Semikov O. Energy efficient electric vehicle electric drive with supercapacitor battery

The work is related to the creation of a laboratory model of an electric vehicle for educational and scientific purposes at the Department “Automated Electromechanical Systems” at NTU “KhPI”. This is necessary for the training of qualified personnel capable for solving problems of diagnosing, programming, operation and repair of electric vehicles. The transition to them reduces the cost of hydrocarbon resources and improves the environmental situation in large cities. Also, their number is growing rapidly in Ukraine. A survey of electric vehicles of leading foreign companies was conducted. The principles of electric vehicles electric drive development are formulated; the functional and basic schemes of electric drive are designed. The use of a supercapacitor battery as a power source is proposed. Methods of electric drive components calculation are offered. The method of load equivalence at the choice of the electric motor by introduction of specific on weight of forces and capacities and mass-dimensional factor is developed. Mathematical and computer models of traction electromechanical system are developed, taking into account: nonlinearity of resistance forces due to aerodynamic component, nonlinearity of wheels coupling forces with a road surface, nonlinearity of magnetization characteristics, pulse width modulation, discreteness of control system. Computer modeling of electromechanical and electromagnetic processes in dynamic and static modes for different conditions of movement is carried out and correspondence of time diagrams character to physical essence of processes is established. The laboratory stand for experimental research of supercapacitors in regenerative modes is designed and expediency of its use is proved. Computer simulation was carried out, the analysis of the results allowed to propose new principles of multiphase pulse-width converter design, which provides a rational distribution of currents between the accumulator battery and supercapacitors. The estimation of energy efficiency of the proposed schemes in various standard cycles of movement taking into account losses in electric drive components is executed. It is shown that the electricity saving is 13...24 % depending on traffic conditions. The anomalous modes of the electric vehicle electric drive operation during wheel slipping are investigated and it is shown that easily measured values of slipping occurrence establishing at the presence of a pulse speed sensor on wheels can be derived armature current, wheel acceleration and its derivative. The first in Ukraine electric vehicle with supercapacitors was developed and created on the basis of “Lanos” car. The operability of the developed electric drive is confirmed.