A Static Var Compensator (SVC) rated at 75 Mvar inductive to 150 Mvar capacitive (-75/+150 Mvar) at 230 kV, supplied and installed by Hitachi Energy, has gone into operation at the Extremoz substation belonging to Chesf, a Brazilian transmission and generation utility located in the state of Rio Grande do Norte in Northeastern Brazil. This equipment is part of a transmission system expansion required to facilitate the integration of renewable energy from more than 1.000 MW collected from a multitude of wind turbine generators located in that region.
The wind energy is first collected at two major points in the grid, João Câmara and João Câmara II, and from there further transmitted to the National Interconnected System (NIS) through the Extremoz 230 kV substation and 500/230 kV transformers.
The Extremoz SVC has been designed to enable the following actions:
- To perform 230 kV busbar voltage control for steady state and contingencies;
- To provide dynamic, fast response reactive power following system contingencies (e.g. network short circuits, line and generator disconnections);
- To enhance first swing stability by maintaining system voltages within the established limits during large disturbances in the power grid.
|System voltage:||138 kV|
|Dynamic var rating||80 Mvar inductive to 110 Mvar capacitive|
|VSC||3-level, neutral point clamping converter, IGBT based, pulse width modulated, Pulse number:21.|
|VSC rating||95 MVA|
|Control system||Three-phase dynamic positive-sequence voltage control, by means of a closed-loop, high sped digital voltage controller. The control includes switching of three MSCs, each rated at 138 kV, 31 Mvar, for steady-state system voltage control.|