On-board Battery Research Articles

Review of on-board conductive charger topologies for electric transportation

This paper presents an overview of on-board conductive charger topologies for electric vehicles (EVs). Battery packs in electric and plug-in hybrid electric vehicles (EVs/PHEVs) need frequent energy refills to fulfil their duty cycles and overcome the range anxiety of vehicle owners. Due to the limited availability of fast charging infrastructures, all automotive manufacturers prefer an on-board battery charger in their vehicles. However, there are power level limitations for these chargers because of the weight, space and cost constraints. On-board charging systems can be either conductive or inductive. This paper reviews the topologies that are involved in conductive charging only. Globally, all automotive companies provide levels 1 and 2 for residential charging of vehicles. Single- and two-stage power converter topologies are summarised with their limitations. Furthermore, the current trends in the DC-DC converters for the two-stage conversion battery charger topologies are also outlined. This paper provides an overview of various topologies and configurations involved in EV charging with their limitations.

INCREASING THE TIME OF USING THE ENERGY RESOURCE OF THE ON-BOARD ACCUMULATORY BATTERY BY IMPROVING THE QUALITY OF CONTROLLING THE ELECTRIC QUADCOPTER'S PROPELLER DRIVES

A review of the current state in quadcopters’ flight control systems showed that the electric drives of their propellers are performed according to single-circuit schemes with feedback on rotational speed in which the error in the results of monitoring the angles of roll, pitch, yaw is worked out by a control system with a PI or PID regulator. There is no astaticism load in such systems and the parameters of the current consumed from the on-board battery are not optimized. The consequence of this is a decrease of service life on-board battery and low quality flight control when the load changes. It is proposed to perform the electric drive system of the quadcopter’s screw according to a two-fold integrating structural scheme in which astaticism is provided during perturbations in control and load.
 A transient speed characteristic based on the optimization results of the double-integration scheme with speed and current circuits in accordance with a symmetrical optimum the parameters of which do not meet the requirements of quadcopter’s high-quality control flight mode was obtained and do not contribute to an increase in the time of using the energy resource of the on-board battery. It is proposed to include additional smoothing differentiating links at its input to eliminate the shortcomings of the obtained transient characteristic of the electric drive system in terms of speed. The parameters of these links were found using the compensation conditions. The obtained transient characteristics of the electric drive system of the quadcopter’s screws in terms of speed and current do not have sudden changes in the adjustable value and do not have overregulation. The result of such parameters in transient characteristics is high-quality control of the quadcopter’s flight mode and an increase in the time of using the energy resource of the on-board battery.

Health State Estimation of On-Board Lithium-Ion Batteries Based on GMM-BID Model

As a single feature parameter cannot comprehensively evaluate the health status of a battery, a multi-source information fusion method based on the Gaussian mixture model and Bayesian inference distance is proposed for the health assessment of vehicle batteries. The missing and abnormal data from real-life vehicle operations are preprocessed to extract the sensitive characteristic parameters which determine the battery performance. The normal state Gaussian mixture model is established using the fault-free state data, whereas the Bayesian inference distance is constructed as an index to quantitatively evaluate the battery performance state. In order to solve the problem that abnormal data may exist in the measured data and introduce errors into evaluation results, the determination rules of abnormal data are formulated. The verification of real-life vehicle operation data reveals that the proposed method can accurately evaluate the onboard battery state and reduce safety hazards of electric vehicles during the normal operation process.

An Integrated Driving/Charging Four-Phase Switched Reluctance Motor Drive With Reduced Current Sensors for Electric Vehicle Application

This article proposes an integrated power converter (IPC) with driving/charging capabilities for four-phase switched reluctance motor (SRM) drive-based electric vehicle (EV) application. With the proposed IPC, only two current sensors are employed for measuring phase currents under all operating conditions. The proposed IPC integrates three circuits. First, during the SRM driving mode, the proposed IPC is utilized as an improved Miller converter. Second, during battery charging mode, the proposed IPC is utilized as an on-board battery charger, which is based on a bridgeless boost power factor correction circuit (PFCC) that incorporates two dc–dc boost converters. The on-board battery charger is realized by utilizing the existing power electronic switches in the proposed IPC and all the phase windings as charging inductors. Third, a front-end bidirectional dc–dc converter is employed for maintaining voltage and current balance between IPC dc-bus and battery. During driving mode, the front-end converter boosts the battery voltage to the IPC dc bus voltage. And during regeneration/braking, the stored magnetic energy is used to charge the battery in constant-current (CC) mode via the front-end converter. During battery charging via ac grid, the bridgeless boost PFCC and the front-end converter operating in buck mode charge the battery in CC/constant-voltage (CV) modes without stepping down the ac grid voltage. The claims of the proposed IPC are validated through simulation and experimental verifications.

Data-Driven In-Orbit Current and Voltage Prediction Using Bi-LSTM for LEO Satellite Lithium-Ion Battery SOC Estimation

Accurate estimation of the battery system state of charge (SOC) is essential to the satellite mission design and fault management. However, it is difficult for low Earth orbit satellites to continuously monitor the battery SOC on the ground due to the noncontact duration. To estimate the battery SOC for the entire orbit, it is necessary to predict or monitor the battery data for all times. Therefore, existing studies use SOC estimation that relies on real-time onboard battery information or utilizes probability-based technique and power budget-based technique. The real-time onboard-based technique is unsuitable for mission design because the status information is not available to the ground during the noncontact duration. Probability-based and power budget-based techniques are not reliable during the noncontact duration. In this study, we propose the ground-based battery SOC estimation technique that predicts the current and voltage by using the bidirectional long short-term memory network for the noncontact duration and estimates the SOC by the unscented Kalman filter for all operating conditions. The proposed technique is tested with in-orbit data of the KOMPSAT-3A satellite, and we demonstrate its superior performance than other conventional ground-based SOC estimation techniques.

Trajectory Design and Communication Resources Allocation for Wireless Powered Secure UAV Communication Systems

Benefiting from the intrinsic convenience, flexibility, low cost, and unmanned aerial vehicles (UAVs) are envisioned to play an important role in future wireless communication systems. However, the limited on-board battery capacities and the broadcast characteristic of air-to-ground wireless channels bring some nonnegligible challenges on achieving secure UAV communications. To tackle these challenges, we propose to apply both the wireless power transfer and physical layer security techniques in a UAV communication system. We investigate the secrecy rate maximization problem by jointly optimizing the wireless charging duration, the trajectory, and transmit power of the UAV, subject to limited battery capacity, maximum flying speed, and energy-harvesting causal constraints. To solve this nonconvex problem, we first transform this problem into an equivalent problem with a smooth objective function, and then propose a low-complexity trajectory design and communication resources allocation algorithm for settling the reformulated problem via employing alternating optimization and SCP. Specifically, the reformulated problem is decomposed into three independent subproblems: the wireless charging duration optimization, the transmit power control, and the trajectory design of the UAV. Subsequently, we iteratively solve one of these three subproblems, while the others being fixed until the proposed algorithm converges. Extensive simulation results are provided to demonstrate that the proposed algorithm can significantly enhance the secrecy rate relative to the benchmark algorithms in absence of rechargeable battery or with fixed trajectory and transmit power.

Evaluation of Over-the-Counter Portable Oxygen Concentrators Utilizing a Metabolic Simulator.

Supplemental oxygen is designed to raise alveolar PO2 to facilitate diffusion into arterial blood. Oxygen is generally delivered by nasal cannula either by continuous or pulsatile flow. Battery-powered portable oxygen concentrators (POCs) facilitate ambulation in patients experiencing exertional hypoxemia. In the United States, the Food and Drug Administration (FDA) clears these devices to be sold by physician prescription. Recently, however, lower-cost devices described as POCs have been advertised by online retailers. These devices lack FDA clearance and are obtained over the counter (OTC) without prescription. This study determined whether a selected group of OTC POCs have oxygen delivery characteristics suitable for use by hypoxemic patients. A metabolic simulator, capable of simulating a range of metabolic rates and minute ventilations, determined effects of oxygen supplementation delivered by a variety of devices on alveolar PO2 . Devices tested included 3 OTC POCs, an FDA-cleared POC, and continuous-flow oxygen from a compressed oxygen cylinder. End-tidal PETO2 , a surrogate of alveolar PO2 , was determined at each of each device's flow settings at 3 metabolic rates. Continuous-flow tank oxygen yielded a linear PETO2 increase as flow increased, with progressively lower slope of increase for higher metabolic rate. The prescription POC device yielded similar PETO2 elevations, though with somewhat smaller elevations in pulse-dose operation. One OTC POC was only technically portable (no on-board battery); it provided only modest PETO2 elevation that failed to increase as flow setting was incremented. A second OTC POC produced only minimal PETO2 elevation. A third OTC POC, a pulsed-dose device, produced meaningful PETO2 increases, though not as great as the prescription device. Only one of 3 OTC POCs tested was potentially of use by patients requiring ambulatory oxygen. Physicians and respiratory therapists should inform patients requiring portable oxygen that OTC devices may not meet their oxygenation requirements.

An interleaved multilevel converter for onboard EV charging application

ABSTRACT This paper proposes an interleaved multilevel converter (MLC)-based charger with power rating 2.8 kW to charge on-board battery of electric vehicle (EV). It comprises two stages: (1) an interleaved multilevel ac–dc converter; and (2) an LLC-resonant dc–dc converter. The interleaved approach efficiently maintains the optimum power level. The switching scheme implemented for MLC maintains the source current sinusoidal, supports unity power factor (UPF) and has the capability to balance the capacitor voltage. The MLC maintains UPF and balances capacitor voltage without any auxiliary circuit. In addition, MLC provides lower voltage stress and reduced total harmonic distortion (THD), therefore, making it a better choice for ac–dc conversion stage in battery charging application. The dc–dc converter furnishes regulated and wide output voltage range for on-board charging system. The principle of operation, modulation technique and control strategy for both the converters are analysed. Following theoretical analysis, laboratory experiments were conducted to validate the implemented approach. The results signify that for output voltage range of 24−72 V, UPF is maintained at input, lower stress across switches and capacitor voltage is balanced. The performance of MLC is satisfactory as it attains a peak efficiency of 97% with THD of 2.07%.

A Review of Lithium-Ion Battery Capacity Estimation Methods for Onboard Battery Management Systems: Recent Progress and Perspectives

With the widespread use of Lithium-ion (Li-ion) batteries in Electric Vehicles (EVs), Hybrid EVs and Renewable Energy Systems (RESs), much attention has been given to Battery Management System (BMSs). By monitoring the terminal voltage, current and temperature, BMS can evaluate the status of the Li-ion batteries and manage the operation of cells in a battery pack, which is fundamental for the high efficiency operation of EVs and smart grids. Battery capacity estimation is one of the key functions in the BMS, and battery capacity indicates the maximum storage capability of a battery which is essential for the battery State-of-Charge (SOC) estimation and lifespan management. This paper mainly focusses on a review of capacity estimation methods for BMS in EVs and RES and provides practical and feasible advice for capacity estimation with onboard BMSs. In this work, the mechanisms of Li-ion batteries capacity degradation are analyzed first, and then the recent processes for capacity estimation in BMSs are reviewed, including the direct measurement method, analysis-based method, SOC-based method and data-driven method. After a comprehensive review and comparison, the future prospective of onboard capacity estimation is also discussed. This paper aims to help design and choose a suitable capacity estimation method for BMS application, which can benefit the lifespan management of Li-ion batteries in EVs and RESs.

Analysis of Various Topologies and Control Circuit used in Single Phase EV Charger

Abstract: In remote electric vehicle charging frameworks utilizing inductive power transfer (IPT), power electronic converters assume a basic part in decreasing size and cost, as well as boosting the proficiency of the whole framework. As of late, analysts have led huge examination studies to work on the exhibition of power transformation frameworks, including power converter topologies and control plans. Incorporated On-Board Battery Chargers (OBC) have been acquainted as ideal arrangement with increase of electric vehicle (EV) market penetration and limit the general expense of EVs. OBCs are by and large arranged into triphasic and monophasic types with unidirectional or bidirectional power stream. Existing electric vehicle (EV) chargers utilize a hard-core non-linear diode bridge-rectifier (BR) to exploit the DC volt at the contribution of the DC converter and acquaint quality of the power is a counted as a problem with the AC input. These problems insist improvement in Power Quality for existing battery charger for this purpose the bridgeless Cuk Converter is used with the flyback converter. Cuk Converter used single diode and switch and provide additional advantage like reduction in the switch volt-stress and higher efficiency equated to the other conventional bridgeless (BL) converters. Similarly, bridgeless isolated Zeta-Luo converter with PF correction is also used. The Zeta and Luo is functioned for the half cycle of the supply individually and give the benefits of the both topologies. In this paper BL Zeta, BL Cuk, BL Buck-Boost, BL Luo, BL Single Ended Primary Inductance Converter (BL SPIC), and Canonical Switched Cell (CSC) converters are reviewed.

Six-phase drive-based integrated onboard battery charger for electric vehicles considering zero-sequence circulating current elimination

Six-phase drive-based integrated onboard battery charger for electric vehicles considering zero-sequence circulating current elimination

Miniature Autonomous Robot Based on Legged In-Plane Piezoelectric Resonators with Onboard Power and Control.

This work reports the design, fabrication, and characterization of a centimetre-scale autonomous robot with locomotion based on in-plane piezoelectric resonators and 3D-printed inclined legs. The robot consists of a pair of cooperative piezoelectric motors, an electronic power circuit and a battery-powered microcontroller. The piezoelectric motors feature a lead zirconate titanate (PZT) plate of dimensions 20 mm × 3 mm × 0.2 mm vibrating on its first extensional resonant mode at around 70 kHz. A particular position of 3D-printed inclined legs allowed the conversion of the in-plane movement into an effective forward thrust. To enable arbitrary trajectories of the robot on a surface, two parallel piezoelectric plate motors were arranged in a differential drive scheme. The signals to excite these plates were generated by the microcontroller and adapted by a supplementary electronic circuit to increase the effective voltage supplied by the onboard battery. The fully assembled robot had a size of 27 mm × 15 mm and a weight of 7 g and reached a linear speed of approximately 15 mm/s and a rotational speed of up to 50 deg./s. Finally, the autonomous robot demonstrated the ability to follow pre-programmed paths.

Bidirectional Converter for Plug-In Hybrid Electric Vehicle On-Board Battery Chargers with Hybrid Technique

Recently, Plug-in Hybrid Electric Vehicles (PHEVs) have gathered a lot of attention by integrating an electric motor with an Internal Combustion Engine (ICE) to minimize fuel consumption and greenhouse gas emissions. The On-Board Chargers (OBCs) are selected in this research because they are limited by dimensions and mass, and also consume low amounts of power. The Equivalent Series Resistance (ESR) of a filter capacitor is minor, so the zero produced by the ESR is positioned at a high frequency. In this state, the system magnitude gradually drops, causing a ripple in the circuit that generates a harmful impact on the battery’s stability. To improve the stability of the system, a Neural Network with an Improved Particle Swarm Optimization (NN–IPSO) control algorithm was developed. This study establishes an isolated converter topology for PHEVs to preserve battery-charging functions through a lesser number of power electronic devices over the existing topology. This isolated converter topology is controlled by NN–IPSO for the PHEV, which interfaces with the battery. The simulation results were validated in MATLAB, indicating that the proposed NN–IPSO-based isolated converter topology minimizes the Total Harmonic Distortion (THD) to 3.69% and the power losses to 0.047 KW, and increases the efficiency to 99.823%, which is much better than that of the existing Switched Reluctance Motor (SRM) power train topology.

Breakthrough Energy Technologies Toward a Solution for Climatic Change

In this age of climate change, the corporate, academic, and government research into new, green sources of power and energy still has not been well-funded nor forthcoming in this century. This presentation will review some of the best emerging energy technologies that promise green and carbon-free sustainable generation as well as food and water energy innovations, including a bioenergetics discovery. Progress is being made presently by academic and industry that will create a future having greater ease in newly developed renewable energy generation with much better, localized energy sources that do not use fossil fuel for power and heat. Beyond the realm of fuel cells and wind power is the non- conventional world of emerging energy technologies. Some of the best examples are new and exciting generators that release trapped potential energy from nature in ways never dreamed of before. Others innovatively apply clean fuels in conventional systems that are the focus of attention for NASA, DARPA, and the USDOE. Some of the more exotic examples include a recent breakthrough with graphene energy harvesting, which has thermal and nonthermal (quantum vacuum) sources to it. This illustrated slideshow presentation summarizes the research that has been accomplished so far in the development of highly efficient, energy harvesting inventions, as well as other future energy breakthroughs. The most exciting reason for the interest in this area of research is the promise that it holds for boosting electric vehicle production by providing an onboard electric battery charger. These energy generation developments, derived from relatively new paradigm science discoveries, also have many other applications, including a design for rural stand-alone electrical generators. Most of them have one thing in common: they are relatively unknown to the general public.

On-Board Physical Battery Replacement System and Procedure for Drones During Flight

One of the major disadvantages of drones is their limited flight time. This paper introduces a new concept and mechanism for an onboard system that physically replaces batteries during flight, analogous to “aerial refueling.” This capability allows drones to remain in mid-air indefinitely while pursuing their mission without forcing them to change flight paths for logistical needs. The concept is composed of an additional UAV array that delivers new batteries from various ground points. We first describe the Flying Hot-Swap Battery (FHSB) system's conceptual design. This unique design uses a FIFO logical process and the force of gravity to replace the energy source. The main innovation involves combining the ability to receive a battery from an external source, connect mechanically, hot-swap between the batteries, and dispose of the discharged battery. We report on the design of a dedicated battery cartridge for reception and connection in any spatial variation or orientation. Each component has a duplicate that works independently to increase system redundancy. Finally, we present the multiple experiments conducted to test the FHSB. The prototype successfully hovered and connected the battery in various reception orientations and hot-swapped the battery, thus maintaining the drone's continuous power supply. This proof of concept of a complete battery replacement process during flight took an average replacement time of 15.2 seconds, which is only a 0.81% energy loss, thus enabling the drone to continue flying indefinitely without needing to modify its flight path (see attached video).

Integrated charging infrastructure planning and charging scheduling for battery electric bus systems

• Integrated optimization of charging infrastructure and charging scheduling. • A two-phase optimization framework is proposed to solve the integrated problem. • Uncertainties in bus energy consumption and vehicle travel time are considered. • A novel rolling horizon approach is proposed to tackle real-time charging scheduling. Studies on the electric bus system planning problem have typically focused exclusively on either the deployment of charging infrastructure or the scheduling of charging events; few have examined the impact of charging facility deployment on charging activities. Considering the interdependence of system design and operational strategies, this study proposes a two-phase optimization framework for charging infrastructure planning and charging scheduling for battery electric bus systems. An integrated optimization model is first developed to simultaneously optimize charger deployment, on-board battery capacity, and charging schedules. A charging scheduling model is further proposed and a rolling horizon approach is utilized in the second phase to optimize the real-time charging scheduling of electric buses. Compared to existing electric bus system planning methods, the proposed integrated model can reduce the total system cost by 19.5%. In addition, compared to uncontrolled charging, the proposed rolling horizon-based charging strategy can reduce the total charging cost by 68.3%.

Analytical Evaluation of Power-Amplifier-Based Charging Methodology and Energy Efficiency Optimization Framework for Aerial Base Stations

In this article, a radio-frequency (RF) power-amplifier (PA) system configuration for the on-board energy conversion is proposed for unmanned aerial vehicle base station’s (UAV-BS’s) battery charging. First, the PA system utilizes the internal RF source for energy conversion so that perpetual battery charging is possible without external power sources. Therefore, a continuous battery charging of the UAV-BS is possible while providing wireless network coverage by hovering over the target location. In addition, the proposed PA system offers a higher RF power control resolution than the existing PA works, which is desirable for precise power control of the UAV-BS. The objective of simultaneous RF power control and battery charging by the PA system is achieved by activating one Wilkinson power divider (WPD) with a specific power splitting ratio in the power divider bank. The simulations show that the dynamic activation of ten distinct unequal split WPDs of the proposed PA system improves the RF power control resolution by $157$ and $396{\,}\%$ compared to the existing PAs. Additionally, the simulations show that the PA’s power added efficiency fluctuation is reduced by $54$ and $82{\,}\%$ compared to the existing PAs. In addition, it will be shown that the proposed on-board battery charging increases the hovering time by $7.4{\,}\%$. Furthermore, an energy-efficiency optimization framework for UAV-BS’s is proposed considering real-world communication system’s hardware imperfections, and the proposed result suggests that UAV-BS’s flight time may decrease by $50{\,}\%$ depending upon the type of UAV-BS RF components.

Pricing Game of Smart Charging Services for Risk-Averse Users in the Smart Grid

Electric vehicles play a key role in the transition to an environmental-friendly transportation system and can meanwhile enhance the power system’s evolution to the smart grid. With the adoption of dynamic pricing and usage scheduling enabled by the smart grid equipment, a variety of smart charging strategies have been designed to make the most of flexibility contained in their considerable electricity demand, whereas less effort is devoted to users’ willingness to participate. In this paper, we model a noncooperative pricing game between two types of charging stations. One offers conventional fast charging and the other uses the electric vehicles’ onboard batteries to provide regulation service to the grid. With drivers’ risk attitudes and bounded rationality taken into consideration, we design a prospect theory-based decision model to calculate the proportion of users that would go for the regulation-providing charging option. The decision model of the customer base is a critical determinant of profitability and it enables two competitors to strategically set their prices that optimally balance between gaining in market share and growing in profit per client. We prove the existence of a pure strategy Nash equilibrium for the game proposed and compute the equilibrium prices in different circumstances with respect to market settings and user segments. A comprehensive analysis of the results gives insights into the key factors at play and provides the grid operators with indications of how to increase the penetration of electric vehicles in the ancillary service market.

A Hybrid Method for State-of-Charge Estimation for Lithium-Ion Batteries Using a Long Short-Term Memory Network Combined with Attention and a Kalman Filter

A battery management system (BMS) is an important link between on-board power battery and electric vehicles. The BMS is used to collect, process, and store important information during the operation of a battery pack in real time. Due to the wide application of lithium-ion batteries in electric vehicles, the correct estimation of the state of charge (SOC) of lithium-ion batteries (LIBS) is of great importance in the battery management system. The SOC is used to reflect the remaining capacity of the battery, which is directly related to the efficiency of the power output and management of energy. In this paper, a new long short-term memory network with attention mechanism combined with Kalman filter is proposed to estimate the SOC of the Li-ion battery in the BMS. Several different dynamic driving plans are used for training and testing under different temperatures and initial errors, and the results show that the method is highly reliable for estimating the SOC of the Li-ion battery. The average root mean square error (RMSE) reaches 0.01492 for the US06 condition, 0.01205 for the federal urban driving scheme (FUDS) condition, and 0.00806 for the dynamic stress test (DST) condition. It is demonstrated that the proposed method is more reliable and robust, in terms of SOC estimation accuracy, compared with the traditional long short-term memory (LSTM) neural network, LSTM combined with attention mechanism, or LSTM combined with the Kalman filtering method.

Enhanced Performance of On-board EV Battery Charger with Universal Power Supply

This paper is intended to provide enhanced features of onboard EV battery chargers in terms of improved power quality feature, reduced voltage stress, reduced filter size, high efficiency and fast dynamic response for universal input voltage range (85–265 V). The proposed configuration comprises of three-level quadratic converter suitable to provide high voltage gain. The detailed operation, analysis and control scheme of the proposed converter rated for 3.2 kW, 400 V are studied under simulation and hardware in a loop environment. The on-board charger performances are assessed by charging a 40 Ah lithium ion EV battery under different charging modes. The state of charge of battery decides converter operating mode i.e. constant current and constant voltage mode to charge the battery. Enhancement in the onboard charger is observed in both operating modes tested for wide variation in supply voltages. The results reveal that the operation of converter depicts unity power factor operation, improvement in supply current harmonics and controlling output voltage/current. Under both operating modes, the proposed charger draws sinusoidal supply current from ac mains and its THD is reduced to specified limit prescribed by IEC-61000-3-2. Furthermore, the charger performance is also investigated for EV battery charging operation at wide input voltage variations and found satisfactory.