Class / Patent application number | Description | Number of patent applications / Date published |
324772000 | Motor or generator fault tests | 19 |
20080303543 | Measuring Device - An apparatus for testing an electric motor is described. The motor comprises stator windings and a rotor arranged along a rotation axis. The apparatus is adapted to measure a physical quantity of the stator winding while the rotor is being rotated about the rotation axis, whereby periodic measuring data concerning the physical quantity are obtained. The apparatus is adapted to collect measuring data concerning at least two periods of the periodic measuring data, to compare the symmetry between at least the fundamentals of two or more half-cycles of the collected data and to generate a signal that indicates the symmetrical relation between at least the fundamentals of two or more half-cycles of the collected measuring data. | 12-11-2008 |
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 |
20080315909 | Method of detecting a malfunction of an encoder for a vehicle drive system - A method of detecting a malfunction of an encoder used in a vehicle drive system includes determining an error of a motor speed based on an estimated motor speed, wherein the estimated motor speed is a function of measured current over a predetermined interval of time. The method further includes determining a maximum allowable error of the motor speed at the measured current. Yet further, the method includes comparing the error of the motor speed with the maximum allowable error of the motor speed, thereby detecting the malfunction of the encoder. | 12-25-2008 |
20090033357 | Winding fault detection system - A control system is disclosed. The control system has an electric machine coupled to provide power to or receive power from a DC bus and a controller in communication with the electric machine and the DC bus. The controller is configured to receive a voltage from the DC bus, compare the voltage from the DC bus to a characteristic indicative of a fault of at least one winding of the electric machine, and take a precaution based on the comparison. | 02-05-2009 |
20090066360 | METHOD FOR DETERMINING AN INDUCTANCE OF A MOTOR - The intention is to simplify the measurement of an inductance characteristic curve of a motor. To this end, provision is made for a current (i) having a non-periodic current offset component and a periodic current component to be injected into the motor's winding so that the motor accelerates. A corresponding voltage (u) across the winding is measured and a voltage interference component and a periodic voltage component are determined from the measurement. The inductance of the winding can finally be determined from these two components. It is thus possible to dispense with the operation of blocking the motor or to dispense with an expensive motor test rig in order to determine the inductance characteristic curve. | 03-12-2009 |
20090146680 | SELF-GUIDING INSTRUMENT CARRIER FOR IN-SITU OPERATION IN A GENERATOR - Removal of the rotor of a large electrical machine is costly and time consuming, and in particular the outage time of a power plant, which is needed for the removal of a generator rotor, is very expensive and should be minimized. To avoid opening of the generator for inspection and maintenance instrument carriages can be used. A method allows the reliable guidance for an in-situ instrument carrier inside the annular gap of a generator and a corresponding instrument carrier. The method avoids the use of sensors and active control systems for the guidance of the instrument carrier. A passively self-guiding system and method takes advantage of the internal structure of a generator and uses the passive centering properties of magnets to guide the instrument carrier through the annular gap of a generator. | 06-11-2009 |
20090219050 | METHOD FOR DETECTING A MALFUNCTION IN AN ELECTROMAGNETIC RETARDER - A method for detecting a malfunction in an electromagnetic retarder. More specifically, the method relates to a retarder comprising: stator primary coils ( | 09-03-2009 |
20090243647 | Non-Invasive monitoring and diagnosis of electric machines by measuring external flux density - System and methods for monitoring electric machines are provided. A magnetic field associated with the electric machine is measured at one or more points external to the electric machine, wherein a respective magnetic field value is associated with each of the one or more points. The one or more measured magnetic field values are compared to one or more corresponding expected values, and a determination of whether a fault is present in the electric machine is made based at least in part on the comparison. | 10-01-2009 |
20090256584 | GAP INSPECTION APPARATUS - An apparatus for inspection of a gap between two surfaces, at least one of which is ferromagnetic, for example in a generator, includes a sensor platform ( | 10-15-2009 |
20090289656 | Dry-type high-voltage load system apparatus and method of preventing chain breaking and arc discharge for use therewith - A dry-type high-voltage load system apparatus has a space-saving structure, which is resistant to chain breaking, arc discharge and vibration, and a method of preventing the chain breaking and the arc discharge for use with the system apparatus. The system apparatus includes a dry-type high-voltage load system circuit including a low-voltage bank formed of lower-capacity configuration banks which include three-phase resistor circuits which are low-voltage resistor circuit. A high-voltage bank includes lower-capacity configuration banks for a high-voltage resistor circuit formed of three-phase resistor circuits. The three-phase resistor circuits are connected to a high-voltage power generator in parallel and are in the form of a Y-connection of three resistor arrays so that an isolated and independent neutral point is unconnected to other neutral points. The three phase resistor circuits may also be in the form of a Δ-connection. | 11-26-2009 |
20090322373 | PERMANENT MAGNET ROTOR CRACK DETECTION - A method and apparatus for permanent magnetic (PM) rotor crack detection includes a sensor which monitors magnetic flux distribution of the PM rotor and identifies the presence of a crack in the PM rotor when a magnetic flux distribution change or anomaly is detected. | 12-31-2009 |
20100045335 | METHODS AND SYSTEMS FOR EVALUATING PERMANENT MAGNET MOTORS - A method for evaluating a permanent magnet motor, which includes a rotor with a plurality of magnets mounted thereon, and a stator with a plurality of windings in proximity to the rotor and coupled to an inverter, includes spinning the motor such that a voltage is induced in the windings of the stator and the inverter; measuring the voltage on the inverter; calculating the voltage constant from the motor from the measured voltage; comparing the voltage constant to accepted voltage constants; and identifying the motor as not acceptable if the voltage constant is outside of a range of the accepted voltage constants. | 02-25-2010 |
20100102846 | ROTOR/STATOR RELATIVE POSITION DETERMINING METHOD AND APPARATUS - A data signal indicative of a gap between a sensor and at least one of a surface of a rotor and a surface of a stator rotating relative to the sensor is sent to a computer processor. The computer implements defining a plurality of lowest values of the data signal over a revolution of relative rotation between the rotor and the stator, and displaying the plurality of lowest values for assessment of the distance between the sensor and a surface of at least one of the rotor and the stator in order to determine a position of the rotor relative to the stator. | 04-29-2010 |
20100117679 | TEST APPARATUS, SYSTEM, AND METHOD HAVING A MAGNETIC FEATURE - A test apparatus involving a rotor coupled to a drive shaft, wherein the drive shaft is mechanically coupled to a drive system; a stator coupled to a brush holder; a brush held by the brush holder, wherein the brush is held in contact with the rotor; a housing for supporting the rotor and the stator; and a superconducting magnet for providing a magnetic field in the vicinity of the brush, in accordance with one embodiment. | 05-13-2010 |
20100141294 | WINDING DIAGNOSTIC SYSTEM AND METHOD - A winding diagnostic system is provided. The system includes a core having a winding to generate a magnetic flux. A retention device for holding the winding in place is provided. The system further includes a sensor disposed in a sensing relation with the retention device to generate signals related to at least one aspect of the winding. | 06-10-2010 |
20100182037 | Diagnostic Method For Load-Testing Self-Excited Three-Phase Generators in a Motor Vehicle - The invention relates to a diagnostic method for self-excited generators, in which a diagnostic decision is made by means of field current monitoring. | 07-22-2010 |
20100182038 | Setup and method for testing a permanent magnet motor - A test setup for a permanent magnet motor provides a method for identifying symmetry or asymmetry in the magnetic fields of the motor's permanent magnets. The setup comprises a test circuit that includes a fixed reference node that provides a stable reference to which the motor's common node can be compared. Observing the waveform of the voltage between the two nodes while the motor is running helps identify an imbalance in the magnetic fields of the motor's permanent magnets. | 07-22-2010 |
20100201396 | METHOD AND DEVICE FOR OFF-LINE TESTING OF ELECTRIC MOTORS - A method for off-line testing of an electric motor is disclosed. The motor having at least one stator winding, and a rotor arranged along a rotation axis. The method includes applying a periodic test signal to the at least one stator winding; collecting first measuring data, related to a physical quantity of the at least one stator winding while the rotor is being rotated about the rotation axis, from one or more waveform periods of the test signal, detecting first peak values of the first measuring data; forming second measuring data based on the first detected peak values, detecting second peak values of the second measuring data for the at least one stator winding; determining a mutual relationship between the at least a portion of the second peak values; and, providing, if the mutual relationship deviates from a predetermined relationship, a signal indicating a fault in the rotor. Also disclosed is an apparatus for performing the disclosed methods. | 08-12-2010 |
20100244887 | METHOD FOR DETECTING A STEP LOSS CONDITION - A method for detecting and correcting for a step loss condition. A back electromagnetic force signal is measured and compared to a reference voltage. The motor continues operating and the back electromagnetic force signal is measured again and compared to the reference voltage. If the measured levels of the back emf voltages are less than the reference voltage, a step loss condition has occurred and the stator field is repositioned. | 09-30-2010 |