Patent application number | Description | Published |
20080300827 | SYSTEM AND METHOD TO DETERMINE ELECTRIC MOTOR EFFICIENCY NONINTRUSIVELY - A system and method for nonintrusively determining electric motor efficiency includes a processor programmed to, while the motor is in operation, determine a plurality of stator input currents, electrical input data, a rotor speed, a value of stator resistance, and an efficiency of the motor based on the determined rotor speed, the value of stator resistance, the plurality of stator input currents, and the electrical input data. The determination of the rotor speed is based on one of the input power and the plurality of stator input currents. The determination of the value of the stator resistance is based on at least one of a horsepower rating and a combination of the plurality of stator input currents and the electrical input data. The electrical input data includes at least one of an input power and a plurality of stator input voltages. | 12-04-2008 |
20080309366 | System and method for bearing fault detection using stator current noise cancellation - A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to repeatedly receive real-time operating current data from the operating motor and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components. | 12-18-2008 |
20090051308 | SYSTEM AND METHOD TO DETERMINE ELECTRIC MOTOR EFFICIENCY USING AN EQUIVALENT CIRCUIT - A system and method for determining electric motor efficiency includes a monitoring system having a processor programmed to determine efficiency of an electric motor under load while the electric motor is online. The determination of motor efficiency is independent of a rotor speed measurement. Further, the efficiency is based on a determination of stator winding resistance, an input voltage, and an input current. The determination of the stator winding resistance occurs while the electric motor under load is online. | 02-26-2009 |
20090051311 | SYSTEM AND METHOD FOR DETERMINING STATOR WINDING RESISTANCE IN AN AC MOTOR - A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current. | 02-26-2009 |
20090146599 | SYSTEM AND METHOD FOR MOTOR FAULT DETECTION USING STATOR CURRENT NOISE CANCELLATION - A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to acquire at least on additional set of real-time operating current data from the motor during operation, redefine the noise component present in each additional set of real-time operating current data, and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components. | 06-11-2009 |
20100156338 | SYSTEM AND METHOD FOR MONITORING AND CONTROLLING STATOR WINDING TEMPERATURE IN A DE-ENERGIZED AC MOTOR - A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings. | 06-24-2010 |
20100179692 | SYSTEM AND METHOD FOR MOTOR PARAMETER ESTIMATION - A system and method for determining unknown values of certain motor parameters includes a motor input device connectable to an electric motor having associated therewith values for known motor parameters and an unknown value of at least one motor parameter. The motor input device includes a processing unit that receives a first input from the electric motor comprising values for the known motor parameters for the electric motor and receive a second input comprising motor data on a plurality of reference motors, including values for motor parameters corresponding to the known motor parameters of the electric motor and values for motor parameters corresponding to the at least one unknown motor parameter value of the electric motor. The processor determines the unknown value of the at least one motor parameter from the first input and the second input and determines a motor management strategy for the electric motor based thereon. | 07-15-2010 |
20100194329 | SYSTEM AND METHOD FOR DETERMINING STATOR WINDING RESISTANCE IN AN AC MOTOR USING MOTOR DRIVES - A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current. | 08-05-2010 |
20100315033 | SYSTEM AND METHOD OF DYNAMIC REGULATION OF REAL POWER TO A LOAD - A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system receives input of an initial voltage-frequency command to the AC motor drive, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and determines a real-time value of a motor parameter based on the real-time output of the AC motor drive. The control system also inputs a plurality of modified voltage-frequency commands to the AC motor drive, determines the real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and identifies an optimal value of the motor parameter based on the real-time values of the motor parameter. The control system maintains an input of a current modified voltage-frequency command when the real-time value of the motor parameter corresponds to the optimal value of the motor parameter. | 12-16-2010 |
20100315034 | SYSTEM AND METHOD OF DYNAMIC REGULATION OF REAL POWER TO A LOAD - A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system input an initial voltage-frequency command to the AC motor drive based on an initial voltage/frequency (V/Hz) curve, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and feedback a plurality of modified voltage-frequency commands to the AC motor drive, each of the plurality of modified voltage-frequency commands comprising a deviation from the initial V/Hz curve. The control system also determines a real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and feeds back a modified voltage-frequency command to the AC motor drive so that the real-time value of the motor parameter is within a motor parameter tolerance range. | 12-16-2010 |
20110050142 | SYSTEM AND METHOD FOR MOTOR SPEED ESTIMATION OF AN ELECTRIC MOTOR - A system and method for a motor management system includes a computer readable storage medium and a processing unit. The processing unit configured to determine a voltage value of a voltage input to an alternating current (AC) motor, determine a frequency value of at least one of a voltage input and a current input to the AC motor, determine a load value from the AC motor, and access a set of motor nameplate data, where the set of motor nameplate data includes a rated power, a rated speed, a rated frequency, and a rated voltage of the AC motor. The processing unit is also configured to estimate a motor speed based on the voltage value, the frequency value, the load value, and the set of nameplate data and also store the motor speed on the computer readable storage medium. | 03-03-2011 |
20110213589 | SYSTEM AND METHOD TO DETERMINE ELECTRIC MOTOR EFFICIENCY USING AN EQUIVALENT CIRCUIT - A system and method for determining electric motor efficiency includes a monitoring system having a processor programmed to determine efficiency of an electric motor under load while the electric motor is online. The determination of motor efficiency is independent of a rotor speed measurement. Further, the efficiency is based on a determination of stator winding resistance, an input voltage, and an input current. The determination of the stator winding resistance occurs while the electric motor under load is online. | 09-01-2011 |
20110241888 | SYSTEM AND METHOD OF DETECTING CAVITATION IN PUMPS - A system and method for detecting cavitation in pumps for fixed and variable supply frequency applications is disclosed. The system includes a controller having a processor programmed to repeatedly receive real-time operating current data from a motor driving a pump, generate a current frequency spectrum from the current data, and analyze current data within a pair of signature frequency bands of the current frequency spectrum. The processor is further programmed to repeatedly determine fault signatures as a function of the current data within the pair of signature frequency bands, repeatedly determine fault indices based on the fault signatures and a dynamic reference signature, compare the fault indices to a reference index, and identify a cavitation condition in a pump based on a comparison between the reference index and a current fault index. | 10-06-2011 |
20110313717 | SYSTEM AND METHOD OF SPEED DETECTION IN AN AC INDUCTION MACHINE - A system and method for determining rotor speed of an AC induction machine is disclosed. The system is programmed to estimate a rotor speed of the induction machine according to a linear speed estimation algorithm and based on name plate information (NPI) of the induction machine and parameters of the AC induction machine during operation thereof. The rotor speed estimation system is also programmed to estimate a rotor speed of the AC induction machine according to a frequency-domain signal processing algorithm and determine if the rotor speed estimated thereby is valid. If the rotor speed estimated by the frequency-domain signal processing algorithm is valid, then a tuned rotor speed of the AC induction machine is estimated according to the linear speed estimation algorithm and based, in part, on the rotor speed estimated by the frequency-domain signal processing algorithm. | 12-22-2011 |
20120001580 | SYSTEM AND METHOD FOR DETECTING FAULT IN AN AC MACHINE - A system and method for detecting a rotor fault condition in an AC induction machine is disclosed. The system includes a processor programmed to receive voltage and current data from an AC induction machine, generate a current frequency spectrum from the current data, and identify rotor-fault related harmonics in the current frequency spectrum. The processor is also programmed to calculate a fault severity indicator using the voltage and current data, identified rotor-fault related harmonics, and motor specifications, analyze the fault severity indicator to determine a possibility of rotor fault. The processor generates an alert based on the possibility of rotor fault. | 01-05-2012 |