Patent application number | Description | Published |
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 |
20140035497 | Method and Apparatus for Reducing Radiated Emissions in Switching Power Converters - A filter for reducing radiated emissions in switching power converters such as a motor drive is disclosed. The switching power converter modulates a DC voltage input to generate a desired AC voltage output. Capacitors are connected in parallel between each output phase and a common connection, which may be a ground connection. The magnitude and layout of the capacitors are selected to minimize current conducted by the capacitors. The capacitors may be surface mount technology located proximate to the switching devices or the capacitors may be incorporated in the circuit board on which the switching devices are mounted. The filter may be applied to any of the switching elements in a motor drive, such as the inverter section, an active rectifier section, or a switched mode power supply. | 02-06-2014 |
20150145463 | Method and Apparatus for Reducing Radiated Emissions in Switching Power Converters - A filter for reducing radiated emissions in switching power converters such as a motor drive is disclosed. The switching power converter modulates a DC voltage input to generate a desired AC voltage output. Capacitors are connected in parallel between each output phase and a common connection, which may be a ground connection. The magnitude and layout of the capacitors are selected to minimize current conducted by the capacitors. The capacitors may be surface mount technology located proximate to the switching devices or the capacitors may be incorporated in the circuit board on which the switching devices are mounted. The filter may be applied to any of the switching elements in a motor drive, such as the inverter section, an active rectifier section, or a switched mode power supply. | 05-28-2015 |
Patent application number | Description | Published |
20090267431 | TERMINATOR FOR REDUCING DIFFERENTIAL-MODE AND COMMON-MODE VOLTAGE REFLECTIONS IN AC MOTOR DRIVES - A terminator reduces reflections on power lines connecting an inverter to an AC motor by providing a differential-mode reflection damping element and at least one common-mode reflection damping element, the latter including a series capacitance to substantially reduce power dissipation in the resistance of the damping elements. | 10-29-2009 |
20090303652 | METHOD AND APPARATUS FOR REDUCING DIFFERENTIAL MODE AND COMMON MODE REFLECTIONS IN MOTOR DRIVES - A filter device reduces reflections on power lines from the motor drive to AC motors by providing a differential mode choke in series with a common mode choke both shunted by resistances tailored to the characteristic impedance of the power cable for differential mode and common mode reflections respectively. By treating both common mode based and differential mode based reflections, superior transient control and motor drive performance may be obtained. | 12-10-2009 |
20100176755 | POWER CONVERSION SYSTEM AND METHOD - Power conversion systems and methods are provided for driving a plurality of motor loads, in which an autotransformer receives AC input currents and provides a plurality of multiphase outputs at a non-zero phase angle relative to one another, and the individual multiphase outputs are provided to corresponding motor drives with rectifiers to convert the multiphase outputs to DC electrical power, and inverters to convert the DC power to AC to drive corresponding motor loads. | 07-15-2010 |
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 |
20110025300 | ELECTRICAL POWER QUALITY TEST CIRCUITRY AND METHOD - Electrical power quality test circuitry for testing response of an electrical device to input power disturbances is provided. The test circuitry includes a power structure having a rectifier configured to convert incoming AC voltage to DC voltage on a DC bus, and a power inverter configured to convert DC voltage from the bus to three-phase output AC voltage applied to the electrical device. The test circuitry also includes a control circuit configured to apply control signals to at least the power inverter to emulate at least one of a change in the amplitude of at least one phase of the output AC voltage at least one phase angle of at least one phase of the output AC voltage, and a frequency change for all phases of the output AC voltage. | 02-03-2011 |
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 |
20110292695 | POWER CONVERTER SYSTEM AND METHOD - A three-phase power converter includes a converter configured to convert a three phase AC power input to a DC power output, the DC power output being provided to high and low sides of a DC bus, and an inverter coupled to the DC bus and configured to convert the DC power to a three phase AC output. The inverter comprises three legs and each leg comprises a pair of solid state switches and a respective output therebetween. The power converter further includes a common mode voltage control filter comprising three filter inputs and two filter outputs, each filter input coupled to an output of a respective leg of the inverter and each filter output coupled to a respective side of the DC bus. | 12-01-2011 |
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 |
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 |
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 |
Patent application number | Description | Published |
20090276375 | Analysis of powder metal production of a component - A method of calculating the cost saving for producing a metallic component by the use of a powder metal process is provided. The method includes the steps of analyzing the current production method of the component, usually machining, to determine the current unit cost. The customer would agree to purchase an agreed supply of components for an agreed period of time for the components that could be supplied with an agreed cost savings. The production of the component utilizing powder metal process is then analyzed to determine the powder metal unit cost. The savings for production of the component utilizing the powder metal process is then presented to the customer. The customer could agree to purchase the agreed supply of components for an agreed period of time. If agreed, the test production of the component utilizing a powder metal process is then performed. If successful, a final tooling and production quotation for the production of the component is then provided to the customer. | 11-05-2009 |
20140190307 | RAILCAR HANDBRAKE WHEEL - A railcar handbrake wheel of polymeric composition including an outer ring connected to a hub by at least two spokes. The hub containing an insert or core molded into the hub. The core is a shaft member having a first end and a second end, with a head connected to the first end. The head on the first end of the core having a greater cross-sectional area than the second end of the core. The core containing an opening extending from the first end to the second end. | 07-10-2014 |
20140345493 | RAILWAY CAR HATCH COVER - A railway car hatch cover includes an exterior shell cover, a gasket, and a mounting ring. The exterior shell cover has an outer-side and an under-side. The gasket is a vented gasket or a non-vented gasket, and the gasket is mounted to the mounting ring. The mounting ring is secured to the under-side of the exterior shell cover. The mounting ring is removable, and the gasket is replaceable with a second gasket. The second gasket can be vented or non-vented. The mounting ring is reinstallable on the under-side of the exterior shell cover. The replaceable gasket allows a single hatch cover to function as a vented hatch cover or a non-vented hatch cover depending on the type of gasket installed. | 11-27-2014 |