Anyway, after seeing your model I would recommend to use a voltage source instead of a generator, it will hold your microgrid as desired but beware of the phase angle, you will have to deal with it manually.
      Check the example attached.

      Best regards

      Davis

       
      • Gunasekaran Madhu

        Hai Davis,
        Thanks for the example attached and in that i cant get the
        unity for pu value of the voltage sources
        One more thing i like to know, it is mentioned in the manual that the
        OpenDSS program has been used for many analysis like which is mentioned
        below

        1. Distribution Planning and Analysis
        2. General Multi-phase AC Circuit Analysis
        3. Annual Load and Generation Simulations.
          Can I have a explanation and example program for each of it, which may help
          me to get understand the software very well. waiting for your response.

        Thanking you

        With regards
        M.Gunasekaran

        On Wed, May 15, 2019 at 6:35 PM Davis Montenegro davismont@users.sourceforge.net wrote:

        Hello,

        Islanding is possible in OpenDSS but you have to be careful. In the power
        flow problem formulation inside OpenDSS the DER is declared as a negative
        load, which is very convenient for many purposes but for islanding is a
        problem. You see, as a negative load there is no enough power injection to
        sustain a zone that's isolated from the main substation, we have discussed
        this topic several times in this forum and published a large amount of
        papers talking about it. Anyway, after seeing your model I would recommend
        to use a voltage source instead of a generator, it will hold your microgrid
        as desired but beware of the phase angle, you will have to deal with it
        manually.
        Check the example attached.

        Best regards

        Davis

        Attachments:


        How to Island two Sources using openDSS?
        https://sourceforge.net/p/electricdss/discussion/beginners/thread/4e5beae3dc/?limit=25#bdb1/2ac0


        Sent from sourceforge.net because you indicated interest in
        https://sourceforge.net/p/electricdss/discussion/beginners/

        To unsubscribe from further messages, please visit
        https://sourceforge.net/auth/subscriptions/

         
  • Gunasekaran Madhu

    Hai Davis,
    Thanks for the example attached and in that i cant get the unity for pu value of the voltage sources
    One more thing i like to know, it is mentioned in the manual that the OpenDSS program has been used for many analysis like which is mentioned below

    1. Distribution Planning and Analysis
    2. General Multi-phase AC Circuit Analysis
    3. Annual Load and Generation Simulations.
      Can I have a explanation and example program for each of it, which may help me to get understand the software very well. waiting for your response.

    Thanking you

    With regards
    M.Gunasekaran

     
    • Davis Montenegro

      Hi,

      1. Distribution Planning and Analysis:
        Yes we do that all the time, but normally those are applications implemented using external code to use OpenDSS through COM/DLL interface. These applications are implemented for us or other users out there, check the examples folder provided with the app.
      2. General Multi-phase AC Circuit Analysis:
        OpenDSS is itself multiphase my friend.
      3. Annual Load and Generation Simulations:
        Check the circuits provided with the app, for example, EPRI Ckt 7 has several load profiles for the loads across the circuit and the example provides annual simulation.

      We have a lot of documentation provided with the program or online: https://sourceforge.net/p/electricdss/code/HEAD/tree/trunk/Version8/Distrib/Doc/

      Best regards

      Davis

       
  • Gunasekaran Madhu

    Hai Davis,
    Thank you for the mail my friend. Can you please send me the Single line diagram of the EPRI Ckt 7, because while simulating it shows error in monitoring part of the script. while inspecting the script the line line.333 is not found but the monitoring element=line.333, so can you help me to simulate it.
    while using openDSS in Centos a linux platform, the plot and show commands are not working. Can you help me to fix the bug too.

     
    • Davis Montenegro

       
    • Davis Montenegro

      Hello,

      The plot capabilities are not avaiable in Linux environments since the plotting routines are in separate programs. These programs are not Linux compatible (yet), so, it looks like you will have to do the plotting yourself.

      Best regards

      Davis

       

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