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Unified Power Flow Controller. Under the guidance of Mr. Debashisha Jena. INTRODUCTION. Two main objectives of FACTS Increase the TX capability of AC line Control of power flow over the TX routes UPFCs - most effective FACTS device
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Unified Power Flow Controller Under the guidance of Mr. Debashisha Jena
INTRODUCTION • Two main objectives of FACTS • Increase the TX capability of AC line • Control of power flow over the TX routes • UPFCs - most effective FACTS device • UPFC – a device which control TX line impedance, voltage and phase angle
BASIC CONSTRUCTION OF A UPFC • Consists of two switching GTO converters • Shunt-connected • Series-connected • Both converters can operate in a rectifier mode or in an inverter mode • A DC branch links these two converters by a storage capacitor.
Operating Principle • Conceptually, a generalized SVS • Converter2 injects a voltage Vpq with phase angle ρ in series with TX line via an insertion transformer • Main function of converter1 is to supply the real power demanded by converter2 at the DC link • No reactive power flow through DC link
TX control capabilities Vpq = ±ΔV (ρ = 0). Vpq = Vq Vpq= Vб Vpq = ΔV + Vq + Vб
Phasor representation of the UPFC Basic asumption (Vpq =0) P0(δ) = {V2/X} sin δ = sin δ Q0(δ) = Q0r(δ) = -Q0r(δ) = {V2/X}{1-cos δ } = I-cos δ
Phasor representation of the UPFC For Vpq0 ,
Conclusion • Most sophisticated power flow controller Expensive • Gives better performance as compared to STATCOM,SSSC and TCSC • Provide simultaneous, real-time control of all basic power system parameters (transmission voltage, impedance and phase angle) and dynamic compensation of ac system