Abstract: A system for distributing DC bus voltage and control power to multiple motors includes a rectifier front end supplying a DC bus voltage and a DC control voltage. Both the DC bus voltage and the DC control voltage are distributed via a common set of conductors. Diodes are operatively connected between the DC control voltage and the common set of conductors. The diodes allow forward conduction of the DC control voltage and distribution of control power to distributed devices when the DC bus voltage is not present. Once the DC bus voltage is present, the diodes block conduction of the DC control voltage. Each of the distributed devices are configured with an internal power supply that is operative to generate an internal control voltage from either the DC control voltage or the DC bus voltage.

Abstract: A system for distributing DC bus voltage and control power to multiple motors includes a rectifier front end supplying a DC bus voltage and a DC control voltage. Both the DC bus voltage and the DC control voltage are distributed via a common set of conductors. Diodes are operatively connected between the DC control voltage and the common set of conductors. The diodes allow forward conduction of the DC control voltage and distribution of control power to distributed devices when the DC bus voltage is not present. Once the DC bus voltage is present, the diodes block conduction of the DC control voltage. Each of the distributed devices are configured with an internal power supply that is operative to generate an internal control voltage from either the DC control voltage or the DC bus voltage.

Abstract: A system for distributing DC bus voltage and control power to multiple motors includes a rectifier front end supplying a DC bus voltage and a DC control voltage. Both the DC bus voltage and the DC, control voltage are distributed via a common set of conductors. Diodes are operatively connected between the DC control voltage and the common set of conductors. The diodes allow forward conduction of the DC control voltage and distribution of control power to distributed devices when the DC bus voltage is not present. Once the DC bus voltage is present, the diodes block conduction of the DC control voltage. Each of the distributed devices are configured with an internal power supply that is operative to generate an internal control voltage from either the DC control voltage or the DC bus voltage.

Abstract: A system for distributing DC bus voltage and control power to multiple motors includes a rectifier front end supplying a DC bus voltage and a DC control voltage. Both the DC bus voltage and the DC, control voltage are distributed via a common set of conductors. Diodes are operatively connected between the DC control voltage and the common set of conductors. The diodes allow forward conduction of the DC control voltage and distribution of control power to distributed devices when the DC bus voltage is not present. Once the DC bus voltage is present, the diodes block conduction of the DC control voltage. Each of the distributed devices are configured with an internal power supply that is operative to generate an internal control voltage from either the DC control voltage or the DC bus voltage.

Abstract: A method for detecting fault conditions in a motor drive at power up is disclosed. During the power up sequence, input power is applied to the motor drive and the DC bus begins to charge to its normal operating level. Once the DC bus has reached a suitable level and prior to commanding motion of the attached motor, the shunt resistor is connected across the DC bus for a short duration. The amplitude of voltage and current present on the DC bus are measured while the shunt resistor is connected across the DC bus. The measurements are then used to detect fault conditions in the motor drive. The presence of the fault conditions are relayed to an operator. Thus, the motor drive may detect certain fault conditions prior to commanding motion from the drive.

Abstract: A system for connecting motor drives to each other is disclosed that does not require the use of wire or tools. The system includes an adapter plug and bus bar modules that connect to each other at a conductive receptacle of the adapter plug to define a splice joint at the point of connect of the bus bar modules. The bus bar modules may include insulating covers and insulating clips may overlie the splice joints so that the system is substantially devoid of exposed surfaces of its conductive materials.

Abstract: A cable clamp assembly includes a bracket and first and second fasteners. The first fastener includes a head, a threaded region, and a neck region. The second fastener includes a head, a lower threaded region, an upper threaded region, a lower neck region, and an upper neck region. The first fastener is captured in a first aperture of the bracket by location of the neck region of the first fastener in the first aperture. The second fastener is captured in a second aperture of the bracket by location of the upper neck region of the second fastener in the second aperture. The cable clamp assembly is captured to a wall by arranging the lower neck region of the second fastener to extend through a bore of the wall such that the upper and lower threaded regions of the second fastener are located on opposite sides of the wall.

Abstract: An inverter executing a PWM routine is configured to synchronize the switching periods of the PWM routine to an external signal. The external signal is generated, for example, by another inverter, a converter, or a high level controller. The external signal is preferably generated periodically, and the switching period is resynchronized to the external signal each time the external signal is received. Optionally, either the start time or the midpoint of the switching period may be aligned with external signal. Further, the external signal may be sent to multiple inverters. Preferably, a first portion of the inverters align the start time of their respective switching period to the external signal and a second portion of the inverters align the midpoint of their respective switching period to the external signal.

Abstract: A method for detecting fault conditions in a motor drive at power up is disclosed. During the power up sequence, input power is applied to the motor drive and the DC bus begins to charge to its normal operating level. Once the DC bus has reached a suitable level and prior to commanding motion of the attached motor, the shunt resistor is connected across the DC bus for a short duration. The amplitude of voltage and current present on the DC bus are measured while the shunt resistor is connected across the DC bus. The measurements are then used to detect fault conditions in the motor drive. The presence of the fault conditions are relayed to an operator. Thus, the motor drive may detect certain fault conditions prior to commanding motion from the drive.

Abstract: A system for connecting motor drives to each other is disclosed that does not require the use of wire or tools. The system includes an adapter plug and bus bar modules that connect to each other at a conductive receptacle of the adapter plug to define a splice joint at the point of connect of the bus bar modules. The bus bar modules may include insulating covers and insulating clips may overlie the splice joints so that the system is substantially devoid of exposed surfaces of its conductive materials.

Abstract: An air cooled switching unit for a motor drive includes a forced air cooling chamber and a convective cooling chamber separate from the forced air cooling chamber. An exhaust port of the forced cooling chamber is configured to direct exhaust air across an outlet of the convective cooling chamber to induce an increased air flow through the convective cooling chamber thereby increasing the cooling capacity of the convective cooling chamber.

Abstract: A cable clamp assembly includes a bracket and first and second fasteners. The first fastener includes a head, a threaded region, and a neck region. The second fastener includes a head, a lower threaded region, an upper threaded region, a lower neck region, and an upper neck region. The first fastener is captured in a first aperture of the bracket by location of the neck region of the first fastener in the first aperture. The second fastener is captured in a second aperture of the bracket by location of the upper neck region of the second fastener in the second aperture. The cable clamp assembly is captured to a wall by arranging the lower neck region of the second fastener to extend through a bore of the wall such that the upper and lower threaded regions of the second fastener are located on opposite sides of the wall.

Abstract: 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.

Abstract: A system for connecting motor drives to each other is disclosed that does not require the use of wire or tools. The system includes an adapter plug and bus bar modules that connect to each other at a conductive receptacle of the adapter plug to define a splice joint at the point of connect of the bus bar modules. The bus bar modules may include insulating covers and insulating clips may overlie the splice joints so that the system is substantially devoid of exposed surfaces of its conductive materials.

Abstract: The present invention includes techniques for configuring an electric drive module designed for various multi-axis drive system configurations. Embodiments include techniques for integrating a three phase dual converter with a diode bridge and drive controller within a single drive module. Further integrating the diode bridge directly within the drive module may result in an integrated, modular building block for multiple electric drive system configurations. In some embodiments, multiple electric drive modules are connected by a DC bus to form a system configured for higher energy efficiency.

Abstract: A method for controlling a motor drive system, the system comprising an AC-DC converter coupled to a DC-AC inverter by a DC bus, a motor coupled to and driven by the inverter, and a load coupled to and driven by the motor is provided. The method includes accessing a motion profile for the motor and load and determining power losses of the converter, the inverter, the motor and the load. The method also includes controlling the voltage of the DC bus based upon the motion profile and the power losses to enhance the motor drive system efficiency, reliability and motor shaft performance.

Abstract: An air cooled switching unit for a motor drive includes a forced air cooling chamber and a convective cooling chamber separate from the forced air cooling chamber. An exhaust port of the forced cooling chamber is configured to direct exhaust air across an outlet of the convective cooling chamber to induce an increased air flow through the convective cooling chamber thereby increasing the cooling capacity of the convective cooling chamber.

Abstract: 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.

Abstract: A system for connecting motor drives to each other is disclosed that does not require the use of wire or tools. The system includes an adapter plug and bus bar modules that connect to each other at a conductive receptacle of the adapter plug to define a splice joint at the point of connect of the bus bar modules. The bus bar modules may include insulating covers and insulating clips may overlie the splice joints so that the system is substantially devoid of exposed surfaces of its conductive materials.

Abstract: An inverter executing a PWM routine is configured to synchronize the switching periods of the PWM routine to an external signal. The external signal is generated, for example, by another inverter, a converter, or a high level controller. The external signal is preferably generated periodically, and the switching period is resynchronized to the external signal each time the external signal is received. Optionally, either the start time or the midpoint of the switching period may be aligned with external signal. Further, the external signal may be sent to multiple inverters. Preferably, a first portion of the inverters align the start time of their respective switching period to the external signal and a second portion of the inverters align the midpoint of their respective switching period to the external signal.