A subsequent commutation failure (SCF) can easily occur during the recovery process after a first (1st CF). This paper analyzes interaction mechanism of extinction angle, AC voltage, DC current and firing reveals that complex coupling relationship dynamic 1st CF has significant effect on SCF. The mathematical equations when considering different fault durations, severities system strengths are then established. An voltage detection method based reactive power duration is also proposed to...

The commutation failure (CF) is the most common fault in line-commutated high voltage direct current (LCC-HVDC) systems that may lead to transient overvoltage sending-side system. In worst condition, CF large-scale wind turbine tripping. To resolve this problem, mathematical relationship between reactive power consumed by rectifier and DC voltage, derived. Then, a calculation method proposed paper. Furthermore, mechanism of caused analyzed; it revealed reason for three times rapid decrease...

This letter proposes an analytical expression on transient overvoltage peak value caused by DC blocking (DCB) and commutation failure (CF). The proposed method can obtain the risk without modeling complex AC/DC hybrid system. only requires equivalent parameters of AC system operation to effectively calculate using dynamic simulation software. results verify effectiveness correctness method.

Wind turbines are vulnerable to negative sequence current injection, the conventional automatic reclosing scheme for wind power outgoing lines, since we may inject components into system and reclose it without distinguishing nature of fault through rectification. Moreover, in permanent faults could induce a secondary impact on system. To solve above problems, an adaptive cross-line double-circuit lines with shunt reactors is proposed. Firstly, new tripping strategy single-side partial-phase...

The uncertainty of high penetration renewable energy brings challenges to the safe and stable operation a power system; virtual synchronous compensation (VSCOM) can shift demand compensate real-time discrepancy between generation demand, improve active support ability for system. This paper proposes novel capacity allocation strategy using VSCOM stations based on fuzzy constraints. Firstly, basic framework is constructed with storage reactive generator (SVG) unit. Secondly, inertia standby...

In this study, the influences of signal delay duration between rectifier and inverter in ultra-high voltage direct current (U-HVDC) transmission systems have been analyzed. The simulation results with different time under same fault condition show that has a significant influence on control system response during recovery periods. worst condition, it may lead to commutation failure inverter. To eliminate DC system, fast calculation method for computing proposed by establishing equivalent...

The application of conventional AC collection for the integration large-scale renewable energy sources may lead to issues concerning harmonic resonance and reactive power transmission. Conversely, utilization an all-DC generation system wind (WDCG) can effectively circumvent such issues. In contrast system, interdependence among subsystems in WDCG renders it susceptible oscillation instability presence minor disturbances. To address this concern, paper first establishes a small-signal model...

In distribution networks, time asynchrony exists between the phasor measuring unit (PMU) at both ends of a line, and effective measurement devices is short, leading to insufficient accuracy in measurements. This paper proposes fault location method for networks that employ an additional inductance strategy address limited caused by inadequate devices. The enhances stability phase connecting after online circuit breaker, thus extending time. It uses symmetrical component obtain...

The Onshore Wind Power All-DC Generation System (OWDCG) is designed to integrate with renewable energy sources by modifying the grid structure. This adaptation supports infrastructure and addresses challenges of large-scale wind power AC collection harmonic resonance during transmission. Crucially, small disturbance stability parameters are essential for ensuring system’s stable operation. Unlike conventional systems, OWDCG exhibits strong coupling between subsystems, accentuating issue due...

After a fault occurs in distribution line, the transient information decays rapidly, effective time window for measuring and sampling is short. At same time, existence of timing errors between different devices also affects accuracy location. For this reason, paper proposes location method lines based on coordination primary secondary devices, provides steady-state by putting auxiliary inductors after tripping; asymmetric short-circuit faults, point voltage solved current at both end ratio...

The onshore full DC wind power generation system can effectively address the challenges of resonance and reactive transmission in large-scale AC convergence. However, transmitted through High-voltage direct current still carries risk high-voltage tripped from grid. To handle this problem, expression transient voltage at grid connection point after blocking is established. And output variation characteristics Grid connected inverter (GCI) are analyzed, bus overvoltage mechanism clarified....