Open AccessBalanced and unbalanced inverter strategies in battery storage systems for low‐voltage grid support
Author(s) -
Geth Frederik,
Tant Jeroen,
Belmans Ronnie,
Driesen Johan
Publication year - 2015
Publication title -
iet generation, transmission and distribution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 110
eISSN - 1751-8695
pISSN - 1751-8687
DOI - 10.1049/iet-gtd.2014.0341
Subject(s) - inverter , battery (electricity) , ac power , energy storage , grid , voltage , power (physics) , grid tie inverter , engineering , computer science , automotive engineering , electrical engineering , maximum power point tracking , physics , geometry , mathematics , quantum mechanics
The design of battery storage systems includes technology choices for the batteries and for the inverter. The impact of the inverter design on the optimal design and operation of the storage system has not been analysed before. Therefore four inverter designs are compared with this research. The most basic inverter model assumes only symmetric active power exchange; the most advanced inverter model allows interphase active power transfer and reactive power control. A multi‐objective optimisation method is used, to visualise the trade‐offs between two technical objective functions for cycling control – voltage regulation and peak power reduction – for a given annual cost. The method is applied to a real‐world scenario, based on an existing feeder in a residential part of a city in Flanders, Belgium. Internal losses and losses in the grid are quantified for the different designs. Modelling a battery storage system purely as a finite source/sink of active power in a low‐voltage grid, strongly underestimates the potential because of the existing phase unbalance. Counteracting phase unbalance through an inter‐phase power transfer capable inverter, even more so than adding reactive power control, improves the performance of battery storage systems.