Aspects are provided for positive displacement pumps and methods and systems for controlling such positive displacement pumps for accurate volume dispensing. The pump may run a calibration procedure to determine a mapping between a pump speed and a flow rate for a current configuration of the positive displacement pump, a tubing size, and a fluid characteristic. A pump controller may determine a pump motion profile based on the mapping. The pump motion profile includes an acceleration phase, a constant speed phase, and a deceleration phase such that a total volume pumped according to the pump motion profile and the mapping is equal to a target volume. The pump controller may determine an adjustment to the pump motion profile based on a constant flow rate measured during operation. The pump controller may decelerate the positive displacement pump according to the adjusted pump motion profile until the target volume is dispensed.

A system for driving a hydraulic fracturing pump includes an electric motor having a drive shaft configured to rotate at a constant speed and a power source electrically connected to the electric motor. The system also includes a motor controller operably connected to the electric motor via a relay, wherein the motor controller is operably connected to the electric motor by the relay to start the electric motor, and is operably disconnected from the electric motor by the relay once the drive shaft reaches the constant speed. The system further includes a pump coupled to the drive shaft via a transmission, wherein the transmission is configured to transfer rotational energy from the drive shaft to the pump via an output shaft of the transmission, the output shaft of the transmission being configured to drive the pump at varying speeds while the drive shaft rotates at the constant speed.

A fracturing apparatus may include a first plunger pump including a first power end and a first hydraulic end; a prime mover including a first power output shaft; and a first clutch including a first connection portion and a second connection portion. The first power end of the first plunger pump includes a first power input shaft, the first connection portion is coupled to the first power input shaft, the second connection portion is coupled to the first power output shaft of the prime mover.

The disclosure provides a method for monitoring a pumping system, comprising measuring the speed of a motor of the pumping system, wherein the pumping system further comprises a first pump and a second pump, wherein a control system is configured to operate the pumping system; determining a timeout period, wherein the timeout period is dependent on the speed of the motor; measuring the speed of the first pump, the second pump, or both, wherein there is a hall-effect sensor coupled to each of the first pump and the second pump; determining a designated operating condition of the pumping system; and determining if the first pump, the second pump, or both are enabled to operate in relation to the designated operating condition.

A system and method of operating a variable-speed electrohydraulic pump, in which a pump delivery mechanism having an adjustable control volume is driven by an electric machine, includes activating the variable-speed electrohydraulic pump with a specific control volume and a specific speed, such that a specific volume flow is provided. The method includes obtaining control information for an actuator which indicates an increase in the volume flow and increasing the speed and reducing the control volume in response to the obtained control information. The method includes activating the variable-speed electrohydraulic pump to increase the volume flow after increasing the speed and reducing the control volume.

Embodiments to help detect operation conditions of a compressor of a TRU in real time by a genset are disclosed. The operation conditions of the compressor can be determined by monitoring a parameter pattern of the genset, such as value changes of a horsepower, a torque, an exhaust temperature, fuel consumption and/or a RPM of a prime mover of the genset, or a current drawn from a generator of the genset, over a period of time. In one embodiment, when a scroll compressor is used in the TRU, the scroll compressor may start a periodical load/unload duty cycle when the TRU reaches its setpoint. The periodical load/unload duty cycle of the scroll compressor can be detected based on a corresponding fluctuation pattern in genset parameters. When this periodically fluctuating pattern of ECU parameters and/or current drawn is detected, the prime mover can be switched to a low operation speed.

A water pumping system, a motor drive, and a method of starting pumping by the motor drive. The method includes powering the electric motor with a motor drive; driving a progressive cavity pump with the electric motor; monitoring a speed difference between an electrical speed and an observed speed of a rotor of the electric motor; and performing a protective action as a function of the speed difference.

According to the present invention, a control method for a clothing treatment device comprises the steps of: transmitting a power-related order to a motor that provides electric power to a drain pump in order to perform a dehydration process; detecting a unit revolution count of the motor while the dehydration process is performed; determining whether the detected unit revolution count exceeds a preset limited revolution count; reducing the unit revolution count of the motor to a predetermined unit revolution count if the detected unit revolution count exceeds the limited revolution count; and repeatedly transmitting the power-related order to the motor.

Provided is a pump apparatus capable of suppressing an unintentional ejection of a high-pressure liquid from a nozzle. A pump apparatus including: an injection chamber having a door; a nozzle arranged in the injection chamber; a pump connected to the nozzle for discharging liquid; a motor for driving the pump; a door sensor for detecting that the door is closed; and a control device capable of communicating with the door sensor, the control device having a motor rotation unit for supplying driving power to the motor only when the door sensor detects that the door is closed.

An operation controlling apparatus of a reciprocating compressor includes: a detector configured to detect a torque output by a motor of the reciprocating compressor, a rotation speed of the motor, a counter electromotive voltage of the motor, and a current applied to the motor; a controller configured to determine a mode switching time point for switching an operation mode of the reciprocating compressor based on the torque, the rotation speed, the counter electromotive voltage, and the current of the motor, and output a control signal for changing a wire ratio of the motor corresponding to the operation mode; and a driver configured to change the wire ratio of the motor based on the control signal and operate the reciprocating compressor in the operation mode among at least two operation modes.