Lithium-ion Battery Energy Storage System Research Articles

Multi-timescale Power and Energy Assessment for Lithium-ion Battery and Supercapacitor Hybrid Energy Storage System

Multi-timescale Power and Energy Assessment for Lithium-ion Battery and Supercapacitor Hybrid Energy Storage System

Stability Analysis and Parameters Optimization of Islanded Microgrid With Both Ideal and Dynamic Constant Power Loads

In this paper, a framework for stability analyses of a typical inverter-based islanded microgrid with two types of nonlinear loads is presented, namely ideal constant power loads (CPLs), which are the loads supplied by tightly regulated power electronics converters, and dynamic CPLs, which are used to represent motor-drive systems with large time constants. The comprehensive dynamic model of the considered microgrid is first developed, based on which a bunch of small-signal models are deduced using Taylor expansion made at different stable operating points. Afterward, eigenvalue-theorem-based stability analysis and parametric sensitivity analysis are successively performed on the obtained small-signal models to verify the stability of the system, predict the system's unstable regions, and identify the effects of parameters on the stability boundaries. In the meantime, the impacts of different kinds of nonlinear loads on the system stability are studied. Hardware-in-the-loop (HIL) real-time simulation platform of a 30-kVA microgrid, which is mainly formed by a 10-kVA photovoltaic (PV) system, a 10-kVA wind energy conversion system, a 10-kVA lithium-ion battery energy storage system, and two CPLs, is established in Typhoon HIL 602 device. The validity of the theoretical results is verified by real-time simulation results.

Application-independent protocol for predicting the efficiency of lithium-ion battery cells in operations

Despite a continuous reduction in battery prices, investment in storage systems carries a high risk. Indeed, many applications lack an adequate test protocol and method to predict the performance of batteries in operations. In this paper, we focus on lithium-ion battery energy storage systems (BESS), for which we introduce a novel method. With this method, predicting the efficiency of lithium-ion BESS becomes possible for any application from a single set of measurements. We show that evaluating the battery resistance as a function of the C-rate provides general “capability charts” based on which the efficiency can be evaluated under arbitrary operation profiles. Application-specific test procedures therefore become unnecessary. We have applied the novel procedure on three different lithium-ion cell technologies and illustrate its accuracy in the example of grid-connected BESS used for primary control reserve.

Cloud-Based Battery Condition Monitoring and Fault Diagnosis Platform for Large-Scale Lithium-Ion Battery Energy Storage Systems

Performance of the current battery management systems is limited by the on-board embedded systems as the number of battery cells increases in the large-scale lithium-ion (Li-ion) battery energy storage systems (BESSs). Moreover, an expensive supervisory control and data acquisition system is still required for maintenance of the large-scale BESSs. This paper proposes a new cloud-based battery condition monitoring and fault diagnosis platform for the large-scale Li-ion BESSs. The proposed cyber-physical platform incorporates the Internet of Things embedded in the battery modules and the cloud battery management platform. Multithreads of a condition monitoring algorithm and an outlier mining-based battery fault diagnosis algorithm are built in the cloud battery management platform (CBMP). The proposed cloud-based condition monitoring and fault diagnosis platform is validated by using a cyber-physical testbed and a computational cost analysis for the CBMP. Therefore, the proposed platform will support the on-board health monitoring and provide an intelligent and cost-effective maintenance of the large-scale Li-ion BESSs.

Efficiency analysis for a grid-connected battery energy storage system

Efficiency is one of the key characteristics of grid-scale battery energy storage system (BESS) and it determines how much useful energy lost during operation. The University of Manchester has been commissioned with 240 kVA, 180 kWh lithium-ion BESS. This paper investigates round-trip efficiencies, comparing energy extracted from and returned to the grid, of the BESS for different operation modes. This is done by developing simulation switch-level model of power components of the BESS. The simulation is validated against hardware test results and used to identify optimum operation modes, which vary depending on SOC and charging and discharging power rates of the BESS.

Comparative Study of Energy Consumption for Electric Vehicles with Various On-board Energy Storage Systems

Electric vehicles are driven by traction motor with intermittent load characteristic. The use of appropriate batteries type is a crucial factor resulting in energy consumption, battery sizing and vehicle design. This paper focuses on the comparison of energy consumption of the electric vehicles in three different energy storage systems consisting of lead-acid battery, lithium-ion battery and hybrid energy storage system (HESS) incorporating with lithium-ion battery and ultracapacitor. The mathematical approach is used to simulate three route vehicle movement which are i) New York city cycle (NYCC), ii) UN/ECE reg. 83 or extra-urban driving cycle and iii) field measured driving profile in Bangkok. Sequential quadratic programming (SQP) is employed to find optimal weights of the energy storage system. The simulation results were consistent for all three routes. The lead-acid battery is heaviest weight but highest energy recovery from the regenerative braking and the energy consumption is greatly different from the others.

Operation of a Grid-Connected Lithium-Ion Battery Energy Storage System for Primary Frequency Regulation: A Battery Lifetime Perspective

Because of their characteristics, which have been continuously improved during the last years, Lithium-ion batteries have been proposed as an alternative viable solution to present fast-reacting conventional generating units to deliver the primary frequency regulation service. However, even though there are worldwide demonstration projects, where energy storage systems based on Lithium-ion batteries are evaluated for such applications, the field experience is still very limited. In consequence, at present, there are no very clear requirements on how the Lithium-ion battery energy storage systems should be operated, while providing frequency regulation service and how the system has to reestablish its state of charge (SOC) once the frequency event has passed. Therefore, this paper aims to investigate the effect on the lifetime of the Lithium-ion batteries energy storage system of various strategies for reestablishing the batteries’ SOC after the primary frequency regulation is successfully delivered.

Grid connected performance of a household lithium-ion battery energy storage system

Lithium-ion Battery Energy Storage Systems (BESS) are to be the next household electrical appliance in a smart grid environment. This is beside the growth of electrical vehicles with lithium-ion batteries. However, these batteries are yet to prove their performances in the household sector.This paper presents the performances of a small household scale battery energy storage system with a lithium-ion battery pack and a single-phase ac-dc inverter. Results of a list of tests conducted in a lab environment are presented explaining the test procedures and results.Test results show that the considered BESS is suitable for daily cycling applications but has low efficiencies at the rated power operations. Converter losses contribute to the low efficiency of the considered BESS. The BESS is more efficient in lower power (lower than rated) operations. However, the effects of the current harmonics need to be considered when it is operated with other appliances.

전기추진선박의 전력품질 개선을 위한 리튬-이온 배터리 에너지저장시스템 적용

This paper explained the application of a lithium-ion battery energy storage system to electric propulsion ships. The power distribution in electric propulsion ships has low power quality because of the variation in the power consumption of the propulsion motor. For proper operation of the ship, the power quality needs to be improved, and the battery energy storage system is used to solve power-quality problems. The simulation models of electric propulsion ship and battery energy storage systems are constructed on MATLAB/Simulink to verify the improvement in power quality. The proposed system is applied in various scenarios of the propulsion motor state. The power quality achieved by using the battery energy storage system in both voltage and frequency satisfies the standards set by IEC-60092/101.

Energy Analysis of a Real Grid Connected Lithium Battery Energy Storage System

Today, in the grid there are more and more installation of renewable energy plants. The renewable sources are so discontinues and they may affect the stability and efficiency of the grid. Many distribution service operators are experimenting the battery energy storage systems (BESSs) to integrate them on the grid and resolve these problems. This paper analyses the energy performance under real conditions of a BESS prototype. The real BESS under focus has made by a lithium battery pack of 16 kWh, a DC/DC converter of 20 kW and an IGBT inverter of 30 kVA with a direct voltage bus of 600 V. The energy analysis has been performed through an integrated data acquisition system that take data from on-board electronic diagnostic measurements and from smart metering data. This latter using remote devices. The tests have been carried out on the system to monitor the following characteristic parameters: current and voltage of the batteries, current and voltage of the grid and current and voltage of the auxiliaries. The system energy performances have been analyzed in dynamic and real conditions with particular reference to the following quantities: energy consumption for the auxiliary system and overall efficiency of the system in a distributed energy resources microgrid. The entire system has been analyzed until twenty-four hours.

Lithium-Ion Battery Energy Storage Systems for Grid Applications

The use of storage devices to support grid functions is seen as a viable option to meet an increasing electricity demand. Simulations performed will provide a look into the sustainability and life of a lithium-ion battery in continuous operation that can be used to support on-grid services. Specifically, COMSOL Multiphysics will be used to model a lithium manganese oxide battery and illustrate the capacity fade, solid-electrolyte interphase (SEI) formation leading to potential drop and electrolyte potential drop in the battery. These simulations will provide insight into continuous cycling phenomena of charging and discharging a battery.

Demonstration Study on the Large-Scale Battery Energy Storage for Renewables Integration

The penetration level of the renewable energy resources has been expected to increase rapidly in several years as government has strongly encouraged those through various policies such as the RPS (Renewable Portfolio Standards) and feed-in tariffs. Because the performance of power system is sometimes critically constrained by stability characteristics, it is very challenging for system operator to realize such a high penetration of the renewable energy resources in power system. It has been proposed that the large-scale Energy Storage Systems (ESS) can be applied to the power system for stabilizing the power supply and improving the energy efficiency ratio by using the stored electrical power in the period of high demand for electricity. To implement the large capacity and improve the effectiveness of the lithium-ion battery ESS, it has been constructed 4MW/8MWh ESS test-bed and developed the operation technology of ESS. In this paper, a demonstration study scheme on the large-scale Battery Energy Storage System (BESS) is proposed to verify the effectiveness and to estimate the performance of BESS.

Development and Testing of Four-Wheel Drive In-Wheel-Motor Electric Vehicle

This paper describes the development of a full electric vehicle prototype with a new generation of drive-by-wire chassis, which consists of a four independently actuated in-wheel-motor drive system, an electric power steering (EPS) system, an electro-hydraulic brake (EHB) system and a lithium battery energy storage system. This novel electric vehicle called I2EV (I2 stands for Intelligent and In-wheel-motor) is designed and tested on a chassis dynamometer to study its performance. Then the road performance of the vehicle is verified through road experiments. These tests clearly show that I2EVcan be employed in further study of intelligent vehicle and advanced integrated chassis control.

OPAL-RT 기반의 Hardware-in-the-Loop Simulation (HILS) 시스템을 이용한 독립운전모드 마이크로그리드 시뮬레이션

A microgrid is a small scale power system. The microgrid is operated in two operation modes, the grid-connected mode and the islanded mode. In the islanded mode, the frequency of a microgrid should be maintained constantly. For this, the balance between power supply and power demand during islanded mode should be met. In general, energy storage systems (ESSs) are used to solve power imbalance. In this paper, the frequency control effect of a Lithium-ion battery energy storage system (Li-ion BESS) has been tested on the hardware-in-the loop simulation (HILS) system environment.

Sizing and Economic Analysis of Lithium-Ion Battery Energy Storage System

Lithium-ion battery energy storage technology has recently made great development, which can play a significant role in power system. Take grid load shifting for example, lithium-ion battery energy storage technology can alleviate the problem of the growing difference between peak and valley, and reduce power system equipment investment, etc. While the high cost of lithium-ion battery energy storage technology limits its large-scale application at present stage. Hence, during early stage of energy storage project investment planning, it is necessary to analyze the economic problems of its investment. Based on the technical level of the lithium-ion battery at present, lithium-ion battery energy storage system capacity configuration strategy is proposed and economic analysis model is established. Finally, economic issues of investment in lithium-ion battery energy storage system for grid load shifting are studied, and the capacity configuration recommendations are given.

Design and Performance of a Bidirectional Isolated DC–DC Converter for a Battery Energy Storage System

This paper describes the design and performance of a 6-kW, full-bridge, bidirectional isolated dc-dc converter using a 20-kHz transformer for a 53.2-V, 2-kWh lithium-ion (Li-ion) battery energy storage system. The dc voltage at the high-voltage side is controlled from 305 to 355 V, as the battery voltage at the low-voltage side (LVS) varies from 50 to 59 V. The maximal efficiency of the dc-dc converter is measured to be 96.0% during battery charging, and 96.9% during battery discharging. Moreover, this paper analyzes the effect of unavoidable dc-bias currents on the magnetic-flux saturation of the transformer. Finally, it provides the dc-dc converter loss breakdown with more focus on the LVS converter.