Improving Battery Lifespan and Service Trip Reliability of EVs in Public Transport by Learning Energy Consumption

Electrification of public transport in cities puts lots of stress onto the vehicle's traction batteries and the power grid during charging. The authors present a self-learning operating strategy to improve the battery life and reduce stress on the power grid by lengthening charging operations as long as possible and avoiding extreme states of charge. During regular service operation, the operating strategy observes the vehicle state and energy flows inside of the vehicle and between vehicle and charging infrastructure. Based on these observations, the operating strategy plans a guidance state of charge trajectory for the trip and dispatches recommendations for charging and discharging the traction battery to the vehicle's ECU. Additionally, the operating strategy ensures reliable service trips by checking if the current state of charge matches the estimated energy consumption for a fixed range laying ahead. The operating strategy can detect and mitigate a situation in which the vehicle may break down during the current service trip early. In such a case, the operating strategy recommends measures which reduce the energy consumption while compromising passenger comfort as little as possible.