Power Distribution Strategy for an Electric Bus with a Hybrid Energy Storage System

• Published in: World electric vehicle journal Vol. 12; no. 3; p. 154
• Main Authors: Zhang, Yu, Li, Kai, Cui, Shumei, Sun, Yutian
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2021
• Subjects: Acceleration; Buses; Control methods; Design; Driving ability; Driving conditions; electric bus; Electric power distribution; Electric power systems; Electric vehicles; Energy distribution; Energy flow; Energy management; Energy storage; Energy utilization; Friction; Fuzzy control; Fuzzy logic; HESS; Hybrid systems; Lithium; Lithium batteries; Neural networks; power distribution; R&D; Research & development; Roads & highways; State of charge; Storage systems; Supercapacitors; Working conditions
• ISSN: 2032-6653; 2032-6653
• DOI: 10.3390/wevj12030154

To address the power distribution problem that occurs in hybrid energy storage systems (HESSs) in electric vehicles, a fuzzy control distribution method is proposed in this paper, taking the vehicle demand power; supercapacitor power, PSC;; and lithium battery power, Pbat, as the inputs and the power distribution factor of the supercapacitor as the output to control the power distribution of the composite energy storage system, in addition to dividing the whole working condition into three time scales, namely, long, medium and short. In this study, we conducted a comprehensive analysis and comparison with typical control methods regarding the energy storage element output power, battery state of charge (SOC) change, energy flow diagram and power frequency. The simulation experiment results show that the proposed strategy is more effective in reducing the peak output power of the power battery, improving the effective power utilization rate of HESS and the effective energy utilization rate. In order to further verify the effectiveness of the control strategy, a pure electric bus power system test bench was built based on similar principles, and a representative time period under the driving conditions of the China city bus (CHTC-B) was selected, involving an acceleration process from 30 to 48 s (process 1), a uniform speed process from 636 to 671 s (process 2) and a regenerative braking process from 1290 to 1304 s (process 3), further verifying the effectiveness and feasibility of the proposed control strategy.