Bus bar arrangement of substation

Busbar arrangement of substation26-Jun-141Types of Busbar Arrangement Single busSingle busbar system with sectionalisationMain and transfer busbar Double bus bar with double breaker One and half breaker busbar Ring busbar

26-Jun-142Single Bus arrangement

26-Jun-143AdvantageDisadvantageRemarks1. Low cost1. Fault of bus or any circuit breaker results in shut-down of entire substation1. Used for distribution substations upto 33kV2. Simple to Operate2. Difficult to do any maintenance2. Not used for large substations.3. Simple Protection3. Bus cannot be extended without completely de-energizing substations3. Sectionalizing increases flexibility4. Can be used only where loads can be interrupted or have other supply arrangements.Single Bus arrangement System26-Jun-144Main & Transfer Bus

26-Jun-1455Main & transfer busbar systemAdvantageDisadvantageRemarks1. Low initial & ultimate cost1. Requires one extra breaker coupler1. Used for 110kV substations where cost of duplicate bus bar system is not justified2. Any breaker can be taken out of service for maintenance. 2. Switching is somewhat complex when maintaining a breaker3. Potential devices may be used on the main bus3. Fault of bus or any circuit breaker results in shutdown of entire substation.26-Jun-1466Double Busbar with Double breaker

26-Jun-1477Double Bus Bar Double Breaker systemAdvantageDisadvantageRemarks1. Each has two associated breakers1. Most expensive1. Not used for usual EHV substations due to high cost.2. Has flexibility in permitting feeder circuits to be connected to any bus2. Would lose half of the circuits for breaker fault if circuits are not connected to both the buses.2. Used only for very important, high power, EHV substations.3. Any breaker can be taken out of service for maintenance.4. High reliability26-Jun-1488One & half breaker scheme

26-Jun-1499 One & half breaker schemeAdvantageDisadvantageRemarks1. Flexible operation for breaker maintenance1. One and half breakers per circuit, hence higher cost1. Used for 400kV & 220kV substations.2. Any breaker can be removed from maintenance without interruption of load.2. Protection and auto-reclosing more complex since middle breaker must be responsive to both associated circuits.2. Preferred.3. Requires 1 1/2 breaker per feeder.4. Each circuit fed by two breakers.5. All switching by breaker.6. Selective tripping26-Jun-141010 Ring Bus

26-Jun-141111 Mesh (Ring) busbar systemAdvantage DisadvantageRemarks1. Busbars gave some operational flexibility1. If fault occurs during bus maintenance, ring gets separated into two sections.1. Most widely used for very large power stations having large no. of incoming and outgoing lines and high power transfer.2.Auto-reclosing and protection complex.3. Requires VTs on all circuits because there is no definite voltage reference point.These VTs may be required in all cases for synchronizing live line or voltage indication4. Breaker failure during fault on one circuit causes loss of additional circuit because of breaker failure.26-Jun-141212Given:- A generating station with 14 generator

Design two alternative way of busbar arrangement of the stationSolutionI assume each generator generates 300MW with voltage 11kv and power factor 0.9 14x300=4200MWAuxiliary service 10%=420MW=14x30MW

Base on this it is done as shown below

26-Jun-1413Option 1

26-Jun-1414Option 2

26-Jun-141526-Jun-1416

Auxiliary ServiceThank you26-Jun-14