A centrifugal pump assembly includes an electric drive motor (6, 8), a driven impeller (14) and a pump casing (2) which surrounds the impeller (14). A movable element (24; 24′) is arranged a valve element. A section of the valve element is movable from a released position into a bearing position, fixed on a contact surface (60), by pressure which is produced by the impeller in the pump casing. A control device (64) moves the valve element from one switching position into another switching position and reduces the speed of the drive motor. Upon pressure in the pump casing dropping such that the valve element is no longer fixed on the contact surface and the valve element has been moved into the other switching position, the control device increases the speed of the drive motor again. A method for moving a valve element is provided.

A computer-controlled motorized pump system is provided. A generator is mechanically connected to a power takeoff. A first controller receives AC power from the generator and converts the AC power to DC power and provides DC power to a computing system that has one or more processors and one or more computer-readable hardware storage media and a user interface. A second controller is directly coupled to the first controller and provides AC power to a motor. The motor is mechanically connected to a pump, and the motor is in communication with, or controlled by, the computing system.

A fume extraction apparatus (1) which comprises an extraction pump (6), and the apparatus further comprising a sensor arrangement (12a, 12b, 13) to measure a differential pressure across the pump and to measure a speed of the extraction pump, and the apparatus comprising a controller (10) which comprises a data processor, the data processor arranged to calculate a flow rate of air through the pump using the measurements from the sensor arrangement, and to compare the calculated flow rate to a target flow rate, and the controller arranged to issue a control signal to control the speed of the pump so as to better align the flow rate with the target flow rate.

Disclosed herein is a user interface that can be universally mounted to a combination variable speed pump and a drive assembly therefor. The user interface is universally configured to be selectively mounted to the drive assembly and/or to an environmental surface that is remotely located from the drive assembly. The user interface is universally configured to be selectively mounted to the drive assembly in any one of a plurality of available positions relative thereto.

A method comprises operating an electric submersible pump (ESP) motor downhole in a well. The ESP motor is electrically connected to a variable speed drive (VSD) proximate to the well. The operating comprises measuring a revolution rate and a motor current of the ESP motor for a first period of time and performing a first adjustment of a voltage output of the VSD. The method comprises measuring, after the first adjustment, the revolution rate and the motor current of the ESP motor for a second period of time determining a difference between the motor current measured for the first period of time and the motor current measured for the second period of time; and performing a second adjustment of the voltage output of the VSD based on a change in the revolution rate and the motor current between the first period of time and the second period of time.

A converterless motor-driven pump system includes an off-grid prime mover, an electric power generator driven by the off-grid prime mover to generate a power output, an electric submersible pump (ESP) system, and a system controller. The ESP system includes a motor coupled to the electric power generator to receive the power output, and a pump driven by the motor to pump a fluid. The system controller includes a processor and a memory. The memory includes instructions that, when executed by the processor, cause the system controller to control the off-grid prime mover as a function of an operational parameter of the ESP system to maintain a desired operating point of the pump, and control the electric power generator to reduce the power output generated by the electric power generator while the desired operating point of the pump is maintained.

A hydraulic system includes at least one circulation pump assembly (2) provided with a speed controller (4, 26), at least one hydraulic circuit (A, B) connected to the circulation pump assembly (2) as well as at least one mechanical switch device (86, 88; 120, 122) which is mechanically subjected to pressure by a fluid in the hydraulic circuit (A, B) and which can be moved into at least two different switch positions. The mechanical switch device (86, 88; 120, 122) moves by the circulation pump assembly (2) hydraulic coupling via the fluid. The speed controller is configured to initiate a movement of the switch device (86, 88; 120, 122), by at least one hydraulic force acting upon the switch device (86, 88; 120, 122) and causing a movement of the switch device (86, 88; 120; 122) via the hydraulic circuit, via a speed adaptation of the circulation pump assembly (2).

A method of setting up an electrical motor speed control in a fluidic system including a turbomachine, an electric motor having a number p of pole pairs rotating the turbomachine, a variable speed drive controlling the speed of the electric motor, a sensor measuring a parameter H, Q of the turbomachine, and a system controller receiving the sensor's measurements and controlling the operation of the fluidic system. The method includes driving the electric motor at a predetermined electrical frequency, Fe, such that the turbomachine rotates with a controlled rotational speed N, determining the point of intersection of the system curve of the fluidic system and of the performance curve of the turbomachine to obtain the turbomachine's nominal operating point, and thus the nominal value, Hn, Qn, of the turbomachine parameter, measuring, with the sensor, the current value, H, Q of the turbomachine parameter, calculating the controlled rotational speed N by inputting, into the Affinity Laws, the determined nominal value, Hn, Qn, the measured current value, H, Q, and the known nominal rotational speed, Nn, of the turbomachine, determining the number p of pole pairs of the electric motor based on the ratio of the electrical frequency Fe and the calculated controlled rotational speed N, and adapting the setup of the variable speed drive to match the determined number p of pole pairs.

An apparatus for controlling a fluid pump for a motor vehicle includes: a first controller configured to actuate an electric prime mover of the fluid pump by impressing at least one motor current with an adapted current intensity and an adapted waveform; and a second controller configured to detect a rotational speed of the electric prime mover and to apply an adapted voltage to the electric prime mover on the basis of the detected rotational speed.

Systems and methods for determining a pump flow (Q) of a pump are disclosed. A method for determining a pump flow (Q) of a pump includes calculating an inverse of a polynomial equation defining a DP-Q performance curve of a pump, where the inverse is a Q-DP polynomial equation defining the performance of the pump, receiving a pump head (DP) value from a pump head sensor associated with the pump, computing a pump flow based on the Q-DP polynomial equation, comparing the computed pump flow to a preset target flow rate, and automatically controlling a pump parameter of the pump such that the calculated flow rate becomes the preset target flow rate.