| The main research object of this paper is the supercapacitor voltage equalization and surplus energy collection circuit applied to non-contact trams.The energy storage power used in non-contact trams is a super capacitor bank formed by series and parallel connection of several single capacitors.Due to production process and other problems,there will be parameter differences between super capacitors,resulting in voltage imbalance between series capacitors and endangering the service life of capacitors.In addition,due to the characteristics of the capacitor itself,the terminal voltage will drop with the decrease of its stored energy.When the terminal voltage is lower than the minimum working voltage of the on-board inverter,the capacitor array will no longer transmit energy outward,resulting in a waste of energy.These two problems restrict the application of supercapacitors in trams.The supercapacitor voltage balance and residual energy collection circuit proposed in this paper can make the monomer capacitors maintain the voltage balance between each other in use,collect the residual energy of the capacitor,and improve the energy utilization rate of the capacitor bank,which has a high research value and application prospect for the tram.First of all,the problems in the use of supercapacitors are analyzed and introduced in detail,and the working principles of several typical voltage equalizing circuits are analyzed.At the same time,the arrangement of the supercapacitor array is analyzed and the connection mode of the single capacitor in the capacitor array is determined.Secondly,this paper analyzes the circuit structure and circuit principle of switching inductance voltage sharing scheme and switching capacitor voltage sharing scheme in detail,and establishes a simulation model through Matlab /Simulink to compare the advantages and disadvantages of the two voltage sharing schemes.Combined with the application scenario of the tram in this paper,the voltage sharing scheme is finally determined as the switching inductor voltage sharing circuit.Then,based on the switching inductor voltage equalizing circuit,the proposed complementary energy collecting circuit is analyzed and verified in detail,and the corresponding simulation model is established.Compared with the traditional energy storage power without the use of residual energy collection circuit,the energy utilization rate of this scheme is greatly improved.Finally,an experimental verification platform for the voltage equalization and residual energy collection technology of the supercapacitor is built.The core of the control system is based on TMS320F28335.The hardware structure of the experimental platform is analyzed in detail and the corresponding software program algorithm is designed.The proposed circuit of voltage equalization and surplus energy collection for supercapacitors is verified by experiments.The experimental results prove the validity and feasibility of the circuit.There are 74 figures,6 tables and 92 references in this paper. |
