Mobile hydraulic generator and control method thereof

A mobile hydraulic generator comprising:

• a storage tub configured to receive hydraulic oil returned from at least one hydraulic actuator;
• a plurality of flow-generator subsystems, each of which comprises
• a motor servo loop controller and
• a flow generator,
• wherein the flow generator is connected to the storage tub,
• wherein the flow generator comprises a pump and a motor,
• wherein the motor generates an amount of flow of a hydraulic fluid, and
• wherein the motor servo loop controller controls the pump based on an RPM input signal;
• a manifold having passages connected to the plurality of flow generators;
• a hydraulic servo loop controller configured to select, from said plurality of flow generators, a number of operating flow generators and to generate RPM input signals for each of the motor servo loop controllers associated with the selected operating flow generators based at least in part on a required hydraulic pressure to operate the at least one hydraulic actuator;
• and
• a proportional hydraulic control valve to control output hydraulic pressure of the manifold to the at least one hydraulic actuator,
• wherein the hydraulic servo loop controller generates a pressure control signal for controlling the proportional hydraulic control valve.