Fuel cells system and method of controlling cells

Abstract

A system which enables fuel cells to be activated at a working point of high energy conversion efficiency. A control unit calculates a required output of an inverter from an input accelerator travel. The control unit specifies an output electric current-output voltage characteristic corresponding to a gas flow rate, obtains a point of highest energy conversion efficiency on the specified characteristic to specify the point as a working point of fuel cells, and computes an output electric power of the fuel cells at the specified working point. The control unit determines an output voltage required to a battery, based on a difference between the calculated required output of the inverter and the computed output electric power of the fuel cells and a state of charge of the battery. The control unit controls a DC—DC converter and regulates the output voltage of the DC—DC converter, so as to cause the battery to generate the output voltage thus determined. The control unit subsequently controls the inverter, so as to cause a motor to consume electric power corresponding to the required output.

Dependencies are inferred from the claim text.