Patent application number | Description | Published |
20130286704 | CASCADED H-BRIDGE (CHB) INVERTER LEVEL SHIFT PWM WITH ROTATION - Cascade H-Bridge inverters and carrier-based level shift pulse width modulation techniques are presented for generating inverter stage switching control signals, in which carrier waveform levels are selectively shifted to control THD and to mitigate power distribution imbalances within multilevel inverter elements. | 10-31-2013 |
20140036557 | CASCADED H-BRIDGE (CHB) INVERTER LEVEL SHIFT PWM WITH ROTATION - Cascade H-Bridge inverters and carrier-based level shift pulse width modulation techniques are presented for generating inverter stage switching control signals, in which carrier waveform levels are selectively shifted to control THD and to mitigate power distribution imbalances within multilevel inverter elements using either complementary carrier or complementary reference modulation techniques. | 02-06-2014 |
20140197774 | METHOD AND APPARATUS FOR CONTROLLING POWER CONVERTER WITH INVERTER OUTPUT FILTER - Power converters and methods are presented for driving an AC load connected through an intervening filter circuit, in which at least one filter current or voltage signal or value is determined according to feedback signals or values representing an output parameter at an AC output of the power converter, and AC electrical output power is generated at the AC output based at least partially on the at least one filter current or voltage signal or value. | 07-17-2014 |
20140300298 | POWER STAGE PRECHARGING AND DYNAMIC BRAKING APPARATUS FOR MULTILEVEL INVERTER - Precharging and dynamic braking circuits are presented for multilevel inverter power stages of a power converter with a shared resistor connected to charge a DC bus capacitor with current from the rectifier circuit in a first operating mode and connected in parallel with the capacitor to dissipate power in a dynamic braking mode. | 10-09-2014 |
20140312811 | POSITION SENSORLESS OPEN LOOP CONTROL FOR MOTOR DRIVES WITH OUTPUT FILTER AND TRANSFORMER - A power converter, control apparatus and methods are presented for driving a permanent magnet motor or other load through a sine wave filter and a transformer, in which inverter output current is controlled using a current-frequency relationship to convert a desired frequency or speed value to a current setpoint, and the inverter output current is regulated to the current setpoint using a control algorithm with a bandwidth below the resonant frequency of the sine wave filter. | 10-23-2014 |
Patent application number | Description | Published |
20080203954 | INDUCTION MOTOR ANALYSIS AND CONTROL METHOD - An induction motor controller that may include three phase paths leading from a power input to a power output, a solid-state switching device interposed between the power input and the power output on each of the three phase paths, a voltage sensor coupled to two of the phase paths between the solid-state switching device and the power input, a current sensor on one of the phase paths, a processor communicatively coupled to the voltage sensor, the current sensor, and the solid state switching device; and a memory coupled to the processor. The processor may be configured to calculate a motor parameter based on a signal from the voltage sensor and a signal from the current sensor and store the calculated motor parameter in memory. | 08-28-2008 |
20090058341 | Control method and system with feedback indicative of load flux - Systems, methods, and devices are disclosed, including an induction-motor controller having a phase path; a solid-state switch interposed on the phase path; and a controller coupled to the solid-state switch. In certain embodiments, the controller is configured to switch the solid-state switch so that the solid-state switch is conductive during a conduction angle of a cycle of an incoming AC power waveform conveyed by the phase path, calculate the conduction angle based on a generally sinusoidal reference value that has a frequency lower than a frequency of the incoming AC power waveform, and adjust the generally sinusoidal reference value based on a value indicative of flux in a load coupled to the phase path. | 03-05-2009 |
20090212732 | UNIVERSAL ADAPTIVE TORQUE CONTROL FOR PM MOTORS FOR FIELD-WEAKENING REGION OPERATION - The invention includes a motor controller and method for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by, among other things, receiving a torque command, determining a normalized torque command by normalizing the torque command to a characteristic current of the motor, determining a normalized maximum available voltage, determining an inductance ratio of the motor, and determining a direct-axis current based upon the normalized torque command, the normalized maximum available voltage, and the inductance ratio of the motor. | 08-27-2009 |
20100060210 | METHOD AND APPARATUS FOR AUTOMATICALLY IDENTIFYING ELECTRICAL PARAMETERS IN A SENSOR-LESS PMSM - A method and apparatus for determining electrical parameters for commissioning a sensor-less permanent magnet synchronous machine uses knowledge of the rotor position to apply balanced pulses along the rotor magnet axis and perpendicular to the rotor magnet axis allowing measurement of q- and d-inductance at multiple current levels without substantial rotor movement. | 03-11-2010 |
20100320948 | Method and Apparatus for Increased Current Stability in a PWM Drive - The present invention provides an improved current regulator for PWM based drives for electric motors. The invention provides compensation for the rotor position signal for delays introduced due to the PWM algorithm and for digital sampling present in such a drive. Current regulator commonly operate in a two-phase reference frame, requiring forward and reverse coordinate transformations between the physical current values and the two-phase reference frame variables. The present invention provides an improved compensation in the forward transformation by determining the phase lag between the commanded voltage reference and the output voltage reference and by further compensating the forward transformation for errors introduced due to sampling the current either at different sampling instances than the rotor position or at multiple sampling instances during a carrier period. Additionally, compensation during the reverse transformation is provided to compensate for errors introduced due to sampling the current and rotor position. | 12-23-2010 |
20110102012 | PARAMETER ESTIMATION SYSTEM AND METHOD FOR AN INDUCTION MOTOR - A method of estimating stator resistance of an induction motor is provided. The method includes applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles to inject current in the motor, wherein the voltage pulses are applied until rotor flux of the motor is substantially stabilized and measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles. The method also includes calculating the stator resistance based upon the measured stator voltages and the stator currents. | 05-05-2011 |
20120223668 | Control Method and System with Feedback Indicative of Load Flux - Systems, methods, and devices are disclosed, including an induction-motor controller having a phase path; a solid-state switch interposed on the phase path; and a controller coupled to the solid-state switch. In certain embodiments, the controller is configured to switch the solid-state switch so that the solid-state switch is conductive during a conduction angle of a cycle of an incoming AC power waveform conveyed by the phase path, calculate the conduction angle based on a generally sinusoidal reference value that has a frequency lower than a frequency of the incoming AC power waveform, and adjust the generally sinusoidal reference value based on a value indicative of flux in a load coupled to the phase path. | 09-06-2012 |
20120268050 | Method and Apparatus for Estimating Rotor Position in a Sensorless Synchronous Motor - The present invention provides a simple, robust, and universal position observer for use with sensorless synchronous machines. The observer may be implemented using an equivalent EMF model of a synchronous machine or, alternately, using a sliding mode controller based on the equivalent EMF model of the synchronous machine. The observer may be used on any type of synchronous machine, including salient or non-salient pole machines such as a permanent magnet, interior permanent magnet, wound rotor, or reluctance synchronous machine. The observer provides low sensitivity to parameter variations and disturbances or transient conditions in the machine. In addition, no knowledge of speed is required as an input to the observer and an estimated position may be calculated using a subset of the machine parameters. | 10-25-2012 |
20140285230 | PARAMETER ESTIMATION SYSTEM AND METHOD FOR AN INDUCTION MOTOR - A method of estimating stator resistance of an induction motor is provided. The method includes applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles to inject current in the motor, wherein the voltage pulses are applied until rotor flux of the motor is substantially stabilized and measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles. The method also includes calculating the stator resistance based upon the measured stator voltages and the stator currents. | 09-25-2014 |