Overview of Power Distribution

OVERVIEW OF POWER SYSTEM DISTRIBUTION

power distribution



For requirement and reliability purpose the various components of a power system can be arranged in different ways. The complexity of the resulting architecture determines the availability of electrical energy and the cost of the investment.

Power distribution for a given application is therefore based on a trade-off between technical necessities and cost.

Architectures include the following:

1. Radial systems
• Single-feeder
• Double-feeder
• Parallel-feeder
• Dual supply with double bus bar
  . 
2. Loop systems
• Open loop
• Closed loop
  . 
3. Systems with internal power generation
• Normal source generation
• Replacement source generation

The table below lists the main characteristics of each architecture for omparison. Illustrations are provided below table.

Architecture	Use	Advantages	Drawbacks
Radial
Single-feeder radial	Processes not requiring continuous supply E.g. a cement works	Most simple architecture Easy to protect Minimum cost	Low availability Downtime due to faults may be long A single fault interrupts supply to the entire feeder
Double-feeder radial	Continuous processes: steel, petrochemicals	Good continuity of supply Maintenance possible on busbars of main switchboard	Expensive solution Partial operation of busbars during maintenance
Parallel-feeder	Large power systems Future expansion is limited	Good continuity of supply Simple protection	Requires automatic control functions
Double busbars	Processes requiring high continuity of service Processes with major load changes	Good continuity of supply Flexible operation: no-break transfers Flexible maintenance	Expensive solution Requires automatic control functions
Loop systems
Open loop	Very large power systems Major future expansion Loads concentrated in different zones of a site	Less expensive than closed loop Simple protection	Faulty segment can be isolated during loop reconfiguration Requires automatic control functions
Closed loop	Power system offering high continuity of service Very large power systems Loads concentrated in different zones of a site	Good continuity of supply Does not require automatic control functions	Expensive solution Complex protection system
Internal power generation
Normal source generation	Industrial process sites producing their own energy E.g. paper plants, steel	Good continuity of supply Cost of energy (energy recovered from process)	Expensive solution
Replacement source (source changeover)	Industrial and commercial sites E.g. hospitals	Good continuity of supply for priority outgoing feeders	Requires automatic control functions

Examples of Power System Architectures