Embodiments of the present disclosure relate to a refrigeration system that includes a compressor configured to circulate refrigerant along a refrigerant loop, a motor configured to drive the compressor, and a variable speed drive coupled to the motor and configured to supply power to the motor. The variable speed drive includes a primary winding of a step down transformer coupled to an alternating current (AC) power source, a first secondary winding of the step down transformer, where the first secondary winding is configured to supply power at a variable supplied voltage to the motor when the motor operates below a threshold voltage, and a second secondary winding of the step down transformer, where the second secondary winding is configured to supply power at a fixed supplied voltage when the motor operates at or above the threshold voltage.

A gas compressor includes inverters, a plurality of compressor units and a control device for controlling each of the inverters. The control device increases the number of compressor bodies to be operated after confirming that the rotational speed of the operational motors will reach a steady value immediately after causing the number of the compressor bodies to be operated to increase.

Embodiments of the present disclosure include a motor controller with a processor and a machine readable medium. The medium includes instructions that, when loaded and executed by the processor, cause the processor to receive an estimated or sensed speed of a motor, extract a mechanical frequency component from the estimated or sensed speed, transform the mechanical frequency into direct quadrature (DQ) domain at the mechanical frequency, control the mechanical frequency to zero, and generate a dampening signal for torque based upon the controlled mechanical frequency.

The present disclosure provides a new and innovative method and system for flow rate compensation in devices, such as medical devices and other electronic devices. In various embodiments, a computer-implemented method includes dispensing, by a pump controlled by a controller, a fluid from a fluid supply in a pulse mode over a period by determining a pulse volume for a pulse, determining a pulse cycle time, and for the period: controlling the position of the pump to perform a delay and perform a pulse to dispense an amount of the fluid, the pulse performed for the pulse cycle time, calculating an overshoot or undershoot of the amount of the fluid dispensed relative to the pulse volume, adjusting the pulse cycle time based on the calculated overshoot or undershoot, and repeating the dispensing until the period has elapsed.

An electronic pressure compensated hydraulic motor pump is controlled to provide variable output power based on a variable input signal. The variable output power feature allows the motor pump to be used with a power management system to better match the output power of the motor pump with the available power of an electrical system. The ability to provide variable output power provides beneficial power management for electrical systems that switch between different power modes, e.g., between a generator power mode and a battery power mode.

A compressor control method of controlling the vibration amplitude of a compressor equipped with a motor by using the motor is provided. The compressor is driven by the motor, and this method includes controlling, in a specific operating area, the vibration amplitude of the compressor such that the vibration amplitude is substantially constant regardless of changes in the load imposed on the motor and in the number of revolutions of the motor per unit time.

A method for controlling a swash plate compressor and a swash plate compressor capable of preventing an overload by reducing an inclination angle of the swash plate if the torque calculated using compressor information is overloaded. Disclosed is a method for controlling a swash plate compressor including: a measuring step for measuring a compressor operation information of a swash plate compressor; a torque calculating step for calculating a calculated torque value of the swash plate compressor based on the compressor operation information; an overload determining step for determining whether an overload occurred or not by comparing the calculated torque value calculated in the torque calculating step with a torque set value; and an overload preventing step for preventing an overload by reducing an inclination angle of the swash plate of the swash plate compressor if the overload determining step determines that an overload occurred.

Proposed is a method of diagnosing abnormality of sensorless control of a motor for an air compressor, the method including estimating a speed of a motor in real time when a motor starts determining whether or not a preset condition for activating a function of diagnosing abnormality of sensorless control is satisfied, from a slope of the estimated speed of the motor performing control for decreasing an amount of electric current to be applied to the motor, in a case where the preset condition is satisfied computing an amount of decrease in the slope of the estimated speed of the motor while the amount of the electric current is decreased; and determining whether or not the sensorless control fails, by comparing the amount of the decrease in the slope of the speed of the motor with a preset value for confirming diagnosis of the abnormality of the sensorless control.

A method for operating an electric air compressor assembly. The assembly includes an electric motor and a compressor which is mechanically coupled to the electric motor and which is capable of providing compressed air to a tank The method comprises monitoring the temperature of at least one component of the electric air compressor assembly and controlling the motor speed as a function of said temperature running the motor at a first speed S1, which results in the temperature increasing; when the temperature reaches a temperature threshold, which is lower than a maximum admissible temperature, running the motor at a second speed S2>S1 until a predetermined desired pressure in the tank is reached.

A method for determining a current wear (w) of a hydrostatic pump, particularly of a radial piston pump, with a variable-speed drive, where the pump is connected to a fluid passage, in which a fluid is pumped by the pump to create a current actual volume flow in the fluid passage. A current actual volume flow (Q.sub.act) is determined, by measuring the volume flow in the fluid passage at a predetermined drive-vector, a computed volume flow (Q.sub.comp) is determined, by a first computational method, at the predetermined drive-vector, and the current wear (w) of the pump is determined, by a second computational method, which relates the current actual volume flow (Q.sub.act) to the computed volume flow (Q.sub.comp).