Abstract: 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.

Abstract: 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.

Abstract: The present invention provides a power converter mounting system including a flange that cooperates with a power converter and an enclosure. The flange includes a through hole that cooperates with an opening in the enclosure to permit the power converter to extend therethrough. A number of fasteners connect to the flange and overhang a portion of the power converter. The fasteners are configured to be manipulated from a front side of the power converter. An outer perimeter of the flange extends beyond the opening in the enclosure. The flange is secured to the enclosure with a number of fasteners that are also operable from the front side of the power converter. The power converter mounting assembly is configured to secure a power converter to an enclosure so as to satisfy a variety of sealing requirements as well as allowing convenient servicing of the power converter system.

Abstract: The present invention relates generally to tuning the flow of cooling air across converter and inverter heat sinks in a motor drive system. More specifically, present techniques relate to motor drive duct systems including heat sinks with separate, sequential heat sink fin sections disposed in a common cooling air path and having different geometries to optimize the flow of cooling air across and between fins of the separate heat sink fin sections. For example, the heat sink fin sections may have different fin lengths, fin heights, fin counts, fin pitch (e.g., distance between adjacent fins), and so forth. Each of these different geometric characteristics may be tuned to ensure that temperatures and temperature gradients across the heat sinks are maintained within acceptable ranges.

Abstract: 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.

Abstract: A method and apparatus for predicting junction device temperature of at least a first switching device in a power conversion module that includes the first switching device and at least a second switching device, the method comprising the steps of identifying a cross thermal impedance value indicative of how the temperature of the second switching device effects the first switching device temperature and using the cross thermal impedance value to predict the temperature of the at least a first switching device.

Abstract: The present invention relates generally to tuning the flow of cooling air across converter and inverter heat sinks in a motor drive system. More specifically, present techniques relate to motor drive duct systems including heat sinks with separate, sequential heat sink fin sections disposed in a common cooling air path and having different geometries to optimize the flow of cooling air across and between fins of the separate heat sink fin sections. For example, the heat sink fin sections may have different fin lengths, fin heights, fin counts, fin pitch (e.g., distance between adjacent fins), and so forth. Each of these different geometric characteristics may be tuned to ensure that temperatures and temperature gradients across the heat sinks are maintained within acceptable ranges.

Abstract: A method and apparatus for predicting junction device temperature of at least a first switching device in a power conversion module that includes a plurality of switching devices, the method comprising the steps of, during switching activity, identifying at least one operating characteristic of the first switching device and solving an equation that uses the identified operating characteristic to predict the temperature of the first switching device where the equation solved is a function of the location of the first switching device with respect to the other switching devices in the plurality.

Abstract: A conformal coating system and method for coating a printed circuit board (PCB) is provided. The system comprises a coating station configured to coat the PCB with a coating material and without cleaning the PCB with a saponifier. A surface energy of the PCB is maintained above a target surface energy at least through the cleaning station to promote adhesion of the coating material.

Abstract: A technique is disclosed for cooling resistive elements, such as brake resistors used in motor drives, as well as other resistors. A phase change heat spreader is thermally coupled to the resistive element and a continuous phase change cycle takes place in the heat spreader to extract heat from the resistive element. The element and heat spreader may be packaged as a modular unit or may be integrated into a system.

Abstract: 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.

Abstract: The present invention provides a power converter mounting system including a flange that cooperates with a power converter and an enclosure. The flange includes a through hole that cooperates with an opening in the enclosure to permit the power converter to extend therethrough. A number of fasteners connect to the flange and overhang a portion of the power converter. The fasteners are configured to be manipulated from a front side of the power converter. An outer perimeter of the flange extends beyond the opening in the enclosure. The flange is secured to the enclosure with a number of fasteners that are also operable from the front side of the power converter. The power converter mounting assembly is configured to secure a power converter to an enclosure so as to satisfy a variety of sealing requirements as well as allowing convenient servicing of the power converter system.

Abstract: 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.

Abstract: A technique is disclosed for cooling connections points in power electronic circuits, such as points at which wire bonding connections are made. A phase change heat spreader is thermally coupled at or near the connection point and a continuous phase change takes place in the heat spreader to extract heat from the connection point during operation. The heat spreader may extend over a area larger than the connection point to enhance cooling and to dissipate heat over a larger area. Small, specifically directed applications are possible in which specific points are cooled together or individually.

Abstract: A technique is disclosed for cooling resistive elements, such as brake resistors used in motor drives, as well as other resistors. A phase change heat spreader is thermally coupled to the resistive element and a continuous phase change cycle takes place in the heat spreader to extract heat from the resistive element. The element and heat spreader may be packaged as a modular unit or may be integrated into a system.

Abstract: A technique for cooling electrical bus structures is disclosed, in which a phase change heat spreader is thermally coupled to the bus. A continuous phase change cycle occurs within the heat spreader to draw heat from the bus during operation. The heat spreader may be planar, and extend over an area greater then the surface area of the bus to enhance cooling and to render the overall assembly more isothermal. The heat spreader may be placed near bus joints and circuits to remove heat caused by increased resistance at such locations.

Abstract: A power electronic module is cooled by a phase change heat spreader or cooling device. The module may include switched or unswitched devices, such as power transistors, diodes, and so forth, forming circuits such as rectifiers, inverters, converters, or the like, or portions of such circuits. Heat is transferred to the heat spreader in which a continuous phase change cycle takes place to cool the circuit components. The heat spreader may extend over an area sufficient to reduce the temperature of the components, and ultimately will render portions of the overall structure more isothermal.

Abstract: A method and apparatus for predicting junction device temperature of at least a first switching device in a power conversion module that includes the first switching device and at least a second switching device, the method comprising the steps of identifying a cross thermal impedance value indicative of how the temperature of the second switching device effects the first switching device temperature and using the cross thermal impedance value to predict the temperature of the at least a first switching device.

Abstract: A method and apparatus for predicting junction device temperature of at least a first switching device in a power conversion module that includes a plurality of switching devices, the method comprising the steps of, during switching activity, identifying at least one operating characteristic of the first switching device and solving an equation that uses the identified operating characteristic to predict the temperature of the first switching device where the equation solved is a function of the location of the first switching device with respect to the other switching devices in the plurality.

Abstract: A method and apparatus for predicting junction device temperature of at least a first switching device in a power conversion module that includes the first switching device and at least a second switching device, the method comprising the steps of identifying a cross thermal impedance value indicative of how the temperature of the second switching device effects the first switching device temperature an using the cross thermal impedance value to predict the temperature of the at least a first switching device.