Support Capability Research Articles

Research on the Voltage Supporting Capability of Multi-VSC-HVDC Subsystems Operation Strategy to Receiving-end LCC-HVDC Network in Weak AC Grid

For the hybrid multi-infeed HVDC system in which the receiving-end grid is a strong AC grid including LCC-HVDC subsystems and multiple VSC-HVDC subsystems, it has higher voltage support capability. However, for weak AC grid, the voltage support capability of the multi-VSC-HVDC subsystems to the LCC-HVDC subsystem (voltage support capability-mVSCs-LCC) can resist the risk of commutation failure. Based on this consideration, this paper proposes an evaluation index called Dynamic Voltage Support Strength Factor (DVSF) for the hybrid multi-infeed system, and uses this index to qualitatively judge the voltage support capability-mVSCs-LCC in weak AC grid. In addition, the proposed evaluation index can also indirectly judge the ability of the LCC-HVDC subsystem to suppress commutation failure. Firstly, the mathematical model of the power flow of the LCC and VSC networks in the steady-state is analyzed, and the concept of DVSF applied to hybrid multi-infeed system is proposed. Furthermore, the DVSF index is also used to qualitatively judge the voltage support capability-mVSCs-LCC. Secondly, the influence of multiple VSC-HVDC subsystems with different operation strategies on the DVSF is analyzed with reference to the concept of DVSF. Finally, the indicators proposed in this paper are compared with other evaluation indicators through MATLAB simulation software to verify its effectiveness. More importantly, the effects of multi- VSC-HVDC subsystems using different coordinated control strategies on the voltage support capability of the receiving-end LCC-HVDC subsystem are also verified.

Role of Distributed Inverter-Based-Resources in Bulk Grid Primary Frequency Response Through HELICS Based SMTD Co-Simulation

In the recent years, there has been an increase in distributed inverter-based resources (D-IBRs) in the system that is impacting the grid performance. Dynamic transmission and distribution (T&D) co-simulation is an effective method to evaluate the impact of D-IBRs on the system response, however, implementation is a challenge. This article innovatively achieves accurate T&D model coordination with inclusion of dynamic models of power electronic controls. It also demonstrates that D-IBRs operating with grid-forming (GFM) controls with frequency support capability can aid in primary frequency regulation in a low-inertia power system. The article discusses the fundamentals of dynamic T&D co-simulation to analyze the primary frequency response on the IEEE 39-Bus transmission system coupled to IEEE 123-Bus distribution system with D-IBRs with GFM controls. To demonstrate scalability, a large system (286383 T&D buses) is co-simulated: IEEE 39-bus transmission system with all load buses coupled to a total of 2328 parallel IEEE 123-Bus distribution feeders containing a mix of D-IBRs is considered. The article also discusses the use of parallel computation used for distribution system solutions enabled in the scalable multi-timescale T&D co-simulation framework along with computation time comparisons between the large and small system simulations with GFM inverter dynamics.

Real-Time Estimation of Support Provision Capability for Poor-Observable Distribution Networks

An indispensable step towards coordinating the actions of distribution and transmission system operators ( <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dso</small> s- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">tso</small> ) is to estimate the range of flexibility that can be offered to the <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">tso</small> by <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dso</small> s. Within this context, a data-driven probabilistic approach is proposed to evaluate the capability of a distribution network in providing active and reactive power support in real-time. To this end, in an offline phase, a linear discriminant analysis model, together with a piecewise linear model of the distribution network are trained to delineate the boundary of a region representing the adherence to distribution network operational constraints. In the implementation phase, this region comprises the feasible set of a series of optimization problems, formulated to determine the support provision capability. These optimization problems are of iterative linear programming type, which allows for real-time applicability. The evaluated support capability can be deemed as the available reserve in real-time transmission operation, which enables providing a coordinated response towards unexpected events, and facilitates the participation of distributed resources in the balancing market by granting an up-to-date estimation of available supports. This approach is tested on the IEEE 123-node system and verified through comparison with an AC optimal power flow technique.

Buckling and Wrinkling of Sandwich Structures Reinforced by Functionally Graded Carbon Nanotubes

Soft-core sandwich structures subjected to coplanar compression loading might exhibit wrinkling behaviors, which will reduce significantly the support capability of the structure. In order to prevent the wrinkling behaviors of sandwich structures, this work attempts to improve stiffness of face sheets reinforced by carbon nanotubes (CNTs). To achieve such a goal, the following work is to be required. First, an equivalent single-layer model will be proposed to accurately analyze the wrinkling behaviors of sandwich structures because only layerwise models possess the capability to accurately predict wrinkling behaviors of sandwich structures, but these models are often computationally expensive. Second, the influence of distributions of the CNTs through thickness on the buckling and wrinkling behaviors for the sandwich beams will be investigated in detail. Moreover, the translation mechanism between the buckling deformation and the wrinkling deformation has been also explored. The proposed model has been verified by using the quasi three-dimensional (3D) elasticity solutions and the 3D finite-element results (3D-FEM). Third, by selecting the proper distributions of the CNTs through the thickness of sandwich structures, the wrinkling behaviors of sandwich structures can be effectively prevented. Thus, a scheme resisting wrinkling deformation of sandwich structures has been proposed, which can provide a reference for other investigators.

영유아교사가 지각한 반성적 사고와 놀이지원 역량 및 놀이중심교육과정실천 역량 간 관계

영유아교사가 지각한 반성적 사고와 놀이지원 역량 및 놀이중심교육과정실천 역량 간 관계

Grid-Forming Converter Overcurrent Limiting Strategy Based on Additional Current Loop

Compared with current source converters, voltage source converters (grid-forming converters) have better frequency support capabilities, voltage support capabilities, and regulation performance, thus they have broad application prospects. However, the grid-forming (GFM) converter has insufficient current control ability, and it easily causes problems such as overcurrent issues when a fault occurs. Thus, this insufficiency is one of the most important challenges the GFM converter is faced with. Aiming to solve the problems mentioned above, this paper proposes a control method of a GFM converter achieved with a low-pass filter structure and an additional current loop. The additional current loop controls the dq-axis current components by acting on the outer loop to generate appropriate phase and voltage amplitude reference. The low-pass filter structure is used to solve the system frequency stability problem caused by the inclusion of the additional current loop. On the premise of ensuring that the system frequency meets the grid-connection requirements, the proposed strategy rapidly limits the output current within the allowable range and guarantees expected voltage source characteristics of the converter during the fault period. Finally, the effectiveness and superiority of the proposed control strategy are verified by MATLAB/Simulink simulations.

Development of a self-management support practice framework for addressing cancer-related fatigue: a modified Delphi study

PurposeManaging cancer-related fatigue requires individuals to adopt a range of self-management behaviours. However, clinicians report the lack of clear guidance on self-management support practices hinders their provision of supportive care. To develop consensus on a framework of core practices required by health professionals to deliver effective self-management support to cancer patients and survivors experiencing cancer-related fatigue.MethodsA preliminary framework of 47 practice items (14 Key Practices, 33 Practice Components) was derived from a systematic review, and a self-management support capability outline for primary care professionals. This preliminary framework was presented for consensus rating and comment in a two-round modified Delphi study conducted with a panel of health professionals, research academics, and cancer consumers.ResultsFifty-two panel participants comprising consumers (n = 25), health professionals (n = 19), and researchers (n = 16) were included in Round 1 of the modified Delphi study. Feedback from the panel produced consensus on retaining 27 of 47 original practice items without change. Seventeen items (including 12 modified, and 5 newly created practice items) were sent to the panel for rating in Round 2. Thirty-six experts produced consensus on retaining all 17 practice items in Round 2. The final framework comprised 44 items (13 Key Practices, 31 Practice Components).ConclusionsThe practice framework offers an evidence- and consensus-based model of best practice for health professionals providing self-management support for cancer-related fatigue.Implications for Cancer SurvivorsThis framework is the first to focus on quality provision of self-management support in managing cancer-related fatigue, one of the most prevalent symptoms experienced by cancer patients and survivors.

Business-to-business co-creation management practices for intellectual property value: Insights from Saudi Arabia

Managing intellectual property (IP) value appropriation remains a central challenge for business-to-business (B2B) networks due to B2B co-creation prospects for improved value-in-exchange and value-in-use for co-creation beneficiaries. This article aims to explore the management practices of B2B networks that enhance IP value from B2B co-creation. Using semi-structured interviews with sixteen IP management experts from the Kingdom of Saudi Arabia, the article proposes an integrated model of management strategies and guidelines for B2B co-creation with respect to IP value. The model posits that at the intra-organisational level, the main enabling processes for value appropriation are building communication skills, implementing hiring processes, and developing management systems for negotiations, talents, and intellectual assets, respectively. This level benefits from priorities placed on selecting strategic partners and fostering learning cultures for knowledge, technology, and venture co-creation processes. For the inter-organisational level, the proposed enabling processes are pursuing research funds and creating optimum designs for technology development and market positioning, respectively. Priorities at this level involve aligning complementary resources, developing clear agreements, and utilising supportive capabilities for technology and market co-creation.

Nonlinear model predictive control-based active power dispatch strategy for wind power plant considering dynamic wake effect

Inappropriate active power dispatch strategies can diminish the active power support capability (APSC) of the wind power plant (WPP) due to the wake effect. In existing strategies, the WPP’s APSC and the time delay of wake effect are not thoroughly investigated. This paper proposes an active power dispatch strategy to increase the WPP’s APSC while tracking the power reference. First, WPP’s temporary and sustained APSCs are analyzed considering dynamic wake effect. Correspondingly, the total stored kinetic energy and increasable power of WPP are introduced as evaluation indicators of the capabilities. Furthermore, a bi-level control framework is proposed to accomplish the dispatch task in different timescales. Aiming at improving WPP’s temporary and sustained APSCs comprehensively, the operating status references of each WT, including the power reference and pitch angle, are optimized in the WPP layer. Taking the time delay and nonlinearity of wake effect into account, the receding horizon optimization is solved in a finite time domain using nonlinear model predictive control (NMPC). During the sampling interval of the NMPC, a coordinated control in the WT layer is developed to modify the active power reference dispatched by the WPP layer in case the wind speed fluctuates. Finally, extensive case studies show that the WPP’s temporary and sustained APSCs are improved with the proposed strategy in different wind conditions and power references.

Roles of Metal Oxide Nanostructure-Based Substrates in Sustainable Electrochemical Water Splitting: Recent Development and Future Perspective

Increasing energy demand to find everlasting and eco-friendly resources is now mainly dependent on green hydrogen production technology. Water electrolysis has been regarded as a clean route for green H2 production with zero carbon emission, but different bottlenecks in the development of electrodes impeded its realization. Recently, transition metal oxides (TMO) have gained tremendous attention as suitable cathodes and anodes due to their sustainability under harsh conditions, high redox features, maximum supportive capability, easy modulation in valence states, and enhanced electrical conductivity. In this review, we have highlighted the role of transition metal oxides as active and supported sites for electrochemical water splitting. We have proposed different perspectives for the rational design of TMO-based electrode materials, i.e., electronic state modulation, modification of the surface structure to control the aerophobicity and hydrophilicity, acceleration of the charge and mass transport, and stability of the electrocatalyst in harsh environments. We have systemically discussed the insights into the relationship among catalytic activity, certain specified challenges, research directions, and perspectives of electrocatalysis of the OER and HER.

PERCEIVED ORGANIZATIONAL SUPPORT PENILAIAN KINERJA DAN INFORMATION TECHNOLOGY CAPABILITY PENGARUHNYA TERHADAP KINERJA KARYAWAN

The purpose of this study is to analyze Perceived Organizational Support (POS), Performance Assessment and IT Capability affect employee performance. Respondents from this study were all employees, namely as many as 75 people, data collection was carried out through a survey with a questionnaire instrument, and data analysis used was multiple linear regression, while F-test and t-test were used to test the hypothesis. The results of this study indicate that POS, Capability of IT, and performance appraisal partially have a significant effect on employee performance, while the hypothesis test as a simultaneously stated that POS, Capability of IT, and performance appraisal have a significant effect on employee performance. This indicates that to improve employee performance, organizational support, IT skills and performance appraisal of employees in the company are needed.

Fuzzy-based coordinated control and parameter correction strategy for speed controller of PMSG wind turbine in frequency response

The purpose of frequency response of PMSG wind turbine is to provide additional energy support to the power system’s frequency regulation demand through its rotor kinetic energy. However, the inherent control loop represented by the PMSG speed controller, and its inherent control purpose is to maintain a stable operation of the rotor speed, thus the difference between these two control blocks will lead to a conflict situation between frequency response performance and operation safety of the wind turbine. Therefore, a novel fuzzy-based coordinated control and parameter correction strategy for speed controller of PMSG wind turbine in frequency response is proposed in this paper. First, to clarify the function role of key parameters of the wind turbine in frequency response process, a mapping equivalence model consisting of wind turbine’s frequency response parameters and operation states is proposed by establishing the energy correspondence relationship between PMSG rotor kinetic energy, de-loading reserve by pitch angle control and power demand of frequency response. Then, the frequency response performances of the speed controller’s parameters are tested under various wind speeds. Moreover, based on the fuzzy logic algorithm, a dynamic operation strategy for the wind turbine’s speed controller is proposed to improve the frequency response performance, which alleviates its conflict against the PMSG frequency response control block. Finally, a simulation model is built to verify the proposed strategy under various wind scenarios. The test results demonstrate that the frequency response performance and the speed controller’s inherent control function of the PMSG-wind turbine can be effectively coordinated by deploying the proposed strategy, and the frequency support capability of the power system is effectively improved.

Abstract B033: Determining the tumor supportive and inhibitory capabilities of cancer associated fibroblast subpopulations in central nervous system metastasis. [R

Abstract Central nervous metastases (CM), like all tumors, are surrounded by a complex tumor microenvironment (TME) comprised of a meshwork of extracellular matrix (ECM) proteins and an assemblage of cell types including endothelial cells, pericytes, immune cells, and cancer-associated fibroblasts (CAFs). We have previously shown that CAFs can either support or inhibit tumor growth, suggesting that CM CAFs comprise a heterogenous subgroup of cells. Recently we reported, based on literature in other cancer types, that CAFs can be categorized into four main subpopulations: ‘desmoplastic’, ‘immune’, ‘contractile’ and ‘aggressive’. Accordingly, the purpose of our study is to identify CAF subpopulations in the TME of CM and determine their impact on CM growth. In order to identify CM CAF subpopulations and their respective markers, we performed single cell RNA sequencing (scRNA-seq) on 7 CM patient tissues and 4 patient-derived CM CAF cell lines established in our lab. We then used fluorescence-activated cell sorting (FACS) to enrich different CAF subpopulations in CAF cell lines for further molecular and functional in vitro and in vivo characterization. ScRNA-seq data in 7 CM tissues revealed the presence of CAFs. Upon further analysis, we identified the desmoplastic, immune, contractile, and aggressive CAF subpopulations. In the CAF cell lines, we identified the desmoplastic and aggressive CAF subpopulations. We propose that desmoplastic CAFs are tumor inhibitory and aggressive CAFs are tumor supporting. The desmoplastic subpopulation is characterized by high expression of Immunoglobulin Superfamily Containing Leucine Rich Repeat (ISLR) and low expression of a classic tumor supportive CAF marker Actin Alpha 2, Smooth Muscle (ACTA2, a-SMA). ISLR has recently been reported to be overexpressed in CAFs with tumor inhibitory capabilities in other cancer types. The aggressive subpopulation shows low ISLR expression and high a-SMA expression. FACS on one of the patient-derived CM CAF cell lines using ISLR antibody enriched ISLRhigh CAFs, with remaining CAFs confirmed to be ISLRlow. Further western blotting analysis revealed lower expression of a-SMA in ISLRhigh cells as compared to ISLRlow cells. This reciprocal expression of ISLR and a-SMA could represent the molecular basis driving the phenotype of desmoplastic and aggressive CAF subpopulations. Further in vitro and in vivo experiments are currently underway in our lab to determine the necessity and sufficiency of ISLR and a-SMA in determining tumor supportive capabilities of both desmoplastic and aggressive CAFs. The present study improves our understanding of the CM TME, which ultimately will help establish new strategies to harness the cancer restraining capabilities of tumor inhibitory CAFs in clinic to improve outcomes for patients with CM. Citation Format: Thomas Simon, David N. Buckley, Gerald C. Gooden, Ben Y. Tew, Gabriel Zada, Bodour Salhia. Determining the tumor supportive and inhibitory capabilities of cancer associated fibroblast subpopulations in central nervous system metastasis. [R [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B033.

영유아교육기관 교사의 놀이신념과 교수창의성이 놀이지원 역량에 미치는 영향

Objectives The purpose of this study was to examine the effects of play beliefs and teaching creativity of teachers at early childhood educational institutions on play support competency.&#x0D; Methods The subjects of this study were 287 teachers at day care centers and kindergartens in Busan and Gyeongsangnam-do. The analysis method was Person's product-moment correlation using SPSS 23 program to examine the relationship between teacher's play belief, teaching creativity, and play support competency, and multiple regression analysis was conducted to verify the influence of teacher's play belief and teaching creativity on play support competency.&#x0D; Results As a result of data analysis, first, there was a positive correlation between teachers' play beliefs, teaching creativity, and play support competency. Second, among the sub-variables of play support competency, teacher's teaching creativity showed higher explanatory power in internal motivation, play goal, play design, and play operation, and teacher's play belief showed higher explanatory power in teacher's emotion and attitude, play support improvement effort, knowledge, play environment creation, and infant evaluation.&#x0D; Conclusions The results of this study are significant in that it reminded the importance of teachers' play beliefs, teaching creativity, and play support capabilities in order for play-based education and childcare courses to be well realized in early childhood education institutions, and that teachers' play beliefs and teaching creativity should be promoted in order to enhance teachers' play support capabilities.

An application of meta‐heuristic and nature‐inspired algorithms for designing reliable networks based on the Internet of things: A systematic literature review

SummaryThe widespread use of Internet of Things (IoT) in various wireless sensor networks applications has increased their importance in recent years. IoT is a smart technology that connects anything anywhere at any time. These smart objects, which connect the physical world with the world of computing infrastructure, are expected to permeate all aspects of our daily lives and revolutionize a number of application domains such as healthcare, energy conservation, and transportation. As wireless networking expands, the disadvantage of wireless communication is clearly obvious. People's apprehension over the IoT's dependability has therefore skyrocketed. IoT networks' key requirements are dependability, channel security, fault tolerance, and reliability. Monitoring the IoT networks depends on the availability and correct functioning of all the network nodes. Recent research has proposed promising solutions to address these challenges. This article systematically examines recent articles that use meta‐heuristic and nature‐inspired algorithms to establish reliable IoT networks. Eighteen articles were analyzed in four groups. Results showed that reliable enhancement mechanisms in IoT networks increase fault node detection, network efficiency, and lifetime and attain energy optimization results in the IoT concept. Additionally, it was discovered in the literature that the current studies focus on how to effectively use edge network capabilities for IoT application executions and support, along with the related needs.

Selection environment, venture learning and capability building: case of Malaysian agriculture incubation system

This paper assesses the venture's learning and capability development during the incubation and post-incubation periods. The case studies show incubatees' capability and learning divergence across multiple cases. First, the selection environments – incubation and market – shape the knowledge and capability development. Specifically, R&D support with greater access to facilities liberates incubatees with domain knowledge to sustain their ventures during and after incubation. Second, learning and capability developments are highly constrained by the owners' domain knowledge distinction that limits their ability to appropriate employees' knowledge and the knowledge from incubation support system. Third, the interplay in the owner's domain knowledge, incubation support system, learning and capability development are dynamic where each reinforces one another. Overall, the selection environment features are critical junctures in driving evolutionary changes only when they co-evolve with other factors. The paper concludes with policy and managerial implications.

Guest Editorial: Grid‐forming converters placement and utilisation to enhance transmission and distribution performances under high penetration of inverter‐based resources

Power systems around the world are rapidly transitioning to much higher shares of inverter-based resources (IBRs) with few synchronous generators remaining online. IBRs and synchronous generators have fundamentally different dynamic performance characteristics resulting in a difference in the overall power system dynamic performance. IBRs are generally more flexible and controllable than synchronous generators; however, at the same time they exhibit significantly more complex control systems. Furthermore, new and emerging capabilities are being developed progressively and in particular the so-called grid-forming inverters (GFM). GFM offer several new capabilities not previously possible with conventional grid-following inverters (GFL). However, they are not well understood currently when applied in a mega scale and moving forward when they will likely take over the role synchronous generators have been performing for several decades as the workhorse of system security support. Key questions currently in the technical community include the extent to which GFM shall be similar or different to each of the synchronous machines and conventional GFL, and how various control strategies can assist in maximising the grid support capabilities sought and minimise or ideally eliminate any adverse impacts. The objective of this special issue is to provide insights into some of these unknowns.

Dynamic simulation of China's water-grain-meat system and evaluation of its support capability based on water footprint theory

Dynamic simulation of China's water-grain-meat system and evaluation of its support capability based on water footprint theory

Unit Commitment Considering the Different Frequency supporting capability of Synchronous Generators

With the high penetration of renewable power in the power system, the inertia level and frequency regulation capability are reduced, the system frequency safety are facing a major challenge. Considering the different frequency support capability of the synchronous generators, the effect of adjustment coefficient of different units on the minimum frequency has been analyzed based on the sensitivity analysis. A multiobjective frequency constraint unit commitment model considering the sensitivity of adjustment coefficient is proposed, and simulation results show that the proposed model increases the minimum frequency value, improves the frequency stability of the power system.

Optimal Configuration Method for the Installed Capacity of the Solar-Thermal Power Stations

Because of the randomness of wind power and photovoltaic (PV) output of new energy bases, the problem of peak regulation capability and voltage stability of ultra-high voltage direct current (UHVDC) transmission lines, we proposed an optimum allocation method of installed capacity of the solar-thermal power station based on chance constrained programming in this work. Firstly, we established the uncertainty model of wind power and PV based on the chance constrained planning theory. Then we used the K-medoids clustering method to cluster the scenarios considering the actual operation scenarios throughout the year. Secondly, we established the optimal configuration model based on the objective function of the strongest transient voltage stability and the lowest overall cost of operation. Finally, by quantitative analysis of actual wind power and photovoltaic new energy base, this work verified the feasibility of the proposed method. As a result of the simulations, we found that using the optimal configuration method of solar-thermal power stations could ensure an accurate allocation of installed capacity. When the installed capacity of the solar-thermal power station is 1 × 106 kW, the transient voltage recovery index (TVRI) is 0.359, which has a strong voltage support capacity for the system. Based on the results of this work, the optimal configuration of the installed capacity of the solar-thermal power plant can improve peak shaving performance, transient voltage support capability, and new energy consumption while satisfying the Direct Current (DC) outgoing transmission premise.