Ultracapacitor Research Articles

Modeling and Management of Hybrid System Photovoltaic-FC-Ultracapacitors Power Systems

This study shows an improved DC microgrid power management technique. The value of utilizing renewable energy has long been debatable, and this article suggests a typical DC microgrid because of the advantages it has over AC technology. A solar cell (PV), fuel cell (FC) and storage component - an ultracapacitor (UC)-make up the standard microgrid. The most important goal of the paper is to optimize the management strategy for the bus voltage with arranged power-sharing between these types of renewable energy that are used here. For variable solar irradiance and various loading conditions, the proposed management seeks to deliver high-quality energy to the load while taking into consideration the FC state. The ultracapacitor was prepared to furnish the transient period due to the FC's slow dynamics. To maintain the DC bus voltage steady in the face of load variations, a management algorithm is put into practice. To generate the references, the management controller relies on a differential flatness method. The electricity from the ultracapacitor controls the DC bus. Earlier studies showed that the circuit of the fuel cell was integrated with a standalone photovoltaic system and discovered that the fuel cell doesn't have the same properties. In the current research, observations were made on power quality elements like voltage, current, and power for energy storage systems. With several self-definition elements of the photovoltaic, fuel cell, and ultracapacitor, along with their parameters, simulation is used as the study method medium. The outcome demonstrates that since the ultracapacitor serves as the primary storage, the fuel cell integration has little impact on it, and only small changes in voltage and current were observed. Due to the fuel cell integration characteristic of providing the system a major perturbation, most perturbation from the system had been absorbed while in an ultracapacitor

PV Fed SEPIC Converter for Grid Tied System with Ultra Capacitor

PV Fed SEPIC Converter for Grid Tied System with Ultra Capacitor

Research on the application of on-board energy storage on an electric locomotive for quarry railway transport

Methods of using on-board energy storage system on rolling stock are considered. Their use ensures a reduction in energy consumption and reduces the impact on the environment. Concepts of managing energy flows in the traction system of an electric rolling stock equipped with onboard energy storage systems are considered. It is proposed to apply the concept of control on an electric locomotive for quarry railway transport, which consists in reducing the current consumption from the traction network during the acceleration of the rolling stock and compensating the power during movement with the lowest voltage on the current receiver. For the selected control concept, a simulation of the train movement on the test section was carried out while varying the value of the limit current consumed by the electric locomotive from the traction network. The power of the energy storage device and its working energy capacity is determined. Based on the results of the study, it is justified to limit the current consumed by the electric locomotive of the traction network at the level of 600 A.

Adaptive energy management strategy based on a model predictive control with real-time tuning weight for hybrid energy storage system

The effective utilization of ultra-capacitor (UC) in the energy allocation process is crucial for improving the efficiency of the energy management strategy (EMS) for hybrid energy storage system (HESS). In this paper, we present an adaptive energy management strategy framework based on a model predictive control (MPC) with real-time tuning weight to optimize UC utilization and extend battery lifetime. Firstly, the adaptive autoregressive integrated moving average model (AARIMA) is developed to accurately predict vehicle velocity and road gradient for online power demand computation, based on local historical information. The differencing order and lags of the model in AARIMA are updated using the augmented Dickey-Fuller (ADF) test and Bayesian Information Criterion (BIC). Secondly, the MPC is developed to optimize power allocation using quadratic programming. Finally, the weight in the cost function is real-time tuned via the fuzzy logic rule according to the predicted power. Furthermore, the proposed strategy is validated using a scale-down hardware-in-the-loop verification platform. Simulation results demonstrate that the UC utilization ratio has a 9.91% improvement, and the battery lifetime has a prolonged by 24.38% across two tested actual and two typical driving cycles. Consequently, the proposed EMS achieves optimization of both energy management efficiency and battery lifetime.

Impact of energy storage devices on microgrid frequency performance: A robust DQN based grade-2 fuzzy cascaded controller

This article intended an advanced deep-Q network (A-DQN) based algorithm for the optimal design of a robust grade-2 fuzzy cascaded controller (G2-FCC) concerning frequency control of an autonomous AC microgrid under several electrical disturbances. The proposed AC microgrid is equipped with a hydraulic electrolyzer fuel cell (HE-FC) that empowers electrically to a variety of local consumers. Apart from the HE-FC, the proposed microgrid model is associated with few fractional megawatts (MW) rated power generating sources such as diesel generators (DEG), micro-turbines (MT), solar power stations (SPS), wind power stations (WPS) and geothermal to maximize the total power of a system. However, to increase system performance and energy quality some energy-storing devices such as ultra-capacitors (UC), flywheel (fw), and battery energy management systems (BEMS) are integrated into the system. Most renewable energy sources such as solar and wind power plants are associated with high uncertainties and exhibit low inertia which severely affects the grid frequency. The proposed fuzzy G2-FCC controller dominates the frequency disturbance gracefully and shows its superiority over a few standard approaches like fuzzy Proportional Integral Derivative (PID) and PID controllers. The energy-storing components also have shown their potential in regard to frequency profile improvement of the microgrid system. Finally, the suggested A-DQN algorithm is proved as the most effective tool to optimal design the parameters of the G2-FCC controller. Finally, it is verified that the suggested G2-FCC controller is found to be the most effective tool to improve the settling time of ΔF by 154.54 and 249.64 % over well-existing grade-1 fuzzy PID and PID approaches, respectively.

Investigation of Low Order Parameters Affecting Tidal Stream Energy Resource Assessments

Tidal stream energy may have the potential to contribute to the baseline energy needs of the UK. There is a significant difference between the existing assessments of the UK’s resource, highlighting the need for a standardised model. The paper investigates some challenges of quantifying tidal stream energy. This study examines the sensitivity of resource assessments to low-order parameters, in order to inform higher order modelling and contribute to defining a standardised model. A combination of channel characteristics, turbine parameters and simulation settings formed the basis of 96+ cases to determine key parameters affecting resource assessments. Two 0-dimensional, idealised channels were modelled using 2-8 constituents from four UK sites spanning the semi-diurnal form factor range. Blockage-corrected blade element momentum theory was used to represent variable-speed, variable-pitch turbines. Three blockage designed rotors and one rotor designed for an unspecified blockage were simulated. Power capping and combined power and thrust capping were implemented.
 
 The study indicates dynamic balance is a key parameter affecting tidal dynamics when turbines are present in a channel. Variability of annual energy production due to the nodal cycle was most significant in the drag dominated channel with increasing blockage. Constituents with large amplitude and phase differences led to greater variability of the resource across the nodal cycle. Results indicate that the maximum deviation from the average annual energy production over the 18.6-year nodal cycle is +/- 8.8%. At a low form factor site, the difference between using 2 or 4 constituents was insignificant. However, for a higher form factor site, that is still semi-diurnal, the peak velocity increases by 0.32 m/s with 8 constituents compared to 2. Random Forest modelling indicates that the most important characteristic point on a variable-speed, variable-pitch turbine performance curve is the rated speed. Comparison of capping strategies highlights that combined power and thrust capping leads to an increase in energy per swept area. Combined capping decreased the variability of the resource over the nodal cycle, which is helpful to maintain a steady supply to the grid and sizing energy storage systems.

Application of inertia emulation control strategy with energy storage system in multi-area hydro -thermal system using a novel metaheuristic optimized tilt controller

This article presents the application of a novel artificial hummingbirds’ algorithm (AHA) based tilt-integral second order of double-derivative controller (TIDD2) in a three-area hydro-thermal power system. Also, the inertia emulation control strategy has been incorporated using various energy storage systems (ESS) to established the frequency in interconnected power system. The supremacy of the proposed controller is established by comparing the system dynamic response with some existing controllers, such as proportional-integral-derivative (PID), tilt-integral-derivative (TID) and cascade of IDD - PID controllers. The fruitfulness of proposed AHA has also been evaluated with system dynamic and convergence characteristics comparison over some of existing metaheuristic optimization techniques such as harris hawk's optimization (HHO) and bird swarm algorithm (BSA). Further, effect of random load pattern (RLP), communication time delay (CTD) and variable CTD on the system dynamic is analyzed. The study of inertia emulation control strategy in a multi-area interconnected power system revealed that, when inertia is emulated with superconducting magnetic energy storage (SMES), the system dynamic exhibits better performance over battery energy storage (BES) and ultra-capacitor (UC). Furthermore, the proposed systems are validated in a real-time environment using OPAL-RT lab software. Also, the scalability of the proposed method is evaluated by using eigenvalue analysis.

A multithreaded CUDA and OpenMP based power‐aware programming framework for multi‐node GPU systems

SummaryIn the article, we have proposed a framework that allows programming a parallel application for a multi‐node system, with one or more graphical processing units (GPUs) per node, using an OpenMP+extended CUDA API. OpenMP is used for launching threads responsible for management of particular GPUs and extended CUDA calls allow to transfer data and launch kernels on local and remote GPUs. The framework hides inter‐node MPI communication from the programmer. For optimization, the implementation takes advantage of the MPI_THREAD_MULTIPLE mode allowing: multiple threads handling distinct GPUs as well as overlapping communication and computations transparently using multiple CUDA streams. The solution allows data parallelization across available GPUs in order to minimize execution time and supports a power‐aware mode in which GPUs are automatically selected for computations using a greedy approach in order not to exceed an imposed power limit. We have implemented and benchmarked three parallel applications including: finding the largest divisors; verification of the Collatz conjecture; finding patterns in vectors. These were tested on three various systems: a GPU cluster with 16 nodes, each with NVIDIA GTX 1060 GPU; a powerful 2‐node system—one node with 8 NVIDIA Quadro RTX 6000 GPUs, the second with 4 NVIDIA Quadro RTX 5000 GPUs; a heterogeneous environment with one node with 2 NVIDIA RTX 2080 and 2 nodes with NVIDIA GTX 1060 GPUs. We demonstrated effectiveness of the framework through execution times versus power caps within ranges of 100–1400 W, 250–3000 W, and 125–600 W for these systems respectively as well as gains from using two versus one CUDA streams per GPU. Finally, we have shown that for the testbed applications the solution allows to obtain high speed‐ups between 89.3% and 97.4% of the theoretically assessed ideal ones, for 16 nodes and 2 CUDA streams, demonstrating very good parallel efficiency.

A Super-twisting SMC Design for Bidirectional DC–DC Converters in Electric Vehicle Applications

Many industrial and electrical systems, such as electric vehicles, employ DC/DC converters. Since DC/DC converters are nonlinear and time-varying systems, it is inappropriate to regulate them using linear control techniques. In this paper, a super-twisting sliding mode control (STSMC) is applied for bidirectional DC-DC converter in electric vehicle applications. The traction chain of the electric vehicle consists of a battery-supercapacitor energy storage system (ESS) linked in parallel to the DC bus through two bidirectional DC–DC converters and a synchronous reluctance motor drive (SynRM). The benefit of sharing power in an HPS, which is primarily made up of a supercapacitor and battery, is the ability to use the strengths of both sources, with the former having high specific energy and the latter having high specific power. The on-board energy storage system's performance is enhanced by this hybridization in terms of cost, mass, and charging time. In addition to the proposed control, the hybrid power system (HPS) needs a strategy for routing energy between the two sources and the motor. This strategy is based on frequency decoupling (DFS), which protects the battery from peak current during the acceleration and deceleration phases. The objective of using the control law based on super-twisting sliding mode control (STSMC) is to follow the reference trajectories in finite time with high precision, very good robustness, and a reduction in chattering. Using the MATLAB/Simulink software, a thorough simulation of an electric vehicle was performed in order to confirm the effectiveness of the suggested control approach and assess the effectiveness of the source's energy management strategy. This control method ensures a reduction in the bus voltage stress (Δv=5V) and improves the quality of the power. The overshoot voltage for a load power of 21 kw is reduced to 15V (3.2%) compared to the linear control techniques, improving the system's robustness and reliability..

Phenology, morphological, and anatomical characteristics of a stinkhorn mushroom in Ghana

The genus Phallus is a member of the group commonly known as stinkhorn fungi belonging to the family: Phallaceae and Order: Phallales. They are distributed in tropical areas of Africa, Asia, Australia, and the Americas but are rarely reported in Ghana. During the recent minor rainy season (September-December 2022) an undocumented member of the Phallales was found in a rock garden located in the Greater Accra Region, Ghana. The subterranean basidioma developed from an egg-like structure, single or gregarious with a thick gelatinous peridium. The primordium was oval/spherical, or ellipsoidal in shape; initially hypogeous becoming epigeous in the habit by maturity; is 4.0-5.0 cm in diameter, creamy to grayish cream with age. Within 48-72 h, the egg broke to expose the pink-colored stalk, sponge, or reticulate with rounded greyish-dark green cap carrying smooth-walled slimy ellipsoidal basidiospores (2 - 5μm) with a fetid rotten smell. Within 2 - 4 h of the emergence of cap, it was depleted of the ellipsoidal spores by foraging bluish-green bottle flies. The transverse section of the columnar stipe (5.0 - 8.0 cm long) showed a hollow orifice serving as the passage of basidiospores in the glebal mass. Occasionally, there was a division of the stipe at the cap to show two distinct stipes and caps from the same volva of the basidioma. The pileus was campanulate (bell-shaped), 2-3cm high dark green in color with vertical granular markings, and rounded to hemispheric in shape. Dark-green basidiospores besmear the cap with slimy glebal mass. These descriptions agree with no known penis-shaped morphology of the Phallus species with a prominent basal volva 2.0 - 3.5 cm high.

Barrier function based adaptive sliding mode controller for the hybrid energy storage system of plugin hybrid electric vehicles

This paper proposes a hybrid energy storage system (HESS) and smart charging mechanism for plug-in hybrid electric vehicles (PHEVs) with the aim of reducing greenhouse gas emissions and fossil fuel consumption. The HESS includes a battery as the main energy source and an ultra-capacitor (UC) as an auxiliary source. Both the power sources are connected to the DC bus through power conditioning circuitry. To regulate the system’s output variable, a barrier function-based adaptive sliding mode controller is proposed, which will achieve finite-time convergence and robustness against disturbances and uncertainties without requiring prior knowledge of the upper bounds of the system. The controller aims to reduce chattering and ensure various control objectives, such as tight regulation of output voltage, perfect tracking of reference currents for the UC and battery, and power factor correction in the grid-to-vehicle (G2V) mode. Simulation results using MATLAB/Simulink show that the proposed controller outperformed sliding mode control (SMC) and finite-time synergetic control (FTSC). The proposed strategy has been validated through real-time hardware-in-the-loop (HIL) experiments using C2000 Delfino Microcontroller F28379D Launchpad.

Use of ultracapacitor for provision of inertial response in virtual synchronous generator: Design and experimental validation

The growing penetration of converter-interfaced renewable energy sources (CI-RES) has revealed several challenges related to the stability of the electrical grids. To mitigate these issues, there is an ongoing research regarding the concept of virtual synchronous generators, where new control schemes are employed to enable CI-RES with integrated fast-acting energy storage system (ESS) to provide ancillary services to the grid, e.g., inertial response (IR). Although several solutions have been proposed in the literature, the proper integration and energy management of the ESS towards IR provision remains an open research topic. In this paper, an holistic control approach is presented regarding IR provision by a system comprising of a CI-RES and an ultracapacitor (UC). The proposed approach is supplemented by an efficient energy management system allowing the UC to release/absorb energy during IR provision while always ensuring the operation of the UC voltage within its technical limits. The robustness and the performance of the proposed method are experimentally evaluated in a lab setup, where all the components of the proposed system, i.e., CI-RES and UC have been analytically implemented.

Towards Improved Power Management in Cloud GPUs

As modern server GPUs are increasingly power intensive, better power management mechanisms can significantly reduce the power consumption, capital costs, and carbon emissions in large cloud datacenters. This paper uses diverse datacenter workloads to study the power management capabilities of modern GPUs. We find that current GPU management mechanisms have limited compatibility and monitoring support under cloud virtualization. They have sub-optimal, imprecise, and non-intuitive implementations of Dynamic Voltage and Frequency Scaling (DVFS) and power capping. Consequently, efficient GPU power management is not widely deployed in clouds today. To address these limitations, we make actionable recommendations for GPU vendors and researchers.

Influence of ultra‐capacitor on AGC of five-area hybrid power system with multi-type generations utilizing sine cosine adopted dingo optimization algorithm

In this article, the load frequency control (LFC) problem of a five-area automatic generation control (AGC) power system with multi-type generations is addressed by utilising a technique that considers the changing of the dingo optimisation algorithm known as sine cosine adopted dingo optimisation algorithm (SCaDOA) based tilt integral derivative (TID) regulator. AGC needs an energy storage system (ESS) and some intelligent adaptable control techniques to guarantee the balance in the system's stability. Consequently, this paper utilizes the TID regulator alongside ultra‐capacitor (UC) ESS to settle the AGC issue. At first, the execution of the sine cosine adopted calculation is tried by contrasting it and the standard DOA calculation by considering different standard benchmark functions. Further, the proposed plan strategy is likewise applied to a five-area system comprising different conventional and non-conventional/renewable energy sources along with UC. The execution of the controller has been finished for different stacking conditions of the power system. It is seen that the said UC with TID controller is more viable contrasted with the other standard controllers.

Comparative analysis of various energy storage systems in a conventional LFC system considering RDSTS, PWTS and AHVDC models

This article examines the performance of various energy storage systems (ESS) in a traditional load frequency control (LFC) interconnected system. ESS like capacitive systems (CS), battery systems (BS), ultra-capacitors (UC), redox flow batteries (RFB) and their combinations are explored. The explored system comprises of conventional three-area thermal with realistic dish-striling solar thermal system (RDSTS) in area-1, precise wind turbine system (PWTS) in area-2 and RDTS-PWTS in area-3. The performance of cascaded PI with PIDN as a secondary controller is employed for the first time. The controller values are simultaneously optimized by hybrid crow search algorithm (HCSA). The effect of introducing RES like RDSTS and PWTS have been studied, and the results shows that RES leads to superior dynamics over thermal. A novel performance index namely HPA-ISE is anticipated and shows improves responses over ISE. Also, investigations are carried on optimal AHVDC and ESS locations. Moreover, the responses with AC-AHVDC and ESS highlights the predominance of ESS over AC-AHVDC and thermal systems. Further, studies comparing other ESS reveal that RFB performs them. Furthermore, when RFB is combined with UC and CS, it is discovered that RFB-UC produces better results.

Optimal driving strategies for emergency operation of high‐speed trains using on‐board energy storage systems

AbstractA power outage occurs when there is an interruption to traction power system. In such emergency situations, trains are expected to achieve autonomy operation powered by on‐board energy storage systems (OESS). This paper presents optimization models and methods to find optimal driving strategies for train emergency operation. Specifically, a nonlinear and non‐convex program is first formulated in space‐domain to minimize trip time under the limits of power and energy capacity of OESS. To improve computational efficiency, the time dynamics is removed from constraints and adjoined to the cost function. Furthermore, convex modelling steps are proposed to reformulate the problem as a convex program that can be solved efficiently. A bi‐level algorithm is designed to obtain optimal driving strategies that can arrive at destinations as soon as possible. Compared to energy‐optimal driving strategies, the proposed methods can effectively reduce the trip time.

Identification of high-power density source requirement for electric vehicle during on-road conditions

This paper describes various setups for testing electric vehicle (EV) on-road operating conditions. The significance of a high-power density energy source during EV acceleration and deceleration is highlighted in this work. The drive motor (DM) draws a large current during acceleration, the magnitude of which is determined by the acceleration time and vehicle parameters. Also, the source must capture all of the regenerative power from the DM during deceleration. The battery life will be reduced if it is used as an energy source for acceleration. Furthermore, due to its low power–density, the battery cannot quickly store regenerative power. To meet the aforementioned requirements, a high power–density source, such as an ultracapacitor (UC), is required. The simulation results as well as hardware results are shown for EV emulation systems.

Test bench setup for emulating electric vehicle on-road conditions

This work provides an electric vehicle (EV) test bench with a motor/dynamometer setup with a battery and ultracapacitor (UC) hybrid energy storage. Extending the driving range and enhancing the battery life are the main concerns with EVs nowadays. The drive motor (DM) used is a three-phase induction motor (IM), which is controlled by the current sensorless indirect vector control method. This fault-tolerant method can be used in the case of current sensor failure. All the resistive forces acting on an EV are emulated based on the concept of vehicle equivalent rotational inertia for different real-life driving cycles, namely ECE R15 and NYCC. The battery alone is not capable of handling the surge current requirement during the acceleration period and is not able to capture the total power during regenerative breaking as it has a low power density. Hence, a high power density source like UC is a must to handle these conditions during frequent stop and go city traffic conditions as per ECE R15 and NYCC driving cycles. This EV emulation technique helps in getting the DC-link power profile for an EV for any driving scenario. Hence, it is possible to test the different powertrain components of an EV using this proposed technique.

Mitigation of AGC Problem of the RES Integrated Hydro-Thermal System Using FACTS and INEC Based AHVDC with ESS Considering the 3DOF-TIDN Controller

This article highlights the mitigation of automatic generation control (AGC) problem considering various FACTS devices and inertia emulation control (INEC) strategies based accurate model of HVDC links using various energy storage systems (ESS). The proposed system comprises a three-area hydro-thermal system integrated with renewable energy sources (RES) such as a realistic dish-Stirling solar thermal system (RDSTS) and a precise wind turbine system (PWTS). A maiden effort has been made to design a novel secondary controller called three degrees of freedom tilt-integral-derivative with filter coefficient (3DOF-TIDN) for the proposed system, and their parameters are successfully optimized by the bird swarm algorithm (BSA). The comparative analysis of system dynamics corresponding to the proposed 3DOF-TIDN controller exhibits betters dynamics over 3DOF-PID and 2DOF-PID controllers. The system dynamic performances are also evaluated considering RDSTS and PWTS in all the areas, and it has been evident that the incorporation of RDSTS and PWTS improves system dynamics. The system with AHVDC link shows quickly damped out the system oscillation. Moreover, the study on inertia emulation using various ESS such as redox flow battery (RFB), ultra-capacitor (UC) and battery energy storage (BES) systems inferred that the system’s initial response with RFB is better than others. Furthermore, the integration of various FACTS devices such as thyristor control phase shifter (TCPS), static synchronous series capacitor (SSSC) and Gate-Controlled Series Capacitor (GCSC) revealed that the system dynamics marginally enhanced with GCSC than TCPS and SSSC.

Frequency Support Studies of a Diesel–Wind Generation System Using Snake Optimizer-Oriented PID with UC and RFB

The present paper discusses the modeling and analysis of a diesel–wind generating system capable enough to cater to the electrical power requirements of a small consumer group or society. Due to high variations of the load demand or due to changes in the wind speed, the frequency of the diesel–wind system will be highly disturbed, and hence to regulate the frequency and power deviations of the wind turbine system, an effective controller design is a necessary requirement, and therefore this paper proposes a novel controller design based on PID scheme. The parameters of this controller is effectively optimized through a new snake optimizer (SO) in an offline manner to minimize frequency and power deviations of an isolated diesel–wind system. The performance of SO-PID for the diesel–wind system is evaluated by considering the integral of time multiplied absolute error (ITAE), integral absolute error (IAE), and integral of time multiplied square error (ITSE). The results were calculated for a step change in load, step change in wind speed, load change at different instants of time with diverse magnitude, and for random load patterns, and they were compared with some of the recently published results under similar working conditions. In addition, the effect of an ultracapacitor (UC) and redox flow battery (RFB) on SO-PID was investigated for the considered system, and the application results demonstrated the advantages of our proposal over other studied designs.