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19 comments
Participant

Join Date: Nov 2006
Posts: 2

Maximum Demand (KVA) Calculation Formula

11/23/2006 5:07 AM

In India the maximum demand cycle is of 30 min. The instant values of the load is said to be integrated for the 30 min period. The clocked highest integrated Maximum Demand(MD) is considered for billing by the energy suppliers.

Can any one suggest a formula by which we can integrate the MD value by some measurable inputs from the system.

Please discuss

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Pathfinder Tags: formula maximum demand MD calculation
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Anonymous Poster
#1

Re: Maximum Demand (KVA) Calculation Formula

11/24/2006 3:04 AM

First what is the end objective? One obvious covariant is fuel consumption at the power generator.

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Participant

Join Date: Nov 2006
Posts: 2
#4
In reply to #1

Re: Maximum Demand (KVA) Calculation Formula

11/26/2006 11:03 PM

The objective is to monitor the KVA value in RTClock and get a predicted KVA (MD) value at the end of the cycle of 30 min.

I should be able to set the value of KVA at which I can control it.

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Anonymous Poster
#7
In reply to #1

Re: Maximum Demand (KVA) Calculation Formula

09/25/2007 2:40 AM

ok,please in design of electrical machine , is maximum demand equal 0.75 of total connected load

Best Regard

Mohammad Arf ALABBADI

Analysis section, Dubai

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Anonymous Poster
#14
In reply to #1

Re: Maximum Demand (KVA) Calculation Formula

03/24/2010 7:52 AM

First what is the end objective? One obvious covariant is fuel consumption at the power generator

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Anonymous Poster
#2

Re: Maximum Demand (KVA) Calculation Formula

11/24/2006 5:09 AM

XM=KB/2ND

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Member

Join Date: Dec 2006
Posts: 5
#6
In reply to #2

Re: Maximum Demand (KVA) Calculation Formula

12/11/2006 1:11 PM

This formulae is interesting, but could you please define the terms? i.e the meaning of those parameters used. Thanks a million.

Regards

Leyonsa

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Anonymous Poster
#3

Re: Maximum Demand (KVA) Calculation Formula

11/24/2006 5:44 AM

Power consumed is measured as KVA* power factor. In this case max. demand is given in KVA. If max demand sanctioned is 100 KVA, then ,

√3V*I = 100,000 V*A. Hence current , I = 131 amps. In a month there are 30 days, and if one is permitted to use only 100 kva as MD then, assuming each day if he exceeds the line current by 131 amps for One minute at any point of the day, then cumulatively on a 30 day contiunous working he may just be in the border line. The consumer has to restrict the power consumed not to go beyond 131 amps for one minute continously in a day.

You can have an alarm mounted to warn you, if the line current exceeds 131 amps.

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Anonymous Poster
#8
In reply to #3

Re: Maximum Demand (KVA) Calculation Formula

02/09/2008 3:27 AM

Excellent explanation & idea .

Really appreciate your effort to answer this in such a descriptive manner .

Aathi , UAE

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Anonymous Poster
#18
In reply to #8

Re: Maximum Demand (KVA) Calculation Formula

07/03/2010 1:00 AM

KVA CAICULATION

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Anonymous Poster
#11
In reply to #3

Re: Maximum Demand (KVA) Calculation Formula

08/28/2008 2:41 AM

What influence will the PF have on the monitored kVA,

if your equipment still need 86kW to do the work in the

example below ?

P=√3.V.I.cos@
kW=v3supply VIcos@
86=1.733801311.00
86=1.733801370.96
86=1.733801460.90
86=1.733801530.85
86=1.733801640.80

Jo

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Participant

Join Date: Dec 2011
Posts: 2
#19
In reply to #3

Re: Maximum Demand (KVA) Calculation Formula

12/08/2011 2:38 AM

I am not able to understand the formula you have given. For the max demand sanctioned 100kva how does this 3V*I=100,000V*Ais getting converted in to 131amps.Explaining how to calculate the formula in detail would really help me in understanding it.

Thanking you
Inderjeet singh

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Power-User

Join Date: Jun 2005
Posts: 398
Good Answers: 1
#5

Re: Maximum Demand (KVA) Calculation Formula

11/27/2006 4:41 PM

They probably do the same thing as in the USA. Here they measure the power consumed for 30 minutes and then multiply it by two to get the demand rate -- note that if you integrate the demand over an interval of time you are in essence measuring consumption for that interval.

We also have power companies that have 15 minute demand windows. In that case they measure the usage for each 15 minutes and then multiply by 4 to get the demand rate for that interval. I have not seen a utility company that uses less than a 15 minute "average" for calculating the billing demand.

The demand charge for the month is typically the maximum demand measured during all the demand intervals in the billing period. Normally the demand intervals coincide with the top of the hour. However different utilities do things differently. Some may take the peak usage occuring each week and average teh 4 or 5 values for the past month. Many employ ratchet charges where the lowest possible demand charge is perhaps 80% of the maximum demand for the past 11 months.

Most electric utilities use electronic demand meters that keep track of a facility's energy consumption per demand interval (a demand profile). This is downloaded and stored by the utility for a few years and is usually available on request in a graphic and/or digital printout. A small fee may be required.

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Anonymous Poster
#9

Re: Maximum Demand (KVA) Calculation Formula

02/17/2008 12:56 AM

Dear all

The standard formula for Demand calculation is as mention below

Maximum demand ( integration period 30 minite)=

( Instantaneous demand1xtime1 )+( Instantaneous demand2xtime2)+( Instantaneous demand "n"xtime "n") / 30

where, Instantaneous demand 1, 2...n is the demand measured based on sampling rate & time 1,2,...n is the time required to complete corrousponding demand value.

Pramod Chavan

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Anonymous Poster
#10

Re: Maximum Demand (KVA) Calculation Formula

07/22/2008 6:15 AM

My load 10 Minute 2500 KVA forward power and 10 Minute 1000 KVA reverse power and then 10 Minute 500 KVA then what is my Max Demand for integration period 30 Minute?

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Anonymous Poster
#12
In reply to #10

Re: Maximum Demand (KVA) Calculation Formula

08/28/2008 4:47 AM
kVAminkWh used
250010417imported
-100010-167exported
5001083imported
333kWh imp
667kW Dem
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Anonymous Poster
#15
In reply to #12

Re: Maximum Demand (KVA) Calculation Formula

03/24/2010 7:59 AM

Sir

We want how to calcaulate maxium demand.

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Anonymous Poster
#13

Re: Maximum Demand (KVA) Calculation Formula

06/24/2009 5:56 AM

I want to know the formula for rise in maximum demand for motor starting current.Thanks

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Participant

Join Date: Aug 2008
Location: Potch, SA
Posts: 2
#16

Re: Maximum Demand (KVA) Calculation Formula

03/24/2010 11:02 AM

Can the demand be predicted by the average measured kVA of the first few minutes? So for example, if you had a 5min integration period, it would look something like this :

Minute StartMinute Endeg. Instantaneous kVAPredicted Maximum Demand
011,0001,000
12800900
23600800
34400700
45200600
.Ave =6005min demand
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Anonymous Poster
#17

Re: Maximum Demand (KVA) Calculation Formula

05/05/2010 6:37 AM

the formula should be

1/T(∫p(t)dt) for the time duration of the cycle...

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Users who posted comments:

Anonymous Poster (14); Howetwo (1); inderjeet singh (1); Krawler (1); Leyonsa (1); renjith2008 (1)

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