Abstract: A motor-drive system may include a rectifier, a metal-oxide varistor (MOV) assembly, and an inverter. The rectifier may generate a direct current (DC) voltage based on a first voltage received from at least one supply voltage line coupled to a voltage source. The MOV assembly may include at least two metal-oxide varistors (MOVs) respectively coupled to the at least one supply voltage lines. The MOV assembly may couple between the voltage source and the rectifier. The motor-drive system may also include a permanently-installed jumper to couple at least one MOV of the at least two MOVs of the MOV assembly to a system ground. The inverter of the motor-drive system may convert the DC voltage to an alternating current (AC) voltage, which may be provided to a load of the motor-drive system.

Abstract: A switch mode power supply includes a bootstrap circuit, control circuits, and an auxiliary winding coupled to the bootstrap circuit and configured to supply power to the control circuits after startup of the power supply. The bootstrap circuit is configured to supply power to the control circuits during startup and includes an isolation circuit to limit current flow between the starting capacitor and the control circuits while the starting capacitor is charged to a starting voltage by the high voltage input. During the initial charge of the starting capacitor, the control circuits do not have power to provide the initial functionality of the power supply. Once the starting capacitor is charged to the starting voltage, the isolation circuit is activated to allow current flow that powers the control circuits during the remainder of the startup until the auxiliary winding is able to power the control circuits.

Abstract: A switch mode power supply includes a bootstrap circuit, control circuits, and an auxiliary winding coupled to the bootstrap circuit and configured to supply power to the control circuits after startup of the power supply. The bootstrap circuit is configured to supply power to the control circuits during startup and includes an isolation circuit to limit current flow between the starting capacitor and the control circuits while the starting capacitor is charged to a starting voltage by the high voltage input. During the initial charge of the starting capacitor, the control circuits do not have power to provide the initial functionality of the power supply. Once the starting capacitor is charged to the starting voltage, the isolation circuit is activated to allow current flow that powers the control circuits during the remainder of the startup until the auxiliary winding is able to power the control circuits.

Abstract: To avoid the catastrophic failure of a drive, protection circuitry is configured to limit current in the DC bus capacitors. The drive may include an isolation circuit and a protection circuit having a comparator. The protection circuit may be configured to compare the voltage measured across a DC bus capacitor with a threshold voltage and activate the isolation circuit when the DC capacitor voltage exceeds the threshold voltage. The drive may also include a low voltage circuit coupled to the isolation circuit, where the low voltage circuit is configured to interrupt the bypass signal to disengage the bypass circuit and activate the precharge circuit when the isolation circuit is activated. Accordingly, the current in the drive and to the DC bus capacitors is limited by the precharge circuit when the voltage of a capacitor in the DC bus exceeds a threshold.

Abstract: To avoid the catastrophic failure of a drive, protection circuitry is configured to limit current in the DC bus capacitors. The drive may include an isolation circuit and a protection circuit having a comparator. The protection circuit may be configured to compare the voltage measured across a DC bus capacitor with a threshold voltage and activate the isolation circuit when the DC capacitor voltage exceeds the threshold voltage. The drive may also include a low voltage circuit coupled to the isolation circuit, where the low voltage circuit is configured to interrupt the bypass signal to disengage the bypass circuit and activate the precharge circuit when the isolation circuit is activated. Accordingly, the current in the drive and to the DC bus capacitors is limited by the precharge circuit when the voltage of a capacitor in the DC bus exceeds a threshold.

Abstract: A motor-drive system may include a rectifier, a metal-oxide varistor (MOV) assembly, and an inverter. The rectifier may generate a direct current (DC) voltage based on a first voltage received from at least one supply voltage line coupled to a voltage source. The MOV assembly may include at least two metal-oxide varistors (MOVs) respectively coupled to the at least one supply voltage lines. The MOV assembly may couple between the voltage source and the rectifier. The motor-drive system may also include a permanently-installed jumper to couple at least one MOV of the at least two MOVs of the MOV assembly to a system ground. The inverter of the motor-drive system may convert the DC voltage to an alternating current (AC) voltage, which may be provided to a load of the motor-drive system.

Abstract: A motor-drive system may include a rectifier, a metal-oxide varistor (MOV) assembly, and an inverter. The rectifier may generate a direct current (DC) voltage based on a first voltage received from at least one supply voltage line coupled to a voltage source. The MOV assembly may include at least two metal-oxide varistors (MOVs) respectively coupled to the at least one supply voltage lines. The MOV assembly may couple between the voltage source and the rectifier. The motor-drive system may also include a permanently-installed jumper to couple at least one MOV of the at least two MOVs of the MOV assembly to a system ground. The inverter of the motor-drive system may convert the DC voltage to an alternating current (AC) voltage, which may be provided to a load of the motor-drive system.

Abstract: Power conversion systems, disclosed examples include power conversion systems, ground fault detection apparatus and methods to detect and identify ground faults in a power conversion system using AC coupling to sense a system voltage to determine a leakage flux linkage, and to identify a faulted converter phase based on a phase shift angle of the leakage flux linkage.

Abstract: A motor-drive system may include a rectifier, a metal-oxide varistor (MOV) assembly, and an inverter. The rectifier may generate a direct current (DC) voltage based on a first voltage received from at least one supply voltage line coupled to a voltage source. The MOV assembly may include at least two metal-oxide varistors (MOVs) respectively coupled to the at least one supply voltage lines. The MOV assembly may couple between the voltage source and the rectifier. The motor-drive system may also include a permanently-installed jumper to couple at least one MOV of the at least two MOVs of the MOV assembly to a system ground. The inverter of the motor-drive system may convert the DC voltage to an alternating current (AC) voltage, which may be provided to a load of the motor-drive system.

Abstract: A motor drive system includes at least one current sensor disposed within a housing of the motor drive system. The at least one sensor is configured to detect a current of output power produced by the motor drive system. The motor drive system also includes a controller configured to determine a resonant frequency of a cable connected to the motor drive system based at least in part on the detected current, and to adjust pulse width modulation (PWM) switching of the motor drive system based at least in part on the determined resonant frequency of the cable.

Abstract: Power conversion systems, ground fault detection apparatus and methods to detect and identify ground faults in a power conversion system using AC coupling to sense a system voltage to determine a leakage flux linkage, and to identify a faulted converter phase based on a phase shift angle of the leakage flux linkage.

Abstract: Power conversion systems, disclosed examples include power conversion systems, ground fault detection apparatus and methods to detect and identify ground faults in a power conversion system using AC coupling to sense a system voltage to determine a leakage flux linkage, and to identify a faulted converter phase based on a phase shift angle of the leakage flux linkage.

Abstract: A motor drive system includes at least one current sensor disposed within a housing of the motor drive system. The at least one sensor is configured to detect a current of output power produced by the motor drive system. The motor drive system also includes a controller configured to determine a resonant frequency of a cable connected to the motor drive system based at least in part on the detected current, and to adjust pulse width modulation (PWM) switching of the motor drive system based at least in part on the determined resonant frequency of the cable.

Abstract: Power conversion systems, disclosed examples include power conversion systems, ground fault detection apparatus and methods to detect and identify ground faults in a power conversion system using AC coupling to sense a system voltage to determine a leakage flux linkage, and to identify a faulted converter phase based on a phase shift angle of the leakage flux linkage.

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: 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: 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: 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.

Abstract: Multiple inverter motor drives are interconnected in parallel to provide a common output to a motor. Common control circuitry is coupled to all parallel drives via optical cables and provides signals to power layer circuitry of each inverter for generation, at the power layer, of timing for gate drive signals for the respective inverter power electronic switches. The resulting timing exhibits a high degree of synchronicity such that very little imbalance occurs in the outputs of the paralleled drives, resulting in very low circulating currents.

Abstract: Control systems, methods and power conversion systems are presented for reducing common mode voltages in AC motor loads driven by inverter PWM control using switching sequences with only active vectors where a first vector of each switching sequence differs by one phase switching state from a last vector of a switching sequence of an adjacent sector, along with enhanced deadtime compensation and reflected wave reduction techniques in providing pulse width modulated switching signals to a switching inverter.