Identification and Isolation of Faults in Multi-terminal High Voltage DC Networks with Hybrid Circuit Breakers

Abstract

This paper presents a protection scheme to protect multi-terminal high voltage dc (MTDC) networks for interconnection of renewable energy sources. The proposed scheme detects faults by using the Consecutive Data Window Method (CDWM) and harmonics of the system voltage to avoid maloperation of breakers without communication. Fault location is classified and faulty parts is isolated from the rest of the healthier network by using hybrid circuit breakers (HCBs). Moreover; it also categorises the fault with the help of the voltage drop. The rapid response to isolate the faulty portion in a few milliseconds is primarily considered to enhance the reliability and security of the network. The results of simulations verify the efficient fault detection and isolation for different DC faults and the investigation for the impact of significant parameters of the proposed scheme has been considered. The simulations are performed in PSCAD for four terminal MTDC networks to validate the proposed scheme. The performance is also verified under different fault conditions by using Matlab after computing the data from simulations.

Analysis of Propagation Delay for Multi-Terminal High Voltage Direct Current Networks Interconnecting the Large-Scale Off-Shore Renewable Energy

“…Equations (13) and (14) are used for the forward and backward traveling waves. However, by considering the forward traveling wave only and taking the initial voltage step of magnitude V 0 at the fault position.…”

“…With the occurrence of fault, a voltage surge propagates to the terminating points of the system and the propagation speed of the signal is taken as the speed of light for communications among the relays. Numerous researchers have considered the random propagation speed of 200 km/ms as the speed of light in the optical cable [9][10][11][12][13][14][15][16]. Besides this, if we assume that a line breakage fault occurs, the direct communication delay between converter stations will be affected.…”

“…In case of a fault adjacent to a sensor, the propagation delay is assumed to be 0.3 ms over a distance of 60 km, which is cogitated for forward and backward traveling waves. Analysis, identification and isolation of faults in MTDC networks have been proposed in References [12][13][14][15]. The propagation delay is considered to be 200 km/ms.…”

New Differential Protection Method for Multiterminal HVDC Cable Networks

“…-Use of HVDC circuit breakers: Circuit breakers based on power electronics can switch off fault currents in less than 2 ms but have considerable losses in normal operation [23]. Hybrid HVDC circuit breakers can cut fault currents up to 5 ms with reasonable losses [24][25][26][27]. Another option is the use of mechanical circuit breakers considering breaking times about 10 ms, voltages up to 250 kV, and fault currents with values in the range of 8 kA [28].…”

Technical and Economic Assessment of VSC-HVDC Transmission Model: A Case Study of South-Western Region in Pakistan

“…This includes high impedance faults without compromising the accuracy of fault location [13,14]. Based on the consecutive data window method (CDWM), another protection scheme is introduced for the VSC-HVDC transmission system, which is capable of prompt fault detection and isolation [15,16]. Furthermore, a new theory for locating line fault in the transmission system is presented in [17], which has thoroughly presented the theoretical aspects, and simulations for the line faults.…”