I'm considering a 6 pulse recitifer which is used to control a dc motor. A delta-wye transformer is located before this rectifer and is being subjected to excessive heating. I am interesting in seeing the Irms^2*R (heat) that is being produced, due to the harmonics of this rectifier. I'd like to...
I'm considering a dc drive which consists of two six-pulse bridges (i.e. 12 pulse converter). One of the bridges is supplied through a wye-wye transformer and the other through a wye-delta.
I'd like to simulate current harmonics produced by this system and I'm looking for a recommendation of...
I'm considering an industrial distribution system which has a variety of harmonic producing equipment. I am interested in predicting the effects of these harmonics on the power system.
With the use of software, is it possible to predict the properties of harmonics in a system ? If so, how...
I'm trying to design a variable frequency RC-component based oscillator (with a large frequency range) using HIGH SPEED OP-AMPS (no special IC's). I want the output to be symmetric sine, square, as well as triangular waveforms with amplitude control.
Has anyone designed such a circuit in the...
I'm considering a distribution system that is not connected to any grid. It is supplied by a Hydel and diesel generating station. The Hydel produces at 600 V and is bumped up (via a x-mer) to 25 kV. There is 5 km of 3/0 Piegon transmission line that is used to connect the Hydel to the diesel...
The following transmission line is being considered:
ACSRSL 167.7 6/1 Pigeon 3/0 25C
If the above 3 phase line was stretched a distance of ~8000 ft, would it be expected to see a large drop over the line ?
i.e. should the current at the end of the line differ a lot (if any) from the current...
I'm performing a fault study on a small distribution system and I was wondering if anyone new of software that would generate impedance diagrams so that later, relay settings can be determined.
I've determined the positive/negative and zero sequence impedance at a variety of locations...
If I'm considering a distribution system that is solely supplied by synch. generators and I have 3 of them running at once......is there any way to model these in terms of reactance (sub-transient, zero sequence, etc.) as one large generator ? Is it as easy as considering them connected in...
I'm trying to compare some impedance values between a table that I've found with values that are modeled through a computer program. The cable that I'm considering is 350 MCM 69 kV (Teck90) 3/C. The software that I'm using models it with the following parameters (this is in p.u., based on a...
Can any tell me where I can find impedance values (R, X, B, Ro, Xo, Bo) for the following cables:
1.) Teck90, 500 MCM, 1kV
2.) Teck90, 350 MCM, 1kV
3.) Submarine Cable, 28 kV, 2/0 Alum., XLPE
Thanks in advance
The software that I'm using to perform a short circuit study asks me the following information when I insert a 2 winding transformer:
KVA/phase, Z+(pu), Zo(pu), configuration, grounding impedance (ohms).
The transformers that I'm considering are 3 phase banks (single phase transformers...
The software that I'm using to perform a fault study requires me to enter the maximum 3 phase fault current and the X/R ratio (of a substation/generator) and from this, it produces the positive and negative sequence impedances. It leaves the zero sequence impedance blank for me to fill in...
Not familiar with short circuit ratio (X/R) of synchronous generator calculation.
Given generator reactances (Xd, X'd, X''d, ....), time constants, stator/rotor resistance, etc.
How would on compute the short circuit ratio ? (if it is possible with the above info.)
Thanks
I'm using some software to perform a fault study on a distribution system. When I input a substation (ie. generator) I have to specify the 3 phase fault current and and the short circuit ratio (X/R). From this, the program determines the positive and negative thevenin impedances....the zero...
I'm trying to determine various faults on a synchronous generator. I received information from the manufacturer -> ie. Xd, X'd, X''d, Xq, X''q ...... The one piece of information that was added that I was not used to seeing was a leakage reactance.
Here are some typical numbers that I have...
I have 3 single phase transformers that have no physical common bond between each other except for the fact that there terminals are connected delta-wye (from a generator (delta) to the main bus (wye)). Each transformer is 250 kVA, 600V-25kV, Z%=6.02.
For simulation purposes, I want to...
If I'm considering a 3 phase transformer bank (made from 3 single phase transformers -> 25kV - 120/208 V, 50kVA, Z=2%, wye-wye), how would I model such a thing as one unit ?
(i.e. what would the impedance be, if I were modeling the above as a 3 phase transformer for computer simulations ?)...
Can anyone give me some info on determine positive and zero sequence impedances for a transformer ? The one that I'm considering is a 3 phase, delta-wye (wye solidly grounded), 250 kVA, 600 V - 25 kV, Z = 3.42 %.
Thanks in advance
Not familar with this topic at all......do manufacturers such as CAT usually have the available short circuit current of their generators ? If not, I would like to know how to calculate it. What I do know about the generator in question is,
1.) 60 Hz, 1200 rpm
2.) 650 kW
3.) 600 V
4.)...
I'm looking at a system that is supplied from a 1 MW sync. generator. The voltage on the primary line is 600 V (from the gen.) and then stepped up through a transformer to 25kV. The transformer is a 3 phase, 250 kVA, Y-Y, Z=3.42%.
I don't know the generator reactances and I want to calculate...
