Modular ESS with second life batteries operating in grid independent mode


This work is part of a bigger project which aims to research the potential development of commercial opportunities for the re-use of batteries after their use in low carbon vehicles on an electricity grid or microgrid system. There are three main revenue streams (peak load lopping on the distribution Network to allow for network re-enforcement deferral, National Grid primary/ secondary/ high frequency response, customer energy management optimization). These incomes streams are dependent on the grid system being present. However, there is additional opportunity to be gained from also using these batteries to provide UPS backup when the grid is no longer present. Most UPS or ESS on the market use new batteries in conjunction with a two level converter interface. This produces a reliable backup solution in the case of loss of mains power, but may be expensive to implement. This paper introduces a modular multilevel cascade converter (MMCC) based ESS using second-life batteries for use on a grid independent industrial plant without any additional onsite generator as a potentially cheaper alternative. The number of modules has been designed for a given reliability target and these modules could be used to minimize/eliminate the output filter. An appropriate strategy to provide voltage and frequency control in a grid independent system is described and simulated under different disturbance conditions such as load switching, fault conditions or a large motor starting. A comparison of the results from the modular topology against a traditional two level converter is provided to prove similar performance criteria. The proposed ESS and control strategy is an acceptable way of providing backup power in the event of loss of grid. Additional financial benefit to the customer may be obtained by using a second life battery in this way.

Publication DOI:
Divisions: College of Engineering & Physical Sciences > Power Electronics, Machines and Power System (PEMPS)
Additional Information: © 2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Event Title: 3rd IEEE international symposium on power electronics for distributed generation systems (PEDG)
Event Type: Other
Event Dates: 2012-06-25 - 2012-06-28
Uncontrolled Keywords: energy storage system,grid independent operation,second-life batteries,voltage and frequency control,Energy Engineering and Power Technology,Electrical and Electronic Engineering
ISBN: 978-1-4673-2021-4, 978-1-4673-2022-1
Last Modified: 22 Feb 2024 08:17
Date Deposited: 18 Feb 2015 16:40
Full Text Link: http://ieeexplo ... rnumber=6254072
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Conference contribution
Published Date: 2012
Authors: Mukherjee, Nilanjan
Strickland, Dani (ORCID Profile 0000-0002-2979-4479)



Version: Accepted Version

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