fundamental of electrical loads chapter 7 7/3/2015prof. magdi el-saadawi1
TRANSCRIPT
Fundamental of Electrical Loads
Chapter 7
04/19/23 Prof. Magdi El-Saadawi 1
The Load Curve • It gives the following information
– Variation of load during different hours of day– Max. and Min. value s of daily load– Average annual load of the station– Information whether the installations is
working efficiently or not
04/19/23 Prof. Magdi El-Saadawi 2
04/19/23 Prof. Magdi El-Saadawi 3
04/19/23 Prof. Magdi El-Saadawi 4
5
حكومى لحمل توضيحى شكل
الحمل يمثل الرأسى المحوروات بالكيلو
الزمن يمثل األفقى المحوربالساعات
04/19/23 Prof. Magdi El-Saadawi
Difference between load curves of summer and winter
04/19/23 Prof. Magdi El-Saadawi 6
04/19/23 Prof. Magdi El-Saadawi 7
04/19/23 Prof. Magdi El-Saadawi 8
04/19/23 Prof. Magdi El-Saadawi 9
Load Duration Curve
04/19/23 Prof. Magdi El-Saadawi 10
Load Duration Curve
04/19/23 Prof. Magdi El-Saadawi 11
Load Curve and Load Duration Curve
04/19/23 Prof. Magdi El-Saadawi 12
• Average Demand: the ratio of kWh delivered by the station in a particular period divided by the hours in that period
• Load FactorMonthly L.F. =
kWh supplied in a month
Maximum demand * 24 * 30Annual L.F. =
kWh supplied in a year
Maximum demand * 8760
04/19/23 Prof. Magdi El-Saadawi 13
• Diversity of Load
فترة فى تعمل ال المختلفة األحمال أن يعنىتتبع الكهرباء شركات أن أو واحدة زمنية
ذلك إلى تدفع سياسات
• Diversity Factor
the ratio of the sum of maximum demands of the individual category to the maximum demand of the power station
04/19/23 Prof. Magdi El-Saadawi 14
Practical Example on Diversity Factor
04/19/23 Prof. Magdi El-Saadawi 15
Solution 1:
Transformer Size (Assuming Diversity Factor of 1.0)
2,000 + 1,500 + 1,000 = 4,500 kVA
Solution 2:
Transformer Size (Assume Diversity Factor of 1.2) Choose 3,750 kVA
(4,500 kVA divided by 1.2 = 3,750 kVA)
?Which is better and why
High or Low load factor value
High or Low diversity factor value
04/19/23 Prof. Magdi El-Saadawi 16
• Plant Factor
Indicates how best the plant capacity has been utilized
Station output in kWh
kW1*h1 + kW2*h2 + kW3*h3 + …….
• Capacity Factor is a value used to express the average percentage of full
capacity used over a given period of time. Average demand on the Station
Maximum Installed Capacity of the Station
04/19/23 Prof. Magdi El-Saadawi 17
• Connected Load Factor
Average kWh
Connected load * 8760
04/19/23 Prof. Magdi El-Saadawi 18
Load Duration Curve
04/19/23 Prof. Magdi El-Saadawi 19