Abstract: A system to detect a ground fault at the output of an inverter section prior to powering up a motor drive system is disclosed. A low voltage power supply is connected to the DC bus prior to connecting the input power source to the rectifier section. If a ground fault exists, the voltage potential on the DC bus causes conduction through one of the freewheeling diodes connected in parallel to the power switching device on the output of the inverter section. A fault detection circuit generates a signal corresponding to the presence of the low voltage potential when the low voltage is applied to the DC bus. If a ground fault is present at the output of one of the inverter sections, the motor drive system prevents the AC voltage from being applied to the rectifier section.

Abstract: A system to detect a ground fault at the output of an inverter section prior to powering up a motor drive system is disclosed. A low voltage power supply is connected to the DC bus prior to connecting the input power source to the rectifier section. If a ground fault exists, the voltage potential on the DC bus causes conduction through one of the freewheeling diodes connected in parallel to the power switching device on the output of the inverter section. A fault detection circuit generates a signal corresponding to the presence of the low Voltage potential when the low voltage is applied to the DC bus. If a ground fault is present at the output of one of the inverter sections, the motor drive system prevents the AC voltage from being applied to the rectifier section.

Abstract: 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.

Abstract: A system configured to reduce the amplitude of reactive current present on a DC bus shared by multiple inverters is disclosed. The start of the switching period for the modulation routines of each inverter is synchronized, and a carrier phase angle is determined for a carrier signal within each of the inverters. The modulation routine of each inverter generates a reactive current on the shared DC bus. By controlling the carrier phase angle for each inverter, the reactive current of a first inverter may be generated at a phase angle that is offset from the phase angle of the reactive current generated by a second inverter. As a result, the reactive current from the first inverter cancels at least a portion of the reactive current from the second inverter, reducing the total reactive current present on the DC bus.

Abstract: 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.

Abstract: 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.

Abstract: A system configured to reduce the amplitude of reactive current present on a DC bus shared by multiple inverters is disclosed. The start of the switching period for the modulation routines of each inverter is synchronized, and a carrier phase angle is determined for a carrier signal within each of the inverters. The modulation routine of each inverter generates a reactive current on the shared DC bus. By controlling the carrier phase angle for each inverter, the reactive current of a first inverter may be generated at a phase angle that is offset from the phase angle of the reactive current generated by a second inverter. As a result, the reactive current from the first inverter cancels at least a portion of the reactive current from the second inverter, reducing the total reactive current present on the DC bus.

Abstract: An integrated DC link inductor and current sensor winding having a core that includes at least two primary legs and at least one secondary leg, two direct current (DC) link windings each wound around one of the two primary legs, and a common mode current sensor winding wound around the secondary leg. Resistors coupled to the common mode current sensor winding may damp the common mode current oscillations.

Abstract: Self-sensing feedback functionality for electromechanical actuators/motors is provided for use in operation and/or as a redundant safety mechanism to attain safety certification without adding extra bulk or wiring to the motor. An actuator can be manufactured having one or more saliencies that cause a spatial variance of inductance. A high frequency signal can be injected into the actuator and sampled to determine a current, voltage, or other electrical parameter. The parameter can be evaluated against the known saliencies of the actuator to determine a position of the actuator and/or an associated rotor. Additionally, the position can be evaluated as a function of time to determine a velocity. This can provide an alternative method for operating the electromechanical actuator according to the position/velocity provided. Additionally, this can provide a redundant feedback channel for safety certification without requiring additional actuator parts.

Abstract: Self-sensing feedback functionality for electromechanical actuators/motors is provided for use in operation and/or as a redundant safety mechanism to attain safety certification without adding extra bulk or wiring to the motor. An actuator can be manufactured having one or more saliencies that cause a spatial variance of inductance. A high frequency signal can be injected into the actuator and sampled to determine a current, voltage, or other electrical parameter. The parameter can be evaluated against the known saliencies of the actuator to determine a position of the actuator and/or an associated rotor. Additionally, the position can be evaluated as a function of time to determine a velocity. This can provide an alternative method for operating the electromechanical actuator according to the position/velocity provided. Additionally, this can provide a redundant feedback channel for safety certification without requiring additional actuator parts.

Abstract: An integrated DC link inductor and current sensor winding having a core that includes at least two primary legs and at least one secondary leg, two direct current (DC) link windings each wound around one of the two primary legs, and a common mode current sensor winding wound around the secondary leg. Resistors coupled to the common mode current sensor winding may damp the common mode current oscillations.