Recent content by nand arora

yes, you can ground a phase but only if you have not grounded your neutral wire ( which may be solidly or high resistance) otherwise it will lead to Line to ground falut current. If you have not grounded neutral and you ground one of your phase wire, neutral will develop voltage w.r.t ground...

I have never seen any transformer with very high neutral grounding resistance. It is uaually around 9.5 ohms. Can I have 1k ohm resistance. What will be its disadvantages? And yes, I do have an Earth fault relay in neutral. But still I don't want the fault current (which may pass through the...

I am working in an industry where my technicians have to short the bus bars on regular basis (manually) for some maintenance purposes. I want to add high neutral grounding resistance to the incoming supply transformer to limit the Line to ground fault. Presently the neutral has been solidly...

can anyone give me a detailed description of working of isolated induction generator or self excited induction generator it has been mentioned about it in the following link in the last paragraph but no details are given...

Thanks for the reply...now i completely understand it. similar description has been given in the explanation of http://electricalstudy.net/lesson/poly-phase-induction-generator-or-asynchronous-generator-2/ where it has been discussed about looking from the view point of rotor conductor.

yes, I believe you are right about the braking mode. But I want to ask about generating mode. Will there be some action similar to braking action in slip between -1 to -2 as this part of the curve is mirror image of the part with slip between 1 to 2 (braking action). Probably nothing should...

for reference see the character-stick curve on the 4th figure of the page displayed by the following link: http://electricalstudy.net/lesson/torque-slip-character-sticks/ Why the portion of curve with speed above twice the synchronous speed not been shown in generating action? Will there be...

Thanks for the reply

speed control of induction motor can be studied from the following link: http://electricalstudy.net/lesson/speed-control-of-poly-phase-induction-motor/ motoring, generating and breaking action and their curve can be studied from the following link...

normally induction motor is used in motoring mode and thus speed of rotor is less than synchronous speed. when we want to use induction machine as an induction generator or say use it in generating mode then rotor speed should be more than the synchronous speed. But I don"t know how the...

What will happen if the rotor is made to rotate at double the synchronous speed i.e slip becomes less than -1. I have never seen any diagram showing torque slip curve with slip less than -1.

Can you please refer me some book or source where i can study crawling in detail. Where i can study the concept you mentioned in detail.

Thanks for the reply. I got it. So, we can say that in a way number of poles increase and thus speed decreases.

thanks for the link. It was informative. But unfortunately my question still remained unanswered in the link. I want to know that why does the speed become one- seventh for seventh harmonic when in formula synchronous speed is directly proportional to frequency?

Thanks for the reply. Can you clear the point that when we know that speed is directly proportional to frequency then why does the speed becomes one-seventh for the seventh harmonic which is the main reason for crawling in induction motor.