1. Fundamental of Electrical Loads
Chapter 7
Fundamental of Electrical Loads
4/17/2017
Prof. Magdi El-Saadawi

2. 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
4/17/2017
Prof. Magdi El-Saadawi

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Prof. Magdi El-Saadawi

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Prof. Magdi El-Saadawi

5. شكل توضيحى لحمل حكومى المحور الرأسى يمثل الحمل بالكيلو وات
المحور الأفقى يمثل الزمن بالساعات
4/17/2017
Prof. Magdi El-Saadawi

6. Difference between load curves of summer and winter
4/17/2017
Prof. Magdi El-Saadawi

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Prof. Magdi El-Saadawi

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Prof. Magdi El-Saadawi

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Prof. Magdi El-Saadawi

10. Load Duration Curve
4/17/2017
Prof. Magdi El-Saadawi

11. Load Duration Curve
4/17/2017
Prof. Magdi El-Saadawi

12. Load Curve and Load Duration Curve
4/17/2017
Prof. Magdi El-Saadawi

13. Average Demand: the ratio of kWh delivered by the station in a particular period divided by the hours in that period
Load Factor
Monthly L.F. =
kWh supplied in a month
Maximum demand * 24 * 30
Annual L.F. =
kWh supplied in a year
Maximum demand * 8760
4/17/2017
Prof. Magdi El-Saadawi

14. Diversity of Load
يعنى أن الأحمال المختلفة لا تعمل فى فترة زمنية واحدة أو أن شركات الكهرباء تتبع سياسات تدفع إلى ذلك
Diversity Factor
the ratio of the sum of maximum demands of the individual category to the maximum demand of the power station
4/17/2017
Prof. Magdi El-Saadawi

15. Practical Example on Diversity Factor
Solution 1: Transformer Size (Assuming Diversity Factor of 1.0)
2, , ,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)
4/17/2017
Prof. Magdi El-Saadawi

16. High or Low load factor value High or Low diversity factor value?
Which is better and why
High or Low load factor value
High or Low diversity factor value
4/17/2017
Prof. Magdi El-Saadawi

17. Indicates how best the plant capacity has been utilized
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
4/17/2017
Prof. Magdi El-Saadawi

18. Connected Load Factor Average kWh Connected load * 8760 4/17/2017
Prof. Magdi El-Saadawi

19. Load Duration Curve
4/17/2017
Prof. Magdi El-Saadawi