| Abstract |
There is an emerging call for applications in energy storage systems which use a mixture of batteries. These hybrid battery solutions may contain different battery types for example; using second life ex-transportation batteries in grid support applications or a combination of high power, low energy and low power, high energy batteries to meet multiple energy requirements or even the same battery types but under different states of health for example, being able to hot swap out a battery when it has failed in an application without changing all the batteries and ending up with batteries with different performances, capacities and impedances. These types of applications typically use multi-modular converters to allow hot swapping to take place without affecting the overall performance of the system. A key element of the control is how the different battery performance characteristics may be taken into account and the how the power is then
shared among the different batteries in line with their performance. This paper proposes a novel control strategy which
allows the power in the batteries to be effectively distributed even under varying parameter conditions such as, capacity
fade conditions using adaptive power sharing strategy. The proposed strategy has been experimentally validated against a system of three different battery types connected to a grid connected multi-modular converter both with and without capacity fade mechanisms in place. |
