Cascaded Delayed Signal Cancellation Based Pre-Filtering Technique to Improve Frequency Locked Loop for Grid Synchronization

A new FLL (Frequency Locked Loop) technique is developed that incorporates advantages of the cascaded delayed signal cancellation and dual second order generalized integrator schemes. A frequency jump detector is applied to cut the tight bond between the estimated frequency and phase of the voltage vector, specifically in case of phase jumps. Experimental results provided by this new and by some already published methods are compared and evaluated for the different grid voltage disturbances.