Under fault conditions, virtual synchronous generators (VSGs) are prone to lose transient stability, similar generators. However, the existing studies on VSG stability not comprehensive. The characteristics of VSGs highly affected by control parameters, but models in overly simplified. In addition, critical clearing angle (CCA) and time (CCT) two indices used measure a system, there few that consider both CCA CCT. this article, we analyze CCT quantitatively describe boundary under different...

The stability of the grid-connected inverter (GCI) system in weak grids is deteriorated due to asymmetric positive-feedback loops (APFLs) introduced by phase-locked loop (PLL) structure. Under same main circuit parameters and control parameters, small-signal models GCI controlled <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i> domain xmlns:xlink="http://www.w3.org/1999/xlink">αβ</i> are constructed, respectively. Compared with model...

A soft open point (SOP) can improve the flexibility of power control and thus further enhance reliability economy distribution networks. However, existing SOP regulation strategies have mainly focused on feeder imbalance line loss optimization in medium-voltage networks, SOPs transformers are often ignored, which has poor applicability low-voltage network (LDN). Therefore, a novel two-layer strategy is proposed for working LDN, system simultaneously. In terms layer, load considering...

The flexible interconnection distribution networks (FIDN) based on soft open points (SOP) provides an opportunity to improve the economy and reliability of networks. However, existing optimal strategies have mainly focused line power loss reduction, characteristic SOPs transformers is ignored. Therefore, capability reducing total for optimization strategy needs further improvement. Thus, SOP's locating, sizing operation, a two-stage FIND proposed considering key equipment including...

The reliable extinguishment of a single phase-to-ground arc is the key issue for safe and operation in distribution network. However, since existing suppression methods are normally affected by line parameters, residual current (RC) at grounding point still exists, then hard to be extinguished reliably. Thus, an adaptive active voltage-type (AAVAS) strategy that can reliably inhibit RC proposed this article. First, mechanism traditional extinguishing method parameters proved, variation rules...

Transient stability and frequency of virtual synchronous generator (VSG)-controlled converters during grid faults are critical for the stable operation high-share renewable energy power systems. However, existing transient methods often overlook consideration stability. This paper presents a method to improve both VSGs faults. The influence mechanism inertia damping on is comprehensively analyzed under two types faults, with or without equilibrium points. To address conflict between large...

The advanced cophase power supply system provides an opportunity to eliminate the problems of neutral section and quality issues. However, existing schemes still have drawbacks, such as numerous electronic devices, high initial cost, poor reliability. Therefore, in this article, a novel hybrid equipment (NH-ACPSE) is proposed based on traction transformer. By common dc bus each port, secondary ripple input ports can be offset. Also, number active/passive devices capacitance capacity reduced....

The advanced cophase traction power supply system (ACTPSS) integrating with photovoltaics (PV) and energy storage (ES) can realize the efficient consumption of regenerative braking (RBE) renewable sources. However, existing single-level management strategies for ACTPSS that only focus on main-station or sub-station have poor performance in economy timeliness. Therefore, a multi-timescale strategy including minutes-level optimal dispatch seconds-level real-time control sub-stations is...

To fully compensate reactive and active components of the single line-to-ground (SLG) fault current, additional DC power supply devices are usually used for arc suppression devices. Therefore, alternate method is proposed non-neutral multi-function device (MF-ASD) in this paper, which can achieve energy self-balance MF-ASD during SLG without Firstly, DC-link charge–discharge characteristic analyzed under different conditions. Then, principle flow law between two non-faulty phases described...

The various hybrid advanced traction power supply systems (HATPSS) received significant attention due to their high equipment utilization and low reconstruction cost. They mainly consist of transformer a "two-phase input port single-phase output port" (2AC-AC) converter. However, as multi-port device with complex fault characteristics, the 2AC-AC converter may cause negative sequence current, insufficient supply, even system instability when any fails. Additionally, if traditional redundant...

Abstract The automatic reclosing strategy is an effective measure to improve the reliability of a distribution network. It can quickly clear instantaneous faults in grid. traditional transformer has proven be reliable and robust during process. However, influence process on operational characteristics solid-state transformers (SST) still unclear. action may generate huge inrush current, resulting shutdown even damage SST. To address this problem, paper proposes current suppression strategy....

When a serious grid fault occurs, virtual synchronous generator (VSG) tends to lose transient power angle stability (TPAS) and cause the current exceed limit. Most existing research usually neglects inherent relationship between instability (TPAI) over-current (FOC), which leads two problems being solved separately rather than simultaneously. In this paper, characteristics of VSG are first studied, causes influencing factors TPAI FOC explored. Then, TPAS analysis is carried out based on...

Silicon/Silicon carbide hybrid switch have been proven to the advantages of high efficiency and low cost. However, existing research switches only focuses on reducing device losses or ensuring reliable operation. In this article, a novel switching strategy based driving voltage sequence for is proposed. Experimental results show that compared with fixed voltage, proposed cannot ensure reliability switch, but also improve efficiency. Then, effectiveness verified in single-phase inverter....

This study seeks to quantify how much insolation varies over the span of a typical photovoltaic (PV) array. A solar sensor array was constructed and deployed at three locations where environmental conditions vary from full sun highly restricted sunlight. Data recorded each location then analyzed find effects shading. In traditional series-parallel systems total power output system is dependent on every cell. One cell with low properties will drag down current an entire series string....

Under weak grid conditions, the impedance and phase-locked loop (PLL) affects robust stability of grid-connected inverters, leading to harmonic resonance, or even instability in system. In this paper, a remodeling control method is proposed enhance inverters with high impedance. First, output PLL reshaped by connecting complex-coefficient filter (CCF) structure series input typical SRF-PLL. The purpose broaden range feasible phase angles that can maintain stability. Then, current reshaped,...

By means of finite element simulation, the power cycling test as submodule a 3300V/1500A IGBT module is simulated. The influence different current and turn-on time combinations on diffusion temperature studied, lifetime bond wire calculated by Coffin-Mason model. simulation results show that with same junction fluctuation highest temperature, maximum surface chip under large short much higher than low long time, shows larger gradient, which leads to failure more easily for high IGBT. This...

The novel hybrid advanced traction power supply device (NH-ATPSD), which consists of a transformer and "two-phase-parallel-input to single-phase-cascaded-output" (2AC-AC) converter, has been proposed recently. It provides opportunities for solving the neutral section negative-sequence quality problems. However, different from single-level electronic with cascade structure, current healthy module overload may occur when input- or output-module fault occurs in NH-ATPSD. Thus, dynamic...