Active power control strategies for inverter-based distributed power generation adapted to grid-fault ride-through requirements

Distributed power generation is expected to deliver power into the grid without interruption during voltage dips. To improve system ride-through capabilities, a generalized active power control strategy is proposed for grid-interfacing inverters. Specifically, a current reference generation strategy based on symmetric-sequence components of unbalanced three-phase three-wire or four-wire systems is derived. It is shown that a single adjustable parameter can smoothly change the relative amplitudes of oscillating active and reactive power. This steering possibility enables grid-side inverters to optimally meet different requirements of coming standards. Simulations and experiments are carried out to validate the proposed strategy.