INTERLINE FLOW CONTROLLER
- 2. It is a combination of series controllers or a unified controller. Unified means that DC terminal of controller converters are connected together for real power exchange The objective of introducing this controller is to address the problem of compensating a number of transmission lines connected at a substation
- 3. The Interline Power Flow Controller (IPFC) provides, in addition to the facility for independently controllable reactive (series) compensation of each individual line, a capability to directly transfer or exchange real power between the compensated lines. Fig 1 Structure of IPFC
- 4. UPFC: Capable of controlling the real and the reactive power flow in the line independently Injects a fully controllable voltage in series with the line and support the resulting generalized real and reactive power compensation by supplying the real power required by the series converter through the shunt-connected converter from the ac bus IPFC: Equalize both real and reactive power flow between the lines; reduce the burden of overloaded lines by real power transfer; compensate against resistive line voltage drops and the corresponding reactive power demand; and increase the effectiveness of the overall compensating system for dynamic disturbances.
- 5. * Converter can be controlled to supply real power to the common dc link from its own transmission line apart from the series reactive compensation *Overall surplus power can be made available from the under utilized lines which then can be used by other lines for real power compensation *Some of the converters, compensating overloaded lines or lines with a heavy burden of reactive power flow can be equipped with full two-dimensional, reactive and real power control capability
- 6. Fig 2 Basic two-converter Interline Power Flow Controller scheme V1s = V2s = V1r=V2r= 1 p.u. δ1 = δ2 = 30º V1pqmax = V2pqmax X1 = X2 = 0.5 p.u.
- 7. Fig 3 IPFC "prime" converter and corresponding phasor diagram
- 8. Fig 4 Variation of receiving-end real and reactive power as a function of the injected compensating voltage in Line 1
- 9. Fig 5 Illustration of the operation of a two-converter IPFC by coordinated phasor diagrams and P - Q plots
- 10. Fig 6 Illustration of the operation of a two-converter IPFC by coordinated phasor diagrams and P - Q plots
- 11. Fig 7 Illustration of the operation of a two-converter IPFC by coordinated phasor diagrams and P - Q plots
- 12. Fig 8 Illustration of the basic relationships governing the operation of a two converter IPFC
- 13. Fig 9 Relationship between transmission angle δ1 and the compensation region in the P-Q plane for a two-converter IPFC
- 14. Fig 10 Basic control scheme for a two-converter IPFC