What is LCI drive & how does it work & why it is used?
Answer / raghavendran.r
An LCI drive using SCRs does not need extra forced turn-off and does not use PWM to vary the frequency. It uses SCRs on the front-end to covert the incoming AC to variable voltage DC, then uses multiple SCRs on the back end to fire into the motor at a varying frequency, but relies upon the motor's rotation itself to make the current passing through the SCRs to cross through zero and turn off (hence the term "Load Commutated"). This is done through very complex firing schemes that require a relatively high powered computer to accomplish. That's why you will not see LCI drives on small motors; the cost is prohibitive and LCI drives cannot compete with PWM where PWM is effective and reliable. But on very large synchronous motors the transistor technology becomes a quantum leap more expensive and highly susceptible to damage, so LCI drives start to make sense again.
Is This Answer Correct ? | 17 Yes | 2 No |
What is the ohms law?
how much current capacity 250 amp. mccb please tell me about whats are the reasons to trip 2 or 3 times in a night. and what are the steps to short out this problem
from where the self excitrd induction generator get the power?why is the voltage regulation is poor of seig?
What is Difference Between static & Dynamic Pressure of Fan & Blowers
why rating in KVA and KVAR?
A 100 kVA , 400 v/250 kv testing transformer has 8% leakage reactance and resistance on 100 KVA base . A cable has to be tested at 500 kv using the above transformer as a resonant transformer at 50 hz . if the charging current of the cable at 500 kv is 0.4 A find the series inductance required . Assume 2% resistance for the inductor to be used and the connecting leads . Neglect dielectric loss of hte cable . what will be the input voltage to the transformer ?
Hot Water System (HWS). Will a 30ma elcb have more nuisance tripping than 100ma elcb
What is the unit of charge and current?
please send previous exams question papers
The knee point of a current transformer is normally unique and known.So why in the nameplate of a CT they put the minimum value like this Vk> 400v.
How much must be gape bitween 2 cable on cable tray?
How the line trap works in substation...?