Patent application number | Description | Published |
20100026223 | METHOD AND APPARATUS FOR IDENTIFYING ORIENTATION OF A STATIONARY ROTOR IN A SENSOR-LESS PMSM - A method and apparatus for determining rotor position in a stationary rotor of a sensor-less permanent magnet synchronous machine that employs a rotating magnetic field to identify a magnetic axis of the stator without a magnetic direction and then determines magnetic direction by applying pulses along the magnet axis in two polarities. | 02-04-2010 |
20100237817 | 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. | 09-23-2010 |
20100301790 | ROTOR POSITION ESTIMATOR FOR AN ELECTRICAL MACHINE - A method for estimating a rotor position in an electrical machine is provided. The method is applicable to electrical machines that have magnetic saliency. The method includes extracting the rotor position from a demodulated output signal generated in response to an injected high frequency carrier signal and determining a position error compensation based upon a demodulation delay and a velocity or rotational frequency of the electrical machine. The method also includes estimating the rotor position by applying the position error compensation to the extracted rotor position. | 12-02-2010 |
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 |
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 |
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 |