Hybrid Energy Storage Power Allocation and Motor Control for Electric Forklifts

Abstract

Enhancing transportation efficiency is the preeminent place to start efforts to minimize emissions of carbon dioxide which is a crucial malefactor in global warming. Due to awe-inspiring advantages over vehicles with internal combustion engines, use of electric vehicles (EVs) finds application in a variety of areas. However, energy storage system (ESS) of the EV plays an important role in EV's performance and can be a limiting factor in its utilization. To mitigate problems arise from ESSs, different storage equipment can be combined into an integrated hybrid energy storage system (HESS). In this paper, the effectiveness of a HESS comprising lithium-ion battery pack and supercapacitors, has been tested by simulating a simple power splitting scheme in an electric forklift application considering a real world drive cycle. With the purpose of numerical investigation, battery and supercapacitor models in Simulink SimPowerSystems are used, induction motor parameters are estimated using data sheet values and field oriented control (FOC) technique is adopted to drive motors. Simulation results have shown that HESS could reduce stress on the battery by limiting peak and surge power demands.