Assessment of energy management factors of large-sized vehicles with hybrid powertrain

Due to the tightening of environmental standards for urban transport, in particular due to the introduction of the EURO-7 standard, the relevance of improving the energy management of large-sized vehicles with a hybrid power plant is increasing. The work demonstrates approaches to optimizing energy consumption in hybrid city buses based on mathematical modeling (functional optimization). The purpose of the research is to build a multifactor mathematical model that allows minimizing fuel consumption and increasing the overall energy efficiency of the hybrid transport system. The work uses the functional optimization method based on variational calculus, in particular, the Lagrange multiplier and the Hamilton condition are applied. The proposed methodology for calculating the efficiency of the energy system is tested on the basis of the Volvo 7900 Hybrid hybrid bus with an assessment of energy consumption and fuel consumption. The analysis was carried out taking into account the real urban traffic cycle, which allows assessing the efficiency of energy use in variable operating conditions. As a result of the modeling and application of functional optimization of energy consumption for the specified bus model, it was possible to achieve significant improvements in energy performance. In particular, the average required power of the diesel engine was reduced from 98.5 to 85 kW, which allowed to reduce the load on the power plant and improve its efficiency. The efficiency coefficient of the internal combustion engine was increased to 0.37 due to the engine operating in optimal modes. The most significant result was a decrease in average fuel consumption from 32.5 to 19 l/100 km, which corresponds to a saving of 42%. Such indicators were achieved due to the reasonable distribution of energy flows between the internal combustion engine, electric motor and battery, the effective use of regenerative braking, as well as taking into account real road conditions and technical parameters of the vehicle. The results obtained prove the feasibility of implementing the proposed model in modern energy management systems of city buses.