Individual Power Sources Research Articles

ANFIS-based power management and islanding detection utilizing permeation rate(γ) and relaxation parameter(ζ) for optimal operation of multiple grid-connected microgrids

Microgrid(s) integration into distribution networks and the growing use of Distributed Generation Systems necessitate the switch from traditional fossil fuel-based power generation methods to renewable resource-based ones. To achieve optimal power delivery, an adaptive method for solving power quality delivery problems posed by this transition is required. Unexpected islanding is an important power security concern that can lead to equipment damage, electrical risks, and decrease in power quality delivery. To address this problem, ANFIS-Based power management and islanding detection utilizing permeation rate(γ) and relaxation parameter(ζ) is proposed in this paper based on a rate of change of output voltage(ROCOV) of power sources at the point of common coupling in a 34-bus distribution network. Modeling of the distribution network, distributed generators, ANFIS training, and simulations was done using MATLAB/Simulink software. Results show that a 0.3 and 1.01 value indicates permeation rate of Microgrid(s) in a grid-tied mode whereas a 0 value indicates relaxation parameter of Microgrid(s) disconnected from the main distribution network. Islanding detection time of 0.02 sec was recorded when all Microgrids were disconnected during disturbances, and a 0.04 sec islanding detection time for disconnecting individual power sources at a time was recorded respectively. In general, islanding causes a system nominal voltage(400 V) deviation of 7 %. However, this was quickly restored without causing network voltage fluctuations due to the adaptive nature of ANFIS. Comprehensive simulations were used to validate the suggested method. The outcomes demonstrated that the proposed approach effectively distinguishes between islanding and non-islanding events and can quickly and accurately identify islanding as compared to other related works.

Electrical Load Forecasting Models for Different Generation Modalities: A Review

The intelligent management of power in electrical utilities depends on the high significance of load forecasting models. Since the industries are digitalized, power generation is supported by a variety of resources. Therefore, the forecasting accuracy of different models varies. The power utilities with different generation modalities (DGM) experience complexities and a noticeable amount of error in predicting future electrical consumption. To effectively manage the power flow with negligible power interruptions, a utility must utilize the forecasting tools to predict the future electricity demand with minimum error. Since the current literature supports individual and limited power sources involved in generation for load forecasting, thus the utilities with multiple power sources or DGM remain unexplored. Therefore, exploration of existing literature is required relating to analyzing the existing models which could be considered in load forecasting for DGM. This paper explores state-of-art methods recently utilized for electrical load forecasting highlighting the common practices, recent advances, and exposure of areas available for improvement. The review investigates the methods, parameters, and respective sectors considered for load forecasting. It performs in-depth analysis and discusses the strengths, weaknesses, and error percentages of models. It also highlights the peculiarities of methods used in residential, commercial, industrial, grid, and off-grid sectors aiming to help the researchers to appraise the common practices. Moreover, trends and research gaps are also discussed.

Exploring Wind and Solar PV Generation Complementarity to Meet Electricity Demand

Understanding the spatiotemporal complementarity of wind and solar power generation and their combined capability to meet the demand of electricity is a crucial step towards increasing their share in power systems without neglecting neither the security of supply nor the overall cost efficiency of the power system operation. This work proposes a methodology to exploit the complementarity of the wind and solar primary resources and electricity demand in planning the expansion of electric power systems. Scenarios that exploit the strategic combined deployment of wind and solar power against scenarios based only on the development of an individual renewable power source are compared and analysed. For each scenario of the power system development, the characterization of the additional power capacity, typical daily profile, extreme values, and energy deficit are assessed. The method is applied to a Portuguese case study and results show that coupled scenarios based on the strategic combined development of wind and solar generation provide a more sustainable way to increase the share of variable renewables into the power system (up to 68% for an annual energy exceedance of 10% for the renewable generation) when compared to scenarios based on an individual renewable power source. Combined development also enables to reduce the overall variability and extreme values of a power system net load.

Analysis of High-Power Charging Limitations of a Battery in a Hybrid Railway System

Fuel cell (FC)-driven railroad propulsion systems (RPSs) have been much appreciated for the past two decades to get rid exhausts of fossil fuels, but the inability of FCs to capture regenerative power produced by propulsion systems during regenerative braking and the dependency of its power density on operating current density necessitates the hybridization of FCs with batteries and/or supercapacitors to utilize the best features of all three power sources. Contrary to the research trend in hybridization where the purpose of hybridization such as fuel saving, high efficiency, or high mileage is achieved by certain operational algorithms without going into detail models, this study using detailed models explores the impact of high-power charging limitations of batteries on the optimization of hybridization, and proposes a solution accordingly. In this study, all three power sources were modeled, the optimal and suboptimal behaviors at the individual level were identified, and power distribution was implemented for a propulsion system, as recommended by the optimal features of all individual power sources. Since the detailed modeling of these power sources involves many mathematical equations and requires the implementation of continuous and discrete states, this study also demonstrates how, using C-MEX S-Functions, these models can be implemented with a reduced computational burden.

Status of tidal energy system in India

ABSTRACT India is the fourth biggest electricity consumer on the planet after the United States, China and Russia. India’s energy strategy concentrates on securing energy sources to address the issue of its developing economy. Service of New and Renewable energy has started an activity to track the advancing Tidal power administrative structure and build up an archive of data in a combined way. The reason for this paper is to show a refreshed diagram and status of tidal energy framework in India, notwithstanding assess the development space of individual sustainable power sources in the post-Statute time by considering the innovation advancement, local conditions and indigenous enterprises identified by the tidal energy framework. This paper includes a potential location for tidal energy generation in India as well as current scenario, grid parity and government support towards tidal energy in India.

Market Opportunity Analysis in Thailand: Case of Individual Power Sources by Thermoelectric-Generator Technology for Portable Electronics

Thermoelectrics, an energy-conversion technology, has been developed for its potential to support portable electronics with an innovative power source. Primarily focusing on the metropolitan market in Thailand, the study, thus, aimed at the market insight into portable electronics users’ characteristics and opinions of thermoelectric-generator (TEG) technology commercialization. The business research was conducted to analyze their behaviors for power-supply lacking problems, encountering heat or cold sources, purchasing decision for a TEG-based charger and key decision factors. For practical applications, an innovative TEG-based charger should be more flexible by harnessing various heat or cold sources from ambient situations to generate electrical power.

Optimising design and power management in energy-efficient marine vessel power systems: a literature review

ABSTRACTThe conventional marine vessel power systems typically have the potential to improve their fuel consumption and their emissions. This can be done by redesigning the system configuration, the machinery and the power management strategy. The addition of options in power management allows for the running of individual power sources closer to their optimal operating point. However, this immediately raises questions about how to redesign the system and how to operate it to maximise the benefits. The information needed to answer these questions is often scattered around separate sectors of the marine industry. The system integrator needs to be able to combine the complex dependencies of these individual sectors to formulate the big picture that describes the whole power system. Numerical optimisation algorithms provide solutions to develop methodologies to solve multi-variable and potentially multi-objective problems. This literature review presents the authors' findings of design and power management optimisation cases in marine vessel power systems.

Transient Stability Guarantees for Ad Hoc DC Microgrids

Ad hoc electrical networks are formed by connecting power sources and loads without planning the interconnection structure (topology) in advance. They are designed to be installed and operated by individual communities---without central oversight---and as a result are well-suited to addressing the lack of electricity access in rural and developing areas. However, ad hoc networks are not widely used, and a major technical challenge impeding their development (and deployment) is the difficulty of certifying network stability without a priori knowledge of the topology. We develop conditions on individual power sources and loads such that a microgrid comprised of many units will be stable. We use Brayton-Moser potential theory to develop design constraints on individual microgrid components that certify transient stability---guaranteeing that the system will return to a suitable equilibrium after load switching events. Our central result is that stability can be ensured by installing a parallel capacitor at each constant power load, and we derive an expression for the required capacitance.

Comparison Study on Power Output Characteristics of Power Management Methods for a Hybrid-electric UAV with Solar Cell/Fuel Cell/Battery

A dual-mode power management for a hybrid-electric UAV with a cruise power of 200W is proposed and empirically verified. The subject vehicle is a low-speed long-endurance UAV powered by a solar cell, a fuel cell, and a battery pack, which operate in the same voltage bounds. These power sources of different operational characteristics can be managed in two different methods: passive management and active management. This study proposes a new power management system named PMS2, which employs a bypass circuit to control the individual power sources. The PMS2 normally operates in active mode, and the bypass circuit converts the system into passive mode when necessary. The output characteristics of the hybrid system with the PMS2 are investigated under simulated failures in the power sources and the conversion of the power management methods. The investigation also provides quantitative comparisons of efficiencies of the system under the two distinct power management modes. In the case of the solar cell, the efficiency difference between the active and the passive management is shown to be 0.34% when the SOC of the battery is between 25~65%. However, if the SOC is out of this given range, i.e. when the SOC is at 90%, using active management displays an improved efficiency of 6.9%. In the case of the fuel cell, the efficiency of 55% is shown for both active and passive managements, indicating negligible differences.

SIZING AND ECONOMIC ANALYSIS OF HYBRID PV-PEMFC SYSTEMS FOR REMOTE AREAS RESIDENTIAL UTILIZATION

One of the obstacles of using the fuel cells in remote areas is the absence of hydrogen infrastructure to supply the required fuel to the unit. However, this can be solved by producing hydrogen on site from water electrolysis. In this paper, the sizing of a standalone hybrid PV/PEMFC system to supply electric power for remote residential areas is discussed. The PV system is used to supply the required electric power to a water electrolyzer. The cost of energy (COE) of the hybrid PV/PEMFC system is compared with previous works by the authors for the same residential system when supplied by two individual power sources as two alternatives. The first one is a stand-alone photo voltaic system (SAPV), while the other one is a standalone PEMFC system. The analysis results will help to define the most economic alternative to supply electricity for remote areas.

An Investigation into Hybrid Catamaran Fishing Vessel: Combination of Diesel Engine, Sails and Solar Panels

Abstract- Development of hybrid technology for vehicle transportation has been extensively carried out worldwide. At present, the technology has been used in automobile industry in a way to reduce the use of fossil fuels and the effect of toxic gases into the atmosphere. In more details, the hybrid technology applies two sources of energy, namely conventional engine together with the consumption of fossil fuels and solar cell panels in conjunction with the use of battery to store the energy gain. The application of hybrid technology for sea transportation has shown a promising development in the last 5 years. The combination use of sail and engine, which is popularly known as sail assisted engine, has been used to power mono hull fishing vessels by Indonesian fishermen. The attractiveness and successful application of catamaran form for passenger vessels has inspired naval architect to use it as fishing vessels due to its advantages such as having better transverse stability and providing wider deck-space area. The current work describes the development of hybrid technology for a catamaran fishing vessel using the combination of conventional diesel engine, the use of sail and solar-cell panels. In details, it explains the utilization of individual power-source and combination of them to power the catamaran. Discussions include the effectiveness of the combination such as its effect to ship stability and general arrangement of the fishing vessel. Finally, it is discovered that the combination of diesel engine and solar-sails have reached the optimum benefit of the hybrid concept.

Loss of Distributed Generation in Case of Fault in Distributing Net

This paper deals with the 22 kV distribution grid with higher penetration of distributed generation and the possibility of loss of this generation in case of fault. In the first part the reasons of distributed generation growth are shortly explained. For simulation of faults of different parts of distribution grid the model of such distribution grid with substantial amount of distributed generation was created. The second part contents the simulations of two-phase faults in two different power lines of model in order to evaluate and analyze the impact of these faults on distributed generation. The second part focuses on the impacts of short circuit occurred in different feeders of distribution grid on individual power sources and on the feeder with higher penetration of distributed generation.

Intellectual system for power supply and control of magnetic component groups of particle accelerators from several MW-power sources

It is necessary for the power-consuming magnetic components of channels for beam transport in accelerators of charged particles be supplied with direct current. An individual power source is typically applied for each group of identical components. A variant of the simultaneous supply of several groups of magnets from a single medium-power source using auxiliary current shunts of different types is given by the example of a LEPTA positron storage ring. One version of using this technology with MW-power sources for a phasotron accelerator is developed. The efficiency of putting this technology into practice with the application of start-stop regimes for the phasotron is estimated.

A reference governor-based hierarchical control for failure mode power management of hybrid power systems for all-electric ships

This paper deals with the design of failure mode power management (PM) of hybrid power systems (HPS) during a shipboard power source failure, which is an important scenario that the all-electric ships (AES) targeting military applications have to deal with. The control objective is to manage the power flow from working power sources and battery to ensure survivability, namely, ensuring system safety and maximizing the load support. The on-demand nature of the problem due to unpredictable failure times makes real-time control a key requirement. The survivability mandates, along with large scale, nonlinear HPS dynamics and long warmup times of the backup power sources, make most of the existing control strategies ineffective to meet the real-time requirements. With the focus on achieving real-time computational efficiency, a novel hierarchical control approach using reference governor is proposed. A top level controller determines a sub-optimal power split between the battery and working source to meet the demand on the HPS and the local controllers govern the power demands for the individual power sources to enforce constraints. A case study of the proposed controller on a scaled HPS test-bed illustrates the real-time computational efficiency and improved HPS survivability.

Energy Management Fuzzy Logic Supervisory for Electric Vehicle Power Supplies System

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper introduces an energy management strategy based on fuzzy logic supervisory for road electric vehicle, combining a fuel cell power source and two energy storage devices, i.e., batteries and ultracapacitors. The control strategy is designed to achieve the high-efficiency operation region of the individual power source and to regulate current and voltage at peak and average power demand, without compromising the performance and efficiency of the overall system. A multiple-input power electronic converter makes the interface among generator, energy storage devices, and the voltage dc-link bus. Classical regulators implement the control loops of each input of the converter. The supervisory system coordinates the power flows among the power sources and the load. The paper is mainly focused on the fuzzy logic supervisory for energy management of a specific power electronic converter control algorithm. Nevertheless, the proposed system can be easily adapted to other converters arrangements or to distributed generation applications. Simulation and experimental results on a 3-kW prototype prove that the fuzzy logic is a suitable energy management control strategy. </para>

Hotspot-Limited Microprocessors: Direct Temperature and Power Distribution Measurements

An experimental technique is presented, which allows for spatially-resolved imaging of microprocessor power (SIMP). In a first step this method utilizes infrared (IR) thermal imaging, while the processor is effectively cooled using an IR-transparent heat sink. In the second step the underlying power distribution is derived by determining the temperature fields for each individual power source on the chip. The measured chip temperature distribution is represented as a superposition of these temperature fields. The SIMP data reveals significant temporal and spatial variations of the microprocessor power/temperature distribution, which can be attributed to the circuit layout as well as to the varying utilization levels across the processor while running full workloads. In this paper we have applied the SIMP method to the dual core PowerPCtrade970MP microprocessor to measure detailed temperature and power distributions under full operating conditions. In the first part of the paper the impact of power and temperature limitations of high performance CMOS chips is discussed in detail, where we distinguish between hotspot-limited (or temperature-limited) and power-limited chips. The discussion shows the importance of temperature and power distributions for chip floor planning, layout, design and architecture. Second, we present the experimental details of the SIMP method, which is applied to the dual core PowerPC970MP to directly measure the temperature and power fields as a function of workload and frequency. A pronounced movement of the hotspot location is observed. Finally, the hotspot of a competitive microprocessor is compared by measuring temperature efficiencies (temperature increase/performance) for the same workloads and cooling conditions

Detailed research for energy consumption of residences in Northern Kyushu, Japan

Energy consumption in residential sector has been increasing year by year since 1965. To improve this situation, it is necessary to reconsider the traditional energy supply systems. Distributed power source systems, such as photovoltaic (PV) system and micro co-generation system, are considered as solutions to current residential energy problems. In order to utilize these systems effectively, understanding detailed energy consumption of residences is required. The purpose of this research is to clarify detailed energy consumption; seasonal and annual energy consumption classified by uses, the effect of energy-saving apparatus and heating demand of residences located in the north of Kyushu, Japan. Major results are as follows: (1) energy consumption for hot water supply is larger than ones for lighting, air-conditioning and cooking among most houses, in the north part of Kyushu, (2) PV system is quite effective to save energy of residential buildings, and (3) Heat demand and electric power demand of residences are clarified by detailed measurement for installing individual dispersed power source system, some houses show high thermoelectricity ratio enough to move micro co-generation system effectively, even at present.

Contributions of individual generators to complex power losses and flows–Part 2: algorithm and simulations

The complex power flow tracing in primary equivalent circuit of a power network is much more important under electricity market deregulation. It is pointed out that the decomposition tracing methods for active and reactive powers (or real and imaginary currents) are not accurate. To trace complex power flows accurately a general principle is proposed to determine the sequence of the element&apos;s equivalent branches in calculation. Then the fundamental theory proposed in Part 1 is applied to the element&apos;s equivalent circuits to derive theoretically the nonlinear relationship between element complex loss components and the complex power components flowing into the element from individual generators. The accurate nonlinear relationship between the complex power components flowing into and out of an element from a power source is therefore obtained. A recursive algorithm is given to find accurately the contributions of individual complex power sources to element complex losses and flows and load powers. Since there is no approximation the algorithm is accurate. Starting from power flow solutions, practical power systems and the IEEE 30-bus system are simulated, and finally analysed.

Contributions of individual generators to complex power losses and flows–Part 1: fundamental theory

The contributions of individual complex power sources to branch complex losses and flows cannot be found using existing circuit theory. However, the contributions are the basis for supplement charge allocation in a competitive environment. To determine the contributions accurately and unequivocally, active and reactive currents flowing into a branch from a generator are defined. Based on the definitions and concepts of total differential and definite integral, a new method is derived theoretically to determine contributions of individual complex power generations to branch active and reactive losses, and contributions of individual active or reactive generations to branch complex losses. The nonlinear relationship between the complex power components flowing into and out of a branch from a power source is established. The interaction between active and reactive power flows is considered accurately throughout the study. The theory for determining branch complex loss and flow components incurred by individual generators is founded. It lays theoretical foundations for complex power tracing in lossy power networks.

Management of Conflict Using Individual Power Sources: A Retailers' Perspective

This study examines the processes of managing conflict in channels of distribution by utilizing opportunistic, reward, coercive, referent, expert, and legitimate individual power sources. By judiciously utilizing these individual power sources to manage conflict, channel members can produce high quality solutions to their problems. For example, the use of opportunistic and coercive power sources will increase conflict and decrease satisfaction. The use of reward, referent, legitimate, and expert power sources, however, will decrease conflict and increase satisfaction. Data were obtained from a survey of 551 independent retailers about their relationships with their primary wholesalers. Among the findings, retailers believed that the only effective strategy for managing conflict was the use of the wholesalers' expert power source. However, the use of power was found to intensify the level of conflict. The use of coercive and opportunistic power sources increased the underlying basis of conflict and produced destructive outcomes. Moreover, the wholesalers' use of power was weakened when they utilized their expert power source.