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Title: Methods, systems and apparatus for adjusting modulation index to improve linearity of phase voltage commands

Abstract

Embodiments of the present invention relate to methods, systems and apparatus for controlling operation of a multi-phase machine in a motor drive system. The disclosed embodiments provide a mechanism for adjusting modulation index of voltage commands to improve linearity of the voltage commands.

Inventors:
; ;
Publication Date:
Research Org.:
GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1346944
Patent Number(s):
9,595,902
Application Number:
13/197,629
Assignee:
GM GLOBAL TECHNOLOGY OPERATIONS LLC NETL
DOE Contract Number:
FC26-07NT43123
Resource Type:
Patent
Resource Relation:
Patent File Date: 2011 Aug 03
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 33 ADVANCED PROPULSION SYSTEMS

Citation Formats

Gallegos-Lopez, Gabriel, Perisic, Milun, and Kinoshita, Michael H. Methods, systems and apparatus for adjusting modulation index to improve linearity of phase voltage commands. United States: N. p., 2017. Web.
Gallegos-Lopez, Gabriel, Perisic, Milun, & Kinoshita, Michael H. Methods, systems and apparatus for adjusting modulation index to improve linearity of phase voltage commands. United States.
Gallegos-Lopez, Gabriel, Perisic, Milun, and Kinoshita, Michael H. Tue . "Methods, systems and apparatus for adjusting modulation index to improve linearity of phase voltage commands". United States. doi:. https://www.osti.gov/servlets/purl/1346944.
@article{osti_1346944,
title = {Methods, systems and apparatus for adjusting modulation index to improve linearity of phase voltage commands},
author = {Gallegos-Lopez, Gabriel and Perisic, Milun and Kinoshita, Michael H.},
abstractNote = {Embodiments of the present invention relate to methods, systems and apparatus for controlling operation of a multi-phase machine in a motor drive system. The disclosed embodiments provide a mechanism for adjusting modulation index of voltage commands to improve linearity of the voltage commands.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Mar 14 00:00:00 EDT 2017},
month = {Tue Mar 14 00:00:00 EDT 2017}
}

Patent:

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  • Embodiments of the present invention relate to methods, systems and apparatus for controlling operation of a multi-phase machine in a vector controlled motor drive system when the multi-phase machine operates in an overmodulation region. The disclosed embodiments provide a mechanism for adjusting a duty cycle of PWM waveforms so that the correct phase voltage command signals are applied at the angle transitions. This can reduce variations/errors in the phase voltage command signals applied to the multi-phase machine so that phase current may be properly regulated thus reducing current/torque oscillation, which can in turn improve machine efficiency and performance, as wellmore » as utilization of the DC voltage source.« less
  • Methods, system and apparatus are provided for controlling third harmonic voltages when operating a multi-phase machine in an overmodulation region. The multi-phase machine can be, for example, a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided. For example, when the reference voltage vector is determined to be within the overmodulation region, an angle of the reference voltage vector can be modified to generate a reference voltage overmodulation control angle, and a magnitude of the reference voltage vectormore » can be modified, based on the reference voltage overmodulation control angle, to generate a modified magnitude of the reference voltage vector. By modifying the reference voltage vector, voltage command signals that control a five-phase inverter module can be optimized to increase output voltages generated by the five-phase inverter module.« less
  • A small sized electro-optic voltage sensor capable of accurate measurement of high levels of voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation into the sensor. A polarization beam displacer serves as a filter to separate the input beam into two beams with orthogonal linear polarizations. The beam displacer is oriented in such a way as to rotate the linearly polarized beams such that they enter a Pockels crystal at a preferred angle of 45 degrees. The beam displacer ismore » therefore capable of causing a linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels electro-optic effect induces a differential phase shift on the major and minor axes of the input beam as it travels through the Pockels crystal, which causes the input beam to be elliptically polarized. A reflecting prism redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization representing the major and minor axes. In crystals that introduce a phase differential attributable to temperature, a compensating crystal is provided to cancel the effect of temperature on the phase differential of the input beam. The system may include a detector for converting the output beams into electrical signals, and a signal processor for determining the voltage based on an analysis of the output beams. The output beams are amplitude modulated by the frequency of the electric field and the amplitude of the output beams is proportional to the magnitude of the electric field, which is related to the voltage being measured.« less
  • A turbine includes upper and lower inner shell sections mounting the nozzles and shrouds and which inner shell is supported by pins secured to a surrounding outer shell. To disassemble the turbine for access to the inner shell sections and rotor, an alignment fixture is secured to the lower outer shell section and has pins engaging the inner shell section. To disassemble the turbine, the inner shell weight is transferred to the lower outer shell section via the alignment fixture and cradle pins. Roller assemblies are inserted through access openings vacated by support pins to permit rotation of the lowermore » inner shell section out of and into the lower outer shell section during disassembly and assembly. The alignment fixture includes adjusting rods for adjusting the inner shell axially, vertically, laterally and about a lateral axis. A roller over-cage is provided to rotate the inner shell and a dummy shell to facilitate assembly and disassembly in the field.« less
  • Methods, system and apparatus are provided for quickly approximating a peak summed magnitude (A) of a phase voltage (Vph) waveform in a multi-phase system that implements third harmonic injection.