FUEL EFFICIENT CRANE SYSTEM

摘要

A system and method for efficiently regulating the fuel consumption of a variable speed combustion engine used to control loads such as a hoist motor in a mobile gantry crane based on load motor speed commands issued by a crane operator. The system and method can rely on a programmable logic controller to issue engine fuel commands to regulate engine speed based on interpolations derived from data representing the relationship between load motor voltage and engine speed and data representing the relationship between engine speed and engine power capacity. The method may also be used in modified form by combustion engines which need digital fixed speed commands.

主权项

1. A method for providing a constant or nearly constant AC voltage to an auxiliary load on a crane having a variable speed combustion engine coupled to a generator producing a variable AC voltage onto a first AC bus which is converted into a variable DC voltage on a DC bus by a diode converter, wherein the variable DC voltage is further converted by an inverter into an AC voltage delivered on a second AC bus to the auxiliary load comprising:
obtaining a signal proportional to the voltage on the DC bus wherein the signal is one selected from the group consisting of a DC bus voltage, an AC voltage, an AC frequency or a generator speed; and calculating a normalized modulation index to present to the modulator inherent in the inverter.