Sliding mode pulse‐width modulation of five‐leg converter for grid‐connected permanent magnet synchronous generator wind turbine

Abstract

SummaryThis paper presents sliding mode pulse‐width modulation (SMPWM) for current‐controlled five‐leg converter (FLC) in wind energy system. The proposed topology substitutes at once two three‐phase converters, classified as back‐to‐back (BTB), by sharing one leg between the permanent magnet synchronous generator (PMSG) and power grid. To overcome the coupling of the two sides, the control of common leg is introduced. SMPWM methodology is designed using system dynamic model and surface decoupling approach to make system tracking desired references. The reference currents are selected to perform control requirements of PMSG wind turbine. The phase currents are controlled simultaneously during normal operation and in the event of unbalanced grid voltages. Different operating conditions are tested under wind variations including a turbulence component. The main objectives are to achieve balanced and sinusoidal currents, as well as smooth active and reactive powers injected into the grid. Simulation results show that FLC can act as BTB converters and demonstrate the effectiveness of the proposed control scheme.