HVDC Tutorial
HVDC
TRANSMISSION
H-HIGH
V-VOLTAGE
D-DIRECT
C-CURRENT
1
WHY HVDC ?
BULK POWER TRANSMISSION WITHLOWER LINE
LOSSES AS NO REACTIVE POWER TRANSFER TAKES PLACE
CONNECT TWO ASYNCHRONOUS SYSTEM.
PROVIDES SYSTEM STABILITY.
CONTROLABILITY OF POWER FLOW AT HIGH SPEED.
LESS RIGHT OF WAY FOR TRANSMISSION LINES.
NO CONTRIBUTION TO SHORT CIRCUIT LEVEL OF THE
AC BUS CONNECTED.
NO CHARGING CURRENT TO DIMINISH THE USEFUL
CAPACITY OF THE LINE.
DISTANCE IS NOT LIMITED BY STABILITY POINT OF
VIEW.
2
BREAKEVEN DISTANCE FOR HVDC
BREAKEVEN POINT FOR HVDC TRANSMISSION IS
ABOVE 700KMS
EXPENDITURE /
COST
BREAKEVEN
POINT
DC LINE COST
DC TERMINAL COST
AC LINE COST
AC TERMINAL COST
DISTANCE
3
CONFIGURATION
• NON CONTROLLABLE
VALVE
• CONTROLLABLE
VALVE
• NON CONTROLLABLE
VALVE GROUP
• CONTROLLABLE
VALVE GROUP
4
TYPES OF CONVERTER BRIDGES
• 6-PULSE
CONVERTER
BRIDGE
• 12- PULSE
CONVERTER
BRIDGE / TWO
6PULSE
BRIDGES
CONNECTED IN
SERIES
5
Different types HVDC Converter Bridge Arrangements
BACK -TO-BACK
This is application where two AC systems to be connected are physically in same substation and no transmission line or cable is required.This is used for interconnection between asynchronous Power System networks.
TRANSMISSION
BETWEEN TWO
SUBSTATION.
This is for bulk power transfer through dc line or cable from one Substation to another which are geographically far away from each other.
MULTITERMINAL
SYSTEM
More than two HVDC Substation, geographically separated are connected to each other by same transmission line then it is multiterminal system.
PARALLEL
MULTITERMINAL
SYSTEM
If one or more converters are connected at same voltage level then system is parallel multiterminal.Here voltage remains same but the current capacity increases.
SERIES
MULTITERMINAL
SYSTEM
If one or more converters are connected in series then system is series multiterminal.Here voltage increases.
UNIT CONNECTION
This is scheme when generator is directly connected to the
converter
TRANSMISSION
H-HIGH
V-VOLTAGE
D-DIRECT
C-CURRENT
1
WHY HVDC ?
BULK POWER TRANSMISSION WITHLOWER LINE
LOSSES AS NO REACTIVE POWER TRANSFER TAKES PLACE
CONNECT TWO ASYNCHRONOUS SYSTEM.
PROVIDES SYSTEM STABILITY.
CONTROLABILITY OF POWER FLOW AT HIGH SPEED.
LESS RIGHT OF WAY FOR TRANSMISSION LINES.
NO CONTRIBUTION TO SHORT CIRCUIT LEVEL OF THE
AC BUS CONNECTED.
NO CHARGING CURRENT TO DIMINISH THE USEFUL
CAPACITY OF THE LINE.
DISTANCE IS NOT LIMITED BY STABILITY POINT OF
VIEW.
2
BREAKEVEN DISTANCE FOR HVDC
BREAKEVEN POINT FOR HVDC TRANSMISSION IS
ABOVE 700KMS
EXPENDITURE /
COST
BREAKEVEN
POINT
DC LINE COST
DC TERMINAL COST
AC LINE COST
AC TERMINAL COST
DISTANCE
3
CONFIGURATION
• NON CONTROLLABLE
VALVE
• CONTROLLABLE
VALVE
• NON CONTROLLABLE
VALVE GROUP
• CONTROLLABLE
VALVE GROUP
4
TYPES OF CONVERTER BRIDGES
• 6-PULSE
CONVERTER
BRIDGE
• 12- PULSE
CONVERTER
BRIDGE / TWO
6PULSE
BRIDGES
CONNECTED IN
SERIES
5
Different types HVDC Converter Bridge Arrangements
BACK -TO-BACK
This is application where two AC systems to be connected are physically in same substation and no transmission line or cable is required.This is used for interconnection between asynchronous Power System networks.
TRANSMISSION
BETWEEN TWO
SUBSTATION.
This is for bulk power transfer through dc line or cable from one Substation to another which are geographically far away from each other.
MULTITERMINAL
SYSTEM
More than two HVDC Substation, geographically separated are connected to each other by same transmission line then it is multiterminal system.
PARALLEL
MULTITERMINAL
SYSTEM
If one or more converters are connected at same voltage level then system is parallel multiterminal.Here voltage remains same but the current capacity increases.
SERIES
MULTITERMINAL
SYSTEM
If one or more converters are connected in series then system is series multiterminal.Here voltage increases.
UNIT CONNECTION
This is scheme when generator is directly connected to the
converter