Evaluation Method Of Capacity Research Articles

Review on the Evaluation and Improvement Measures of the Carrying Capacity of Distributed Power Supply and Electric Vehicles Connected to the Grid

With the increasing number of distributed power sources such as photovoltaic power and wind power and electric vehicles connected to the grid, the structure and operation state of the traditional distribution network have undergone great changes. Therefore, through the establishment of a distributed power grid-connected evaluation system, it has become an important research topic to evaluate the access of distributed power and the carrying capacity of electric vehicles in the distribution network of new power systems. Firstly, the situation of distributed power supply and electric vehicles and the impact of grid connection are introduced. Secondly, the traditional distribution network carrying capacity evaluation method is studied and introduced. Then, the distribution network carrying capacity evaluation considering uncertainty is reviewed and investigated. Finally, in view of the lack of existing research, further research is needed, aiming to provide a reference for the realization of distributed power supply and grid-connected EV carrying capacity evaluation and a scientific basis for the future operation planning of distributed power supply and EV integration into the distribution network.

Multihazard resilience and economic loss evaluation method for cable-stayed bridges under the combined effects of scour and earthquakes

Cable-stayed bridges (CSBs) commonly experience scour-induced foundation issues during their service life, impacting both structural seismic resilience and economic losses. Nonetheless, these aspects remain inadequately addressed in existing seismic codes. This paper presents a comprehensive probabilistic multihazard fragility, resilience, and economic loss evaluation method for CSBs influenced by scour and earthquakes. Numerical models with various scour depths considering epistemic uncertainties in loads, structural properties, and soil conditions are first established using the Latin-hypercube sampling (LHS) method. Incremental dynamic analyses (IDAs) are then conducted on these models in cases with near-fault and far-field bidirectional ground motions, yielding probabilistic multihazard demand models and component- and system-level multihazard fragility surfaces for diverse limit states. Subsequently, resilience and economic losses are comparatively evaluated by integrating damage probabilities with corresponding uncertain functional recovery functions. Eventually, a rapid bridge traffic capacity evaluation method based on the critical traffic capacity surface concept is devised to effectively assess CSB open patterns under various peak ground accelerations (PGAs), scour depths, and repair times. The numerical results show apparent shifts in the nonmonotonic seismic fragility, resilience, and economic loss of the case CSB due to scour effects, with the rates of change reaching 31.4 %, 34 %, and 24.8 %, respectively, associated with a critical scour depth of 12 m at IM = 0.8 g. The developed analysis framework provides a reference for the life-cycle design and maintenance of CSBs affected by multihazard scour and earthquakes.

Comprehensive Evaluation of Urban Road Network Capacity Using Fractal Theory in the Context of the Internet of Things

Abstract In order to make a good assessment of road traffic status, this paper proposes a comprehensive evaluation method of urban road network capacity based on soft computing under the background of Internet of Things. The focus of the research is to use a variety of soft computing technologies such as Hausdorff dimension simplification method, branch dimension measurement algorithm, multifractal method, etc., to analyze the overall traffic load and guide the traffic channelization in an optimal way, considering various factors comprehensively. The model helps to optimize infrastructure and reduce road traffic congestion. This avoids traffic congestion, ultimately reducing the carbon footprint and promoting a green environment. This method analyzes the network capacity, network load and corresponding conversion coefficient of all levels of highway. Based on the multi-component linear regression method, this paper evaluates the urban road network capacity, and constructs the urban road network capacity planning model according to the traffic volume constraints and travel time constraints. The test results show that under the application of this method, the road capacity of the planned route exceeds 4000 pcu. The pcu is a passenger vehicle unit that measures the extent to which different types of vehicles have an impact on road capacity. When the capacity of a planned road exceeds 4000 pcu, it means that the road can carry a large number of different types of vehicles at the same time, and the average operating speed of the line can reach 42.3 km/h. After 5 years of planning, the efficiency of road use is still above 75 %. It can be proved that this method can obtain the optimal traffic path through better route planning and avoid traffic congestion and pollution.

Study of an evaluation method of earthquake-proof capacity of a community during an earthquake

In dealing with the occurrence of earthquakes, urban communities and people within the system should primarily consider the geological background, secondary hazards caused by earthquakes, countermeasures to mitigate earthquake disasters, community connectivity, and the impact of various indicators and criteria on the earthquake-proof capacity of the community. It is important to comprehensively assess these factors to ensure that a community is well-prepared to withstand an earthquake. This study takes Shenzhen (China) as an example to conduct a preliminarily evaluation of a method of earthquake-proof capacity during an earthquake, with the results reflecting the comprehensive capacity of communities. The evaluation framework focuses more on effectively improving the disaster response capacity and resilience of urban communities.

Evaluation of shale gas reservoir reserves and production capacity based on Arps regression

ABSTRACT At present, global energy conflicts are prominent and the world’s attention is focused on energy security. In order to evaluate the reserves and production capacity of the shale gas, which is a special fossil energy source, the study proposes a reserve and production capacity evaluation design for its reservoirs based on Arps decrement. The study intersects the material balance method and Arps reconciliation decrement method to achieve the evaluation of shale gas reservoir reserves. The shale gas reservoir production capacity was calculated using Integrated Geostatistical and Geomechanical Modeling (IGIG) based on Genliang Guo’s fractured horizontal wells, and Effective Fracture Radius (EFR) formula based on large capsule-shaped flow zones. Experimental data showed that the capacity evaluation method based on the binomial dynamic coefficient inverse calculation of formation pressure can calculate the current unobstructed flow rate and allotted production rate to provide data support for the extraction of shale gas reservoirs.

Evaluation method of distributed photovoltaic maximum access capacity based on ADMM

With the increasing penetration rate of distributed photovoltaics in the distribution network, new requirements are put forward for the operation and control of distribution networks. In order to ensure that the distribution network can operate stably within a safe range, it is important to evaluate the maximum capacity of the distribution network that can be connected to distributed photovoltaics. Considering the high cost of centralized computing, high communication requirements, and poor reliability, it is difficult to adapt to the actual needs of the distribution network with large-scale access to distributed photovoltaics. Therefore, this paper proposes an ADMM-based distributed PV maximum access capacity evaluation method. This method takes the distributed photovoltaic access capacity and the active power loss of the distribution network line as the objective function and considers the power flow equation constraints, node voltage constraints, and line current carrying capacity constraints of the distribution network. By simplifying the model, the non-convex optimization problem is transformed into a convex quadratic programming problem, and the ADMM algorithm is used to solve the distributed solution to obtain the access strategy of distributed PV in various regions under different operating conditions. Finally, the IEEE-33 system is used as an example to simulate the calculation, and the experimental results verify the correctness and effectiveness of the method.

New Method for Capacity Evaluation of Offshore Low-Permeability Reservoirs with Natural Fractures

In recent years, the development of two offshore low-permeability oil fields has revealed unexpected challenges. The actual productivity of these fields significantly deviates from the designed capacity. Some wells even outperform the expectations for low-permeability limestone fields. This discrepancy primarily stems from a lack of accurate understanding of natural fractures before and after drilling, resulting in substantial errors in capacity assessment. This paper addresses these challenges by proposing a new production capacity model and evaluation method for both vertical and horizontal wells in low-permeability limestone reservoirs. The method leverages logging curve data, incorporating vertical gradation and fractal analysis to effectively represent the fracture’s complexity and connectivity. It uniquely considers factors such as fracture fractal dimensions, threshold pressure, and stress sensitivity, significantly enhancing prediction accuracy. Furthermore, by analyzing the longitudinal gradient in logging curves, the method effectively identifies strong heterogeneity, leading to more accurate capacity evaluations in actual fields. The results demonstrate that our model reduces the average prediction error to less than 15%, markedly outperforming traditional methods. Calculation results of the newly developed capacity formula align closely with actual production data and tracer test results, showcasing its practical applicability and potential for widespread use. This study notably advances the evaluation of reasonable production capacity in similar offshore reservoirs.

Evaluation method of environmental carrying capacity of tourist attraction to be developed based on marginal utility analysis

Evaluation method of environmental carrying capacity of tourist attraction to be developed based on marginal utility analysis

Evaluation method of renewable energy absorptive capacity based on Monte Carlo

Evaluation method of renewable energy absorptive capacity based on Monte Carlo

Evaluation method of tourism environmental capacity in nature reserves based on data mining

Evaluation method of tourism environmental capacity in nature reserves based on data mining

Evaluation method of environmental carrying capacity of tourist attraction to be developed based on marginal utility analysis

Evaluation method of environmental carrying capacity of tourist attraction to be developed based on marginal utility analysis

Evaluation method of renewable energy absorptive capacity based on Monte Carlo

Evaluation method of renewable energy absorptive capacity based on Monte Carlo

Pipeline sharing: Boosting multi-product pipeline transport biofuels in the shift to low-carbon energy

Under the dual pressures of oil depletion and low carbon transition, biofuels are considered effective alternatives for fuel oil due to their renewable nature and environmental friendliness. However, oil demand remains high, which indicates that biofuels and fuel oil will coexist for a long time to come. While pipelines offer an efficient means of transporting liquid fuels, the initial investment required is substantial. Therefore, this paper proposes a comprehensive framework that focuses on sharing already existing multi-product pipelines with biofuels, thus evaluating the pipeline remaining potential to transport biofuels. The core component of this framework is the evaluation method for determining the multi-product pipeline remaining capacity. We coupled fuel oil consignment contracts into the remaining capacity evaluation method and developed a model for evaluating the multi-product pipeline transport biofuels potential, aiming to maximize biofuels pipeline transport volume. The objective of this model is to optimize the transportation volume of biofuels through pipelines. Various constraints are taken into account, such as product batch movement, prohibited sequences, operational constraints, delivery time frames, and inventory levels. Moreover, this study evaluates and discusses the benefits of biofuels transportation capacity using eight real-world multi-product pipeline systems without impacting fuel oil consignment contracts. The findings indicate that pipelines are capable of transporting 49,849 m3 of biofuels per week, increasing revenue by 1.78 million CNY. Simultaneously, the low energy consumption for pipeline transportation can lead to a weekly reduction of 34.6 tons in carbon emissions. The evaluation model anticipatively provides the ability to respond to future market developments.

Influence of manufacturing surface topography on torque and load bearing capacity of hydro-viscous drive clutch under mixed lubrication stage

PurposeHydro-viscous drive (HVD) clutches are widely used in equipment requiring soft start, such as fans and pumps, to transmit torque and adjust speed by changing the gap distance between friction pairs. This paper aims to propose a novel two-parameter evaluation method for HVD during the mixed lubrication stage. The objective is to develop an effective model that establishes the relationship between these parameters and the actual surface topography.Design/methodology/approachIn the presented methods, the fractal features of the real manufacturing surface are calculated based on the power spectrum function by the ultra-depth three-dimensional microscope. After that, the hybrid friction model of the friction plate is established based on mixed elasto-hydrodynamic lubrication theory, boundary friction model and fractal theory. Then the torque and load bearing characteristics of the clutch are obtained, and the influences of the surface fractal features are investigated and discussed. Finally, the Weierstrass–Mandelbrot function is adopted for the surface topography characterization and evaluation.FindingsThe results indicate that the proposed method exhibits good accuracy, while the speed difference between the friction pair exceeds 2,500 rpm. It is concluded that this paper proposed a way to evaluate the torque and loading capacity of HVD considering the real manufacturing surface topography and is helpful for surface optimization.Originality/valueThe originality and value of this study lie in its development of a novel torque and load bearing capacity evaluation method for HVD in mixed lubrication stage, considering manufacturing surface topography and describing the real manufacturing surface.

Assembly line balancing and capacity evaluation based on interval grey processing time

PurposeAssembly line is a common production form and has been effectively used in many industries, but the imprecise processing time of each process makes production line balancing and capacity forecasting the most troublesome problems for production managers. In this paper, uncertain man-hours are represented as interval grey numbers, and the optimization problem of production line balance in the case of interval grey man-hours is studied to better evaluate the production line capacity.Design/methodology/approachFirst, this paper constructs the basic model of assembly line balance optimization for the single-product scenario, and on this basis constructs an assembly line balance optimization model under the multi-product scenario with the objective function of maximizing the weighted greyscale production line balance rate, second, this paper designs a simulated annealing algorithm to solve problem. A neighborhood search strategy is proposed, based on assembly line balance optimization, an assembly line capacity evaluation method with interval grey man-hour characteristics is designed.FindingsThis paper provides a production line balance optimization scheme with uncertain processing time for multi-product scenarios and designs a capacity evaluation method to provide managers with scientific management strategies so that decision-makers can scientifically solve the problems that the company's design production line is quite different from the actual production situation.Originality/valueThere are few literary studies on combining interval grey number with assembly line balance optimization. Therefore, this paper makes an important contribution in this regard.

Adjustable Capability Evaluation of Integrated Energy Systems Considering Demand Response and Economic Constraints

The coupling between multiple energy sources such as electricity, gas, and heat is strengthened in an integrated energy system (IES), and this, in turn, improves the operational flexibility of the IES. As an upper-level energy supply system, an IES can play a role as virtual energy storage, which can provide regulating power to smooth out the volatility from large-scale renewable energy generation. The establishment of an aggregating virtual energy storage model for IESs has become an important issue. Under this background, a multi-objective optimization-based adjustable capacity evaluation method is proposed in this paper. Firstly, the mathematical model of an IES considering the coupling of multiple kinds of energy forms is proposed. Then, an aggregating model considering demand response and economic constraints is established to demonstrate the adjustable capacity of the IES. In addition, multi-objective optimization is used to identify parameters in the proposed model, and the normal boundary intersection (NBI) method is used to solve the problem. Finally, a simulation example is provided to verify the effectiveness and feasibility of the proposed method. The external energy demand boundary of the IES can be modeled as virtual energy storage, and the coupling relations of electricity and gas can be presented. Case studies demonstrate that economic constraints narrow the adjustable capacity of the IES while the demand response extends it.

Research on the Capacity of Shale Fracture Network based on Fractal Dimension

The quantitative evaluation method of fracture network capacity after shale fracturing is crucial for optimizing hydraulic fracturing of shale gas reservoirs and improving shale gas recovery. In order to quantitatively evaluate the shape of the shale fracture network after fracturing, the mud shale cores from the Longmaxi Formation were taken to carry out the constant-rate strain method fracturing pressure experiment. The fracture information of the two-dimensional lateral development surface after the core is compressed, and the surface fracture rate, concentrative value and fractal dimension of the fractures after compression are calculated. Through multiple linear regression, it is found that the fractal dimension is positively correlated with the surface fracture rate, which describes the number of fractures, and the concentrative value, which describes the spatial distribution of fractures, and the former has a greater impact on the size of the fractal dimension. Considering the above parameters comprehensively, a fracture network capacity evaluation model is established, which is in good agreement with the rock mechanical characteristics reflected by the strain-stress curve and the reconstructed three-dimensional fracture morphological characteristics. It has a certain guiding significance for shale brittleness research and fractability evaluation.

Evaluation Method for Hosting Capacity of Rooftop Photovoltaic Considering Photovoltaic Potential in Distribution System

Regarding the existing evaluation methods for photovoltaic (PV) hosting capacity in the distribution system that do not consider the spatial distribution of rooftop photovoltaic potential and are difficult to apply on the actual large-scale distribution systems, this paper proposes a PV hosting capacity evaluation method based on the improved PSPNet, grid multi-source data, and the CRITIC method. Firstly, an improved PSPNet is used to efficiently abstract the rooftop in satellite map images and then estimate the rooftop PV potential of each distribution substation supply area. Considering the safety, economy, and flexibility of distribution system operation, we establish a multi-level PV hosting capacity evaluation system. Finally, based on the rooftop PV potential estimation of each distribution substation supply area, we combine the multi-source data of the grid digitalization system to carry out security verification and indicator calculation and convert the indicator calculation results of each scenario into a comprehensive score through the CRITIC method. We estimate the rooftop photovoltaic potential and evaluate the PV hosting capacity of an actual 10 kV distribution system in Shantou, China. The results show that the improved PSPNet solves the hole problem of the original model and obtains a close-to-realistic rooftop photovoltaic potential estimation value. In addition, the proposed method considering the photovoltaic potential in this paper can more accurately evaluate the rooftop PV hosting capacity of the distribution system compared with the traditional method, which provides data support for the power grid corporation to formulate a reasonable PV development and hosting capacity enhancement program.

A multi-time scale schedulable capacity evaluation method for stations considering user wishes

As a flexible resource, electric vehicles (EVs) can realize various auxiliary services such as peak shaving, reactive power optimization, fault recovery, and emergency power supply. It is essential to quickly and accurately evaluate the EV schedulable capacity to realize auxiliary services. In this context, this paper first simulates EV charging demand using trip chain and Monte Carlo (MC) methods based on the 2017 National Household Travel Survey (NHTS2017) results to provide a multi-time scale estimation of EV charging station schedulable capacity to provide a data foundation. Then, considering incentive price, price sensitivity, and user credit, a demand response model is established to describe the uncertainty of user response and constraints such as differentiated demand on both sides of the grid user, battery charging and discharging state, battery loss, and response uncertainty are integrated to establish a multi-time scale evaluation model of the schedulable capacity of EV charging stations. Finally, the effectiveness of the proposed evaluation model is verified by simulation, and the effects of site area, incentive price, and dispatching time scale on the maximum schedulable capacity of EV charging stations are analyzed.

A review of electric vehicle hosting capacity quantification and improvement techniques for distribution networks

AbstractThe electrification of the transport sector to control the carbon footprint has been gaining momentum over the last decade with electric vehicles (EVs) seen as the replacement for conventional internal combustion engines. Economic incentives, subsidies, and tax exemptions are also paving the way for rising EV penetration in the power distribution networks. However, the exponential EV adoption requires careful technical and regulatory analysis of traditional networks to satisfy the network reliability constraints. Therefore, it would be vital to find EV hosting capacity (HC) limits of networks from a multifaceted approach involving various market players, mainly distribution system operators and EV owners. This review provides a systematic categorization of EV hosting capacity evaluation and improvement methods, thus enabling researchers and industry personnel to navigate the advancing landscape of EVs. This novel framework extends beyond the theoretical implication of diverse objective functions and HC improvement methods to the actual numerical values of EV HC across varying geographical settings. Therefore, this unique synthesis of varying aspects of EV HC facilitates the in‐depth understanding of the integration of sustainable energy and transport sector.