Development of integrated fuel cell hybrid power source for electric forklift
ABSTRACT A hybrid drivetrain comprising a 16 kW polymer electrolyte membrane fuel cell system, ultracapacitor modules and a lead-acid battery was constructed and experimentally tested in a real counterweight forklift application. A scaled-down version of the hybrid system was assembled and tested in a controlled laboratory environment using a controllable resistive load. The control loops were operating in an in-house developed embedded system. The software is designed for building generic control applications, and the source code has been released as open source and made available on the internet. The hybrid drivetrain supplied the required 50 kW peak power in a typical forklift work cycle consisting of both loaded and unloaded driving, and lifting of a 2.4 tonne load. Load variations seen by the fuel cell were a fraction of the total current drawn by the forklift, with the average fuel cell power being 55% of nominal rating. A simple fuel cell hybrid model was also developed to further study the effects of energy storage dimensioning. Simulation results indicate that while a battery alone significantly reduces the load variations of the fuel cell, an ultracapacitor reduces them even further. Furthermore, a relatively small ultracapacitor is enough to achieve most of the potential benefit.Research highlights► We built a hybrid power source for a heavy electric counterweight forklift. ► We study hybrid drivetrain with real work cycle data to validate modelling tools. ► Embedded control system hardware and software are released under open source license.
- SourceAvailable from: Mykhaylo V LOTOTSKYY[Show abstract] [Hide abstract]
ABSTRACT: A light electric vehicle (golf cart, 5 kW nominal motor power) was integrated with a commercial 1.2 kW PEM fuel cell system, and fuelled by compressed hydrogen (two com-posite cylinders, 6.8 L/300 bar each). Comparative driving tests in the battery and hybrid (battery þ fuel cell) powering modes were performed. The introduction of the fuel cell was shown to result in extending the driving range by 63e110%, when the amount of the stored H 2 fuel varied within 55e100% of the maximum capacity. The operation in the hybrid mode resulted in more stable driving performances, as well as in the increase of the total energy both withdrawn by the vehicle and returned to the vehicle battery during the driving. Statistical analysis of the power patterns taken during the driving in the battery and hybrid-powering modes showed that the latter provided stable operation in a wider power range, including higher frequency and higher average values of the peak power.International Journal of Hydrogen Energy 01/2013; 38:10630. · 2.93 Impact Factor