Hybrid Energy Sources Research Articles

A switching capacitor based multi‐port bidirectional DC–DC converter

This paper introduces a novel bidirectional multi-port DC–DC converter recommended for electric vehicle applications. The proposed structure has three ports with bidirectional features which can be operated in both step-up and step-down modes. This converter can supply the load from two independent voltage sources and can obtain a high voltage conversion ratio in both step-up and step-down operations. The low voltage stress throughout the power switches, high efficiency, and low components count are the characteristics of the proposed topology. For demonstrating the proposed structure's performance, the principle of operation modes, steady-state analysis, and comparison results with other similar works are provided. Finally, an experimental prototype is built with a 120 W power level at 50 kHz operating, which validates the suggested converter's effectiveness and bidirectional trait. The suggested converter's efficiency in boost and buck mode is obtained about 94.2% and 94.37%, respectively that makes this converter to be used in renewable energy systems and electric vehicles with hybrid energy sources.

Optimal Economic Modelling of Hybrid Combined Cooling, Heating, and Energy Storage System Based on Gravitational Search Algorithm-Random Forest Regression

The hybridization of two or more energy sources into a single power station is one of the widely discussed solutions to address the demand and supply havoc generated by renewable production (wind-solar/photovoltaic (PV), heating power, and cooling power) and its energy storage issues. Hybrid energy sources work based on the complementary existence of renewable sources. The combined cooling, heating, and power (CCHP) is one of the significant systems and shows a profit from its low environmental impact, high energy efficiency, low economic investment, and sustainability in the industry. This paper presents an economic model of a microgrid (MG) system containing the CCHP system and energy storage considering the energy coupling and conversion characteristics, the effective characteristics of each microsource, and energy storage unit is proposed. The random forest regression (RFR) model was optimized by the gravitational search algorithm (GSA). The test results show that the GSA-RFR model improves prediction accuracy and reduces the generalization error. The detail of the MG network and the energy storage architecture connected to the other renewable energy sources is discussed. The mathematical formulation of energy coupling and energy flow of the MG network including wind turbines, photovoltaic (PV), CCHP system, fuel cell, and energy storage devices (batteries, cold storage, hot water tanks, and so on) are presented. The testing system has been analysed under load peak cutting and valley filling of energy utilization index, energy utilization rate, the heat pump, the natural gas consumption of the microgas turbine, and the energy storage unit. The energy efficiency costs were observed as 88.2% and 86.9% with heat pump and energy storage operation comparing with GSA-RFR-based operation costs as 93.2% and 93% in summer and winter season, respectively. The simulation results extended the rationality and economy of the proposed model.

Modeling, Control System Design and Preliminary Experimental Verification of a Hybrid Power Unit Suitable for Multirotor UAVs

A key drawback of multirotor unmanned aerial vehicles (UAVs) with energy sources based solely on electrochemical batteries is related to the available on-board energy. Flight autonomy is typically limited to 15–30 min, with a flight duration upper limit of 90 min currently being achieved by high-performance battery-powered multirotor UAVs. Therefore, propulsion systems that utilize two or more different energy sources (hybrid power systems) may be considered as an alternative in order to increase the flight duration while retaining key performance benefits of battery energy storage use. The research presented in this work considers a multirotor UAV power unit, based on the internal combustion engine (ICE) powering an electricity generator (EG) connected to the common direct current (DC) bus in parallel with the lithium-polymer (LiPo) battery, and the respective modeling and identification of individual power unit subsystem, along with the dedicated control system design. Experimental verification of the proposed hybrid power unit control system has been carried out on the custom-build power unit prototype. The results show that the proposed control system combines the two power sources in a straightforward and effective way, with subsequent analysis showing that a two-fold energy density increase can be achieved with a hybrid energy source, consequently making it possible to achieve higher flight autonomy of the prospective multirotor (hover load around 1000–1400 W) equipped with such a hybrid system.

Design and Control of Micro-Grid fed by Renewable Energy Generating Sources

This paper presents a control of a micro-grid at an isolated location fed from wind and solar based hybrid energy sources. The machine used for wind energy conversion is doubly fed induction generator (DFIG) and a battery bank is connected to a common DC bus of them. A solar photovoltaic (PV) array is used to convert solar power, which is evacuated at the common DC bus of DFIG using a DC-DC boost converter in a cost effective way. The voltage and frequency are controlled through an indirect vector control of the line side converter, which is incorporated with droop characteristics. It alters the frequency set point based on the energy level of the battery, which slows down over charging or discharging of the battery. The system is also able to work when wind power source is unavailable. Both wind and solar energy blocks, have maximum power point tracking (MPPT) in their control algorithm. The system is designed for complete automatic operation taking consideration of all the practical conditions. The system is also provided with a provision of external power support for the battery charging without any additional requirement. A simulation model of system is developed in Matlab environment and simulation results are presented for various conditions e.g. unviability of wind or solar energies, unbalanced and nonlinear loads, low state of charge of the battery. Finally a prototype of the system is implemented using a 5 kW solar PV array simulator and a 3.7 kW wound rotor induction machine and experimental results are produced to reaffirm the theoretical model and design.

The Efficient Implementation of Hybrid Power Plants in Indonesia

The energy crisis is a serious issue that all countries around the world are dealing with, particularly the energy sources used to generate electricity. There are numerous alternative energy sources available in nature, such as solar energy, wind energy, and so on. Wind and solar energy as hybrid energy sources are thought to be promising in electric generation technology. Hybrid Power Plants can also be used to address the issue of limited electrical energy supply in Indonesia's remote areas. The purpose of this study is to describe the effectiveness of the hybrid power plants implementation in Indonesia. The study was conducted using the narrative literature review method. It can be inferred that the purpose of developing this hybrid technology, among others, is to obtain more efficient electrical energy generation by combining the advantages of two or more types of power generation systems that work in an integrated manner as a compact system. The produced electric energy can be stored in the battery. In terms of use, the produced direct current (DC) is converted into alternating current (AC) using the inverter system prior to distribution to consumers. Therefore, this hybrid power plant is suitable to be implemented in Indonesia.

Social Impact on Hybrid and Retrofitted Three-Wheelers

To boost electric vehicles on Indian roads government brought up a policy that can eliminate personal vehicles in the upcoming decades. With an increase in shared mobility such as metros, monorails, and BRT systems, last-mile connectivity has already acquired the importance of never before. Bicycles and electric three-wheelers can fit this sector. Electrically operated three-wheelers will also gain importance in last-mile goods delivery. Similarly, the Internal Combustion Engine (ICE) based three-wheelers will pass through a phase of retrofitting and use of hybrid energy sources to fulfill economic and technological needs. It is very important to study retrofitting and hybrid three-wheelers in detail to understand how they can fill the gap of transition from ICE based system to a fully electrically operated model. These vehicles will have a social impact on consumers as they are cost-effective vehicles. Innovative, swapping of battery and fuel tank is proposed to address some of the needs in this transition. This paper presents techno-commercial aspects of retrofitted three-wheelers and how to bring an economically viable hybrid version of three-wheelers.

MPC-informed ECMS based real-time power management strategy for hybrid electric ship

Shipboard power systems (SPS) are complex systems connecting multiple power sources, energy storage systems (ESSs) and various types of loads. However, the fluctuated propulsion loads may lead to a low power quality of the system. In this paper, a power management system (PMS) is designed for SPS in the framework of an optimization-based method. With equivalent consumption minimization strategy (ECMS), the proposed method is able to provide an optimal power-split between hybrid energy sources in real time, while minimizing the fuel consumption of the system. Furthermore, the equivalence factor is adjusted by model predictive control (MPC) of PMS. The performances of the proposed approach are evaluated by simulations.

Dynamic Voltage Restorer Integrated with Photovoltaic-Thermoelectric Generator for Voltage Disturbances Compensation and Energy Saving in Three-Phase System

The dynamic voltage restorer (DVR) combined with a photovoltaic–thermoelectric generator (PV-TEG) system is proposed for voltage disturbance compensation in the three-phase four-wire distribution system. The PV-TEG hybrid energy source is used in the DVR system to improve the system ability for deep and long-period power quality disturbance compensation. In addition, the DVR will save grid energy consumption when the hybrid PV-TEG module generates sufficient power to meet the load demand. An enhanced variable factor adaptive fuzzy logic controller (VFAFLC)-based maximum power point tracking (MPPT) control scheme is proposed to extract the maximum possible power from the PV module. Since the PV and TEG combine a hybrid energy source for generating power, the DVR can work efficiently for the voltage sag/swell, outage compensation, and energy conservation mode with minimum energy storage facilities. The in-phase compensation method and the three-leg voltage source inverter (VSI) circuit are chosen in the present system for better voltage and/or power compensation. To confirm the effectiveness of the proposed hybrid PV-TEG integrated DVR system, a simulation-based investigation is carried out with four different operational modes with MATLAB software. The study results confirm that the proposed DVR system can compensate power quality disturbances of the three-phase load with less total harmonics distortion (THD) and will also work efficiently under energy conservation mode to save grid energy consumption. Moreover, the proposed VFAFLC-based control technique performs better to achieve the maximum power point (MPP) quickly and accurately, thereby improving the efficiency of the hybrid energy module.

A bidirectional multiport DC‐DC converter applied for energy storage system with hybrid energy sources

SummaryThis paper presents a novel bidirectional multiport DC‐DC converter for the electrical vehicles with hybrid energy sources. The benefits of the suggested converter are high voltage conversion ratio and high efficiency, simple structure, low voltage stress across the semiconductor elements, low number of components, and common ground features. It has two bidirectional ports, which are suitable for energy storage systems (ESS) such as a battery. Due to the step‐up and step‐down operations of the proposed converter, it can charge and discharge the ESS. Additionally, only two power switches with low ON‐state resistance are utilized that make the control circuit to be simple. Furthermore, the suggested converter has low number of component, which leads to decrease its volume and cost. The operation principle in buck and boost mode is analyzed thoroughly. Finally, to verify the analysis and effectiveness of the proposed structure, a laboratory prototype is built with 12‐ and 20‐V input voltages and a power rating of 120 W used in 50‐kHz operating frequency.

Hybrid Energy Source Fed Fuzzy-Based SVPWM for 5-Level NPC Inverter with Grid Connected System

This paper presents the fuzzy-based Space Vector Pulse Width Modulation (SVPWM) for 5-level Neutral Point Clamped inverter with hybrid energy source fed grid connected system. The proposed scheme is energized using Photovoltaic and Wind energy system combination. The Neural Network-(NN) based Maximum Power Point Tracking algorithm (MPPT) has been implemented to track maximum power under different operating conditions. First, we proposed fuzzy-based SVPWM, which is developed for 5-level NPC inverter to provide voltage and current control, reduced THD, predetermined switching pattern, capacitor voltage unbalance minimization and maintain good control under nonlinearities and suspicions of PV-Wind energy connected hybrid system. Second, we proposed the inverter output voltage, which has been synchronized with grid connected system using split inductor (SI). The reference voltages for SVPWM implementation were obtained using feedback current control method. Third, we proposed different solar radiations, the proposed system has attained better performance by trailing maximum power from hybrid energy system. The simulation and experimental responses have been validated using Matlab/simulink and FPGA processor.

Research on Zero Voltage Switching Non-inductive Current Circulation Control of Bidirectional DC/DC Converter for Hybrid Energy Source System of Electric Vehicle

The hybrid energy source system (HESS) with batteries and super-capacitor can effectively prolong the cycle life of batteries in electric vehicles (EVs). In order to further highlight the advantages of HESS in improving EVs efficiency, The DC/DC converter in HESS should have the advantages of high efficiency and fast response speed. Therefore, a soft-switching non-isolated buck-boost bidirectional DC/DC converter is applied to the HESS system of EVs in this paper. The converter has the advantages of being a simple circuit, a reduced number of components and can realize ZVS of all switches without an auxiliary circuit. In addition, a non-inductive current circulation control method is adopted in order to further improve the efficiency of the converter. The controller of the converter is designed based on small signal modeling, and an experimental prototype has been developed. The experimental results show that, compared to the inductive current circulation method, the non-inductive current circulation control method can effectively reduce the loss of the inductor, and the maximum efficiency of the converter is 92.8% in step-down mode and 93.2% in step-up mode.

Optimal Design and Operation of Fast Charging Station for Electric Vehicle Via Renewable Energy in Wadi El-Natrun-El Alamein Road, Egypt

The cost of Electric Vehicle Charging Station (EVCS) infrastructure is one of the problems which stand as a barrier in the way of widespread Electric Vehicles (EV). In this paper, the optimal design and operation of a renewable-powered EVCS will be introduced with minimizing cost and air pollution. By considering the station located in isolated area and will be supplied by hybrid Energy Sources. Configuration, sizing, economic optimization, operation and its effect on the environment are discussed. The proposed hybrid micro-grid consists of, photovoltaic panels, storage batteries, wind turbines, biogas generator and also a diesel generator. The case study of this work is to satisfy the 1056 KWh/day demand of EVCS for using at the selected site. Five different configurations of energy sources are studied to get the optimum case. HOMER software is used to implement the simulation model; the model is based on economic and environmental factors. Finally, the study introduces a cost-effective, socially and sustainable accepted design that can be useful in specifying the appropriateness of optimal design for other EVCSs.

Design and Analysis of Sustainable Green Data Center with Hybrid Energy Sources

Development of renewable energy (RE) and mitigation of carbon dioxide, as the two largest climate action initiatives are the most challenging factors for new generation green data center (GDC). Reduction of conventional electricity consumption as well as cost of electricity (COE) with preferred quality of service (QoS) has been recognized as the interesting research topic in Information and Communication Technology (ICT) sector. Moreover, it becomes challenging to design a large-scale sustainable GDC with standalone RE supply. This paper gives spotlight on hybrid energy supply solution for the GDC to reduce grid electricity usage and minimum net system cost. The proposed framework includes RE source such as solar photovoltaic, wind turbine and non-renewable energy sources as Disel Generator (DG) and Battery. A hybrid optimization model is designed using HOMER software for cost assessment and energy evaluation to validate the effectiveness of the suggested scheme focusing on eco-friendly implication.

Hybrid Wind/PV/Battery Energy Management-Based Intelligent Non-Integer Control for Smart DC-Microgrid of Smart University

Global environmental changes, nuclear power risks, losses in the electricity grid, and rising energy costs are increasing the desire to rely on more renewable energy for electricity generation. Recently, most people prefer to live and work in smart places like smart cities and smart universities which integrating smart grid systems. The large part of these smart grid systems is based on hybrid energy sources which make the energy management a challenging task. Thus, the design of an intelligent energy management controller is required. The present paper proposes an intelligent energy management controller based on combined fuzzy logic and fractional-order proportional-integral-derivative (FO-PID) controller methods for a smart DC-microgrid. The hybrid energy sources integrated into the DC-microgrid are constituted by a battery bank, wind energy, and photovoltaic (PV) energy source. The source-side converters (SSCs) are controller by the new intelligent fractional order PID strategy to extract the maximum power from the renewable energy sources (wind and PV) and improve the power quality supplied to the DC-microgrid. To make the microgrid as cost-effective, the (wind and PV) energy sources are prioritized. The proposed controller ensures smooth output power and service continuity. Simulation results of the proposed control schema under Matlab/Simulink are presented and compared with the super twisting fractional-order controller.

A Modified Hybrid Particle Swarm Optimization With Bat Algorithm Parameter Inspired Acceleration Coefficients for Solving Eco-Friendly and Economic Dispatch Problems

The paper presents a modified hybrid particle swarm optimization with bat algorithm parameter inspired acceleration coefficients (MHPSO-BAAC) without and with the constriction factor to find the optimal solution of the economic dispatch problems (EDPs) incorporating conventional as well as hybrid and renewable energy sources (RESs) based plants. The algorithm is designed by modifying the recently presented hybrid PSO and BA (HPSOBA) algorithm applied for the achievement of the optimal solution of the EDPs. The modified algorithm is implemented to solve EDPs of all RESs-based power systems for three scenarios, without constraints, with time-varying demand, and with the consideration of regional load sharing dispatch (RLSD). The performance of the algorithm is also verified through the implementation of various combinations of hybrid as well as thermal power plants (TPPs). The case of TPPs consists of three different scenarios: 1) a small-scale system with constraints like ramp-rate limits (RRLs), prohibited operating zones (POZs), and power losses; 2) a medium-scale power system with consideration of emission-economic dispatch (EED); 3) a large-scale power system with valve-point loading (VPL) effect. The results of the designed MHPSO-BAAC algorithm are compared with the various metaheuristic algorithms available in the literature and the comparative analysis shows the superior performance of the developed algorithm in terms of fuel cost reduction, fast convergence, and computational time.

Power quality enhancement of a hybrid energy source powered packed e-cell inverter using an intelligent optimization technique

The most installed Renewable Energy Sources (RES) in micro-grids (MG) are Photovoltaic (PV) power and wind power. Due to the intermittent behaviour of renewable sources, parallel operation of RES and battery storage known as hybrid system is important particularly in remote micro-grids to reduce the fuel consumption by diesel generators and continuity of supply to the load. In this paper, multilevel inverter called Packed E-Cell (PEC) is used for parallel operation of RES and battery storage optimally for micro-grid applications. The PEC requires less components compared to other Multi-level inverters (MLI) topology with relatively low total harmonic distortion (THD). Further, selective harmonic technique based on optimization principle is used to enhance the harmonic profile using low frequency switching technique. The 3rd and 5th harmonics are eliminated using Genetic Algorithm (GA) optimization technique. The simulation-based analysis is done using Simulink/MATLAB and the results obtained for THD in the output current and voltage are presented and discussed in the paper. A comparative analysis is also presented with high frequency modulation technique phase disposition pulse width modulation (PDPWM) technique. The experimental validation of the proposed scheme is done using Typhoon HIL (hardware in loop).

Quality-Aware Video Streaming for Green Cellular Networks With Hybrid Energy Sources

Mobile video traffic has experienced explosive growth in recent years due to the rapid development of mobile intelligent terminals and cellular communication technologies. The rapid growth of mobile video traffic has brought significant energy expenditure for mobile network operators. To reduce the energy expenditure, one promising solution is to exploit renewable energy harvested from surrounding environments for cellular traffic delivery. In this article, we investigate mobile video streaming in green cellular networks with hybrid energy sources, i.e., grid energy and ambient energy, to optimize both video quality and energy expenditure. Specifically, we formulate a stochastic optimization problem to maximize the long-term time-averaged network service utility, which is the difference of video quality and energy expenditure. The problem formulation takes the following factors into account: time-varying grid electricity price, energy harvesting process, and different time scales of rate adaptation (RA), resource management, and electricity price fluctuation. We exploit Lyapunov optimization framework to decompose the problem into three subproblems: 1) RA subproblem; 2) battery energy management subproblem; and 3) joint power control and subchannel assignment subproblem. We propose an efficient online green video streaming algorithm to solve these subproblems. We analyze the stability of the proposed algorithm with respect to lengths of energy queue and user request queues. Extensive simulations are conducted and the results validate the efficiency of the proposed algorithm.

Battery-Aware Green Cellular Networks Fed By Smart Grid and Renewable Energy

The increase of energy demand in cellular networks imposes big economic and ecological challenges. Answering to these challenges requires complex energy frameworks that consider Smart Grid, renewable energy, battery systems and employs efficient management of radio as well as energy resources. In this context, lithium batteries present very good performance indicators (e.g., high energy density, large service life and environmental friendliness) but can also have very poor use duration when the energy management system is not suitable. This is linked to the important consequences of radio resource allocation on energy consumption and operational cost. In this article, we study and propose energy and radio allocation mechanisms for cellular networks supplied with hybrid energy sources (grid and renewable). We propose a Battery Aging and Price-Aware (BAPA) algorithm that brings down the grid energy consumption of the operator while including battery degradation constraints. We decompose the problem into three subproblems: radio resource allocation problem, grid energy purchase problem and power allocation problem. We show that our algorithm performs very close to the optimal solution and outperforms a benchmark algorithm, allowing more efficient battery use, energy savings and network operation cost reduction with no impact on the QoS of users. Finally, we provide some insights into how the advancement in base station technology will help reducing the investment cost in future cellular networks.

Power quality improvement based on hybrid coordinated design of renewable energy sources for DC link channel DSTATCOM

This paper presents a comprehensive analysis of power quality for static synchronous compensator on the distribution power system (DSTATCOM) when a different types of energy sources are used to supply the dc link channel of DSTATCOM. These types of power supplies have a different effect on the compensation of DSTATCOM due to operation nature of these sources. The dynamic response of the DSTATCOM has been investigated that produced by individual and hybrid energy sources to evaluate the influence of these sources in terms of time response, compensation process and reduce the harmonics of current for source. Three cases have been considered in this study. First the photovoltaic (PV) cells alone second the battery storage alone and third a hybrid coordinated design between (PV cells with battery storage) is used. A boost Dc-Dc circuit has been connected to a photovoltaic cell with Maximum Power Point Tracking (MPPT) while a Dc-Dc buck-boost circuit is used with a battery. High coordination between PV and battery circuits in the hybrid system is used in order to improve the performance. A synchronous reference frame (SRF) with unit vector has been used to control the STATCOM circuit. The simulation results show that the hybrid design has the superiority response compared to the individual sources.

Mathematical Analysis and Simulation of Permanent Magnet Synchronous Motor for Electric Vehicle Application

Permanent magnet synchronous motors in electric vehicles are gaining more and more attention because of its high performance and high torque to inertia and high power density. PMSM Motor should operate in four quadrant operation at different driving characteristics the torque speed characteristics of the motor is observed. Battery and super capacitor is used for energy sources to the permanent magnet synchronous motor the design of electric vehicle is onboard charging system. Battery and supercapacitor are hybrid energy sources. PMSM motor is controlled by using field oriented control technique. Voltage source inverter is used to control the speed of the PMSMS motor at different frequencies. The control technique used for VSI is space vector control technique. Using MATLAB/Simulink.