Direct Seamless Transfer Strategy by Limiting Voltage Drop of Interface Filter in Energy Storage Equipment of Microgrid

This document researchs on 55kW GSHP black start based on 250kW/250kWh battery system and 50kW/10s super capacitor. The modeling methods of asynchronous motor, battery system, super capacitor and PCS are given. According to three black start conditions: direct start, star delta start and frequency conversion start, simulates and analyses the results. During black start, the max AC bus voltage drop reaches 60%, and hybrid energy storage system is able to effectively inhibit the inrush current.

Download Full-text

Parallel Operation Control Method of Grid-connected Inverters with Seamless Transfer for Energy Storage System in Microgrid

The Transactions of the Korean Institute of Power Electronics ◽

10.6113/tkpe.2016.21.3.200 ◽

2016 ◽

Vol 21 (3) ◽

pp. 200-206

Author(s):

Sung-Youl Park ◽

Joo-Ha Kim ◽

Ah-Jin Jung ◽

Se-Wan Choi

Keyword(s):

Energy Storage ◽

Control Method ◽

Storage System ◽

Energy Storage System ◽

Parallel Operation ◽

Operation Control ◽

Seamless Transfer

Download Full-text

The Key to the Problem of Reversible Chemical Hydrogen Storage and Reversible Energy Storage Alike is 12 kJ (mol H2)-1

10.26434/chemrxiv.6940379.v5 ◽

2019 ◽

Author(s):

Roland Hermann Pawelke

Keyword(s):

Energy Storage ◽

Hydrogen Storage ◽

Voltage Drop ◽

Reaction Pathway ◽

Cell Voltage ◽

Ideal Gas ◽

Battery Cell ◽

Ideal Gas Law ◽

Starting Point ◽

Probable Reaction

<div>This article outlines a potent theoretical formalism illuminating the boundaries to reversible solid hydrogen storage based on the ideal gas law and classic equilibrium thermodynamics. A global picture of chemical reversible hydrogen sorption is unveiled including a thermodynamic explanation of partial reversibility. This is utilized to elucidate a multitude of issues from metal hydride chemistry (as ESI): Highlights are explanations why the substitution of a mere 4 mol % Na by K in Ti-doped NaAlH<sub>4</sub> raises the reversible storage capacity by 42 % and elaboration of the utmost probable reaction pathway in (Rb/K)H-doped Mg(NH<sub>2</sub>)<sub>2</sub>/2LiH. The ESI further contains a demonstration of relevance to electrochemistry by means of the NAS-battery cell, concisely predicting the starting point of the cell voltage drop where experiment shows it to be. The findings of this work allow for a change of paradigm towards the understanding of reversible chemical energy storage and provide a hitherto sorely missing tool of tremendous analytic and predictive power, complementary to experiment.</div>

Download Full-text

Research on Seamless Transfer Strategy of Micro-Grid Based on Energy Storage

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.805-806.1129 ◽

2013 ◽

Vol 805-806 ◽

pp. 1129-1135

Author(s):

Qi Zhang ◽

Zai Jun Wu ◽

Xiao Bo Dou ◽

Chun Jun Sun ◽

Bo Zhao

Keyword(s):

Energy Storage ◽

Vital Role ◽

Control Mode ◽

Three Phase ◽

Point Of Common Coupling ◽

Micro Grid ◽

Common Coupling ◽

Voltage Control Mode ◽

Seamless Transfer ◽

And Control

Energy storage plays a vital role in the reliable operation of Micro-Grid (MG) due to its characteristic of running stabilization and control flexibility. It can act as the master inverter and maintain system voltage and frequency stability as MG in off-grid mode under voltage control mode. During the transfer of MG from grid-connected mode to off-grid mode, the PCC (point of common coupling) three-phase static switch cant shut off at the same time. Moreover it needs to match the MG voltage and utility grid voltage when the islanded MG needs to reconnect to the utility grid.In order to solve these problems, a control strategy of grid-connected/off-grid seamless transfer based on energy storage is proposed. Simulation was presented from a MG platform including photovoltaic (PV), wind turbine (WT) and energy storage and the result shows the feasibility of the proposed approach.

Download Full-text

A Comparative Study of Supercapacitor-Based STATCOM in a Grid-Connected Photovoltaic System for Regulating Power Quality Issues

Sustainability ◽

10.3390/su12176781 ◽

2020 ◽

Vol 12 (17) ◽

pp. 6781 ◽

Cited By ~ 1

Author(s):

Muhammad Moin Afzal ◽

Muhammad Adil Khan ◽

Muhammad Arshad Shehzad Hassan ◽

Abdul Wadood ◽

Waqar Uddin ◽

...

Keyword(s):

Energy Storage ◽

Power Quality ◽

Reactive Power ◽

Voltage Drop ◽

Storage System ◽

Energy Storage System ◽

Photovoltaic System ◽

Renewable Energy Resources ◽

Pv System ◽

Quality Issues

Renewable energy resources (RERs) play a vital role in reducing greenhouse gases, as well as balancing the power generation demand in daily life. Due to the high penetration of RERs and non-linear loads into utility power systems, various power quality issues arise, i.e., voltage drop, harmonic distortion, reactive power demand, etc. In order to handle these power quality issues, there is a need for smart flexible alternating current transmission system (FACTS) devices. In this paper, a super capacitor energy storage system (SCESS)-based static synchronous compensator (STATCOM) is designed in order for the grid-connected photovoltaic (PV) system to overcome the abovementioned power quality issues. A voltage controller and a d-q axis controller are used for the efficient performance of the STATCOM. In order to show the superiority of the supercapacitor, a detailed comparison is made between a battery energy storage system (BESS)-based STATCOM and a SCESS-based STATCOM. Four scenarios are studied to evaluate the performance of the proposed STATCOM design. The proposed SCESS-based STATCOM not only boosts the voltage but also stabilizes it from 368 V to 385 V (Ph-Phrms). The simulated results have confirmed that the proposed design is not only superior to a BESS-based STATCOM but also has the capability to overcome the power quality issues as well.

Download Full-text

Limitations and Characterization of Energy Storage Devices for Harvesting Applications

Energies ◽

10.3390/en13040783 ◽

2020 ◽

Vol 13 (4) ◽

pp. 783 ◽

Cited By ~ 5

Author(s):

Roberto de Fazio ◽

Donato Cafagna ◽

Giorgio Marcuccio ◽

Paolo Visconti

Keyword(s):

Energy Storage ◽

Energy Harvesting ◽

Voltage Drop ◽

Discharge Rate ◽

Open Circuit ◽

The Self ◽

Discharge Process ◽

Energy Storage Devices ◽

Time Duration ◽

Storage Devices

This paper aims to study the limitations and performances of the main energy storage devices commonly used in energy harvesting applications, namely super-capacitors (SC) and lithium polymer (LiPo) batteries. The self-discharge phenomenon is the main limitation to the employment of SCs to store energy for a long time, thus reducing efficiency and autonomy of the energy harvesting system. Therefore, the analysis of self-discharge trends was carried out for three different models of commercial SCs, describing the phenomenon in terms of self-discharge rate and internal resistance. In addition, physical interpretations concerning the self-discharge mechanism based on the experimental data are provided, thus explaining the two super-imposed phenomena featured by distinct time constants. Afterwards, the dependence of self-discharge phenomenon from the charging time duration (namely, SCs charged at 5 V and then kept under charge for one or five hours) was analyzed; by comparing the voltage drop during the self-discharge process, a self-discharge reduction for longer charging durations was obtained and the physical interpretation provided (at best −6.8% after 24 h and −13.4% after 120 h). Finally, self-discharge trends of two commercial 380 mAh LiPo batteries (model LW 752035) were acquired and analyzed; the obtained results show an open circuit voltage reduction of only 0.59% in the first 24 h and just 1.43% after 124 h.

Download Full-text