The atom-cluster interaction has recently been exploited as an effective way to increase the performance of metal-nitrogen-carbon catalysts for oxygen reduction reaction (ORR). However, rational design such and understanding their structure-property correlations remain a great challenge. Herein, we demonstrate that introduction adjacent metal (M)-N4 single atoms (SAs) could significantly improve ORR well-screened Fe atomic cluster (AC) catalyst by combining density functional theory (DFT)...

For pt.II see ibid., vol.13, no.4, p.1355-62 (1998). This paper presents the establishment of linearized Phillips-Heffron model a power system installed with unified flow controller (UPFC). Two applications based on are demonstrated: (1) study effect UPFC DC voltage regulator oscillation stability; and (2) selection damping control signal for design controller.

The paper considers the optimal power flow (OPF) of a meshed AC/DC transmission network with voltage source converter based multi-terminal DC (VSC-MTDC) networks. OPF problem is formulated to minimize loss whole two different VSC control strategies considered, constant (master-slave control) and droop control. In addition, Grid Code compliance wind farms also embedded in formulation. presented evaluated demonstrated by example systems.

The increased interconnectivity and complexity of supervisory control data acquisition (SCADA) systems in power system networks has exposed the to a multitude potential vulnerabilities. In this paper, we present novel approach for next-generation SCADA-specific intrusion detection (IDS). proposed analyzes multiple attributes order provide comprehensive solution that is able mitigate varied cyber-attack threats. multiattribute IDS comprises heterogeneous white list behavior-based concept make...

A frequency-based approach is proposed in this paper to size a battery-supercapacitor energy storage system for maintaining power balance of an isolated with high penetration wind generation, thus maintain the grid frequency stability stochastic fluctuations being considered. The sizing method makes full use combined technical merits two types systems, battery and supercapacitor, as their specific power/energy densities corresponding expected life cycle cost/year are different. imbalance...

Frequency deviations of power systems caused by grid-connected wind fluctuations is one the key factors which restrains increase penetration level. This paper examines a combined and hybrid energy storage system (HESS, supercapacitor, battery) to smooth fluctuations. A fuzzy-based wind-HESS (FWHS) controller proposed suppress The takes full advantage complimentary characteristics supercapacitor battery with in charge high middle frequency components fluctuations, respectively. differential...

This paper examines the small-signal angular stability of a power system affected by virtual synchronous generator (VSG). The examination is based on an interconnected model with two subsystems. VSG under modeled as subsystem. rest (ROPS) forms other Damping torque analysis applied to indicate that when oscillation mode subsystem in proximity electromechanical ROPS complex plane, strong dynamic interactions are introduced decrease system. implies parameters set, modal should be examined...

This paper presents an improved corrective security constrained optimal power flow (CSCOPF) for a meshed AC/DC transmission network with voltage source converter based multi-terminal HVDC (VSC-MTDC) grids. The constrains of N-1 contingencies both AC and DC networks are fully considered in the CSCOPF problem. actions employed this include not only traditional long-term rescheduling control system, but also short term post-contingency fast VSC-HVDC. A hybrid method is developed to solve...

Grid connection of a DFIG for power generation changes the system load flow and introduces dynamic interactions with synchronous generators (SGs). A method is proposed in this paper separate examination impact those two affecting factors, change interaction brought about by DFIG, on electromechanical oscillation modes system. The developed establishment "closed-loop control system" type state space model where treated as feedback controller. established unambiguously indicates that can be...

Frequency deviation of power systems caused by grid-connected wind fluctuations is one the key factors limiting level penetration. Applying an energy storage system (ESS) to overcome constraint frequency can increase permitted This paper proposes a method evaluate penetration as limited grid and size ESS expected level. The proposed treats stochastic process rather than deterministic signal takes response characteristics into full consideration. Application based on theoretical derivations...

This paper presents a derivation of the small-signal stability limit grid-connected wind farm with M permanent magnet synchronous generators (PMSGs) as determined by dynamics phased locked loops (PLLs). The reveals mechanism whereby PLLs can destabilize in case weak grid connection. Computation derived is simple and obviates need to establish parametric model farm. approximately indicate potential instability risk collectively posed Case studies are presented evaluate analytical conclusions...

The grid connection of a large-scale wind farm could change the load flow/configuration power system and introduce dynamic interactions with synchronous generators (SGs), thus affecting small-signal angular stability. This paper proposes an approach for separate examination impact those factors, i.e., brought about by farm, on Both cases either displacing or being directly added into system, are considered. By using proposed approach, how much effect can be examined, while degree interaction...

This paper examines the dynamic aggregation of a group M same wind turbine generators (WTGs) in parallel connection. The WTGs could either be part grid-connected farm or constitute entire farm. Analytical derivation this indicates that is equivalent to dynamically independent subsystems. Each subsystems comprised single WTG. Hence, connection can represented by single-WTG for studying oscillation stability. Further analysis reveals when number increases, it possible modes may move into right...

In the process of trajectory tracking using linear quadratic regulator (LQR) for driverless wheeled tractors, a weighting matrix optimization method based on an improved quantum genetic algorithm (IQGA) is proposed to solve problem weight selection. Firstly, kinematic model tractor established according Ackermann steering model, and linearized discretized. Then, gate rotation angle adaptive strategy optimized adjust required individual evolution ensure timely jumping out local optimum....

SUMMARY This paper investigates the impact of a grid‐connected large photovoltaic (PV) power generation station on system small‐signal stability. The focus discussion in is damping local‐mode oscillations. Hence, simple single‐machine infinite‐bus with PV used. Firstly, comprehensive model integrated established. Then conventional technique torque analysis employed to examine effect Analysis reveals that there exists critical operating condition when contribution from electromechanical...

In conventional optimal power flow (OPF), parameters of electrical components such as resistance and thermal ratings the overhead lines, are assumed to be constant despite fact that they strongly sensitive weather effect (e.g., temperature or wind speed) which influences accuracy results. This paper introduces a weather-based (WB-OPF) algorithm with farm integration by considering related dynamic line rating (DLR) transmission lines. A method calculating current-temperature relationship bare...

This paper investigates the probabilistic small-signal rotor angle/voltage stability of an AC/DC power system to which offshore wind generation is connected through a multi-terminal HVDC (MTDC) network. The applies analytical method based on multi-point linearization improve accuracy assessment stability. It proposes examine voltage as always concern participation factor then employed further analyze this phenomenon and give effective remedial measures. In paper, example 16-machine three...