Abstract: A phase angle detector with a PLL, a power converter, and a method for reducing offsets in an input signal, in which an adaptive offset processor selectively removes a DC offset component from the input signal to generate a modified signal including a fundamental frequency component and higher order harmonics of the input signal with the DC offset component removed, and the PLL provides a phase angle signal at least partially according to the modified signal.

Abstract: A phase angle detector with a PLL, a power converter, and a method for reducing offsets in an input signal, in which an adaptive offset processor selectively removes a DC offset component from the input signal to generate a modified signal including a fundamental frequency component and higher order harmonics of the input signal with the DC offset component removed, and the PLL provides a phase angle signal at least partially according to the modified signal.

Abstract: Methods and systems for tracking an electronic signal corresponding to an operating frequency of an electronic component are provided. A method may include sampling the signal to determine previous and current time samples of the signal. A frequency of interest in the signal may also be pre-warped to decrease adverse warping effects resulting from processing signals having relatively higher operating frequencies. The previous and current time samples of the signals, along with the pre-warped frequency of interest, may be input into a digital tracking filter. The digital tracking filter may be configured to execute one or more algorithms on the previous and current time samples and the pre-warped frequency of interest to estimate a current operating frequency.

Abstract: Methods and systems for synchronizing an electric grid having unbalanced voltages are provided. A voltage vector may be filtered in a quadrature tracking filter (QTF) to generate a quadrature signal. The inputs to the QTF may be either single input, multiple outputs, or alternatively, multiple inputs, multiple outputs. Furthermore, the second state of either of the two QTF transformations may be either positive or negative. A phase-locked-loop (PLL) operation may be performed on the quadrature signal to monitor a voltage vector between the grid and a connected power converter. The QTF and PLL methods are suitable for either single-phase applications or n-phase (any number of phases) applications.

Abstract: Methods and systems for synchronizing an electric grid having unbalanced voltages are provided. A voltage vector may be filtered in a quadrature tracking filter (QTF) to generate a quadrature signal. A phase-locked-loop (PLL) operation may be performed on the quadrature signal to monitor a voltage vector between the grid and a connected power converter. The QTF and PLL methods are suitable for either single-phase applications or n-phase (any number of phases) applications. A frequency estimator estimates the grid frequency of the electric grid and outputs the estimated frequency to the QTF algorithms. The frequency estimator may include a three-phase phase-locked-loop (three-phase PLL) suitable for estimating the center frequencies of multiple phases of the electric grid. The frequency estimator may also include means for reducing the harmonics in the grid system.

Abstract: Single-phase voltage operation techniques are provided for a three-phase drive system. A drive system may include a rectifier configured to couple to a three-phase AC voltage source. The rectifier may be configured to convert AC voltage from the three-phase AC voltage source to a direct current (DC) voltage. The drive system may also include a controller configured to send a plurality of switching signals to a plurality of switches in the rectifier such that the plurality of switching signals minimizes a current provided to the rectifier when only a single-phase of the three-phase AC voltage source is available.

Abstract: A phase angle detector with a PLL, a power converter, and a method for reducing offsets in an input signal, in which an adaptive offset processor selectively removes a DC offset component from the input signal to generate a modified signal including a fundamental frequency component and higher order harmonics of the input signal with the DC offset component removed, and the PLL provides a phase angle signal at least partially according to the modified signal.

Abstract: Embodiments of the present invention provide novel techniques for using a switched converter to provide for three-phase alternating current (AC) rectification, regenerative braking, and direct current (DC) voltage boosting. In particular, one of the three legs of the switched converter is controlled with a set of pulse width modulation (PWM) control signals so that the input AC phase having the highest voltage is rectified and one of the switches in the two other legs is turned on to allow for added voltage. This switching activity allows for voltage from multiple AC line mains to be combined, resulting in an overall boost of the DC voltage of the rectifier. The DC voltage boost can then be applied to the common DC bus in order to ameliorate voltage sags, help with motor starts, and increase the ride-through capability of the motor.

Abstract: Methods and systems for synchronizing an electric grid having unbalanced voltages are provided. A voltage vector may be filtered in a quadrature tracking filter (QTF) to generate a quadrature signal. The inputs to the QTF may be either single input, multiple outputs, or alternatively, multiple inputs, multiple outputs. Furthermore, the second state of either of the two QTF transformations may be either positive or negative. A phase-locked-loop (PLL) operation may be performed on the quadrature signal to monitor a voltage vector between the grid and a connected power converter. The QTF and PLL methods are suitable for either single-phase applications or n-phase (any number of phases) applications.

Abstract: Methods and systems for synchronizing an electric grid having unbalanced voltages are provided. A voltage vector may be filtered in a quadrature tracking filter (QTF) to generate a quadrature signal. A phase-locked-loop (PLL) operation may be performed on the quadrature signal to monitor a voltage vector between the grid and a connected power converter. The QTF and PLL methods are suitable for either single-phase applications or n-phase (any number of phases) applications. A frequency estimator estimates the grid frequency of the electric grid and outputs the estimated frequency to the QTF algorithms. The frequency estimator may include a three-phase phase-locked-loop (three-phase PLL) suitable for estimating the center frequencies of multiple phases of the electric grid. The frequency estimator may also include means for reducing the harmonics in the grid system.

Abstract: Methods and systems for tracking an electronic signal corresponding to an operating frequency of an electronic component are provided. A method may include sampling the signal to determine previous and current time samples of the signal. A frequency of interest in the signal may also be pre-warped to decrease adverse warping effects resulting from processing signals having relatively higher operating frequencies. The previous and current time samples of the signals, along with the pre-warped frequency of interest, may be input into a digital tracking filter. The digital tracking filter may be configured to execute one or more algorithms on the previous and current time samples and the pre-warped frequency of interest to estimate a current operating frequency.

Abstract: Embodiments of the present invention provide novel techniques for using a switched converter to provide for three-phase alternating current (AC) rectification, regenerative braking, and direct current (DC) voltage boosting. In particular, one of the three legs of the switched converter is controlled with a set of pulse width modulation (PWM) control signals so that the input AC phase having the highest voltage is rectified and one of the switches in the two other legs is turned on to allow for added voltage. This switching activity allows for voltage from multiple AC line mains to be combined, resulting in an overall boost of the DC voltage of the rectifier. The DC voltage boost can then be applied to the common DC bus in order to ameliorate voltage sags, help with motor starts, and increase the ride-through capability of the motor.

Abstract: Embodiments of the present invention provide novel techniques for using a switched converter to provide for three-phase alternating current (AC) rectification, regenerative braking, and direct current (DC) voltage boosting. In particular, one of the three legs of the switched converter is controlled with a set of pulse width modulation (PWM) control signals so that the input AC phase having the highest voltage is rectified and one of the switches in the two other legs is turned on to allow for added voltage. This switching activity allows for voltage from multiple AC line mains to be combined, resulting in an overall boost of the DC voltage of the rectifier. The DC voltage boost can then be applied to the common DC bus in order to ameliorate voltage sags, help with motor starts, and increase the ride-through capability of the motor.

Abstract: Methods and systems for tracking an electronic signal corresponding to an operating frequency of an electronic component are provided. A method may include sampling the signal to determine previous and current time samples of the signal. A frequency of interest in the signal may also be pre-warped to decrease adverse warping effects resulting from processing signals having relatively higher operating frequencies. The previous and current time samples of the signals, along with the pre-warped frequency of interest, may be input into a digital tracking filter. The digital tracking filter may be configured to execute one or more algorithms on the previous and current time samples and the pre-warped frequency of interest to estimate a current operating frequency.

Abstract: Embodiments of the present invention provide novel techniques for using a switched converter to provide for three-phase alternating current (AC) rectification, regenerative braking, and direct current (DC) voltage boosting. In particular, one of the three legs of the switched converter is controlled with a set of pulse width modulation (PWM) control signals so that the input AC phase having the highest voltage is rectified and one of the switches in the two other legs is turned on to allow for added voltage. This switching activity allows for voltage from multiple AC line mains to be combined, resulting in an overall boost of the DC voltage of the rectifier. The DC voltage boost can then be applied to the common DC bus in order to ameliorate voltage sags, help with motor starts, and increase the ride-through capability of the motor.

Abstract: A method and apparatus for use with a controller for controlling a machine wherein a torque reference value is provided, the method for identifying an error representative of the difference between the torque reference value and the torque applied to the machine and using the error value to modify machine operation, the method comprising the steps of obtaining feedback current values corresponding to the currents provided to the machine, mathematically combining the feedback current values to generate an error value, mathematically combining the error value and the torque reference value to generate a torque command value and using the torque command value to control the machine.

Abstract: A method and apparatus for use with a three phase AC motor controller linked to a three phase motor, the controller receiving a torque command signal and generating a voltage phase angle as a function of the torque command signal, the voltage phase angle in turn used to generate modulating waveforms to drive a PWM inverter that provides voltages on three motor supply lines, the method comprising the steps of during a commissioning procedure, identifying at least one compensation angle that, when mathematically combined with the voltage phase angle, drives the motor to zero operating frequency when a zero torque command is received and, during normal operation and when a zero torque command is received, mathematically combining the compensation angle and the voltage phase angle to generate a compensated phase angle and using the compensated phase angle to generate the modulating waveforms.

Abstract: A method and apparatus for use with a controller that samples a command frequency and provides modulating waveforms to a PWM inverter as a function of the sampled command frequency, the inverter also receiving a carrier signal having a carrier frequency, the method for reducing distortions in the modulating waveforms that result from sampling characteristics of the controller, the method comprising the steps of sampling the command frequency at a sampling frequency to generate a series of sampled signals, integrating the sampled signals to generate a phase angle, identifying a correction angle as a function of the sampling frequency, adding the correction angle to the phase angle to generate a corrected phase angle and using the corrected phase angle to generate the modulating waveforms to be provided to the PWM inverter.

Abstract: A method and apparatus for use with a controller that samples a command frequency and provides modulating waveforms to a PWM inverter as a function of the sampled command frequency, the inverter also receiving a carrier signal having a carrier frequency, the method for reducing distortions in the modulating waveforms that result from sampling characteristics of the controller, the method comprising the steps of sampling the command frequency at a sampling frequency to generate a series of sampled signals, integrating the sampled signals to generate a phase angle, identifying a correction angle as a function of the sampling frequency, adding the correction angle to the phase angle to generate a corrected phase angle and using the corrected phase angle to generate the modulating waveforms to be provided to the PWM inverter

Abstract: A method for use with an adjustable frequency controller to deliver current to an electromagnetic load including a stator and a rotor, the method for identifying a flux current estimate and comprising the steps of (a) identifying a rated torque value; (b) providing an initial q-axis current estimate; (c) using the q-axis current estimate to identify a d-axis current estimate; (d) mathematically combining the d-axis current estimate and the q-axis current estimate to identify a torque estimate; (e) comparing the rated torque value to the torque estimate; (f) where the torque estimate is similar to the rated torque value skipping to step (i); (g) altering the q-axis current estimate; (h) repeating steps (c) through (f); and (i) storing the d-axis and q-axis current estimates as flux and torque current values for subsequent use.