Previous in Forum: ELCB CIRCUIT DIAGRAM   Next in Forum: Automatic Door Opening with barrier
Close
Close
Close
7 comments
Rate Comments: Nested
Active Contributor

Join Date: Mar 2009
Posts: 15

Non Linear loads

08/29/2009 9:13 AM

Dear sir,

Please give me your suggestions regarding the following

1. What is the effect of N-L loads (25-30%) on system voltage , AC & DC drives inspite of using power capacitor with reactors ?

2. Is there any effect if the %age is below 25 , then what is the minimum permisible %age ?

3. Is there any speed variations on the AC& DC drives, or malfunctioning of the system?

4. then what is the remidial actionfor this ?

5. If we use LED lighting insted of CFL system , can we minimize the harmonic effect?

6. For calculating N-L load %age , should we take power factor as 0.8 ( std. in India) or the monthly average power factor ?

7. What are the steps to conserve the power in the Boiler ( fuel used is Paddy husk)?

(qtn .no. 7 is exclusevely of N-L loads)

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Good Answers:

These comments received enough positive votes to make them "good answers".
3
Guru

Join Date: Sep 2006
Posts: 4513
Good Answers: 88
#1

Re: Non Linear loads

08/29/2009 2:09 PM

Pop Quiz

Let's assume for a moment that I've been tasked with designing a 750 MW nuclear power plant, its control systems, its safety systems, all the other systems, the distribution grid, the substations, the infrastructure, the billing software that helps me pay for it all, and to hire a security force to watch over the plant and fend off the protesters.

Let's further assume that I don't know how to do any of this. What should I do?

A. Ask an online engineering forum.

B. Hire an expert.

Register to Reply Good Answer (Score 3)
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15603
Good Answers: 982
#2
In reply to #1

Re: Non Linear loads

08/29/2009 8:56 PM

Well put europium. A GA from me.

It does make me wonder why the OP posed the convoluted question in the first place though. Could it be a malevolent professor needs to cull the size of his class by frightening the students the first week with an impossible homework assignment, or will some distant power generator go off line real soon?

__________________
"Don't disturb my circles." translation of Archimedes last words
Register to Reply
Power-User

Join Date: Apr 2009
Location: FL USA
Posts: 372
Good Answers: 9
#4
In reply to #1

Re: Non Linear loads

09/01/2009 2:37 PM

Europium

GA from me also - I can see a question when someone wants to understand a technology or some help with a material or trouble issue, but when a turn key answer like this is solicited, how can it be for anything but the desire to avoid the cost of hiring an expert?

__________________
What is right is not always popular. - What is popular is not always right.
Register to Reply
Guru

Join Date: Sep 2006
Posts: 4513
Good Answers: 88
#5
In reply to #4

Re: Non Linear loads

09/01/2009 3:28 PM

"... but when a turn key answer like this is solicited, how can it be for anything but the desire to avoid the cost of hiring an expert?"

I'm not so sure the OP is trying to avoid the cost of hiring an expert. Rather, I suspect the OP is a junior engineer who is trying to avoid being fired by his boss who sees the degree but doesn't suspect the OP is actually incapable of doing the job. Consider the naivete and scope of his query. It's ludicrous.

I suspect he did in engineering school exactly what he is doing here: trying to get someone else to do his work for him. He got the grades by the sweat of someone else's brow and graduated without actually getting an education. His degree is probably a sham but his boss hasn't yet realized this and the OP is trying to keep it that way. His question strongly suggests (to me, at any rate) that he is responsible for solving these problems, but hasn't one clue how to go about doing it. Whoever gave him that responsibility evidently believes he is capable of solving them. Conclusion: Somebody's fooling somebody.

I know this post sounds harsh and it probably is, but there are many precedents right here on CR4, people asking these same sorts of questions. I'm astonished at this, quite honestly, and it is definitely on the rise. I'm astonished at the sheer numbers of people who come here and ask others to fully shoulder their loads. It certainly doesn't smack of integrity. I'd hang my head in shame if that were my post.

Register to Reply Off Topic (Score 5)
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15603
Good Answers: 982
#6
In reply to #5

Re: Non Linear loads

09/01/2009 4:30 PM

While I still like my idea for a professor culling a class, it just came to my mind another benign scenario with both this much detail and the OP having so little of a clue what the details mean. This might be somebody (accounting, HR, etc.) who was CC'd on a memo between engineers. They posted what they thought was pertinent from the memo for us to translate. (Can I really be naive, when it's by choice. )

In any case the real answers to this belch of questions can only be found with many years of schooling, followed by real field experience. Neither of these can be obtained solely from this forum.

__________________
"Don't disturb my circles." translation of Archimedes last words
Register to Reply Off Topic (Score 5)
Power-User

Join Date: Apr 2009
Location: FL USA
Posts: 372
Good Answers: 9
#7
In reply to #5

Re: Non Linear loads

09/01/2009 4:54 PM

Both you and Redfred post some believable scenarios, but after reviewing some of this OPs posts, I believe you have hit the nail on the head!

__________________
What is right is not always popular. - What is popular is not always right.
Register to Reply Off Topic (Score 5)
Guru
Canada - Member - Specialized in power electronics

Join Date: Feb 2008
Location: Montreal, Canada.
Posts: 1372
Good Answers: 80
#3

Re: Non Linear loads

08/30/2009 8:20 AM

While my colleagues above think that this is not a legitimate post, I will give you the benefice of the doubt. You might be a plant manager trying to understand the black magic of harmonics.

1- What are those power capacitors and reactors? If they are properly designed and tuned harmonics filters, the plant is probably OK. If not, you might get various resonance overvoltage.

2- "permisible %age " of what? IEEE519 recommends approximately 8-10% current distortion and 5% voltage distortion at the PCC. But what is acceptable for your plant depends on its configuration.

3- You tell us. It is your plant.

4- Hire an expert who has done this before. Ask for references and check the results.

5- It depends on the specific product and where it is used.

6- PF Not related to harmonics.

7- Not my field of expertise.

__________________
Experienced is earned, common sense is taught, both are rare essentials of life.
Register to Reply
Register to Reply 7 comments

Good Answers:

These comments received enough positive votes to make them "good answers".
Copy to Clipboard

Users who posted comments:

marcot (1); redfred (2); U NO WHO (2); user-deleted-13 (2)

Previous in Forum: ELCB CIRCUIT DIAGRAM   Next in Forum: Automatic Door Opening with barrier

Advertisement