An Exact Self-synchronized Realization of Park Transformation Equations for PLL-free Inverter Control

Synchronization of 3-phase AC voltages is crucial for voltage-oriented control (VoC) of grid-tied inverters and field-oriented control (FoC) of AC machines. Conventional phase-locked loop (PLL) systems cannot guarantee accurate synchronization during disturbances (such as phase jump events and fast frequency or speed variations). This paper proposes an efficient exact self-synchronized realization of Park and inverse Park transformation equations. In this formulation, the synchronized cosine and sine outputs are expressed as a function of the instantaneous 3-phase measurements. Superior synchronization and control capabilities of the proposed method under phase jump events and fast frequency variations are demonstrated using PSCAD
^TM
simulations.