An Improved Fault Recovery Strategy for Active Distribution Network Considering LVRT Capability of DG

摘要

The growing integration of distributed generation (DG) has changed the operation characteristics of traditional distribution network, and so the active distribution network (ADN) has emerged. Fault recovery is significant to reduce the loss of power failure, but the traditional control strategy without consideration of DG is no longer suitable for ADN. An improved fault recovery strategy is proposed to coordinate the fault reclosing and the low voltage ride through (LVRT) capability of DG. The influence of fault reclosing on the voltage variation of the point of common coupling (PCC) of DG is analyzed, with different relative locations of fault and PCC, and a critical LVRT voltage is extracted from the scenario where fault reclosing fails. In order to avoid DG outage, a blocking criterion of fault reclosing is presented according to the fault location and the first voltage dip of PCC. Then, the ADN can be split into planned islands considering the balance of DG power and loads and the load priorities, once the fault reclosing is blocked. Moreover, the WAMS Light is implemented for high-speed synchronous data collection and online central control. A case study is conducted to verify the effectiveness of proposed approach.