TCSC for stable transmission of surplus power from Eastern to Western India
Power Grid Corporation of India Ltd (PGCIL) has purchased two Thyristor Controlled Series Capacitors (TCSC) from Hitachi Energy. The banks were installed on the Rourkela-Raipur double circuit 400 kV power transmission interconnector between the Eastern and Western regions of the grid. The length of the interconnector amounts to 412 km.
The main purpose of this major AC inter connector is to enable export of surplus energy from the Eastern to the Western regions of India during normal operating conditions, and also during contingencies. The TCSC are located at the Raipur end of the lines. The TCSC enable damping of interarea power oscillations between the regions, which would otherwise have constituted a limitation on power transfer over the interconnector. Dynamic simulations performed during the design stage, and subsequently confirmed at the commissioning and testing stage, have proved the effectiveness of the Raipur TCSC as power oscillation dampers. Furthermore, system studies performed showed no risk for Sub-Synchronous Resonance (SSR) in the Indian network.
|Parameter||Fixed Segment||TCSC Segment|
|Nominal system voltage||400 kV||400 kV|
|Rated line current||1550 A||1550 A|
|Line current overload, 30 minutes||2093 A||2093 A|
|Line current overload, 10 minutes||2325 A||2325 A|
|Physical capacitor reactance||54,7 Ω||6.83 Ω|
|Nominal capacitive boost factor||1.0||1.2|
|Boost factor range||-||1.0-3.0|
|Rated capacitor reactive power||394 Mvar||71 Mvar|
|Rated capacitor bank voltage||84.8 kV||12.7 kV|
|Degree of compensation||40%||5% (@ 1.0 boost factor)|
|ZnO rating (incl. redundancy)||56 MJ||15 MJ|