Abstract: A system includes a control module that controls a motor based on a first rotor angle and an angle determination module that generates the first rotor angle. An estimator module determines an estimated rotor angle of the motor. A transition module generates a transition signal in response to convergence of the estimator module. The angle determination module initially generates the first rotor angle based on an open loop angle. In response to the transition signal, the angle determination module switches to generating the first rotor angle based on the estimated rotor angle and an offset value. The offset value is based on a difference between the estimated rotor angle and the open loop angle at the time when the transition signal is generated.

Abstract: A system includes a pulse-width modulation (PWM) module, a subtraction module, an error reducing module, and a summing module. The PWM module controls switching of an inverter that powers a motor. The PWM module controls the switching based on a first angle in a first mode and a second angle in a second mode. The subtraction module determines a difference between the first and second angles. The error reducing module (i) stores the difference when a transition from the first mode to the second mode is commanded and (ii) decreases a magnitude of the stored difference to zero. The summing module calculates a sum of the stored difference and the second angle. The PWM module controls the switching based on the sum in the second mode.

Abstract: A power factor correction (PFC) system includes a period determination module, a frequency generation module, an angle generation module, a signal generation module, and an angle correction module. The period determination module determines a period of an input alternating current (AC) line signal based on a time between rising edges of the input AC line signal. The frequency generation module generates a frequency based on the period. The angle generation module generates an angle based on the frequency. The signal generation module generates a sinusoidal reference signal based on the frequency and an adjusted angle. The angle correction module generates the adjusted angle based on the angle and based on a comparison of a falling edge of the sinusoidal reference signal, the period, and a rising edge of the input AC line signal.

Abstract: A system includes a compressor having a shell housing a compression mechanism driven by an electric motor in an on state and not driven by the electric motor in an off state. The system also includes a variable frequency drive that drives the electric motor in the on state by varying a frequency of a voltage delivered to the electric motor and that supplies electric current to a stator of the electric motor in the off state to heat the compressor.

Abstract: A power factor correction (PFC) system includes a direct current (DC) module, an error control module, an offset module, and a duty cycle control module. The DC module determines an average current value based on a plurality of current values over at least one cycle of an input alternating current (AC) line signal of the PFC system. The error control module generates an error signal based on the average current value. The offset module offsets a desired instantaneous current based on the error signal. The duty cycle control module controls at least one duty cycle of switches of the PFC system based on the offset desired instantaneous current.

Abstract: A power factor correction (PFC) system includes a comparison module, an adjustment module, a compensation module, and a duty cycle control module. The comparison module measures N currents having different phases, and generates (N?1) comparisons based on the N measured currents, wherein N is an integer greater than one. The adjustment module determines (N?1) time advance adjustments based on the (N?1) comparisons, respectively. The compensation module generates N compensated versions of an input alternating current (AC) line signal based on the input AC line signal, a sinusoidal reference signal, and the (N?1) time advance adjustments, wherein the sinusoidal reference signal is synchronized to the input AC line signal in phase and frequency. The duty cycle control module controls PFC switching based on the N compensated versions of the input AC line signal.

Abstract: A power factor correction (PFC) system includes an adjustment module, a compensation module, and a duty cycle control module. The adjustment module generates N time advances based on N predetermined time advances and (N?1) time advance adjustments, wherein N is an integer greater than zero. The compensation module generates N compensated versions of an input alternating current (AC) line signal by predicting ahead of the input AC line signal using a gradient of a sinusoidal reference signal and the N time advances, respectively, wherein the sinusoidal reference signal is synchronized with the input AC line signal in phase and frequency. The duty cycle control module generates PFC duty cycles based on the N compensated versions of the input AC line signal.

Abstract: A controller includes a voltage determination module, a bus voltage command module, and a power factor correction (PFC) control module. The voltage determination module determines a desired direct current (DC) bus voltage for a DC bus electrically connected between a PFC module and an inverter power module that drives a compressor motor. The voltage determination module determines the desired DC bus voltage based on at least one of torque of the compressor motor, speed of the compressor motor, output power of the inverter power module, and drive input power. The bus voltage command module determines a commanded bus voltage based on the desired DC bus voltage. The PFC control module controls the PFC module to create a voltage on the DC bus that is based on the commanded bus voltage.

Abstract: A current control module generates a voltage request based on a d-axis current (Idr) demand. A switching control module controls a motor based on the voltage request and generates an out-of-volts (OOV) signal based on a comparison of the voltage request and an available voltage. An Idr injection module generates the Idr demand based on a direct current (DC) bus voltage, a rotational speed, and a demanded torque and selectively applies a first adjustment to the Idr demand. The Idr injection module identifies whether an improvement resulted from the first adjustment, wherein the improvement is identified based on at least one of (i) a measured current of the motor and (ii) the OOV signal. The Idr injection module selectively applies a second adjustment to the Idr demand based on whether the improvement is identified.

Abstract: A motor control system includes a control module, a switching module, and a filtering module. The control module determines output voltages for operating a motor based on a torque demand. The switching module generates switching signals for an inverter that drives the motor. The switching module generates the switching signals based on the output voltages. The switching module generates an out-of-volts (OOV) signal according to a comparison based on the output voltages, a maximum duty cycle, and a voltage of a direct current (DC) bus that provides power to the inverter. The filtering module generates an OOV amount by filtering the OOV signal. The control module selectively limits the torque demand based on the OOV amount.

Abstract: A first rectifier diode is electrically connected between a first input terminal where an alternating current (AC) power is received and a first output terminal where a direct current (DC) power is output. A second rectifier diode is electrically connected between the first input terminal and a second output terminal. The first and second rectifier diodes rectify first and second portions of the AC power into the DC power, respectively. When switching of a plurality of power factor correction (PFC) switches is enabled, the plurality of PFC switches increases a voltage of the DC power to greater than a peak voltage of the AC power. An inductor is electrically connected between a second input terminal and two of the plurality of PFC switches. When the switching is disabled, first and second bypass diodes provide a current path past the plurality of PFC switches and the inductor.

Abstract: A power factor correction (PFC) system includes a period determination module, a frequency generation module, an angle generation module, a signal generation module, and an angle correction module. The period determination module determines a period of an input alternating current (AC) line signal based on a time between rising edges of the input AC line signal. The frequency generation module generates a frequency based on the period. The angle generation module generates an angle based on the frequency. The signal generation module generates a sinusoidal reference signal based on the frequency and an adjusted angle. The angle correction module generates the adjusted angle based on the angle and based on a comparison of a falling edge of the sinusoidal reference signal, the period, and a rising edge of the input AC line signal.

Abstract: A system includes a pulse-width modulation (PWM) module, a subtraction module, an error reducing module, and a summing module. The PWM module controls switching of an inverter that powers a motor. The PWM module controls the switching based on a first angle in a first mode and a second angle in a second mode. The subtraction module determines a difference between the first and second angles. The error reducing module (i) stores the difference when a transition from the first mode to the second mode is commanded and (ii) decreases a magnitude of the stored difference to zero. The summing module calculates a sum of the stored difference and the second angle. The PWM module controls the switching based on the sum in the second mode.

Abstract: A switched reluctance machine system includes a stator, a rotor situated to rotate relative to the stator and a plurality of phase windings situated in the stator. A power supply is connected to the phase windings via power converter and a controller outputs control signals to the power converter to selectively apply power to the phase windings. The controller receives feedback signals from the phase windings that provide phase current information to the controller. The controller is programmed to analyze the phase current information and control the power converter to inject diagnostic pulses into any of the phase windings in which current in the phase winding is below a predetermined level. The rotor position is determined based on detected characteristics of the diagnostic pulses, and the characteristics may be weighted, for example, in response to an estimated position of the diagnostic pulses.

Abstract: An improved process for bleaching cellulosic pulp in a first chlorination stage of a multi-stage bleaching process is provided, which involves an improved process for bleaching cellulosic pulp in a first chlorination stage of a multi-stage bleaching process, comprising: (a) admixing cellulosic pulp with a first chlorine dioxide charge and reacting the cellulosic pulp and said chlorine dioxide for a period of time ranging from about 1 second to about 10 minutes; (b) admixing the cellulosic pulp effluent obtained after step (a) wtih chlorine and chlorine dioxide and reacting the thus-obtained cellulosic pulp for a period of time ranging from 1 second to about 10 minutes; and then (c) admixing the cellulosic pulp effluent obtained after step (b) with a second chlorine dioxide charge and reacting the thus-obtained cellulosic pulp effluent for a period of time ranging from about 1 second to about 10 minutes, wherein the pH of the reaction mixture is maintained throughout the bleaching process at from about 5.

Abstract: A static distributor is provided with a top surface that slopes upwardly from the center port opening through which chlorine dioxide and pulp stock are pumped into a bleaching tower. The upwardly sloping sides of the distributor provide a dish-shaped or concave configuration influencing the flow from the center port opening upwardly and outwardly toward the circumference of the tower. The static distributor is provided with side openings formed by vertical support plates. The vertical support plates are spaced about the circumferences of the concave or dish-shaped flow surface to support the same on a base and change the flow distribution so that a good portion of the flow is radial between the plates rather than vertical. The radial flow is mixed with the flow undergoing upward influence provided by the dish-shaped center portion of the distributor, which causes more complete mixing and the formation of a vortex-type flow in the bleaching tower.

Abstract: This invention relates to thermoplastic molding compositions suitable for molding or extruding articles such as thin-walled battery containers which possess high heat distortion temperatures and which also simultaneously possess excellent impact resistance at low temperature.

Abstract: This invention relates to thermoplastic molding compositions suitable for molding or extruding articles such as thin-walled battery containers which possess high heat distortion temperatures and simultaneously excellent impact resistance at low temperature.

Abstract: A transducer of acoustic energy through seawater couples its active element o an acoustic window using polyalkylene glycol. The particular polyalkylene glycol selected exhibits improved acoustic, chemical, physical, and environmental properties. Two satisfactory liquids marketed under the trade designation's "UCON Transducer Fluid 28" and "UCON Lubricant LB-135" have satisfactory properties for being the coupling medium.