Research On Dynamic Contactless Power Supply System And Application In Tram

With the rapid development of modern electrical engineering,power consumption devices are having increasingly higher requirements for the power supply system.The traditional power supply method is difficult to meet the needs of power consumption devices under the conditions of running in water,below ground,in rain or snow,and relative motion between power supply system and receiving equipment.The development of dynamic contactless power supply technology can effectively solve the above problems.At present,trams use overhead lines power supply or the third rail power supply technology as their main power supply method,but such power supply methods generally come with problems including affecting the appearance of the city and inducing the wear of the wires and pantograph slide plate.In order to solve these problems,this paper applies dynamic contactless power supply technology to moving trams through studying the transmission characteristics of dynamic contactless power supply system.The main research contents of this paper are:1.The dynamic contactless power supply model with double primary windings is established.Newman formula and finite element software Maxwell are used to calculate the mutual inductance of the system,and analyze the change of magnetic field.The main affecting factors of mutual inductance changes are discussed,and the transmission characteristic effecting rules of the system by the space of the transmitting coils and the turn number of the receiving coil are obtained in this paper.2.The dynamic Contactless power supply system with multiple primary windings is established.The total mutual inductance of the system is deduced by Biot-Savart law and vector magnetic potential principle.Based on the Newman formula,the mutual inductance network model is established,and the total mutual inductance of the system is calculated.The variation of magnetic field is discussed and analyzed,and the transmission characteristics of the dynamic contactless power supply system with double primary and multiple primary windings are compared.3.The dynamic contactless power supply system of the tram is established.According to the actual running conditions of tram,the dynamic magnetic coupling mechanism is designed,and the parameters of each power conversion device of the system are determined.This paper analyzes the transmission characteristics of the system under different operating conditions of trams,and determines the influence of resonance frequency and load resistance on the transmission characteristics of the system.The results show that the mutual inductance calculation method in this paper can relatively accurately calculate the mutual inductance of dynamic contactless power supply system.The arrangement spacing of the transmitting coils and the number of turns of the receiving coil have a significant effect on the transmission characteristics.Compared with the double primary windings system,the multiple primary winding dynamic contactless power supply system can transmit the electric energy more efficiently for the moving tram.By adjusting the load resistance,the transmission power of the system can be changed to meet the power demand of the tram at different speeds.The designed dynamic contactless power supply system can meet the electricity demand of trams,and the optimal resonance frequency and load resistance of the system during high efficiency power transmission are also given.