JUSTIFICATION OF THE PARAMETERS OF THE PASSENGER CAR SERIES HYBRID POWER PLAN

Abstract

The use of hybrid power plants in road transport can significantly improve driving dynamics and driving comfort, reduce its operating fuel consumption and emissions of harmful substances with exhaust gases. Due to the large number of used cars with internal combustion engines (ICE) in Ukraine, it is of interest to convert them into a hybrid power drive. However, the analysis of the literature revealed extremely limited information about the work in this direction. The paper proposes a method for selecting the parameters of elements of a series hybrid power drive based on a used Chevrolet Lacetti car. The technique is based on the use of mathematical models of the working process of the internal combustion engine, the dynamics of the acceleration of the car, the determination of the parameters of the series hybrid power plant in the modes of the European NEDC test cycle. Using the developed mathematical models, the rated power of the traction electric motor is 86 kW, the nominal and maximum rotational speed of its shaft, respectively, are 1860 and 7000 min-1. It is shown that the car will accelerate to 100 km/h in 11.4 seconds, which fully satisfies the conditions of comfortable driving in urban conditions. As part of a hybrid power plant, the internal combustion engine operates in one mode. The paper substantiates the choice of the operating mode of the internal combustion engine, where it has the best fuel efficiency. At the same time, its power is 34 kW, and the crankshaft speed is 2200 min-1. Accordingly, the power of the current generator will be 30 kW at a shaft speed of 2200 min-1. The paper analyzes the influence of the battery capacity, the presence of braking energy recuperation, the operating range of battery capacity change on the average operating fuel consumption of internal combustion engines. It is shown that an increase in the battery capacity, the presence of recuperation, and the expansion of the operating range of changes in the battery capacity lead to an improvement in the operational fuel efficiency of an internal combustion engine. Based on the results of computational studies, the maximum battery capacity of 1.3 kWh was selected; the operating range of capacity change was 0.8 kWh. The use of elements with such parameters will ensure the average operating fuel consumption of the internal combustion engine is 6.5 l/100 km, and with the recovery of braking energy - 6 l/100 km.