Extremum seeking control with fractional-order switching technique design for maximum power point tracking in photovoltaic systems
This paper considers a novel extremum seeking control with fractional-order switching technique (ESC-FOST) as a maximum power point tracking (MPPT) algorithm for a PV system. The proposed ESC-FOST combines extremum seeking controller with FO sliding mode dynamics, in which FO proportional-integral (PI) switching surface is adopted. The ESC-FOST can not only guarantee the output power is maintained around the maximum power point but that it will also have a faster tracking performance and higher accuracy than the ESC with integer-order switching technique (ESC-IOST). Simulation and experimental results demonstrate the effectiveness and benefit of the ESC-FOST for the PV plant.
The paper presents an analytical approach to extract machine parameters for creating a machine model under stator turn fault condition for a surface permanentmagnet (SPM) motor. The development of an accurate model of turn faulted SPM motor is essential to study motor and drive behavior under fault conditions, and to develop effective turn fault detection algorithms. The main contribution of the paper is to propose a completely analytical approach to modeling turn fault in SPM machine, which has not been reported so far in literature. Further to validate the analytical method, finite element (FE) analysis of an SPM motor with stator turn fault is performed and the results are compared with the analytical prediction. It is shown that the proposed model achieves good match with the FE results.