Abstract: An example welding wire feeder includes: a push motor configured to feed welding wire from a wire source; a first sensor configured to provide push motor velocity feedback; and control circuitry configured to control the push motor and a pull motor of a welding torch coupled to the welding wire feeder by: controlling a push motor velocity of the push motor and a pull motor velocity of the pull motor based on a target wire feed speed; and compensating each of the push motor velocity of the push motor and the pull motor velocity of the pull motor based on the push motor velocity feedback and based on pull motor velocity feedback, wherein the push motor velocity and the pull motor velocity are based on a target wire tension.

Abstract: A semi-automatic torch trigger for a rotating power connector in use in a welding torch cables is provided. In some examples, a trigger mechanism is configured to transmit control signals through a transmission channel that is not subject to mechanical wear from rotational movement of the rotating power connector, providing reliable communication between a welding torch trigger and a welding power supply without breaking electrical contact or putting unnecessary strain on the welding cable, even as the welding torch rotates relative to the welding torch cable.

Abstract: A method of determining electromagnetic characteristics of an asynchronous motor system is described. A motor system model is presented including a stator resistance, a transient inductance, a magnetizing inductance and a rotor resistance. A DC sequence is used to determine the stator resistance, a voltage pulse is used to determine the transient inductance, a binary injection frequency search algorithm is used to determine the magnetizing inductance, and an AC sine wave at slip frequency with DC offset is used to determine the rotor resistance.

Abstract: A method of determining electromagnetic characteristics of an asynchronous motor system is described. A motor system model is presented including a stator resistance, a transient inductance, a magnetizing inductance and a rotor resistance. A DC sequence is used to determine the stator resistance, a voltage pulse is used to determine the transient inductance, a binary injection frequency search algorithm is used to determine the magnetizing inductance, and an AC sine wave at slip frequency with DC offset is used to determine the rotor resistance.

Abstract: The present invention relates to a method for regulating a set of first noise harmonics from an electronic device operatively connected to a power supply unit, the method comprising the step of injecting a second set of harmonics into a representation of a drive current provided to the electronic device in order to regulate at least part of the noise harmonics of the first set, wherein the harmonics of the second set is/are different from the noise harmonics of the first set. The invention further relates to a power supply unit for performing the method of the present invention.

Abstract: An electrical system comprising an electrical motor and a method for controlling the electrical motor. The system comprises the electrical motor, a power source connection, a first motor control device placed between the power source connection and the motor, and a second motor control device placed in parallel with the first motor control device, the first motor control device supplying electrical power to the motor at least one first operating condition of the motor, and the second motor control device supplying electrical power to the motor at least one second operating condition of the motor, wherein the at least one first operating condition differs from the at least one second operating condition of the motor.

Abstract: A controller continually updates rotor time constant estimation of an induction machine by interrogating the induction machine with a small signal oscillation and monitoring the response. The small signal oscillation is injected onto the d-axis current command signal, and is generated at a frequency that represents the most recent estimate of the rotor time constant (i.e., rotor time constant equal the inverse of the frequency). The controller monitors rotor flux generated in response to the small signal oscillation, and updates the most recent estimate of the rotor time constant based on the monitored rotor flux. This process is repeated continuously to allow for the continuous updating of the rotor time constant.

Abstract: A power turbine speed control system for a turbo-shaft type gas turbine engine that has a gas generator compressor spool and a power turbine spool and drives an electrical generator that powers at least one electrical load by way of at least one electrical bus, comprises a power turbine controller that senses the rotary speed of the power turbine spool and generates at least one signal that changes the torque of the electrical generator in response to the sensed change in the rotary speed of the power turbine spool.

Abstract: A power turbine speed control system for a turbo-shaft type gas turbine engine that has a gas generator compressor spool and a power turbine spool and drives an electrical generator that powers at least one electrical load by way of at least one electrical bus, comprises a power turbine controller that senses the rotary speed of the power turbine spool and generates at least one signal that changes the torque of the electrical generator in response to the sensed change in the rotary speed of the power turbine spool.

Abstract: A power turbine speed control system for a turbo-shaft type gas turbine engine that has a gas generator compressor spool and a power turbine spool and drives an electrical generator that powers at least one electrical load by way of at least one electrical bus, comprises a power turbine controller that senses the rotary speed of the power turbine spool and generates at least one signal that changes the torque of the electrical generator in response to the sensed change in the rotary speed of the power turbine spool.

Abstract: A power turbine speed control system for a turbo-shaft type gas turbine engine that has a gas generator compressor spool and a power turbine spool and drives an electrical generator that powers at least one electrical load by way of at least one electrical bus, comprises a power turbine controller that senses the rotary speed of the power turbine spool and generates at least one signal that changes the torque of the electrical generator in response to the sensed change in the rotary speed of the power turbine spool.

Abstract: A power turbine speed control system for a turbo-shaft type gas turbine engine that has a gas generator compressor spool and a power turbine spool and drives an electrical generator that powers at least one electrical load by way of at least one electrical bus, comprises a power turbine controller that senses the rotary speed of the power turbine spool and generates at least one signal that changes the torque of the electrical generator in response to the sensed change in the rotary speed of the power turbine spool.

Abstract: A controller continually updates rotor time constant estimation of an induction machine by interrogating the induction machine with a small signal oscillation and monitoring the response. The small signal oscillation is injected onto the d-axis current command signal, and is generated at a frequency that represents the most recent estimate of the rotor time constant (i.e., rotor time constant equal the inverse of the frequency). The controller monitors rotor flux generated in response to the small signal oscillation, and updates the most recent estimate of the rotor time constant based on the monitored rotor flux. This process is repeated continuously to allow for the continuous updating of the rotor time constant.

Abstract: A controller estimates a motor position. The controller includes a driver and an injector. The driver generates a fundamental control signal. The injector generates a position carrier voltage that superimposed on the fundamental control signal. The injector alters the magnitude of the carrier voltage signal in response to the corresponding amplitude of the fundamental control signal. In a disclosed example, the injector increases the carrier voltage signal magnitude as the fundamental control current signal approaches a zero crossing. The injector then gradually decreases the carrier voltage signal magnitude as the fundamental control current signal magnitude increases from zero.

Abstract: A controller applies a pattern of pulses to switching elements within a multi-level controller to effectuate control of the fundamental voltage magnitude and phase associated with the converter, as well as providing harmonic minimization of the 5th and 7th level harmonics. The controller combines a first pattern of pulses with a second pattern of pulses phase shifted by an amount based on the desired fundamental voltage magnitude to create a third pattern of pulses. The controller applies a phase shift to the third pattern of pulses based on the desired fundamental voltage phase. The controller supplies switching control waveforms to active components within the multi-level controller based on the phase shifted third pattern of pulses such that the desired fundamental voltage magnitude and phase is generated and selected harmonics are minimized.

Abstract: A power turbine speed control system for a turbo-shaft type gas turbine engine that has a gas generator compressor spool and a power turbine spool and drives an electrical generator that powers at least one electrical load by way of at least one electrical bus, comprises a power turbine controller that senses the rotary speed of the power turbine spool and generates at least one signal that changes the torque of the electrical generator in response to the sensed change in the rotary speed of the power turbine spool.

Abstract: A field oriented control system for a brushless wound field synchronous machine that determines positioning of a rotor for the machine from exciter stator electrical potentials and current harmonics.