Research On Regenerating Energy Storage System Of Electric Bus

With the growing of car ownership, the energy crisis and environmental pollution are more and more serious, electric vehicles play an important role as an effective way to solve these problems and are favored by the government gradually. But batteries are expensive and have a limited cycle life, it is difficult to accept the frequent replacement of battery. With the development of technology, super capacitor as a new type of components has appeared in the developer’s vision. Super capacitor’s high power density, fast charge and discharge rate and long cycle life make up with the deficiencies of battery, this paper use a combination of batteries and super capacitors as the energy storage system (ESS) to make full use of super capacitor’s high power density and battery’s high energy density, it will eventually become the most effective way to solve the problem of promotion and development of electric vehicles.Firstly, this paper has explained the charge and discharge characteristics of battery and super capacitor, and introduced several models of super capacitor and pressure technologies briefly, and focused on the array configuration optimization from the super capacitor deviations, given the optimal configuration and combinations.Secondly, this paper has described the working principle of the structure with super capacitor and battery energy storage system in detail, calculated the parameters of super capacitor and battery’s capacities in the selected models. This paper alse has used a bi-directional half-bridge DC/DC converter as the main circuit topology to connect the super capacitor considered the characteristics of the ESS, and calculated the parameters of the components converter, then established the bi-directional DC/DC converter’s mathematical model and proposed voltage current loop and power current loop control strategies.Thirdly, this paper has made a comparative analysis between the single battery ESS and super capacitor and battery ESS by using Matlab/Simulink,and the simulations have verified the limitations of the single ESS and reflected the superiorities of compound ESS. This paper has studied a power allocation strategy based on logic threshold control with filtering thought in the compound ESS, and utilized the outer power and inner current loop to achieve the super capacitor for braking energy recovery and reuse.Finally, this paper has used the electric vehicle simulation software Advisor2002and made the second development, explained the outline of second development process from the super capacitor battery model, bi-directional DC/DC power distribution models, and simulated electric buses in ECE, NYCC and1015three kinds of conditions by using this software ultimately, the simulation waveform display has proved compound ESS plays load shifting role, compound ESS can extend the driving range and battery life, improve storage energy efficiency.