Analytical Phasor-Based Fault Location Enhancement for Wind Farm Collector Networks

TL;DR

The paper tackles inaccuracies in one-terminal phasor-based fault location in wind-farm collector networks caused by downstream IBR injections. It introduces a simple, analytically derived compensation framework that adds a distance-dependent voltage term to the loop equation, enabling accurate fault location using only local measurements across various fault types. Through PSCAD EMT simulations on a realistic wind-farm model, the method yields substantial reductions in both average and maximum location errors, with ground faults benefiting the most and wind-penetration sensitivity being largely eliminated. The approach preserves the intuitive, low-complexity structure of classical methods, making it a practical enhancement for renewables-dominated grids. Overall, it provides a robust, implementable solution to maintain reliable protection and fault-location performance as IBR penetration increases.

Abstract

The increasing integration of Inverter-Based Resources (IBRs) is reshaping fault current characteristics, presenting significant challenges to traditional protection and fault location methods. This paper addresses a key limitation in fault location within wind farm collector networks, i.e., one-terminal phasor-based methods become inaccurate when IBRs are electrically located downstream from the fault. In such cases, the voltage drop caused by IBR fault current injections is not captured by the Intelligent Electronic Device, resulting in a systematic overestimation of fault distance. To mitigate this issue, a general compensation framework was proposed by augmenting classical loop formulations with a distance-dependent voltage correction term. The methodology was derived analytically using a sequence-domain representation and generalized to multiple fault types through a unified notation. It maintains the simplicity and interpretability of conventional approaches and can be implemented using only local measurements. The method was evaluated through EMT simulations in PSCAD using a realistic wind farm model. Results show significant improvements in location accuracy, with average and maximum errors notably reduced, especially for ground-involved faults where reductions exceed 90\%. Furthermore, the compensation eliminates sensitivity to wind penetration levels and ensures uniform performance across feeders, positioning the method as a practical solution for modern renewable-dominated grids.

Figures (11)

• Figure 1: Schematic overview of a wind-farm collector system with multiple IBRs connected along radial feeders.
• Figure 2: Sequence-network representation of a feeder with all IBRs located upstream from the fault.
• Figure 3: Sequence-network representation of a feeder with one IBR located downstream from the fault.
• Figure 4: Sequence representation of an SLG fault on a feeder with intermediate inverters.
• Figure 5: Current-divider illustration for one IBR in the positive-sequence network.