itsmoked
It is not a question of ground reference. It is simply a way that makes a connection between two points and simply doubles the rated output voltage. To lose all the connected instrumentation it is not a simple failure.
Diodes on both the negative and positive. Thanks LionelHutz but if you have an electrical connection between the positive output of power supply #1 and the negative output of power supply #2 (both grounded, as an example-it is not a short circuit because some diodes are blocked) you will double...
It is an old question, still unclear: Why some designers apply 4 blocking diodes, instead of 2, when connecting two DC power sources in parallel. There is a risk of, under certain circumstances, the output voltage be the sum of the two sources. Is there a reason that justifies this risk?
After all these years, sometimes my wish is to leave this forum. I suppose that is absolutely clear when a thread is written by someone that is not fluent in English. Most of answers are educated and respectly sent. Others don't. I had received answers explaining the risk of re-start after few...
Thanks all of you. The concern is related to a 4,16kV system, induction motor 4,0kV,low inertia load, capacitors bank connected to the motor terminals, DC control power from batteries and AC undervoltage relay not fast enough to detect a deep grid peak. It makes sense this concern related to...
So, considering the rotary compensator, the field forcing can provide a faster response and a better regulation performance when field weakening becomes necessary. Am I right? Thanks waross.
Even new synchronous machines, specially Rotary Compensators, still use brushes/rings for field winding excitation current instead of brushless system. Probably the possibility of field polarity reversion is the reason.
When/why is this reversion necessary? Thanks.
It is an old question : some important switchgear designers apply 4 blocking diodes when connecting two control DC power supplies in parallel. Others, 2 just at positive leads. It is well known the risk of serious continuous overvoltage ( 2 times Vnom) at load, under certain fault conditions...
I am not sure if costs more. I will check it. Accuracy is better, no need of high dynamic and thermal capabilities, possibility of very low setting points (less than 10% of CT nominal current), less weigth and reduced dimensions. Really, is the only place, I guess, that I could use metering CTs...
I think that a metering CT can be connected to a protection ground relay if installed at HRG circuits of transformers and generators.
I can see some pros and no cons. Am I right? Is this feasible/usual? Thanks.
This subject was discussed recently. It was explained the reason of a time delay during high speed to low speed switching.
The example of Panter (to see above) 2MW motor, Dahlander connection, it means "0.5MW/2,0MW motors" (1 to 4 power ratio if variable torque/Y-YY connection)L/H speeds...
As Waross had said:Thanks for the chance to share memories. "My" 60Hz/50Hz Rotary Converter is now clear, a synchronous motor stator turning some degrees to compensate generator load angle. A hidraulic cilinder doing it, a set of directional valves, a set of blocking valves to withstand short...
