Comparison of Battery Architecture Dependability

Abstract

This paper presents various solutions for organizing an accumulator battery. It examines three different architectures: series-parallel, parallel-series and C3C architecture, which spread the cell output current flux to three other cells. Alternatively, to improve a several cell system reliability, it is possible to insert more cells than necessary and soliciting them less. Classical RAMS (Reliability, Availability, Maintainability, Safety) solutions can be deployed by adding redundant cells or by tolerating some cell failures. With more cells than necessary, it is also possible to choose active cells by a selection algorithm and place the others at rest. Each variant is simulated for the three architectures in order to determine the impact on battery-operative dependability, that is to say the duration of how long the battery complies specifications. To justify that the conventional RAMS solutions are not deployed to date, this article examines the influence on operative dependability. If the conventional variants allow to extend the moment before the battery stops to be operational, using an algorithm with a suitable optimization criterion further extend the battery mission time.Batteries 2018, 4, 31 2 of 12 seen in Figure 1. In this, a cell is represented as a series association of an open-circuit voltage (OCV), an equivalent series resistance (ESR) and a parallel RC circuit. The ESR corresponds to the battery terminals voltage V cell , only if it is measured without an external load connection and with the cell at rest for an adequate time. This time is necessary for balancing internal electrical charges (relaxation phenomenon). A double-layer capacitance (C w ) and a charge transfer resistance (R w ) complete the model by describing relaxation. Other internal phenomena such as a hysteresis voltage can also be modeled by additional subcircuits. Hysteresis consists in a shifting on the open-circuit voltage for the same contained charge between current direction, an upward offset with a negative current I cell in charging phase and a downset offset with a positive current in the discharge phase.Batteries 2018, 4, x FOR PEER REVIEW 2 of 12 an equivalent series resistance (ESR) and a parallel RC circuit. The ESR corresponds to the battery terminals voltage Vcell, only if it is measured without an external load connection and with the cell at rest for an adequate time. This time is necessary for balancing internal electrical charges (relaxation phenomenon). A double-layer capacitance (Cw) and a charge transfer resistance (Rw) complete the model by describing relaxation. Other internal phenomena such as a hysteresis voltage can also be modeled by additional subcircuits. Hysteresis consists in a shifting on the open-circuit voltage for the same contained charge between current direction, an upward offset with a negative current Icell in charging phase and a downset offset with a positive current in the discharge phase.

Comparing lithium-ion battery architecture performances with Colored Petri Net

“…For the C3C architecture, balancing between idle cells can also help improve the lifespan, extend to 332 cycles instead of 320. The results obtained with this simplified model, using a PN, are similar to those obtained using a formal model described in Matlab [5], in particular the achievements provided by each control law optimization solution are of the same order.…”

“…Rather than activate them only in the case of a failure, it is possible to use at any time only the cells most able to provide the request current I applic while reducing their aging and place the others at rest. To do this, it is necessary to define a control law leading to a battery reconfiguration when the active cells less perform than those at rest [5]. SoH is a good indicator to estimate cell aging.…”

“…The switches S ij A and S ij Z when they are respectively OFF and ON, allow to disconnect Cell ij and replace it by a short circuit. The switches S ij B , S ij C , S ij D,..., S ij X make possible to distribute the upstream current flow from node a to different cells of the downstream row by nodes b to x [5] or allow a parallel cell association. Finally, the switches S ij + and S ij − ensure the balancing function, which will be presented at point 4.1.…”

Batteries and Supercapacitors Aging

“…Topics of interest include, but are not limited to: In response to this call of papers, 12 research papers [1][2][3][4][5][6][7][8][9][10][11][12] and one review article [13] from seven different countries have been published. Researchers from academic institutions from France [1,[3][4][5][6][7]9], Germany [2,9,10,12,13], United States [8,11], Russia [4], Spain [9], Belgium [9] and Ethiopia [13] participated, sometimes in collaboration with industrial partners of energy or automotive sectors.…”

“…The dominant energy storage technology treated in this special issue is without a doubt lithium-ion batteries [1,2,[4][5][6][7][8][9][10]13]. However, other technologies are of interest as for example supercapacitors [2] or NiCd batteries [12] and the emerging technology of Lithium-ion capacitors [3,11].…”