A brushless DC motor system includes a brushless DC motor having phases and a controller in communication with the motor for operating the motor in accordance with a commutation table. The controller further has nodes. The system further includes phase wires electrically coupling the motor and the controller at the nodes to form wire-to-node connections for establishing electrical communication paths between the motor and controller along each phase wire. Each phase wire corresponds to one phase of the motor. The controller is programmed to, in response to a user-selected configuration of the wire-to-node connections, generate the commutation table.

The device coupled between a grid and a motor can dynamically soft start and soft stop a motor without the motor experiencing any power surges or jerks.

A vacuum pump drive having an electric motor and a frequency converter electrically connected to the electric motor and arranged at a distance to the motor, wherein in the electric feed line from the frequency converter to the electric motor a transformer in the form of a transmitter of ferrite or sinter material is arranged.

The apparatus according to the present invention comprises a command voltage determination circuit section configured to determine a predetermined first compensation voltage as a command voltage upon initial startup and provide the command voltage to an inverter; a conversion circuit section configured to convert an output current of the inverter into a q-axis current on a synchronous reference frame; and a compensation voltage determination circuit section configured to determine a second compensation voltage based upon the q-axis current and to provide the second compensation voltage to the command voltage determination circuit section.

In a method for actuating a motor for starting up a mill containing material to be ground, the motor for triggering sedimentation of the material to be ground in the mill is initially fed by a first inverter. The motor is subsequently disconnected from the first inverter, and in a further step the motor is connected to a first supply which has a first supply voltage. The maximum output voltage of the first inverter is lower than the first supply voltage.

An electric submersible pump (ESP) variable speed drive (VSD) controller is described. A VSD control system includes a pump assembly including an induction motor operatively coupled to a pump, a power cable and a transformer electrically coupled between the induction motor and a VSD controller that controls a speed of the induction motor, the VSD controller including a converter section that sends a direct current (DC), a DC link including a DC smoothing capacitor that smooths the DC, an inverter that converts the smoothed DC to a pulse width modulated (PWM) output voltage, the inverter including at least one silicon carbide (SiC) power semiconductor module, and a PWM filter that filters the PWM output voltage to produce near sinusoidal voltages, the PWM filter including inductors, and the PWM filter sending voltage to the transformer.

The invention relates to a control apparatus for a refrigerator compressor having at least one two-phase AC asynchronous motor (K1, K2), having mains connection means (10) for connection to a preferably public voltage supply network Which nominally provides a mains AC voltage of between 85 V and 264 V, in particular between 100 V and 230 V, first voltage converter means (14) which are connected downstream of the mains connection means and are intended to generate an intermediate voltage, in particular an intermediate DC voltage, from the mains AC voltage, second voltage converter means (16-1, 16-2) which are connected downstream of the first voltage converter means and are intended to generate an output signal which is independent of a level and a mains frequency of the mains AC voltage, in particular has a constant voltage and/or frequency in periods, and is intended to control the refrigerator compressor with an AC voltage of a plurality of differently predefinable voltage levels, wherein the mains connection means are assigned voltage detector means (12) for capturing the mains AC voltage, the detector output signal from which can be evaluated by the second voltage converter means or control means (24) assigned to the latter for the purpose of generating a mains-voltage-dependent maximum value for a current of the output signal.

A pump assembly (1) includes a pump unit (2), an electrical drive motor (203) for driving the pump unit (2), and a control unit (201) for controlling the drive motor (203). The control unit (201) includes a frequency converter (209), a voltage converter (207) and a controller (211). The voltage converter (207) is configured to provide an input voltage (U.sub.in) to the frequency converter (209). The input voltage (U.sub.in) is adjustable within a voltage range between a minimum input voltage (U.sub.min) and a maximum input voltage (U.sub.max). The controller (211) is configured to determine an actual power consumption of at least one of the drive motor (203), the frequency converter (209) and the voltage converter (207) during operation of the pump unit (2). The controller (211) is further configured to tune the input voltage (U.sub.in) depending on the determined actual power consumption during operation of the pump unit (2).

The present invention relates to a system for applying maximum driving efficiency point of load, comprising: a motor for driving a load; an inverter for controlling the speed and the voltage of the motor; a sensor unit for measuring the magnetic flux maintaining current and the torque current of the motor; and a control unit determining the speed of the inverter and using the proportional value of the magnetic flux maintaining current and the torque current measured within a range in which the total current does not increase when the motor is driven at the determined speed, or determining the optimum voltage of the inverter at the point where the power factor becomes maximum. The motor inverter control system as described above controls both motor speed and voltage to select the lowest frequency within the permissible range and at the same time control the voltage at the water head to maximize power, this can reduce power consumption to a minimum and reduce energy consumption to a maximum.

The present invention provides an acceleration method for V/f controlled induction motor in flux-weakening region, which comprises: acquiring no-load magnetizing current I.sub.m of the induction motor at current stator frequency; selecting a smaller one of 0.5.Math.I.sub.m(1/+1) and (I.sub.m.sup.2+)/(I.sub.m+I.sub.m) as magnetizing current set point, in which is an estimated total leakage inductance coefficient; getting an error signal by subtracting the magnetizing current of the induction motor from the magnetizing current set point; determining the stator frequency for the next control period according to the error signal which is provided as a controlling variable of negative feedback. The acceleration method of the present invention can provide the maximum output torque in flux-weakening region and has a larger tolerance for the error of the estimated leakage inductance.