Abstract: The subject matter disclosed herein describes a switch embedded in a motor controller and a network protocol executing on the switch to provide communication between devices connected to the motor controller in a motor drive application. The embedded switch is configured to communicate via separate ports with an external controller, a network interface for the motor controller, additional motor controllers, and with the motor or other devices mounted on the motor. The network protocol includes a first tier for data that requires deterministic delivery at a high data rate, a second tier for data that requires a high delivery rate but is also tolerant of some variation in delivery time, and a third tier for data that may be delivered at a slower data rate. The embedded switch receives data at any port, identifies the communication tier to which the data belongs, and delivers it to another port accordingly.

Abstract: The subject matter disclosed herein describes a method and system to monitor and identify vibrations in a rotational mechanical system. Various fault conditions in a rotating machine operating at variable speeds may be identified, at least in part, by identifying the multiple of the fundamental frequency, or order, at which the vibration occurs. The orders of vibration present in a measured vibration signal may be determined by finding an order spectrum of a measured vibration signal in the position domain. A fault vector is generated from the order spectrum that identifies the magnitude of each order of vibration present in the measured vibration signal. The fault vector may be plotted on a radar chart to provide a visual indication of the type of fault present in the mechanical system. Evaluation models for each fault determines a probability and magnitude for each fault condition being present in the sampled vibration signal.

Abstract: A motor having a circuit board including at least two MEMS sensors. The circuit board is mounted within a housing of the motor using the same fasteners as an encoder of the motor. Mounting the MEMS sensors to the circuit board simplifies assembly of the motor and standardizes the positioning of the MEMS sensors within the housing, while the overall motor footprint is unaffected.

Abstract: The subject matter disclosed herein describes a switch embedded in a motor controller and a network protocol executing on the switch to provide communication between devices connected to the motor controller in a motor drive application. The embedded switch is configured to communicate via separate ports with an external controller, a network interface for the motor controller, additional motor controllers, and with the motor or other devices mounted on the motor. The network protocol includes a first tier for data that requires deterministic delivery at a high data rate, a second tier for data that requires a high delivery rate but is also tolerant of some variation in delivery time, and a third tier for data that may be delivered at a slower data rate. The embedded switch receives data at any port, identifies the communication tier to which the data belongs, and delivers it to another port accordingly.

Abstract: The subject matter disclosed herein describes a switch embedded in a motor controller and a network protocol executing on the switch to provide communication between devices connected to the motor controller in a motor drive application. The embedded switch is configured to communicate via separate ports with an external controller, a network interface for the motor controller, additional motor controllers, and with the motor or other devices mounted on the motor. The network protocol includes a first tier for data that requires deterministic delivery at a high data rate, a second tier for data that requires a high delivery rate but is also tolerant of some variation in delivery time, and a third tier for data that may be delivered at a slower data rate. The embedded switch receives data at any port, identifies the communication tier to which the data belongs, and delivers it to another port accordingly.

Abstract: The subject matter disclosed herein describes a method and system to monitor and identify vibrations in a rotational mechanical system. Various fault conditions in a rotating machine operating at variable speeds may be identified, at least in part, by identifying the multiple of the fundamental frequency, or order, at which the vibration occurs. The orders of vibration present in a measured vibration signal may be determined by finding an order spectrum of a measured vibration signal in the position domain. A fault vector is generated from the order spectrum that identifies the magnitude of each order of vibration present in the measured vibration signal. The fault vector may be plotted on a radar chart to provide a visual indication of the type of fault present in the mechanical system. Evaluation models for each fault determines a probability and magnitude for each fault condition being present in the sampled vibration signal.

Abstract: The subject matter disclosed herein describes a switch embedded in a motor controller and a network protocol executing on the switch to provide communication between devices connected to the motor controller in a motor drive application. The embedded switch is configured to communicate via separate ports with an external controller, a network interface for the motor controller, additional motor controllers, and with the motor or other devices mounted on the motor. The network protocol includes a first tier for data that requires deterministic delivery at a high data rate, a second tier for data that requires a high delivery rate but is also tolerant of some variation in delivery time, and a third tier for data that may be delivered at a slower data rate. The embedded switch receives data at any port, identifies the communication tier to which the data belongs, and delivers it to another port accordingly.

Abstract: A motor having a circuit board including at least two MEMS sensors. The circuit board is mounted within a housing of the motor using the same fasteners as an encoder of the motor. Mounting the MEMS sensors to the circuit board simplifies assembly of the motor and standardizes the positioning of the MEMS sensors within the housing, while the overall motor footprint is unaffected.

Abstract: The present techniques include methods and systems for operating converter to maintain a lifespan of the converter. In some embodiments, the operating frequency of the converter may be increased such that stress may be reduced on the bond wires of the converter. More specifically, embodiments involve calculating the aging parameters for certain operating conditions of the converter operating in a maximum power point tracking (MPPT) mode and determining whether the MPPT operation results in aging the converter to a point which reduces the converter lifespan below a desired lifespan. If the MPPT operation reduces the converter lifespan below the desired lifespan, the frequency of the converter may be increased such that the converter may be controlled to operate at a percentage of MPPT. Thus, in some embodiments, power output may be optimized with respect to maintaining a desired lifespan of the converter.

Abstract: 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.

Abstract: An improved system for monitoring vibration of an electric machine is disclosed. According to one embodiment, sensors are positioned in a plane orthogonal to the motor shaft and each sensor detects vibration along at least one axis of the motor. The sensors are oriented such that the polarity of each sensor is reversed. The pairs of sensors may be used to isolate specific vibrations within the motor. According to another embodiment, a sensor may be mounted directly to the motor shaft. The sensor on the motor shaft directly detects vibrations along the motor shaft. Optionally, a second sensor may be mounted to a fixed location within the motor housing, and the combination of the sensor on the motor shaft and the sensor at a fixed location may be used to isolate specific vibrations within the motor. A motor controller may adjust operation of the motor to reduce the isolated vibration.

Abstract: A double fed induction generator (DFIG) converter, methods and computer readable mediums are presented in which rotor side current spikes are attenuated by selectively activating at least one series damping circuit to conduct current through a series damping circuit resistance coupled in series between one or more DFIG rotor leads and a grid side converter in response to a grid fault occurrence or a grid fault clearance, and selectively bypassing the series damping circuit resistance after activating the series damping circuit.

Abstract: Methods and apparatus are presented for unintentional islanding detection for grid tie converters in which the phase angle disturbance is introduced by modification of grid side converter switching control signals and a mismatch of reactive power between generation and the grid load is formed upon the occurrence of unintentional islanding, where the applied phase disturbance is determined according to two pre-defined curves to form an equivalent positive feedback at different frequencies to prevent the converter from forming an island at a new stable frequency after the grid is disconnected.

Abstract: An improved system for monitoring vibration of an electric machine is disclosed. According to one embodiment, sensors are positioned in a plane orthogonal to the motor shaft and each sensor detects vibration along at least one axis of the motor. The sensors are oriented such that the polarity of each sensor is reversed. The pairs of sensors may be used to isolate specific vibrations within the motor. According to another embodiment, a sensor may be mounted directly to the motor shaft. The sensor on the motor shaft directly detects vibrations along the motor shaft. Optionally, a second sensor may be mounted to a fixed location within the motor housing, and the combination of the sensor on the motor shaft and the sensor at a fixed location may be used to isolate specific vibrations within the motor. A motor controller may adjust operation of the motor to reduce the isolated vibration.

Abstract: A double fed induction generator (DFIG) converter, methods and computer readable mediums are presented in which rotor side current spikes are attenuated by selectively activating at least one series damping circuit to conduct current through a series damping circuit resistance coupled in series between one or more DFIG rotor leads and a grid side converter in response to a grid fault occurrence or a grid fault clearance, and selectively bypassing the series damping circuit resistance after activating the series damping circuit.

Abstract: A double fed induction generator (DFIG) converter method are presented in which rotor side current spikes are attenuated using series-connected damping resistance in response to grid fault occurrences or grid fault clearances.

Abstract: 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.

Abstract: Methods and apparatus are presented for unintentional islanding detection for grid tie converters in which the phase angle disturbance is introduced by modification of grid side converter switching control signals and a mismatch of reactive power between generation and the grid load is formed upon the occurrence of unintentional islanding, where the applied phase disturbance is determined according to two pre-defined curves to form an equivalent positive feedback at different frequencies to prevent the converter from forming an island at a new stable frequency after the grid is disconnected.

Abstract: The present techniques include methods and systems for operating converter to maintain a lifespan of the converter. In some embodiments, the operating frequency of the converter may be increased such that stress may be reduced on the bond wires of the converter. More specifically, embodiments involve calculating the aging parameters for certain operating conditions of the converter operating in a maximum power point tracking (MPPT) mode and determining whether the MPPT operation results in aging the converter to a point which reduces the converter lifespan below a desired lifespan. If the MPPT operation reduces the converter lifespan below the desired lifespan, the frequency of the converter may be increased such that the converter may be controlled to operate at a percentage of MPPT. Thus, in some embodiments, power output may be optimized with respect to maintaining a desired lifespan of the converter.

Abstract: A method of estimating stator resistance of an induction motor 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.