A drilling fluid pump system includes a plurality of modular pump units that are each driven by a linear electric motor. A control system that can include positional feedback information which is used to control all of the linear motors in the pump system and reduce pressure pulsation. The linear motors can be controlled to reduce fluid pressure pulsation by controlling velocity and relative timing between pistons. To accommodate removal and addition of individual pump units the pump modules can be isolated electrically and hydraulically. This can improve scalability, reliability, and serviceability of the pump system.

Presented herein are systems and methods for attenuating flow ripple generated by a hydraulic pump. In certain aspects, a method and system for operating a hydraulic positive displacement pump according to a stabilized command profile are disclosed, such that flow ripple generated by operation of the pump according to the stabilized command profile is attenuated as compared to operation of the pump according to a corresponding nominal command profile. In other aspects, a pressure-balanced active buffer is disclosed that allow for at least partially cancelling flow ripple in a hydraulic circuit comprising a pump. In another aspect, a method for generating ripple maps for a pump is disclosed. Such ripple maps may be used, for example, to determine the stabilized command profile used to operate the pump, or may be used by the pressure-balanced active buffer to counteract ripple in the hydraulic circuit.

Presented herein are systems and methods for attenuating flow ripple generated by a hydraulic pump. In certain aspects, a method and system for operating a hydraulic positive displacement pump according to a stabilized command profile are disclosed, such that flow ripple generated by operation of the pump according to the stabilized command profile is attenuated as compared to operation of the pump according to a corresponding nominal command profile. In other aspects, a pressure-balanced active buffer is disclosed that allow for at least partially cancelling flow ripple in a hydraulic circuit comprising a pump. In another aspect, a method for generating ripple maps for a pump is disclosed. Such ripple maps may be used, for example, to determine the stabilized command profile used to operate the pump, or may be used by the pressure-balanced active buffer to counteract ripple in the hydraulic circuit.

A pumping system includes at least three electrically driven pumping units. Each pumping unit includes a linear actuator driven by at least one electric motor and driving a shaft. Pistons on each end of the shaft move within fixed cylinders to draw fluid from an inlet and expel the fluid to an outlet. Each pumping unit draws fluid at one end while expelling an equal quantity of fluid at the opposite end. The shaft velocity is controlled such that a total flow of the pumping system is constant, eliminating flow ripple.

A metering pump is joined to the stepping motor, includes an eccentric mechanism converting a revolving motion of the stepping motor into a reciprocating motion of a plunger, and makes a constant liquid delivery by sucking and discharging an anesthetic agent through variations in the cubic volume of a cylinder caused by the reciprocating motion of the plunger. The control section: calculates a suction and discharge cycle T of the metering pump on the basis of a set anesthetic-gas concentration and a fresh-gas flow rate; sets a discharge period T2 of the cycle T to be longer than a suction period T1 of the cycle T; and controls the revolution speed of the stepping motor so that the travelling speed of the plunger is kept constant during the discharge period T2.

A control system and method of a VFD-based pump. The control system controls an electric motor via a VFD, and the electric motor drives the pump. The control system comprises: an anti-ripple injection module for injecting an anti-ripple signal into a control path, the anti-ripple signal causing pressure ripples in the pump output to be at least partially cancelled. Further a pump system, comprising: a VFD, an electric motor, and a pump, wherein the VFD comprises the control system stated above.

A method is provided for actively compensating for pressure changes of a working fluid within a conduit. A first cavity is provided in fluid communication with the conduit. A second cavity is in fluid communication with a control fluid. A plunger is in communication with both the first cavity and the second cavity and is movable in response to pressure changes of the working fluid in the conduit. The plunger is re-centered. Re-centering the plunger includes the following steps. Position data representative of movement of the plunger is collected. The position data is analyzed with a control unit to determine an average position of the plunger which is offset relative to a center position. The average position of the plunger is compared, with a control unit, to the center position. A signal is relayed from the control unit to a control valve to urge the plunger toward the center position.

The present invention relates to a volumetric pump that comprises an inlet section and an outlet section. The pump also comprises a first volume with variable geometry that is connected through a first suction valve to said inlet section and through a first delivery valve to said outlet section, and a second volume with variable geometry that is connected through a second suction valve to said inlet section and through a second delivery valve to said outlet section. There are also provided first means for varying the volume of said first volume with variable geometry and second means for varying the volume of said second volume with variable geometry, and actuator means of said first means for varying the volume of said first volume with variable geometry and of said second means for varying the volume of said second volume with variable geometry. Advantageously, said actuator means comprise a servo motor.

A monitoring system for a plurality of pressure pumps may include, for each pump, a strain gauge, a position sensor and a pressure transducer. A strain gauge may be positionable on each pump to generate a strain measurement corresponding to strain in each pump. A position sensor may be positionable on each pump to generate a position measurement corresponding to a position of a rotating member corresponding of each pump. A pressure transducer is positionable on each pump to generate a boost pressure measurement that is usable with the strain measurement and the position measurement to determine a cavitation threshold for each pump.

Presented herein are systems and methods for attenuating flow ripple generated by a hydraulic pump. In certain aspects, a method and system for operating a hydraulic positive displacement pump according to a stabilized command profile are disclosed, such that flow ripple generated by operation of the pump according to the stabilized command profile is attenuated as compared to operation of the pump according to a corresponding nominal command profile. In other aspects, a pressure-balanced active buffer is disclosed that allow for at least partially cancelling flow ripple in a hydraulic circuit comprising a pump. In another aspect, a method for generating ripple maps for a pump is disclosed. Such ripple maps may be used, for example, to determine the stabilized command profile used to operate the pump, or may be used by the pressure-balanced active buffer to counteract ripple in the hydraulic circuit.