Research On Modeling And Energy Distribution Algorithm For Extended-range Electric Bicycle

The extended-range electric bicycle (EREB) is an electric bicycle installed with an extra range-extender (RE) which consists of an engine and an integrated-starter-generator (ISG) motor. The EREB works in extended range mode with insufficient battery or power undercapcity, which greatly enlarges the driving mileage. The RE, battery and the driving motor are connected using electrical connections, thus the working condition of RE is relatively independent from the bicycle operation mode. Then we can use the reasonable energy distribution algorithm to control the RE works at the lower emission and better fuel economy area.This article designs the energy management algorithm in order to optimize the fuel economy based on an EREB while ensuring the performance and cycle life of battery. The main content and conclusions are as follows:Firstly, the model is built on the software simulation platform AVL Cruise using the power system of the real EREB by the vehicle kinetic equation theory. The parameters of the battery what is entered into the battery module in Cruise can establish the efficiency model of the battery combining with the theoretical analysis. The performance test which is taken into consideration for RE can construct the steady-state fuel consumption model of RE and combine the theoretical modeling method to establish the RE’s model in Cruise.Secondly, investigate on the energy flow and the efficient characteristics of the components of EREB and research on the vehicle energy management algorithm in order to optimize the fuel economy of EREB. This paper introduces the conception of "the instantaneous equivalent consumption of battery", a theoretical basis for the electric energy consumption or replenishment of the battery converted to the fuel consumption of RE, and an energy minimization distribution algorithm based on the instantaneous equivalent consumption. At the meantime, research about the traditional energy distribution algorithm of EREB.Finally, choose the target vehicle conditions in order to study about the fuel economy of EREB based on the established EREB’s module. Based on the co-simulation method with Cruise and MATLAB/Simulink demarcate the equivalent fuel conversion coefficient of the charge and discharge battery and analysis the simulation result of different algorithms. Based on the selected target vehicle conditions and the condition in which the initial SOC of battery is 45%, the integrated fuel consumption rate of the instantaneous optimization algorithm, the power follow strategy and constant power strategy are separately 0.724L/100km,1.340L/100km and 0.889L/km which shows that the instantaneous optimization algorithm can significantly improve the vehicle fuel economy.