Ultracapacitor-Based Auxiliary Energy System for Construction Machinery

摘要

Regenerative braking is an effective approach for construction machinery to extend their driving range. In the system, an ultracapacitor is preferred for high power buffer and regenerative braking energy storage because it has the advantages of high power density, long life cycles, and high efficiency. Bidirectional dc-dc converters for the automotive applications typically are limited to generate only a small voltage ripple, especially when the ultracapacitor with a limited ripple current capability is interfaced by the converter. This paper presented an ultracapacitor-based energy storage system design for motor hoist. In order to provide constant input and output current for the ultracapacitor, this design uses a double proportional-integral (PI) control strategy in regulating the duty cycle of Pulse Width Modulation (PWM) to the DC/DC converter. The simulation experiment proved the correctness of theoretical analysis.