Abstract: Examples of the disclosure include a UPS comprising an output to be coupled to a load, a first converter leg to provide a first voltage to the output and including at least one of a first relay or fuse, a second converter leg in parallel with the first converter leg including at least one of a second relay or fuse and configured to provide a second voltage to the output out of phase with the first converter leg providing the first voltage signal, current sensors coupled to the first and second converter legs, respectively, and configured to provide a first signal indicative of a current in the first converter leg and a second signal indicative of a current in the second converter leg, respectively, and at least one controller to receive the signals, determine a current difference between the converter legs based on the signals, and decrease the current difference.

Abstract: A system for turning on thyristors is presented, the system comprising: an input configured to be coupled to a power source; an output configured to be coupled to a load; a first branch coupled between the input and the output and including a first thyristor having a first threshold voltage; a second branch coupled between the input and the output and coupled in parallel with the first branch, the second branch including a second thyristor having a second threshold voltage higher than the first threshold voltage; and at least one controller configured to control the system to selectively generate a biasing voltage across the second thyristor to induce a change in a voltage across the second thyristor from a first voltage to a second voltage, the first voltage being less than the second threshold voltage and the second voltage being greater than the second threshold voltage.

Abstract: Examples of the disclosure include a UPS comprising an output to be coupled to a load, a first converter leg to provide a first voltage to the output and including at least one of a first relay or fuse, a second converter leg in parallel with the first converter leg including at least one of a second relay or fuse and configured to provide a second voltage to the output out of phase with the first converter leg providing the first voltage signal, current sensors coupled to the first and second converter legs, respectively, and configured to provide a first signal indicative of a current in the first converter leg and a second signal indicative of a current in the second converter leg, respectively, and at least one controller to receive the signals, determine a current difference between the converter legs based on the signals, and decrease the current difference.

Abstract: Examples of the disclosure include a power system including an input power connection, a return connection, a power converter having a converter input, a backfeed switch coupled between the input power connection and the converter input, at least one safety switch coupled between the converter input and the return connection, and at least one control circuit configured to control the at least one safety switch to be closed when the backfeed switch opens.

Abstract: A multi-transformer assembly includes a first transformer having a first core and a first set of windings, a second transformer having a second core and a second set of windings, and a heatsink positioned between the first core and the second core. The heatsink includes a first side and a second side. The first side of the heatsink is opposite the second side of the heatsink, and thermally coupled to the first core and the first set of windings. The first side is thermally coupled to the first core and the first set of windings by a first thermal conductor. The second side is thermally coupled to the second core and the second set of windings. The second side is thermally coupled to the second core and the second set of windings by a second thermal conductor.

Abstract: Examples of the disclosure include a UPS comprising an output to be coupled to a load, a first converter leg to provide a first voltage to the output and including at least one of a first relay or fuse, a second converter leg in parallel with the first converter leg including at least one of a second relay or fuse and configured to provide a second voltage to the output out of phase with the first converter leg providing the first voltage signal, current sensors coupled to the first and second converter legs, respectively, and configured to provide a first signal indicative of a current in the first converter leg and a second signal indicative of a current in the second converter leg, respectively, and at least one controller to receive the signals, determine a current difference between the converter legs based on the signals, and decrease the current difference.

Abstract: Examples of the disclosure include a UPS comprising an output to be coupled to a load, a first converter leg to provide a first voltage to the output and including at least one of a first relay or fuse, a second converter leg in parallel with the first converter leg including at least one of a second relay or fuse and configured to provide a second voltage to the output out of phase with the first converter leg providing the first voltage signal, current sensors coupled to the first and second converter legs, respectively, and configured to provide a first signal indicative of a current in the first converter leg and a second signal indicative of a current in the second converter leg, respectively, and at least one controller to receive the signals, determine a current difference between the converter legs based on the signals, and decrease the current difference.

Abstract: Examples of the disclosure include a UPS comprising an output to be coupled to a load, a first converter leg to provide a first voltage to the output and including at least one of a first relay or fuse, a second converter leg in parallel with the first converter leg including at least one of a second relay or fuse and configured to provide a second voltage to the output out of phase with the first converter leg providing the first voltage signal, current sensors coupled to the first and second converter legs, respectively, and configured to provide a first signal indicative of a current in the first converter leg and a second signal indicative of a current in the second converter leg, respectively, and at least one controller to receive the signals, determine a current difference between the converter legs based on the signals, and decrease the current difference.

Abstract: According to one aspect, an uninterruptible power supply system is provided including an input configured to receive input power, an interface configured to be coupled to a backup power supply and to receive backup power from the backup power supply, an output configured to provide output power derived from at least one of the input power and the backup power to a load, a power converter coupled to the input, a capacitor, and a shoot-through detector coupled to the capacitor. The shoot-through detector is configured to obtain a first voltage value indicative of a first voltage across the capacitor, obtain a second voltage value indicative of a second voltage across the capacitor, compare the first voltage value to the second voltage value, determine, based on the comparison, that the capacitor is experiencing a shoot-through condition, and provide an output signal indicative of the shoot-through condition.

Abstract: According to one aspect, a power device is provided. The power device includes an input having at least a first connection and a second connection, and configured to be coupled to an AC power source to receive input AC power, a converter circuit coupled to the input and configured to convert an input AC voltage to a DC voltage, a load output configured to provide output power derived from the DC voltage, a rectifier circuit coupled to the input and having a first output and a second output, and a first capacitor coupled to the first output of the rectifier circuit and the second output of the rectifier circuit.

Abstract: An Uninterruptible Power Supply (UPS) system is provided which includes an input configured to receive input power, an output configured to provide output power to a load, power conversion circuitry coupled to the input and the output, a capacitor coupled to the power conversion circuitry, and a controller coupled to the power conversion circuitry. The controller is configured to determine a first value indicative of an equivalent series resistance of the capacitor, determine, based on the first value, if the capacitor satisfies at least one criterion, and execute, responsive to determining that the relative value satisfies the at least one criterion, one or more actions to address degradation of the capacitor.

Abstract: According to one aspect, a power device is provided. The power device includes an input having at least a first connection and a second connection, and configured to be coupled to an AC power source to receive input AC power, a converter circuit coupled to the input and configured to convert an input AC voltage to a DC voltage, a load output configured to provide output power derived from the DC voltage, a rectifier circuit coupled to the input and having a first output and a second output, and a first capacitor coupled to the first output of the rectifier circuit and the second output of the rectifier circuit.

Abstract: According to one aspect, embodiments of the invention provide a UPS comprising a plurality of inputs, a PFC converter configured to convert 3-phase input power into DC power, an inverter coupled to a positive DC bus and a negative DC bus and configured to convert the DC power received from the positive DC bus and the negative DC bus into output AC power, a first output configured to provide a first portion of the output AC power from the inverter to a load, a second output configured to provide a second portion of the output AC power from the inverter to the load, a third output configured to be selectively coupled to a neutral line via the inverter, and a controller configured to operate the inverter to generate current between the load and the neutral line via the third output and the inverter.

Abstract: According to one aspect, embodiments of the invention provide a UPS comprising a plurality of inputs, a PFC converter configured to convert 3-phase input power into DC power, an inverter coupled to a positive DC bus and a negative DC bus and configured to convert the DC power received from the positive DC bus and the negative DC bus into output AC power, a first output configured to provide a first portion of the output AC power from the inverter to a load, a second output configured to provide a second portion of the output AC power from the inverter to the load, a third output configured to be selectively coupled to a neutral line via the inverter, and a controller configured to operate the inverter to generate current between the load and the neutral line via the third output and the inverter.

Abstract: According to one aspect, an uninterruptible power supply system is provided including an input configured to receive input power, an interface configured to be coupled to a backup power supply and to receive backup power from the backup power supply, an output configured to provide output power derived from at least one of the input power and the backup power to a load, a power converter coupled to the input, a capacitor, and a shoot-through detector coupled to the capacitor. The shoot-through detector is configured to obtain a first voltage value indicative of a first voltage across the capacitor, obtain a second voltage value indicative of a second voltage across the capacitor, compare the first voltage value to the second voltage value, determine, based on the comparison, that the capacitor is experiencing a shoot-through condition, and provide an output signal indicative of the shoot-through condition.

Abstract: An Uninterruptible Power Supply (UPS) system is provided which includes an input configured to receive input power, an output configured to provide output power to a load, power conversion circuitry coupled to the input and the output, a capacitor coupled to the power conversion circuitry, and a controller coupled to the power conversion circuitry. The controller is configured to determine a first value indicative of an equivalent series resistance of the capacitor, determine, based on the first value, if the capacitor satisfies at least one criterion, and execute, responsive to determining that the relative value satisfies the at least one criterion, one or more actions to address degradation of the capacitor.

Abstract: According to one aspect, embodiments of the invention provide a power supply system comprising a power factor correction circuit coupled to an input and configured to draw input current from the input, an inverter coupled to an output and configured to provide output current to the output, a bus coupled to the power factor correction circuit and the inverter, and a switching circuit, the switching circuit configured to direct power from the power factor correction circuit to the inverter in a first mode of operation and from the bus to the inverter in a second mode of operation, wherein the switching circuit includes a neutral clamp circuit coupled to the power factor correction circuit and the inverter, the neutral clamp circuit configured to control a level of the input current drawn by the power factor correction circuit and a level of the output current provided by the inverter.

Abstract: According to one aspect, embodiments of the invention provide a power supply system comprising an input, an output, a neutral point, a converter configured to convert input AC power into converted DC power, the converter including a first converter switch, a positive DC bus configured to receive the converted DC power, a negative DC bus configured to receive the converted DC power, an inverter configured to convert DC power from the positive and negative DC busses into output AC power, the inverter including a first inverter switch, and a clamp circuit coupled to the positive DC bus and coupled across at least one of the first converter switch and the first inverter switch, the clamp circuit configured, during switching operation, to clamp a voltage across the first converter switch and/or the first inverter switch to a voltage level of the positive DC bus or the negative DC bus.

Abstract: According to one aspect, embodiments of the invention provide a power supply system comprising an input configured to receive input power from an input power source, an output configured to provide output power to a load, a power factor correction circuit coupled to the input, an inverter coupled to the output, a bus coupled to the power factor correction circuit and the inverter, and a switching circuit coupled to the inverter, the switching circuit configured to direct power from the power factor correction circuit to the inverter when in a first mode of operation and from the bus to the inverter when in a second mode of operation.

Abstract: According to one aspect, embodiments of the invention provide a UPS comprising a plurality of DC busses configured to receive DC power from a converter, the plurality of DC busses including a positive DC bus configured to maintain a positive DC voltage level, a mid-point DC bus, and a negative DC bus configured to maintain a negative DC voltage level, a 3-level inverter coupled to the plurality of DC busses and configured to convert the DC power from the plurality of DC buses into output AC power, and a controller configured to monitor the positive and negative DC voltage levels, identify an imbalance between the positive and negative DC voltage levels, and selectively control, based on the imbalance, the 3-level inverter to operate in a 2-level mode of operation and a 3-level mode of operation to transfer energy between the positive and negative DC busses.