配备SAPF与基于SOSF-SOFLL同步的主动孤岛检测功能的构网型电力电子变换器

Conventional active islanding detection (AID) techniques are mostly discussed for voltage source converter in grid following mode of operation. But rarely AID method is discussed for the readiness of power converter for re-synchronization purposes in grid forming mode. Further, the implementation becomes more challenging under non-linear loads, as suitable filter need to be designed that can effectively differentiate between harmonics & intentionally injected signal in AID technique. In the proposed work, a control strategy is derived for Shunt Active Power Filter (SAPF) operation in grid connected mode & AID in grid forming mode utilizing Battery Energy Storage System (BESS) connected Flexible Power Converter (FPC). To facilitate SAPF operation, filtration and synchronization are managed through a dual fundamental component extraction scheme coupled with a Second Order Sequence Filter-Second Order Frequency Locked Loop (SOSF-SOFLL). In this context, SAPF utilizes SOSF-SOFLL to extract fundamental components from load currents. Moreover, a section of controller utilizing SOSF-SOFLL and Frequency of Absolute Voltage Variation Mean (FAVVM) parameter computation block is also embedded for AID. The section for AID also filters out any DC offset error arises due to the sensor or any transient in the system. To assess the efficacy of the proposed approach, MATLAB simulations and experimental validation are conducted on the 2 kW developed hardware prototype.