Coordinated control of grid-connected PMSG based wind energy system with STATCOM and supercapacitor energy storage

This article designs three coordinated control schemes for a grid-connected wind energy conversion system based on a permanent magnet synchronous generator. The system includes a static synchronous compensator (STATCOM) and a supercapacitor energy storage (SCES) to maintain stable operation during different operating conditions. Coordinated control scheme-I (CCS-I) integrates the SCES into the DC-link via a bidirectional DC/DC converter to stabilize the voltage under varying wind speeds and grid disturbances. Coordinated control scheme-II (CCS-II) uses a STATCOM at the point of common coupling (PCC) to enhance the grid voltage stability during voltage sag or swell, where the SCES balances active power, and the grid side converter (GSC) provides reactive power support. The STATCOM is only activated when the PCC's reactive power requirement exceeds the GSC's support capacity. Coordinated control scheme-III (CCS-III) considers simultaneous disturbances on both the wind turbine and grid side to stabilize the DC-link and grid voltage. The proposed control schemes have been experimentally implemented with a dSpace MicroLabBox. Additionally a Lyapunov function based stability analysis of the system including the SCES is presented in the paper.