Enhanced Fault Current-Limiting Circuit Design for a DC Fault in a Modular Multilevel Converter-Based High-Voltage Direct Current System

Abstract

The main weakness of the half-bridge modular multilevel converter-based high-voltage direct current (MMC-HVDC) system lies in its immature solution to extremely high current under direct current (DC) line fault. The development of the direct current circuit breaker (DCCB) remains constrained in terms of interruption capacity and operation speed. Therefore, it is essential to limit fault current in the MMC-HVDC system. An enhanced fault current-limiting circuit (EFCLC) is proposed on the basis of fault current study to restrict fault current under DC pole-to-pole fault. Specifically, the EFCLC consists of fault current-limiting inductance L F C L and energy dissipation resistance R F C L in parallel with surge arrestor. L F C L reduces the fault current rising speed, together with arm inductance and smoothing reactor. However, in contrast to arm inductance and smoothing reactor, L F C L will be bypassed via parallel-connected thyristors after blocking converter to prevent the effect on fault interruption speed. R F C L shares the stress on energy absorption device (metal oxide arrester) to facilitate fault interruption. The DCCB requirement in interruption capacity and breaking speed can be satisfied effortlessly through the EFCLC. The working principle and parameter determination of the EFCLC are presented in detail, and its effectiveness is verified by simulation in RT-LAB and MATLAB software platforms.

Traveling Waves-Based Method for Fault Estimation in HVDC Transmission System

“…Lots of discussions were carried out to find the relationship between natural frequency of traveling wave and distance of fault point from terminal under all system boundary conditions. The significant advantages of the natural frequency-based fault location detection technique are that it does not need to observe traveling wavefront and it does not require two terminal measurements for accuracy as are required in fault location techniques based on satellite time references and wavelets [7,[49][50][51][52][53][54][55]. In the proposed research, this problem is solved by finding the DC component, dominant AC component and THD values of traveling wave for fault estimation.…”

Protection Scheme for Multiterminal HVDC System Based on Wavelet Transform Modulus Maxima

“…A given signal or image can be decomposed into detailed and approximated versions using multi-resolution signal decomposition technique [34]. The original signal can be decomposed into signals of different frequency bands by applying Mallat algorithm.…”

“…The relay operation of transmission line fault in HVDC system is described in Fig. 3, which has been thoroughly analyzed by our group in fault current limiting study [34]. As indicated in Fig.…”

Review on Short-circuit Current Analysis and Suppression Techniques for MMC-HVDC Transmission Systems

“…The current-limiting DC inductors are usually installed at both ends of the transmission lines in series in order to achieve better fault current suppression performance [48,49]. Figure 11 shows the short circuit current with different inductive fault current limiters in a four-terminal MMC-based power gird.…”