25-05-2012, 04:10 PM
Advanced FACTS Devices and Applications
[attachment=23042]
The Concept and Challenges
A transmission system can carry power up to its thermal loading limits. But in practice the system has the following constraints:
-Transmission stability limits
-Voltage limits
-Loop flows
Transmission stability limits: limits of transmittable power with which a transmission system can ride through major faults in the system with its power transmission capability intact.
Voltage limits: limits of power transmission where the system voltage can be kept within permitted deviations from nominal.
Loop flows can be a problem as they are governed by the laws of nature which may not be coincident with the contracted path. This means that power which is to be sent from point ”A” to point ”B” in a grid will not necessarily take the shortest, direct route, but will go uncontrolled and fan out to take unwanted paths available in the grid.
System Architectures and Limitations
System Architecture
Radial, interconnected areas, complex network
Power Flow in an AC System
Power Flow in Parallel and Meshed Paths
Transmission Limitations
Steady-State (angular stability, thermal limits, voltage limits)
Stability Issues (transient, dynamic, voltage and SSR)
System Issues (Post contingency conditions, loop flows, short-circuit levels)
Power Flow and Dynamic Stability Considerations
Controllable Parameters
Basic FACTS Devices - Impact of Energy Storage
Power Flow Control on AC Systems
Control of X can provide current control
When angle is large X can provide power control
Injecting voltage in series and perpendicular to the current flow, can increase or decrease
FACTS Devices
Shunt Connected
Static VAR Compensator (SVC)
Static Synchronous Compensator (STATCOM)
Static Synchronous Generator - SSG
Battery Energy Storage System (BESS)
Superconducting Magnetic Energy Storage (SMES)
Combined Series and Series-Shunt Connected
Static Synchronous Series Controllers (SSSC)
Thyristor Controlled Phase-Shifting Transformer or
Phase Angle Regulator (PAR)
Interline Power Flow Controller (IPFC)
Thyristor Controlled Series Capacitor (TCSC)
Unified Power Flow Controller (UPFC)
Power Electronics - Semiconductor Devices
Principal Characteristics
Voltage and Current
Losses and Speed of Switching
Speed of Switching
Switching Losses
Gate-driver power and energy requirements
Parameter Trade-off
Power requirements for the gate
di/dt and dv/dt capability
turn-on and turn-off time
Uniformity
Quality of silicon wafers
[attachment=23042]
The Concept and Challenges
A transmission system can carry power up to its thermal loading limits. But in practice the system has the following constraints:
-Transmission stability limits
-Voltage limits
-Loop flows
Transmission stability limits: limits of transmittable power with which a transmission system can ride through major faults in the system with its power transmission capability intact.
Voltage limits: limits of power transmission where the system voltage can be kept within permitted deviations from nominal.
Loop flows can be a problem as they are governed by the laws of nature which may not be coincident with the contracted path. This means that power which is to be sent from point ”A” to point ”B” in a grid will not necessarily take the shortest, direct route, but will go uncontrolled and fan out to take unwanted paths available in the grid.
System Architectures and Limitations
System Architecture
Radial, interconnected areas, complex network
Power Flow in an AC System
Power Flow in Parallel and Meshed Paths
Transmission Limitations
Steady-State (angular stability, thermal limits, voltage limits)
Stability Issues (transient, dynamic, voltage and SSR)
System Issues (Post contingency conditions, loop flows, short-circuit levels)
Power Flow and Dynamic Stability Considerations
Controllable Parameters
Basic FACTS Devices - Impact of Energy Storage
Power Flow Control on AC Systems
Control of X can provide current control
When angle is large X can provide power control
Injecting voltage in series and perpendicular to the current flow, can increase or decrease
FACTS Devices
Shunt Connected
Static VAR Compensator (SVC)
Static Synchronous Compensator (STATCOM)
Static Synchronous Generator - SSG
Battery Energy Storage System (BESS)
Superconducting Magnetic Energy Storage (SMES)
Combined Series and Series-Shunt Connected
Static Synchronous Series Controllers (SSSC)
Thyristor Controlled Phase-Shifting Transformer or
Phase Angle Regulator (PAR)
Interline Power Flow Controller (IPFC)
Thyristor Controlled Series Capacitor (TCSC)
Unified Power Flow Controller (UPFC)
Power Electronics - Semiconductor Devices
Principal Characteristics
Voltage and Current
Losses and Speed of Switching
Speed of Switching
Switching Losses
Gate-driver power and energy requirements
Parameter Trade-off
Power requirements for the gate
di/dt and dv/dt capability
turn-on and turn-off time
Uniformity
Quality of silicon wafers