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...
Thanks for the reply....When looking at manufacturers data sheets for different generators, the reciprocal of the synchronous reactance or subtransient reactance doesn't give the correct short circuit ratio that was also included on the data sheet. Could this be the X/R ratio and not the short...
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 ?)...
