Search results for query: *

Guys, like I said it is used as a inductor. I measured the inductance of the device with a Variac and a LCR meter, and it's inductance is ~40mH. Is there any reason it behaves signifcally different from a ideal inductor?

Hi, i have a question about a transformer/inductor i am curious about, pictured below. It seems to have 2 coils on a laminated closed U core. The nameplate says 'transformer', but is used as a inductor/reactor. The two coils seem to be connected in series. Does these setup have 'special'...

Yep, no AVR. For full schematic of the exciter: http://members.home.nl/damellema/CS4.PNG The dc smoothing caps are way to small to smooth the voltage. This brings me to the duality of capacitors vs inductors; voltage vs current smooting. Does it matter that the power delivered to the field...

Didn't bother with the current, i expect it to be constant ie flat dc. The generator is not running, and the exciter is in 'drying' mode, supplying unregulated power to the field to keep the generator warm when it is off-line. Instead of being self-excited (the exciter voltage shunted off the...

Hi, i succeeded in 'safely' connecting the scope to the rotor winding through the panel voltmeter connectors and took photo's of the screen. As you can see the voltage across the winding is not constant, but pulsating which verifies the simulation results. Very satisfying indeed. PS: Do...

I want to measure the voltage across and current through a generator field winding in steady state, and compare the waveforms to the ones i simulated in MATLAB. There are already panel voltage and shunt current meters present in the turbine room, so i use the terminals at the back op these...

I want to connect a TEK scope to a 100mv 200A current shunt to analyse the wave shape How do I proceed?

Just a quick thought. Due to the reactor and big inductive load the pf must be very bad (0, phi +90 deg). Has this any effect on the commutation of the diodes?

The last line i meant current source ;)

The problem is we are dealing here with current sources. They want current flowing, and develop voltages until that happens (or the core saturates). For the diodes to conduct they need to be forward biased with a voltage right? I simulated this circuit in Matlab Simulink and found a smooth...

Below is a circuit consisting of a current limiting reactor (L1), and a current transformer (T1) whose outputs are connected to two 3-phase diode bridges (R1 & R1). The bridges are series connected to a RL load. What is the purpose of the CT? It seems to shift the current 180 degrees...

Droop Mode: It is the mode of operation in which the machine will react to the load variation by changing its speed Shouldn't the generor output frequency be fixed at 50 or 60Hz? Or are these changes in frequency very small?

Hi, What are typical inductance & resistance values of generator field windings? Do these values change during operation?

After reading a PDF, i was finally able to assign a vector group to the CT. The primary side has vector group Y0, and the secondary Z7uw. 0-7=-7 or +5 phase shift (150 degrees) --> Yzn5 Another PDF mentions the following: "Taking no special measures, following connection modes amount to 100%...

I've read that the zigzag winding is used for absorbing triple-N harmonics, but doesn't the secondaries have to be symmetrical? What is the effect of 2 asymmetrical secondaries? (PS: I hate it when you can't edit your own threads)

Just got a stroke of genius: it looks like a weird kind of zigzag or interconnected wye connection. This is my interpretation of it:

Hi, i managed to obtain some information about a special wound CT used in a compound-source static excitation system. There was a 'nameplate' located on the back of the CT, which in turn was directed to the wall. It seems the wound CT has one primary and 2 secondary coils. The primary has 3...

Hi, at my work we got a 70kV Delta-Zigzag transformer that i am currently analysing. The primary side is 3.3kv, the secondary is 400V and the vector group is Dzn0 (Delta-zigzag + neutral(grounded) 0 phase shift). The primary is connected to a generator (wye connected) and the secondary is...

10000A fault?? Is that possible for a 6.4 MVA, 3.3 KV gen with Inom 1175A? Also a 1kW resistor would be huge and expensive. A more readily avaiable 200W resistor can handle up to 4243A primary current.

Are any of these devices of any use? http://www.chipcatalog.com/Cat/83.htm