PSCAD simulation model of D-PMSGs interfaced with AC power grid
The converter controller of wind turbine presents capacitive impedance characteristics with negative resistance at subsynchronous frequencies. When it is connected to weak AC power grid, it will form an LC resonant circuit with system-side inductance, and generate sub-/super-synchronous oscillations due to negative damping effect. A PSCAD simulation model of direct-drive wind farm connected to AC power grid is provided to study the above phenomenon.
Open the file in PSCAD, and change the frequency or amplitude of subsynchronous oscillation(SSO) by changing the equivalent impedance of the system, the number of grid-connected WTGs, the proportional factor of the inner loop of the grid-side converter(GSC) or the proportional coefficient of the phase-locked loop.