Emergency-Aware and Frequency-Constrained HVDC Planning for A Multi-Area Asynchronously Interconnected Grid

TL;DR

This paper introduces an emergency-aware, frequency-constrained HVDC planning method for multi-area interconnected grids, optimizing inter-area HVDC capacity while ensuring frequency security during faults.

Contribution

It develops a novel emergency frequency control scheme and integrates it into a planning model considering all HVDC fault emergencies, enhancing security and efficiency.

Findings

Improved frequency security during HVDC faults.

Optimized HVDC capacity planning balancing cost and security.

Effective emergency control resource allocation.

Abstract

High-voltage direct current (HVDC) technology has played a crucial role for long-distance transmission of renewable power generation. However, the integration of large-capacity HVDC lines introduces significant frequency security challenges during HVDC fault emergencies. This paper proposes an emergency-aware and frequency-constrained HVDC planning method to optimize the capacity of inter-area HVDC tie-lines in a multi-area asynchronously interconnected grid. Firstly, a coordinated emergency frequency control scheme is proposed to allocate the emergency control resources during HVDC faults. Then, an enhanced system frequency response model integrating event-driven emergency frequency control is developed and a weighted oblique decision tree approach is employed to extract frequency nadir security constraints. The proposed planning model considers all potential HVDC fault emergencies while treating candidate HVDC capacities as decision variables. Simulation results demonstrate superior performance in balancing economic efficiency with frequency security requirements, providing a practical solution for inter-area HVDC planning.