SYSTEM AND METHOD FOR ANTI-ISLANDING PROTECTION OF DISTRIBUTED GENERATORS

摘要

System and method for anti-islanding protection of distributed generators. The system comprises a power converter (8) for transferring power from a distributed generator (9) to the grid (1) and a controller (5) that measures the grid frequency (F_grid) and grid reactive power (Q_grid) and provides the power converter (8) with a reactive power perturbation, to be repeatedly injected into the grid (1), dependent upon a correlation coefficient (R_xy) between a grid frequency derivative signal (δF_grid) and a grid reactive power derivative signal (δQ_grid). The reactive power perturbation is increased for strong correlations and decreased for weak correlations, so that upon islanding condition this active protection modifies the reactive power perturbation to reach the limits of a passive protection. The controller (5) then detects the islanding condition and commands the trip of a breaker (7).