PURPOSE: To optimize response characteristics of control by controlling increase and decrease of engine power in proportion to fuel flow demand, and granting braking function to a fuel supply portion when the fuel decrease demand exceeds a predetermined fuel decrease rate.

CONSTITUTION: A fuel flow demand signal generated by a speed controller in a front stage is inputted to a proportional amplifier 26 and an integrator 22 in a pump controller 14 to obtain difference with a speed signal in accordance with the output of a tachometer 18 by the proportional amplifier 26 and the difference is integrated by the integrator 22. An output pulse signal is generated by a drive pulse width controller 28 in accordance with the output of the proportional amplifier 26 and integrator 22. An output pulse signal is generated by a brake pulse width controller 40 in accordance with the output of the proportional amplifier 26. A part of the outputted pulse signal is impressed to a powered drive 20 via an FF 32 or 42 driven by the output of a brake threshold circuit 34 to control a fuel pump/electrical motor 16.