Grid forming controllers need to operate with a large variation of grid parameters and grid structures

for instance

during black-start operation

connection to HVDC diode rectifiers

etc. This paper proposes a methodology for the synthesis of robust grid forming controllers for HVDC diode rectifier based wind power plants using

$\mathcal{H}_{\infty}$

control. The different operating modes of an HVDC diode rectifier based wind power plant should be considered for the controller synthesis using the proposed

$\mathcal{H}_{\infty}$

controller design methodology. The proposed methodology for grid forming controller design improves the performance and robustness of well tuned standard proportional-resonant based controllers. The results have been validated experimentally at the wind turbine level by means of a small power prototype. The validation at the system level has been carried out using a realistic simulation of the HVDC diode rectifier-connected wind power plant.