EE544 Distribution Systems 1

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EE544 Distribution Systems 1

• Satish J Ranade

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Short Term Planning

• Distribution System Modeling
• Load
• Feeders
• Analysis
• Power flow
• Back of the envelope
• Power Flow Algorithms
• Applications
• Short Circuit
• Motor Start
• Application
• Basic Planning Studies
• Capacitor Application
• Voltage Regulators
• Project

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Distribution Feeder
From Kersting Text
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Distribution Feeder
From Kersting Text
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Load
Load data comes from Customer
meter Substation The simplest customer meter
KWH Meter - measure ENERGY over a specific time
- Rotation of Induction Disk - Number of
rotations between reads proportional to
energy - Read Manually Demand Meter - records
rotation for uniform time intervals ( 15 or 30
min) Modern Meters ( Automatic Meter
Infrastructure) - Can record additional data -
one- and two-way communication
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Load
Load is described in terms of DEMAND DEMAND
Energy KWH over demand interval / demand
interval Maximum Demand Highest Demand over
the demand intervals Average demand - Time
average demand, proportional to energy Energy
over billing cycle Average demand Intervals
in billing cycle Demand factor Ratio of
maximum demand to connected load Load Factor
Average demand/ Maximum demand Utilization or
plant factor Maximu demand/ Rated Service
Capacity
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Demand Interval 15 min
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Load
15 min Demand shown for 24 Hours ( 96
Points) DEMAND Energy KWH over demand interval
/ demand interval Maximum Demand Highest
Demand over the demand intervals Customer 1 2 3 4
Total 2.6 3.5 4.2 2.3 11.2 Note sum of max.
customer demand ? max. Total demand Average
demand -Customer 1 1.5 kW Daily Energy
1.5(15/60) 24 8.8 KWH Load Factor Average
demand/ Maximum demand 1.5/2.6 57 Utilization
or plant factor 1.5 / ( 200 AMP120/1000) 62.5
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Load
15 min Demand shown for 24 Hours ( 96
Points) DEMAND Energy KWH over demand interval
/ demand interval Maximum Demand Highest
Demand over the demand intervals Customer 1 2 3 4
Total 2.6 3.5 4.2 2.3 11.2 Note sum of max.
customer demand ? max. Total demand Average
demand -Customer 1 1.5 kW Daily Energy
1.5(15/60) 24 8.8 KWH Load Factor Average
demand/ Maximum demand 1.5/2.6 57 Utilization
or plant factor 1.5 / ( 200 AMP120/1000) 62.5
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Diversity
sum of max. customer demand ? max. Total
demand Diversified demand sum of customer
demand period by period Maximum Non-coincident
sum of max. customer demand without regard
to interval that each
customer peaks Max. Diversified demand is also
called max. coincident demand Diversity factor
max non-coincident demand 1.13 max.
diversified demand
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Diversity
Diversity Table is from Kersting Text Origin
Unknown The other texts also have such tables but
specific numbers may be different At 60 customers
the DF saturates 3.2
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