Patent application number | Description | Published |
20120169263 | METHODS, SYSTEMS AND APPARATUS FOR ADJUSTING DUTY CYCLE OF PULSE WIDTH MODULATED (PWM) WAVEFORMS - 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 well as utilization of the DC voltage source. | 07-05-2012 |
20120187876 | METHODS, SYSTEMS AND APPARATUS FOR CONTROLLING THIRD HARMONIC VOLTAGE WHEN OPERATING A MULTI-PHASE MACHINE IN AN OVERMODULATION REGION - 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 vector 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. | 07-26-2012 |
20130020971 | TEMPERATURE COMPENSATION FOR IMPROVED FIELD WEAKENING ACCURACY - Methods and apparatus are provided for rotor and stator temperature compensation for field weakening current. The method comprises generating a phase voltage feed back signal V | 01-24-2013 |
20130033206 | METHODS, SYSTEMS AND APPARATUS FOR ADJUSTING MODULATION INDEX TO IMPROVE LINEARITY OF PHASE VOLTAGE COMMANDS - 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. | 02-07-2013 |
20130175960 | METHODS, SYSTEMS AND APPARATUS FOR GENERATING CURRENT COMMANDS USED TO CONTROL OPERATION OF AN ELECTRIC MACHINE - Embodiments of the present disclosure relate to methods, systems and apparatus for mapping torque to current to generate current commands used to control operation of an electric machine. Based on a DC input voltage, lookup tables (LUTs) are selected. Each of the selected LUTs includes a plurality (B) of first entries that correspond a particular input value of an angular rotation speed of the electric machine, and a set of coefficients are output from each of the selected LUTs that can be applied within a first polynomial function to generate a plurality of first polynomial functions each having a different sets of coefficients. A plurality of particular output values for a first current command are generated via the plurality of first polynomial functions. The particular output values for the first current command can be interpolated to generate a final output value for the first current command. | 07-11-2013 |
20130207579 | METHOD AND SYSTEM FOR ESTIMATING ELECTRICAL ANGULAR SPEED OF A PERMANENT MAGNET MACHINE - Methods, systems and apparatus are provided for estimating electrical angular speed of a permanent magnet machine based on two-phase stationary reference frame feedback stator current samples, and a dimensionless gain (K) that is computed based on a sampling time (T) and machine parameters. | 08-15-2013 |
20130249457 | METHODS, SYSTEMS AND APPARATUS FOR GENERATING VOLTAGE COMMAND SIGNALS FOR CONTROLLING OPERATION OF AN ELECTRIC MACHINE - Embodiments of the present disclosure relate to methods, systems and apparatus for generating voltage command signals for controlling operation of an electric machine. The disclosed embodiments can reduce current and torque oscillation, which can in turn improve machine efficiency and performance, as well as utilization of the DC voltage source. | 09-26-2013 |
20130278182 | METHODS, SYSTEMS AND APPARATUS FOR GENERATING VOLTAGE COMMANDS USED TO CONTROL OPERATION OF A PERMANENT MAGNET MACHINE - Embodiments of the present disclosure relate to methods, systems and apparatus for generating voltage commands used to control operation of a permanent magnet machine. | 10-24-2013 |
20130304782 | METHOD FOR SEARCHING A LOOKUP TABLE - Methods and apparatus are provided in which a computed vector index (CVI) can be generated/computed based on an input value being searched for within an index vector of a lookup table. When the CVI is greater than a length of an index vector, the CVI can be re-computed to generate a re-computed vector index (RVI). When the value of the CVI is determined to be correct, or when the RVI is generated, an interpolation routine for a linearly indexed index vector can be executed using a presently computed vector index (e.g., either the CVI or the RVI) to determine an interpolated output value that corresponds to the input value. By contrast, when the value of the CVI is determined to be incorrect, an interpolation routine for a piecewise indexed index vector can be executed to determine the interpolated output value. | 11-14-2013 |
20140354292 | METHOD AND APPARATUS FOR MONITORING A MULTI-PHASE ELECTRICAL SYSTEM ON A VEHICLE - An electric machine electrically connects to an inverter via a multi-phase power circuit. A method for monitoring the multi-phase power circuit includes non-intrusively adjusting a commanded AC electric current from the inverter after a prescribed time period and comparing a measured magnitude of AC electric current in the multi-phase power circuit with a minimum threshold. Presence of an open circuit fault in the multi-phase power circuit can be detected based upon the comparison. | 12-04-2014 |