Backup-Protection Scheme for Multi-Terminal HVDC System Based on Wavelet-Packet-Energy Entropy

Abstract

DC fault protection is a major issue in multiterminal high-voltage DC current transmission systems. Most studies have focused on primary protection, which considers a different theory. However, the poor sensitivity of primary protection under high-resistance fault and maloperation still affect the protection feasibility to a certain extent. Thus, backup protection is definitely required to enhance the stability of an entire system considering the limit in primary protection. This paper proposes a backup-protection strategy based on wavelet-packet-energy entropy as mitigation for primary protection. The pole-to-ground (PG) fault with high resistance is highlighted because detecting the fault transient of PG fault with high resistance is difficult in the most primary relay. Fault detection and classification are achieved using the proposed backup-protection method based on theoretical study and simulation verification. The proposed method also presents the expected robustness of fault resistance, fault distance, and different operating conditions. INDEX TERMS Backup protection, DC faults, MMC-HVDC, wavelet-packet-energy entropy.

MMC Based MTDC Grids: A Detailed Review on Issues and Challenges for Operation, Control and Protection Schemes

“…Reference [57] proposes a hybrid approach that consists an ANN based technique for fault detection and the discrete wavelet transform (DWT) to extract the information from ANN for MMC based MTDC grids. A wavelet package energy entropy based backup protection method is proposed by [58]. The proposed method is efficient for of fault resistance, fault distance and different operating conditions.…”

Primary and backup fault detection techniques for multi‐terminal HVdc systems: a review

“…Similarly, in [110], a communication network causes delays in the fault calculation rate and leads to increased costs. In the MTdc network, the parameters, such as complexity issues, communication links, calculation rate, costs, and noise concerns, determine the efficiency of dc fault detection and the location techniques [111]. As shown in Table 1, the brief comparisons on the methods mentioned in this paper are provided to interpret their parametric efficiency, because any weak link in these parameters can lead down to the failure of primary protection.…”

Improved Hausdorff Distance Based Pilot Protection for Multi-terminal HVDC system

“…Different from the stringent speed requirement in main protection, the timing demand for backup protection is less restricted [9]. Thus, the communication among substations can be utilized in backup protection.…”