hi researchers, I have a querry w.r.t ieee_519.dss example file given in opendss folder.
ieee_519.dss example problem is from ieee 519-1992 standard document (pp.81-84) http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=210894
1) I am intersted to validate the results given in the document through opendss. At this juncture i understand that the results given in docuemnt are %Vthd & %Ithd. With my earlier discussion in the forum, I have learnt that opendss is capable of giving different harmonic voltages and currents at the appropriate places (by placing monitors)
2) By using formula we can calculate %Vthd & %Ithd. as per the need of hour. (through matlab /excel)
3) Furhter, I understand that the csvfiles (spectrum_1,spectrum_2 & spectrum_3) represnt the harmonics currents induced by different types of loads considered.
4) In the ieee_519.dss example only spectrum_1(i.e. fundamental) & spectrum_2 are used.
5) The monitor placed at linegives results if exported, in the form of ieee_519_mon_mpcc.csv.
4) Careful observation of the csv fiie indicates that voltages & currents at different harmonics are generated as output (these can be used to to calculate %Vthd & %Ithd.).
5) But, there are multiple results, voltages & currents at different harmonics are given for 1,3,5,7,9,11,13 and 15. Wheresas at the end of the 900hz, again 1,3,5,7,9,11,13 and 15, these harmonic numbers are repeated 2 more times (with different maginuted of v & current).
6) What is the intrepretation of these values?
6) How, the above mentioned 3 differnt values can be used to compute %THD
7) Can these values be used to arrive at %thd at diifrent buses,eg. (115kv,13.8kv or 0.4kv) or pcc??
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
You can compute the %THD at any bus if you place a monitor there to capture the results at each harmonic.
One thing you may have trouble with: The harmonic current sources for the LOAD element are Norton equivalents with finite shunt impedances with some options. This will alter slightly the injection currents. If you need the values precisely, you can Set NeglectLoadY=Yes. This will prevent the shunt admittance from the Norton model from bleeding off some current. You will get a harmonic current injection that exactly matches the spectrum.
Be advised that there is a little danger associated with this: If you have a sharply resonant condition, you will get unrealistic estimates of the voltage distortion. But it may match the results in the IEEE 519 example.
See also Harmonics Load Modeling.pdf in the Doc folder.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
hi researchers, I have a querry w.r.t ieee_519.dss example file given in opendss folder.
ieee_519.dss example problem is from ieee 519-1992 standard document (pp.81-84) http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=210894
1) I am intersted to validate the results given in the document through opendss. At this juncture i understand that the results given in docuemnt are %Vthd & %Ithd. With my earlier discussion in the forum, I have learnt that opendss is capable of giving different harmonic voltages and currents at the appropriate places (by placing monitors)
2) By using formula we can calculate %Vthd & %Ithd. as per the need of hour. (through matlab /excel)
3) Furhter, I understand that the csvfiles (spectrum_1,spectrum_2 & spectrum_3) represnt the harmonics currents induced by different types of loads considered.
4) In the ieee_519.dss example only spectrum_1(i.e. fundamental) & spectrum_2 are used.
5) The monitor placed at linegives results if exported, in the form of ieee_519_mon_mpcc.csv.
4) Careful observation of the csv fiie indicates that voltages & currents at different harmonics are generated as output (these can be used to to calculate %Vthd & %Ithd.).
5) But, there are multiple results, voltages & currents at different harmonics are given for 1,3,5,7,9,11,13 and 15. Wheresas at the end of the 900hz, again 1,3,5,7,9,11,13 and 15, these harmonic numbers are repeated 2 more times (with different maginuted of v & current).
6) What is the intrepretation of these values?
6) How, the above mentioned 3 differnt values can be used to compute %THD
7) Can these values be used to arrive at %thd at diifrent buses,eg. (115kv,13.8kv or 0.4kv) or pcc??
You can compute the %THD at any bus if you place a monitor there to capture the results at each harmonic.
One thing you may have trouble with: The harmonic current sources for the LOAD element are Norton equivalents with finite shunt impedances with some options. This will alter slightly the injection currents. If you need the values precisely, you can Set NeglectLoadY=Yes. This will prevent the shunt admittance from the Norton model from bleeding off some current. You will get a harmonic current injection that exactly matches the spectrum.
Be advised that there is a little danger associated with this: If you have a sharply resonant condition, you will get unrealistic estimates of the voltage distortion. But it may match the results in the IEEE 519 example.
See also Harmonics Load Modeling.pdf in the Doc folder.
Thank you sir