Custom Power Research Articles

Economic benefit evaluation model of distributed energy storage system considering custom power services

This paper proposes an economic benefit evaluation model of distributed energy storage system considering multi-type custom power services. Firstly, based on the four-quadrant operation characteristics of the energy storage converter, the control methods and revenue models of distributed energy storage system to provide reactive power compensation, new energy consumption, peak-valley arbitrage and other customized power services are analyzed. Secondly, an economic benefit evaluation model of custom power services is formulated, considering the life cycle degradation cost, investment payback period, net present value, and internal return rate of energy storage. Finally, demonstrate the effectiveness and superior performance of the proposed methodology through comparative studies on the economic benefits and practical value. The influence of reserve capacity ratio of energy storage converter, additional price for power quality management, peak-valley price difference, battery cost and project cycle on the annual return and internal rate of return is revealed through the sensitivity analysis, which provides the decision-making reference for battery selection and capacity allocation of distributed energy storage system participating in various custom power services.

OPTIMAL PLACEMENT AND RATING OF CUSTOM POWER DEVICES IN 15-BUS SYSTEM FOR POWER QUALITY IMPROMENT WITH STATIC SYNCHRONOUS COMPENSATORS (STATCOMs) AND ACTIVE LINE POWER CONDTIONER

This paper presents on power quality improvement in distributed radial network by using custom power device (CPD). In power system, the power quality issue become more complex at all level. Here, for this concern, we introduce a concept of custom power, basically it is a power electronics controller, to provide a quality of power to the supplier as much as for consumers. Custom power device (CPD) including active power line conditioner (APLC) and static synchronous compensators (STATCOMs), simulating on modified distributed IEEE-15 bus distorted bus system with the help of MATLAB Simulink software to explore performance and the efficiency of each device under various quality (power)disturbances includes voltage swell and sag, interruption in power and total harmonics distortion as well as the performances of allocated CPD in control the voltage quality and reactive power. Here, we used the particle swarm optimization to determine optimal location and sizes of CPD. Here, simulation results reveal all the effect of each device to compensate several types of power quality disturbance depends on the devices configurations and in this paper we much emphasized on STATCOMs and its arrangement.

Premium power investment strategy utilizing the economy of scale of custom power devices

The possible existence of ‘economy of scale’ in manufacturing poor power quality (PQ) mitigation devices motivates customers to participate in a common mitigation solution. A custom power park (CPP) is an option where the CPP operator offers a set of custom solutions to a group of customers. Given that these custom solutions comprise one or many custom power devices, both CPP operators and the customers are expected to coordinate to obtain individual mitigation device ratings while maximizing the overall utility of customers. Here, CPP operators would calculate ratings of custom solutions and associated unit cost for the minimal total cost, while the customers are expected to select custom solutions to maximize their overall benefit. Furthermore, the customers utilize their willingness-to-pay function in this process and strictly participate in this arrangement if the utility received is more than their self-generated non-negative utility. Without the CPP operator, customers would form a CPP-like arrangement to recover the cost of investment and operation and maintenance. This combinatorial problem has been solved in two stages, involving the calculation of independently generated utility in the first stage and the overall CPP designing problem in the second stage. While customer and operator-side nonlinearities in the cost functions have been suitably discretized, the proposed methodology ensures that the solution space remains intact. The proposed method is illustrated using three devices, three custom solutions, and three customers. • Existence of economy of scale is a motivating factor for common mitigation solution. • A system-wide PQ improvement might not lead to a socially justifiable outcome. • Customers participate if utility received is more than self-generated utility. • Proposed method converts the MINLP problem into MIP. • Proposed methodology could be used for complex problems with similar structure.

A Machine Learning Approach to Fault Prediction of Power Distribution Grids under Heatwaves

Climate change is increasing the occurrence of the so-called heatwaves with a trend that is expected to worsen in the next years due to global warming. The growing intensity and duration of these extreme weather events are leading to a significant number of power system failures, especially in urban areas. This is drastically affecting the reliability and normal operation of power distribution grids around the world, with high financial costs and huge negative impacts on people's life. Typically, the response to these failure events is approached by post-event analysis, aimed at identifying the grid areas that require resources to increase the resilience of the system and prevent future outages. Nevertheless, understanding the nature of heatwaves and forecasting their impact on power distribution systems can be useful to anticipate them and accelerate a reaction, possibly avoiding negative impacts on power systems and customers. In this study, a structured method to predict distribution grid disruptions caused by heatwaves is defined. The proposed method relies on machine learning to analyze previous failure data and forecast power grid outages using operational and meteorological information. The method is evaluated using real failure data from a large power distribution network located in southern Italy.

Recent advances in material chemistry for zinc enabled redox flow batteries

AbstractThe pursuit of green and sustainable energy is a long‐term goal for modern society and people's life. Particularly under the context of carbon neutralization, decarbonization has become a consensus and propels the turning of research enthusiasm to explore new materials and chemistries for energy conversion and storage at a low expenditure. Zinc (Zn) enabled redox flow batteries (RFBs) are competitive candidates to fulfill the requirements of large‐scale energy storage at the power generation side and customer end. Considering the explosive growth, this review summarizes recent advances in material chemistry for zinc‐based RFBs, covering the cathodic redox pairs of metal ions, chalcogens, halogens, and organic molecules. After a brief introduction of common issues for Zn2+/Zn conversion reaction at the anode side, the focus is devoted to expounding challenges of redox species and possible problem‐solving strategies at the cathode side. Besides, the auxiliary components of separator and current collector are also discussed for achieving optimal RFBs' performance. At last, the conclusion and outlook of future endeavor for Zn‐based RFBs implementation are put forward.

A novel premium power supply scheme against harmonic suppression for non-linear park

• A method for harmonic-suppression needs identification is proposed to guide non-linear customers to actively participate in harmonic mitigation. • The novel premium power supply scheme against harmonic suppression for non-linear park can effectively solve the harmonic problems with the situations that all the participants are satisfied. • A DEA-based method is proposed to reasonably realize allocation of the scheme costs. • The proposed scheme provides the possibility for the power grid and customers to jointly control harmonic problems. With the continuous development of power grids, the power electronization rates of power systems are increasing, and problems caused by harmonic pollution are becoming major concerns. Generally, harmonic problems result from the electric utility and non-linear customers, thus the mutual collaboration of both parties is crucial to addressing these problems. However, due to the indeterminate needs of non-linear customers for harmonic suppression and high investment pressure for harmonic suppression, customers are reluctant to participate in mitigation, which makes harmonic suppression appear prevarication. As a result, harmonic suppression cannot be carried out smoothly. To solve this problem, a novel premium power supply scheme against harmonic suppression for non-linear park is proposed. Firstly, this paper presents a method for harmonic-suppression needs identification based on super-efficiency interval model to attract customers to participate in harmonic suppression. Secondly, a premium power supply scheme is proposed, which consists of harmonic-suppression needs identification, suppression strategy design and scheme cost allocation. Furthermore, to reasonably allocate the scheme costs among each participant, this paper proposes a data envelopment analysis (DEA) based method considering the influence of both harmonic contribution and harmonic-suppression needs. Finally, case studies are used to verify the effectiveness and correctness of the proposed methods and the scheme.

Unified Power Quality Conditioners Based Different Structural Arrangements: A Comprehensive Review

Mitigating power quality issues in distribution systems is of utmost importance to both electricity consumers and suppliers as it improves the distribution system’s efficiency, reduces electricity costs, maintains continuous supply, and diminishes the requirement for frequent maintenance. Custom power devices were introduced to eliminate power quality issues like voltage sags, swells, transients, imbalances, and current harmonics arising in distribution systems. Unified power quality conditioner (UPQC) is one such frequently used custom power device that enhances the power quality of distribution systems. Various structural arrangements of UPQCs with improved performance capability were introduced within the last few decades. The main aim of this paper is to review the most frequently explored UPQC models in literature and to observe the impact of these UPQC structural configurations on their performance as well as that of the overall distribution system. Also, this study investigates the properties, applications, and control techniques used by these structural configurations of UPQCs to mitigate power quality issues.

Published Papers Volume 30 - Issue 4 (Award Issue) Awarded Paper Use of insulation resistance imbalance degree for the condition assessment of power distribution cables

Medium-voltage (MV) underground power distribution cables are critical assets of The Hong Kong Electric Co., Ltd. (HK Electric) for ensuring reliable customer power delivery. The inspection and condition assessment of these power distribution cables are conducted regularly to determine their health. During diagnostic tests, all MV cables have to pass a threshold of insulation resistance (IR) before they can be energised. Low IR readings may indicate a deterioration in insulation related to a high leakage current. However, defining a threshold value to assess the intrinsic condition of the power distribution cables for every test is challenging. This is because the reference value is determined by several factors such as cable length, the composition of the cable circuit, e.g., cable type, number and types of cable joints, service years and surface leakage from cable splices and terminations. In order to tackle this problem, a concept of imbalance degree in IR testing is developed to supplement the existing tests on dielectric losses for the purpose of enhancing the condition assessment of three-phase power MV distribution cables when performing IR measurement. The effectiveness of this method has been validated with historical testing records of 11kV distribution power cables at HK Electric. Based on our experience and study results, this improved method could further enhance the diagnosis and maintenance efficacy of HK Electric’s power distribution cables.

Performance Evaluation of Weighted Feedback Based UPQC under Various Power Quality Issues

Power efficiency is one of the big issues in the energy sector today. It becomes much more critical with the advent of sophisticated and complex systems, whose output is highly dependent on the efficiency of the power supply. Electronic systems are extremely vulnerable to disturbances, so industrial loads are less tolerant to power quality issues like voltage dips, voltage sags, voltage flickers, harmonics, and load unbalance, among others. For custom power applications, a variety of highly modular controllers that take advantage of newly available power electronics components are currently on the market. This paper introduces the concept of a unified power quality conditioner based on the VSC theorem, which is used to increase power quality. Capacitor banks, a series-active filter, and a shunt active filter make up the model. Negative-sequence current and harmonics are primarily compensated by series-active and shunt-active filters, while capacitor banks are used to compensate the reactive power of power frequency. This paper also includes using a weighted feedback algorithm to manage the PCC parameters as well as the UPQC performance. The proposed architecture has been put through its paces with a variety of distributed systems and fault scenarios. The entire framework was designed and analyzed with the help of MATLAB simulink and code.

A Consensus-Based Transactive Energy Design for Unbalanced Distribution Networks

This study develops a consensus-based transactive energy design managed by an Independent Distribution System Operator (IDSO) for an unbalanced distribution network. The network is populated by welfare-maximizing customers with price-sensitive and fixed loads who make multiple successive power decisions during each Operating Period (OP). The IDSO and customers engage in a negotiation process in advance of each OP to determine retail prices for OP that align customer power decisions with network constraints in a manner that preserves customer privacy. Convergence and optimality properties of this proposed design are established for an analytically formulated illustration: an unbalanced radial distribution network, populated by households, that is electrically connected to a relatively large RTO/ISO-managed transmission network. Numerical test cases are reported for a 123-bus unbalanced radial distribution network that demonstrate these properties.

Influence of photovoltaic microgeneration on the demand profile and its effects on the grid power quality

• Demand profile effects can cause a false impression of low power quality. • High PV inverter loading percentage conditions can improve the grid power quality. • PV inverter active current has a linear relationship with inverter loading. • PV inverter non-active current does not vary considerably with inverter loading. The connection of small-scale photovoltaic (PV) generation into the grid requires attention to the changes in load curve profile, the harmonic components in the current waveform, and the customer power factor (PF) variation measured by the grid operator. This paper evaluates aspects that can influence the power quality (PQ) at the point of common coupling (PCC) due to PV generation's insertion in the distribution grid, given the consumer demand profile. That evaluation considers different inverter loading percentage situations and the effects of the consumer's electric current considering its active and non-active components. This study used four grid-connected PV systems and a programmable electronic load to perform tests at different load demand situations. A data acquisition system collects the voltage waveforms at the PCC, and the grid's current waveforms, load, and PV inverter. Thus, it is possible to evaluate the effects of load profile (current intensity and waveform) on PQ at the PCC. At this point, there are different values of active and non-active currents, total harmonic distortion (THD), and PF when measured from the PV system, the grid, or the load sides. Depending on where the measure is, the PV system can cause a false impression of reducing the grid PQ.

Energy efficiency evaluation method for power customers based on demand-side response

Energy efficiency evaluation method for power customers based on demand-side response

Energy efficiency evaluation method for power customers based on demand-side response

Energy efficiency evaluation method for power customers based on demand-side response

Power Converter Circuit Design Automation Using Parallel Monte Carlo Tree Search

The tidal waves of modern electronic/electrical devices have led to increasing demands for ubiquitous application-specific power converters. A conventional manual design procedure of such power converters is computation- and labor-intensive, which involves selecting and connecting component devices, tuning component-wise parameters and control schemes, and iteratively evaluating and optimizing the design. To automate and speed up this design process, we propose an automatic framework that designs custom power converters from design specifications using Monte Carlo Tree Search. Specifically, the framework embraces the upper-confidence-bound-tree (UCT), a variant of Monte Carlo Tree Search, to automate topology space exploration with circuit design specification-encoded reward signals. Moreover, our UCT-based approach can exploit small offline data via the specially designed default policy and can run in parallel to accelerate topology space exploration. Further, it utilizes a hybrid circuit evaluation strategy to substantially reduce design evaluation costs. Empirically, we demonstrated that our framework could generate energy-efficient circuit topologies for various target voltage conversion ratios. Compared to existing automatic topology optimization strategies, the proposed method is much more computationally efficient—the sequential version can generate topologies with the same quality while being up to 67% faster. The parallelization schemes can further achieve high speedups compared to the sequential version.

Research on design of customer portrait system for E-commerce

Abstract Customer portrait is the customer information that is labelled and digitised. Collecting and studying consumer data is highly helpful to enterprises because it empowers them to use these data to locate target groups and meet various customer needs. With the continuous rise of the e-commerce market, major e-commerce websites list providing customer value and being data-driven as company values. Traditional customer portraits rely excessively on objective and past experience; so, a simple but powerful customer portrait system is required to make the customer analysis platform simple and intelligent, and to make the data accumulated at ordinary times bring practical value to e-commerce companies. Based mainly on addressing this requirement, this paper proposes an effective customer portrait system for e-commerce. First, the research background and significance is expounded, which lays a theoretical foundation for this research. Then, the customer portrait system is designed, including the overall design scheme and functional framework of the system. The improved FCM algorithm is used as the basis for building the customer portrait model, and the performance of this algorithm is analysed and compared with that of the improved algorithm used in this paper.

STRATEGIES AND TECHNOLOGIES TO SUSTAIN NATIONWIDE IMPLEMENTATION OF ALIVIADO DEMENTIA CARE

Abstract It is well documented that knowledge improvement alone is not sufficient to sustain systems level changes. Through supporting dementia care workforce training and the embedding of Aliviado program tools (treatment algorithms, assessments, care plans, and caregiver education materials) into hospices’ clinical workflow across the U.S., we learned that both technologies and human support strategies are essential for lasting changes. In this presentation, we first discuss our experience leveraging a powerful customer relationship management software (Salesforce) to assign, manage, and encourage completion of the interprofessional Aliviado Dementia Care training for thousands of active users across the nation. We then share how we provide additional human support and implementation tools in the face of COVID-19, which can inform implementation of similar trials, including office hours, training reports, Plan-Do-Study-Act worksheets, symptom management cheat sheets, champion calls, and electronic health records integration meetings with each agency to locally tailor and embed Aliviado tools.

Why Have Package Tour Itineraries Been Homogeneous? Insights From Industry Subgroup Relations

In addressing one of the least-researched areas in tourism—the formation of product strategies—this study focuses on the homogeneous package tour phenomenon. It draws on Industrial Organization theory to explore the impact of relationships between industry subgroups on the development of such products. With a specific focus on Chinese package tours to the UK, tour itineraries were firstly mapped to provide a visualization of relative homogeneity. Then, by examining the resource traits of participating firms, two subgroups in the industry were distinguished: tour operators (including wholesalers and retailers) and travel agencies (including Online Travel Agencies). It was found that the determination of product homogeneity involves a combination of the dependent relationship between tour operators; a more independent relationship between travel agencies; and the nature of the interdependence between the two. Strong bargaining power on the part of suppliers and weaker customer power further strengthened product homogeneity.

Feasible operation region of an electricity distribution network

In the course of net zero carbon transition, electricity distribution networks are faced with great challenges brought by increasing total and peak demand due to the electrification of transport and heat, as well as the significant uncertainties from renewable power generation and customer behaviors (such as electric vehicle travelling behaviors). Therefore, distribution network operators (DNOs) need effective tools to assess the capability of distribution networks in integrating generation and demand to conduct active management and efficient expansion of networks. However, conventional scenario-based assessment methods only provide conservative and limited information on the network capability, also with exponentially increased computational burden. By contrast, another stream of methods with different philosophy, named as operation region-based methods, describe the overall picture of the network capability analytically with little computational power needed. However, the existing linearized analytical regions, which are mainly applied to electricity transmission networks, cannot describe the capability of distribution networks accurately enough. To solve these problems, a novel feasible operation region (FOR) method with quadratic analytical expressions was proposed to characterize the range of the operating states of distribution networks, where the thermal and voltage constraints will not be violated. The FOR is a geometry in a high-dimensional space, and thus a high-dimensional error analysis approach was further developed for validating the proposed method. The boundary errors are described by multiple distance functions and operational indices, and the conservativeness of the analytical boundaries are quantified. An 11 kV radial distribution network from the United Kingdom Generic Distribution System (UKGDS) was used for the case study. The simulation results show that the quadratic analytical boundaries well approximated the real boundaries of FOR. The maximum errors for thermal and voltage boundaries would maximally cause an overcurrent up to 116 % and an undervoltage down to 0.96p.u., which are able to satisfy the requirements of engineering practice. Compared to the existing linear approximation (termed as hyperplane expressions) of FOR boundaries, the proposed quadratic expressions were proved to have higher accuracy.

Comparative Performance of DVR and STATCOM for Voltage Regulation in Radial Microgrid with High Penetration of RES

In recent years, the penetration of renewable energy sources (RES) in microgrids and distribution system feeders has increased manifold. Moreover, the advancement of power electronics-based devices in the distribution system has significantly increased the number of sensitive loads. Variations in the voltage under intermittent RES create functional problems with sensitive loads, necessitating voltage regulators (VR) installation. In this paper, two custom power devices: dynamic voltage restorer (DVR) and static synchronous compensator (STATCOM), used for voltage regulation in a microgrid, are investigated under different operating conditions. The efficacy of DVR and STATCOM for voltage regulation in an 11-node radial microgrid with high penetration of RES is simulated under a MATLAB Simulink environment. Furthermore, the simulated microgrid voltage profile results are analyzed to evaluate the efficacy of both voltage regulators.

The Effectiveness of the Implementation of the Indonesian Standard Quick Response Payment System (QRIS) on MSMEs in Banten


 
 
 
 Purpose - This study aims to provide an overview of the effectiveness of implementing the Indonesian Standard Quick Response Payment System as an alternative digital payment method that can be used by small and medium businesses
 
 
 
 
 Design/methodology/approach - qualitative descriptive method is used as a research method that is applied in this study. the data in the study were taken from small and medium business owners in the province of Banten. data collection through structured interview techniques and literature study
 
 
 
 
 Finding - the implementation of the Quick Response Payment System has had a positive impact in supporting the business development of small and medium enterprises. the presence of this digital payment method encourages the acceleration of the payment transaction process, easier recording of business results and up-to-date business processes so as to attract more customer spending power with the various conveniences presented.
 
 
 
 
 Originality -