Optimizing charging infrastructure for electrically driven buses

Electrically driven buses for public transportation become more and more popular. But even efficient batteries need to be recharged during operation. The charging infrastructure is expensive and must be planned carefully. Finally, this planning process is a problem of optimization. Some non-linearity of the batteries and of the energy consumption of the buses increases the difficulty of the problem. In this paper, we develop a multi-stage and iterative processing line to solve this problem of optimization. Initially a mathematical optimization based on a linearized model computes a solution that is optimal to a simplified linear model. In a second step, an event driven simulator validates the result from the first step. If the first solution does not hold, the first step is repeated with less restrictive constraints. The last step is a post simulation with a fine granular physical model embedded in a second optimization loop.