Adaptive Dynamic Voltage Support Scheme for Fault Ride-Through Operation of a Microgrid

Abstract

This paper proposes a control strategy for enabling voltage fault ride-through (VFRT) operation with adaptive dynamic voltage support (DVS) scheme using the energy storage in a microgrid. Firstly, the condition for maximum DVS from the microgrid is presented and its dependency on the parameters of the equivalent network seen by the microgrid is elucidated. Considering the impediments associated with the real-time parameter estimation during the short-term voltage disturbances, reference current signals based on the extreme voltage tracking algorithm are proposed in this paper to achieve an adaptive DVS irrespective of the varying system conditions. Secondly, a control strategy is proposed to enable the energy storage-based VFRT operation of a microgrid. Thirdly, a unique methodology of sizing the energy storage for VFRT operation is presented considering the grid code requirements, equivalent network characteristics, and the maximum current rating of the power electronic interface with the grid. The proposed control strategy is validated through real-time digital simulation case studies for low-voltage, high-voltage, and multiple-fault scenarios. The scalability of the proposed approach is illustrated using the CIGRE distribution test network.