Patent application number | Description | Published |
20080278109 | System and Method for Controlling Input Line Harmonics in a Motor Drive - A motor drive system is disclosed that includes a power input configured to receive alternating current (AC) power and a rectifier having a switching frequency selected to convert the AC power to direct current (DC) power. The motor drive unit also includes an input filter circuit connected between the power input and the rectifier and configured to suppress frequency harmonics across a range of harmonics. Additionally the motor drive unit includes a block filter circuit connected between the power input and the rectifier and configured to substantially block frequency harmonics associated with the switching frequency of the rectifier. Furthermore, the motor drive unit includes an inverter configured to receive the DC power from the rectifier and convert the DC power to a series of pulses configured to drive a motor. | 11-13-2008 |
20090058350 | JUNCTION TEMPERATURE REDUCTION FOR THREE PHASE INVERTERS MODULES - Provided is a motor controller and method of controlling a motor with an improved maximum junction temperature rating. In accordance with one aspect of the present invention, a motor is controlled by varying a common mode voltage duty ratio for a plurality of solid state switching devices in a power inverter, generating drive signals for the solid state switching devices based at least in part upon the common mode voltage duty ratio, and changing states of the solid state switching devices based upon the drive signals. | 03-05-2009 |
20090251081 | ELECTRIC MOTOR DRIVE EMPLOYING HYBRID, HYSTERETIC/PULSE-WIDTH-MODULATED DYNAMIC BRAKING - A dynamic braking circuit for an electronic motor drive shunts the DC link of the drive with a resistor using two control strategies. The first control strategy used for lower levels of braking employs a pulse width modulated signal and the second control strategy used for higher levels of braking uses a hysteretic signal significantly reducing switching losses in the semiconductor devices controlling the dynamic braking resistor allowing higher braking capacity. | 10-08-2009 |
20090276165 | POWER MODULE LIFE ESTIMATION FATIGUE FUNCTION - A system and method for estimating a condition of a power module is provided. In accordance with an embodiment, a motor controller may be maintained by tracking a total proportion of power module life expended by a power module in a variable frequency motor controller based on a minimum junction temperature or a mean junction temperature and a junction temperature change, and indicating when the power module is estimated to fail. | 11-05-2009 |
20100078998 | POWER ELECTRONIC MODULE PRE-CHARGE SYSTEM AND METHOD - A power electronics device with an improved pre-charge circuit configuration is provided. More specifically, the input of the motor drive module may accept an AC or DC source voltage. In this way, the pre-charge circuit of the motor drive module may be utilized whether the motor drive is coupled to an AC or DC source. | 04-01-2010 |
20100079230 | POWER ELECTRONIC MODULE WITH AN IMPROVED CHOKE AND METHODS OF MAKING SAME - An improved choke assembly for a power electronics device is provided. More specifically, a choke assembly with improved protection from environmental conditions such as dirt and water is provided. An improved choke assembly may include an insulative housing for an inductor coil that seals the inductor coil from the environment. | 04-01-2010 |
20100080024 | POWER ELECTRONIC MODULE IGBT PROTECTION METHOD AND SYSTEM - A power electronics device with an improved IGBT protection mechanism is provided. More specifically, systems and methods are provided for reducing the switching frequency of an inverter module based on the junction temperature variation of the IGBT. | 04-01-2010 |
20100177452 | DC BUS CLAMP CIRCUIT TO PREVENT OVER VOLTAGE FAILURE OF ADJUSTABLE SPEED DRIVES - The present invention relates to a protective circuit to provide over voltage protection for an ASD. The protective circuit provides the benefits of fewer components with lower power ratings than existing protective circuits. The protective circuit may be incorporated directly in the ASD for continuous protection or mounted externally and connected to the ASD under operating conditions that require the circuit. This flexibility for mounting the protective circuit allows the capacitor of the protective circuit to be sized either in relation to capacitive elements on the DC bus within the ASD or according to external capacitance observed at the output of the ASD. In addition, the circuit is only operative during an overvoltage condition allowing for power ratings lower than would be required for continuous operation. | 07-15-2010 |
20110101897 | DC BUS BOOST METHOD AND SYSTEM FOR REGENERATIVE BRAKE - Embodiments of the present invention provide novel techniques for using a switched converter to provide for three-phase alternating current (AC) rectification, regenerative braking, and direct current (DC) voltage boosting. In particular, one of the three legs of the switched converter is controlled with a set of pulse width modulation (PWM) control signals so that the input AC phase having the highest voltage is rectified and one of the switches in the two other legs is turned on to allow for added voltage. This switching activity allows for voltage from multiple AC line mains to be combined, resulting in an overall boost of the DC voltage of the rectifier. The DC voltage boost can then be applied to the common DC bus in order to ameliorate voltage sags, help with motor starts, and increase the ride-through capability of the motor. | 05-05-2011 |
20110103096 | THIRTY-SIX PULSE POWER TRANSFORMER AND POWER CONVERTER INCORPORATING SAME - Embodiments of the present invention provide novel techniques for using multiple 18-pulse rectifier circuits in parallel. In particular, each rectifier circuit may include an autotransformer having 15 inductors coupled in series, joined by 15 nodes interposed between pairs of the inductors. The inductors may be represented as a hexagon in which alternating sides of the hexagon have two and three inductors, respectively. Each rectifier circuit may also include three inputs for three-phase AC power coupled to alternating vertices of the hexagonal representation and nine outputs for AC power coupled between each node that is not a vertex of the hexagonal representation and a respective diode bridge. Outputs of the diode bridges for the rectifier circuits may be coupled to a DC bus. In addition, a means for reducing circulating current between the parallel rectifier circuits and for promoting load sharing between the parallel rectifier circuits is also provided. | 05-05-2011 |
20110103105 | POWER TRANSFORMER AND POWER CONVERTER INCORPORATING SAME - Embodiments of the present invention provide novel techniques for using multiple 18-pulse rectifier circuits in parallel. In particular, each rectifier circuit may include an autotransformer having 15 inductors coupled in series, joined by 15 nodes interposed between pairs of the inductors. The inductors may be represented as a hexagon in which alternating sides of the hexagon have two and three inductors, respectively. Each rectifier circuit may also include three inputs for three-phase AC power coupled to alternating vertices of the hexagonal representation and nine outputs for AC power coupled between each node that is not a vertex of the hexagonal representation and a respective diode bridge. Outputs of the diode bridges for the rectifier circuits may be coupled to a DC bus. In addition, a means for reducing circulating current between the parallel rectifier circuits and for promoting load sharing between the parallel rectifier circuits is also provided. | 05-05-2011 |
20110153234 | GROUND FAULT DETECTION SYSTEM AND METHOD - A ground fault detection system is provided. The ground fault detection system includes a magnetic core having first and second primary legs and a secondary leg disposed between the first and second primary legs. The ground fault detection system also includes first and second primary windings disposed around the first and second primary legs respectively and configured to introduce current in the first and second primary legs. Further, the ground fault detection system includes first and second secondary windings disposed around the first and second primary legs respectively and configured to detect a ground fault based upon a magnetic flux generated in response to the introduced current. | 06-23-2011 |
20110286244 | ADJUSTABLE SPEED DRIVE LIFETIME IMPROVEMENT METHOD - The present techniques include methods and systems for operating an inverter to maintain a lifespan of the inverter. In some embodiments, the switching frequency and/or the output current of the inverter may be changed such that stress may be reduced on the inverter bond wires of the inverter. More specifically, embodiments involve calculating the aging parameters for certain operating conditions of the inverter and determining whether the operating conditions result in aging the inverter to a point which reduces the inverter lifespan below a desired lifespan. If the operating conditions reduce the inverter lifespan below the desired lifespan, the switching frequency may be reduced to a lower or minimum switching frequency of the inverter and/or the output current of the inverter may be reduced to a maximum output current at the minimum switching frequency. | 11-24-2011 |
20110295437 | WIND POWER CONVERTER SYSTEM WITH GRID SIDE REACTIVE POWER CONTROL - The present techniques include methods and systems for operating a wind power system to maintain a lifespan of the rotor side converter. In some embodiments, the current of the rotor side converter may be minimized to reduce the stress and/or junction temperature variation in the switching transistors and bond wires of the converter. More specifically, embodiments involve using a minimal current in the rotor side converter based on the rotor side and grid side reactive powers. If the grid side reactive power is greater than a maximum grid side reactive power, the grid side reactive power may be reduced. Further, if the total reactive power does not meet the grid reactive power requirements, the minimal current in the rotor side converter may be adjusted such that the system may sufficiently power the grid. | 12-01-2011 |
20110309875 | CONVERTER LIFETIME IMPROVEMENT METHOD FOR DOUBLY FED INDUCTION GENERATOR - 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. | 12-22-2011 |
20120086458 | SYSTEM FOR DETECTION OF A GROUND FAULT IN A HIGH RESISTANCE GROUND NETWORK - A method is provided for detection of a ground fault in a high resistance network in a voltage source power conversion circuit comprising a power converter that converts incoming AC power to DC power applied to a DC bus and an inverter that converts DC power from the DC bus to output AC power. The method includes detecting a midpoint-to-ground voltage between a low side of the DC bus and a ground potential and detecting the presence of a ground fault in a high resistance network based upon the detected midpoint-to-ground voltage. | 04-12-2012 |
20120086532 | MULTI-PHASE TRANSFORMER - A transformer for converting 3 phase AC to 9 phase AC power is provided. The transformer includes first, second and third coils, each coil having a plurality of serial windings coupled together to form a polygon. The transformer further includes first, second and third input terminals each linked to a respective winding of the first, second and third coils. The input terminals are configured to receive a first, second and third phases of input AC power and at least one selected input terminal of the first, second and third input terminals is adjustable to alter a number of turns of the respective winding of the corresponding first, second or third coil on either side of the selected input terminal. The transformer further includes first through ninth output terminals linkable to first through ninth output power lines. | 04-12-2012 |
20120086533 | MULTI-PHASE TRANSFORMER - A transformer for converting 3 phase AC to 9 phase AC power is provided. The transformer comprising a laminated core, first, second and third coils constructed on the laminated core, each coil including several windings. Cooling ducts are provided in each coil, wherein at least one cooling duct is disposed between the laminated core and an adjacent winding of the respective coil. The transformer further includes first, second and third input terminals each linked to the first, second and third coils, and configured to receive a first, second and third phases of input AC power and first through ninth output terminals linkable to first through ninth output power lines. | 04-12-2012 |
20120112757 | Ground Fault Detection and Location System and Method for Motor Drives - A motor drive system provides for analysis of current flow in the DC bus to identify ground faults and their locations. Low-frequency positive polarity and negative polarity current differences indicate ground faults from the positive DC bus and negative DC bus respectively. High-frequency signals indicate ground faults in the motor windings and connecting leads. | 05-10-2012 |
20120144658 | POWER ELECTRONIC MODULE WITH AN IMPROVED CHOKE AND METHODS OF MAKING SAME - An improved choke assembly for a power electronics device is provided. More specifically, a choke assembly with improved protection from environmental conditions such as dirt and water is provided. An improved choke assembly may include an insulative housing for an inductor coil that seals the inductor coil from the environment. | 06-14-2012 |
20120194202 | DRIVE FAILURE PROTECTION - The present techniques include methods and systems for detecting a failure in a capacitor bank of an electrical drive system. Embodiments include using discharge resistors to discharge capacitors in the capacitor bank, forming a neutral node of the capacitor bank. In different capacitor configurations, the neutral node is measured, and the voltage is analyzed to determine whether a capacitor bank unbalance has occurred. In some embodiments, the node is a neutral-to-neutral node between the discharged side of the discharge resistors and a neutral side of the capacitor bank, or between the discharged side of the discharge resistors and a discharged side of a second set of discharge resistors. In some embodiments, the node is a neutral-to-ground node between the discharged side of the discharge resistors and a ground potential. | 08-02-2012 |
20120201056 | POWER CONVERTER WITH COMMON MODE VOLTAGE REDUCTION - Power conversion systems are presented with common mode reduction by space vector pulse width modulation zero vector selection to counteract common mode contribution of active vectors. | 08-09-2012 |
20120212982 | CMV REDUCTION UNDER BUS TRANSIENT CONDITION - Power conversion systems and control techniques are presented in which a bus transient control component bypasses selected phases of a rectifier during a protective mode of operation to reduce common mode voltages or currents. | 08-23-2012 |
20120235607 | DC BUS BOOST METHOD AND SYSTEM FOR REGENERATIVE BRAKE - Embodiments of the present invention provide novel techniques for using a switched converter to provide for three-phase alternating current (AC) rectification, regenerative braking, and direct current (DC) voltage boosting. In particular, one of the three legs of the switched converter is controlled with a set of pulse width modulation (PWM) control signals so that the input AC phase having the highest voltage is rectified and one of the switches in the two other legs is turned on to allow for added voltage. This switching activity allows for voltage from multiple AC line mains to be combined, resulting in an overall boost of the DC voltage of the rectifier. The DC voltage boost can then be applied to the common DC bus in order to ameliorate voltage sags, help with motor starts, and increase the ride-through capability of the motor. | 09-20-2012 |
20120249038 | GROUND SCHEME IDENTIFICATION METHOD - The present techniques include methods and systems for detecting the grounding condition of an electrical system to automatically determine a suitable electrical drive configuration. The drive includes a test resistor which may be connected or disconnected from the drive to measure different drive voltages. The measured drive voltages are analyzed to determine a type of grounding configuration of the electrical system in which the drive is to be installed. Embodiments also include determining ground resistance condition such as a high resistance ground (HRG) fault or a ground resistance fault when the drive is in operation. | 10-04-2012 |
20120262129 | DOUBLE FED INDUCTION GENERATOR CONVERTER AND METHOD FOR SUPPRESSING TRANSIENT IN DEACTIVATION OF CROWBAR CIRCUIT FOR GRID FAULT RIDETHROUGH - A double fed induction generator (DFIG) system and controller are presented in which the rotor side converter is preloaded with one or more initial values for resuming regulated operation to counteract transients upon deactivation of the crowbar protection circuit to provide grid fault ride through. | 10-18-2012 |
20130010504 | POWER CONVERTER AND INTEGRATED DC CHOKE THEREFOR - A power conversion system and a DC link choke therefore are presented, in which a continuous core structure is provided with first and second legs around which four or more windings are located, with one or more shunt structures providing a magnetic flux path between intermediate portions of the first and second legs. | 01-10-2013 |
20130119903 | AC PRE-CHARGE CIRCUIT - AC pre-charging techniques are provided for pre-charging the DC bus on a motor drive. AC pre-charging techniques involve pre-charge circuitry including a manual switch, an automatic switch, and pre-charge control circuitry to switch the automatic switch between pre-charge and pre-charge bypass modes in response to an initialized pre-charge operation, input voltage sags, etc. In some embodiments, the pre-charge operation may be initialized by switching the manual switch closed. In some embodiments, the pre-charge operation may also be initialized by a detected voltage sag on the DC bus. The pre-charge circuitry may also be configured to disconnect a motor drive from the AC power supply under certain fault conditions. | 05-16-2013 |
20130121051 | DC PRE-CHARGE CIRCUIT - Systems and methods are provided for pre-charging the DC bus on a motor drive. Pre-charging techniques involve pre-charge circuitry including a manual switch, an automatic switch, and pre-charge control circuitry to switch the automatic switch between pre-charge and pre-charge bypass modes in response to an initialized pre-charge operation, input voltage sags, and so forth. In some embodiments, the pre-charge operation may be initialized by switching the manual switch closed. In some embodiments, the pre-charge operation may also be initialized by a detected voltage sag on the DC bus. The pre-charge circuitry may also be configured to disconnect to isolate a motor drive from the common DC bus under certain fault conditions. | 05-16-2013 |
20130218491 | FAULT IDENTIFICATION TECHNIQUES FOR HIGH RESISTANCE GROUNDED SYSTEMS - The present techniques include methods and systems for detecting a high resistive ground fault condition in an HRG system. Embodiments include systems and methods of measuring drive voltages and detecting voltage changes in the drive once the drive is in operation, particularly for drives operating at relatively low voltages and frequencies. In some embodiments, an integrator is utilized to detect peaks in the measured voltage changes. Relatively small ground currents are also measured to determine HRG faults. Moreover, in some embodiments, the detection of an HRG fault for one of several motor drives provide indication for the particular motor drive in fault. | 08-22-2013 |
20130241451 | APPARATUS AND METHOD FOR ENERGY EFFICIENT MOTOR DRIVE STANDBY OPERATION - Motor drive apparatus and methods are presented in which a standby controller uses at least one switching device to power an inverter in a normal mode and to remove power from the inverter and other motor drive components during a standby mode for improved energy efficiency. | 09-19-2013 |
20130242623 | POWER CONVERTER AND INTEGRATED DC CHOKE THEREFOR - A power conversion system with multiple parallel connected motor drives including a plurality of rectifiers and a corresponding inverters connected by windings of a single common mode choke. | 09-19-2013 |
20130249501 | DOUBLE FED INDUCTION GENERATOR (DFIG) CONVERTER AND METHOD FOR IMPROVED GRID FAULT RIDETHROUGH - 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. | 09-26-2013 |
20130286692 | FILTER CAPACITOR DEGRADATION DETECTION APPARATUS AND METHOD - Power conversion systems and methods are presented for detecting input filter capacitor degradation or approach of end of operational life based on filter capacitor current measurements using single and/or dual threshold comparisons for computed instantaneous sum of squares of filter currents or power values. | 10-31-2013 |
20130286702 | ADJUSTABLE SPEED DRIVE LIFETIME IMPROVEMENT SYSTEM - The present techniques include methods and systems for operating an inverter to maintain a lifespan of the inverter. In some embodiments, the switching frequency and/or the output current of the inverter may be changed such that stress may be reduced on the inverter bond wires of the inverter. More specifically, embodiments involve calculating the aging parameters for certain operating conditions of the inverter and determining whether the operating conditions result in aging the inverter to a point which reduces the inverter lifespan below a desired lifespan. If the operating conditions reduce the inverter lifespan below the desired lifespan, the switching frequency may be reduced to a lower or minimum switching frequency of the inverter and/or the output current of the inverter may be reduced to a maximum output current at the minimum switching frequency. | 10-31-2013 |
20130289911 | POWER CONVERTER RESONANCE DETECTION APPARATUS AND METHOD - Power conversion systems and methods are presented for detecting filter capacitor resonance conditions in a power conversion system in which filter currents are measured and filtered using a bandpass filter, and one or more computed mean, RMS, and/or Fourier transform values are computed based on the filtered value(s). The computed measurement value or values are compared with a predetermined threshold and a suspected filter capacitor resonance condition is selectively identified based on comparison result. | 10-31-2013 |
20140035492 | SINGLE PHASE OPERATION OF A THREE-PHASE DRIVE SYSTEM - Single-phase voltage operation techniques are provided for a three-phase drive system. A drive system may include a rectifier configured to couple to a three-phase AC voltage source. The rectifier may be configured to convert AC voltage from the three-phase AC voltage source to a direct current (DC) voltage. The drive system may also include a controller configured to send a plurality of switching signals to a plurality of switches in the rectifier such that the plurality of switching signals minimizes a current provided to the rectifier when only a single-phase of the three-phase AC voltage source is available. | 02-06-2014 |
20140132295 | DRIVE FAILURE PROTECTION - The present techniques include methods and systems for detecting a failure in a capacitor bank of an electrical drive system. Embodiments include using discharge resistors to discharge capacitors in the capacitor bank, forming a neutral node of the capacitor bank. In different capacitor configurations, the neutral node is measured, and the voltage is analyzed to determine whether a capacitor bank unbalance has occurred. In some embodiments, the node is a neutral-to-neutral node between the discharged side of the discharge resistors and a neutral side of the capacitor bank, or between the discharged side of the discharge resistors and a discharged side of a second set of discharge resistors. In some embodiments, the node is a neutral-to-ground node between the discharged side of the discharge resistors and a ground potential. | 05-15-2014 |
20140253055 | CONVERTER LIFETIME IMPROVEMENT METHOD FOR DOUBLY FED INDUCTION GENERATOR - 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. | 09-11-2014 |
20140265976 | METHOD TO IMPLEMENT DRIVE DIAGNOSTICS AND PROGNOSTICS AUTOMATICALLY - An electric motor drive system includes a fan configured to cool power electronic components of the electric motor drive system. The electric motor drive system also includes a temperature sensor disposed proximate an air inlet of the fan and configured to sense an ambient temperature of air entering the air inlet. In addition, the electric motor drive system includes a processor communicatively coupled to the temperature sensor and configured to determine at least one of a drive prognostic and a derating requirement based on the sensed ambient temperature. | 09-18-2014 |