Simulation of the electric starter system of the internal combustion engine start-up to study the impact on its operation of the pre-start battery discharge

The article is devoted to the actual problem of starting an automobile engine in conditions of low negative temperatures. To increase the likelihood of starting the engine when using autonomous means of pre-heating, it is necessary to optimally distribute the battery energy to the pre-start and start-up discharges. As a part of the creation of a system, an automated pre-start thermal preparation of an automobile engine the need arises to conduct research on the influence of the battery starting-up discharges on the parameters characterizing the functioning of the electric starter system.

Research methods. A mathematical model of the electric starter system for starting the internal combustion engine is presented. The model is implemented using the software Mathcad 15.

Results. As a result of the simulation of the start-up system, the dependencies of the crankshaft rotation speed on time have been obtained for various values of battery discharge and temperature. According to the frequency of rotation of the crankshaft and the coefficient of dynamism of the battery discharge and the temperature of the electrolyte are also derived.

Findings. As a result of analyzing the data obtained in mathematical modelling it was determined that with decreasing electrolyte temperature the effect of the pre-discharge of the battery on the rotational speed of the crankshaft increases significantly. The ratio of the maximum rotational speed to the rotational speed of the crankshaft at the end of the start-up is almost independent of the degree of the battery discharge.