Fault analysis on DC transmission system of PV generation

Abstract

Summary Compared with conventional AC transmission systems of PV generation, its DC counterpart is more resilient for improving the PV utilization. However, in the clamped double submodule‐modular multilevel converter (CDSM‐MMC) and DC/DC converter‐based PV grid‐connection system, pole‐to‐ground and pole‐to‐pole fault characteristics still need investigation. The equivalent model of PV stations and current circuits of the CDSM‐MMC, before and after the fault, are studied first. Secondly, the influence of different connection groups of the converter transformer on the DC fault characteristic and that of DC faults on AC‐side electrical quantities are discussed. Subsequently, development stages of DC faults are divided according to the charging and discharging processes of the CDSM‐MMC and the DC/DC converter, and corresponding equivalent models are established and solved. Finally, the DC transmission system of the PV generation is modeled in Power Systems Computer Aided Design/Electromagnetic Transients including DC to verify the theoretical analysis. The DC fault analysis can provide reference for the subsequent protection system design.

Fault tolerance enhancement of the PV module system by improving the topology and control strategy

“…where n = 2k + 1(k = 1, 2, 3,…). It can be found from (19) that the grounding fault in dc side will deteriorate the power quality in the ac side. Specifically, there exists the third-harmonic component and dc voltage bias component, which will damage the lifespan of the three-phase capacitor.…”

“…Second, the short-circuit problem will appear among the PV modules because of the loosening lines or aging insulation. The authors of [18][19][20] analysed in detail the transient process of the pole-to-pole short-circuit fault and pole-to-ground fault in PV power cables, in which Zhang et al [18] pointed out that the overcurrent would damage the uncontrollable diode and challenge the protection system, and proposed a novel structure of dc-dc converter to protect the diode. Varma et al [21] proposed a shortcircuit current detection method based on the evaluation of the slope (d/dt) and the magnitude of the PV inverter current.…”

A Dynamic-SUGPDS Model for Faults Detection and Isolation of Underground Power Cable Based on Detection and Isolation Algorithm and Smart Sensors

“…In the last decade, a vast number of research work have been reported on different aspects related to various faults in the area of underground power distribution system likely analysis of faults [25][26][27][28][29][30], adaptive fault [31][32][33], SC, OC and ground faults [34][35][36][37], detection [38,39], classification [40] and fault location [41][42][43][44][45][46], sustainable protection [47,48], noise monitoring [49], and for thermal test [50].…”

Fault detection and location estimation forLVDCmicrogrid using self‐parametric measurements

“…The location of fault with good accuracy is discussed with some complex computation method using medium-range sampling frequency. 18,19 Fault analysis for the photovoltaic generation system has been done for solar fluctuations and DC transmission systems 20,21 in some literature. The distance-based fault detection and isolation technique for an MVDC system has been discussed 22,23 which deals with zero-mode fault network to detect and isolate the fault.…”