Analysis of the Problem of Electric Buses Charging in Urban Transport

The electric bus is an ecological means of transport. Its operation reduces the negative impact on the environment. The transition to electric urban transport is in line with the concept of sustainable development of the European Union and the Polish "Act on Electromobility and Alternative Fuels". Today, on the streets of Polish cities, electric buses are increasingly replacing diesel-powered vehicles. The electrification of the bus fleet requires the establishment of an appropriate infrastructure for charging vehicle batteries. Electric chargers are placed at the end stops of the communication lines. When the bus stops at the end of the route, it is possible to partially recharge the energy consumed. The amount of recharged energy depends on many factors, such as the power of the charger, bus stop time, possible waiting time for a free charger, etc. In the event of incomplete replenishment of the consumed energy, the completion of subsequent courses may be endangered. The article proposes an approach to the analysis of the process of charging electric buses at the end stops of the route, taking into account the characteristics of the vehicle battery, the intensity of vehicle traffic, the characteristics of stationary chargers and its quantity. The proposed approach uses queue theory to describe the process of bus charging. The result of the research is the estimation of the use of the chargers in different configurations and the estimation of the state of charge of the bus battery for selected timetables.