We experimentally demonstrate, for the first time to our knowledge, an ultrafast photonic high-order (second-order) complex-field temporal integrator. The demonstrated device uses a single apodized uniform-period fiber Bragg grating (FBG), and it is based on a general FBG design approach for implementing optimized arbitrary-order photonic passive temporal integrators. Using this same design app...

The existence of harmonics will cause the quality power supply in a system to decline and affect normal use system. Therefore, it is important suppress system, first step harmonic suppression detection. To address this phenomenon, fast detection method proposed paper. It based on input observer theory construct state space model original signal components estimate variables so as achieve extrac...

High-voltage flexible power systems, with their intrinsic characteristics, play an increasingly important role in electronic systems. Synchronization between the inverter and grid needs to be achieved by a phase-locked loop (PLL), performance of which determines quality transmission. This paper proposes PLL adapted extremely harsh conditions. Firstly, traditional synchronous reference frame dua...

We assess the performance of an exponential integrator for advancing stiff, semidiscrete formulations of the unsaturated Richards equation in time. The scheme is of second order and explicit in nature but requires the action of the matrix function φ(A) = A−1(eA − I) on a suitability defined vector v at each time step. When the matrix A is large and sparse, φ(A)v can be approximated by Krylov su...