Abstract: A static transfer switch includes first and second inputs, an output, first and second bypass breakers, first and second power stages, first and second contactors, a load switch, and a controller. The first and second inputs are configured to selectively couple with a first power source via a first circuit breaker and a second power source via a second circuit breaker, respectively. The first and second bypass breakers are configured to selectively couple the first and second input with the output, respectively. The first and second contactors are configured to selectively couple the first input with the first power stage and the second input with the second power stage, respectively. The load switch is configured to selectively couple the first and second power stages with the output, and the controller is configured to modify an operating state of the first and second contactors and the first and second power stages.

Abstract: Disclosed herein is a static transfer switch and methods of operating the same. The static transfer switch includes a first switch between a first voltage source and a load, and a second switch between a second voltage source and the load. The first switch and the second switch are configured to alternate power to the load between the first voltage source or the second voltage source. The static transfer switch also includes a first parallel circuit branch coupled in parallel to the first switch, the first parallel circuit branch comprising a first passive element and a first auxiliary switch.

Abstract: In one aspect, a controller for managing electrical faults in a microgrid is provided. The microgrid includes electrical loads, electrical sources, and circuit protection devices that selectively couple the electrical loads and the electrical sources with each other. The controller comprises at least one processor configured to direct a grid tie switch to open to electrically isolate the microgrid from an electric grid, determine, in response to directing the grid tie switch to open, that an electrical fault exits in the microgrid, and determine whether a fault current of the electrical fault is less than a threshold value. The at least one processor is further configured to direct the grid tie switch to close to electrically connect the microgrid to the electric grid and increase the fault current above the threshold value in response to determining that the fault current is less than the threshold value.

Abstract: The disclosed system for automatic startup for a static transfer switch (STS) includes multiple controlled switches for connecting to multiple power sources, and an output controlled switch for connecting to a load. The system also includes an STS circuit selectively coupled between the controlled switches and the output controlled switch. The system further includes a controller that monitors the power sources and the load and control the controlled switches and the output controlled switch. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: In one aspect, a transfer switch configured to operate in different transfer modes is provided. The transfer switch includes first and second inputs, first and second contactors, an output, first and second power stages, and a controller. The first and second inputs are configured to couple with first and second power sources, respectively. The first and second contactors are configured to selectively couple with the first and second inputs, respectively. The output is configured to couple with a load. The first and second power stages are configured to conduct electrical power when active. The controller is configured to determine whether a trigger condition has occurred while the first power stage is active, and in response thereto, to open the first contactor and activate the second power stage to transfer the load from the first power source to the second power source.

Abstract: A solid-state circuit breaker includes an input, an output, a solid-state switch, a protection circuit, and a control circuit. The input is configured to connect to a source. The output is configured to couple with at least a first load via a first electromechanical breaker and a second load via a second electromechanical breaker. The solid-state switch selectively couples the input with the output. The protection circuit is configured to open the solid-state switch in response to the fault current exceeding an overcurrent protection threshold. The control circuit is configured to determine whether an electrical fault is present, and in response to determining that the fault is present, operate the solid-state switch in a pulse conduction mode during the fault to current-limit the fault current to less than the overcurrent protection threshold and enable one of the first and second electromechanical breakers to trip and isolate the fault.

Abstract: A transfer switch for hybrid switching between a first power source and a second power source, the transfer switch includes a first switch and a second switch, the first and second switch connecting a load to a first power source and a second power source, respectively. The first switch includes at least one first solid state switching device (SSSD) pair. The second switch includes at least one second SSSD pair. The at least one first SSSD pair includes a different type of switching devices relative to the type of switching devices of the at least one second SSSD pair. Moreover, a controller may be configured to selectively cycle the at least one first SSSD pair and the at least one second SSSD pair on and off to electrically couple one of the first power source and the second power source to the load.

Abstract: Systems and methods for a transfer switch including a first switch device at a first leg between a first power source and an electrical load, and a second switch device at a second leg between a second power source and the electrical load and a first resistor circuit including a third switch device connected to the first leg. The third switch device switches between open and closed states in response to the state of the first switch device to limit back feed voltage generated as a result of leakage current when the first power source is inactive. The system may also include a second resistor circuit including a fourth switch device connected to the second leg. The fourth switch device switches between open and closed states in response to the state of the second switch device to limit back feed voltage as a result of leakage current when the second power source is inactive.

Abstract: A method operable by a controller of a static transfer switch (STS) is provided. The STS includes first and second inputs selectively coupled with first and second power sources via first and second circuit breakers, respectively, an output coupled with a load, first and second bypass breakers selectively coupling the first and second inputs, respectively, with the output, at least one removable power stage module including first and second power stages configured to conduct electrical power when active, first and second contactors selectively coupling the first and second inputs with the first and second power stages, respectively, and a load switch selectively coupling the first and second power stages with the output. The method includes modifying an operating state of the first and second contactors and the first and second power stages to implement a bypass operation and an un-bypass operation of the STS in response to a trigger condition.

Abstract: A static transfer switch (STS) system for transferring power between power sources is provided. The STS system includes first and second alternate-current (AC) switch assemblies. The first AC switch assembly includes a first current interrupter, and a first controller configured to control the first current interrupter. The second AC switch assembly includes a second current interrupter, and a second controller configured to control the second current interrupter. The first AC switch assembly and the second AC switch assembly are in communication with one another and are each configured to monitor an output power to the load, the first power source, and the second power source and transfer power when disturbance is detected in the output power, the first power source, and/or the second power source.

Abstract: Disclosed herein is a static transfer switch and methods of operating the same. The static transfer switch includes a first switch between a first voltage source and a load, and a second switch between a second voltage source and the load. The first switch and the second switch are configured to alternate power to the load between the first voltage source or the second voltage source. The static transfer switch also includes a first parallel circuit branch coupled in parallel to the first switch, the first parallel circuit branch comprising a first passive element and a first auxiliary switch.

Abstract: Disclosed herein are a static transfer switch with redundant rapid turn-off (RTO) unit switching, and methods of operating the same. The static transfer switch includes a first switch between a first voltage source and a load, and a second switch between a second voltage source and the load, wherein the first switch and the second switch are configured to alternate power to the load between the first voltage source or the second voltage source. The static transfer switch also includes an RTO system coupled across the first and second switches. The RTO system includes a first RTO unit coupled in parallel with the first switch, a second RTO unit coupled in parallel with the second switch, and a first switched path connected between the first RTO unit and the second switch.

Abstract: A modular static transfer switch (STS) assembly comprises a semiconductor powertrain constructed with wide-bandgap transistors. A first input of the STS assembly is electrically coupled to a first power source and a second input of the STS assembly is electrically coupled to a second power source. An output of the STS assembly is electrically coupled to a load, wherein the load is powered using the first power source via the STS modular assembly. A galvanic isolator like relay or contactor or breaker or fuse disconnects any faulty semiconductor powertrain. The STS also comprises a controller to execute the transfer of power supplied to the load from the first power source to the second power source by electrically decoupling the first power source from the load, verifying that the first power source is disconnected from the load, and providing instructions to electrically couple the second power source to the load.

Abstract: Systems and methods for a transfer switch including a first switch device at a first leg between a first power source and an electrical load, and a second switch device at a second leg between a second power source and the electrical load and a first resistor circuit including a third switch device connected to the first leg. The third switch device switches between open and closed states in response to the state of the first switch device to limit back feed voltage generated as a result of leakage current when the first power source is inactive. The system may also include a second resistor circuit including a fourth switch device connected to the second leg. The fourth switch device switches between open and closed states in response to the state of the second switch device to limit back feed voltage as a result of leakage current when the second power source is inactive.

Abstract: A method operable by a controller of a static transfer switch (STS) is provided. The STS includes first and second inputs selectively coupled with first and second power sources via first and second circuit breakers, respectively, an output coupled with a load, first and second bypass breakers selectively coupling the first and second inputs, respectively, with the output, at least one removable power stage module including first and second power stages configured to conduct electrical power when active, first and second contactors selectively coupling the first and second inputs with the first and second power stages, respectively, and a load switch selectively coupling the first and second power stages with the output. The method includes modifying an operating state of the first and second contactors and the first and second power stages to implement a bypass operation and an un-bypass operation of the STS in response to a trigger condition.

Abstract: Systems and methods for reducing inrush current to energize a transformer from a first power source or second power source using a transfer switch device including monitoring input phase voltage at a first and second switching pair, sending a first set of gate signals to the first switching pair and second set of gate signals to the second switching pair to selectively couple the transformer to the first power source or second power source, and operating the first switching pair and second switching pair in a normal operating mode at a next cycle once transformer flux reaches a saturation point. The transfer switch device includes a first switch and second switch connected to the first power source and second power source, respectively, and each switch including the first switching pair and second switching pair connected in a reverse orientation to enable a bi-directional flow of current at each phase.

Abstract: A transfer switch for hybrid switching between a first power source and a second power source, the transfer switch includes a first switch and a second switch, the first and second switch connecting a load to a first power source and a second power source, respectively. The first switch includes at least one first solid state switching device (SSSD) pair. The second switch includes at least one second SSSD pair. The at least one first SSSD pair includes a different type of switching devices relative to the type of switching devices of the at least one second SSSD pair. Moreover, a controller may be configured to selectively cycle the at least one first SSSD pair and the at least one second SSSD pair on and off to electrically couple one of the first power source and the second power source to the load.

Abstract: A method for performing recloser operations at a transfer switch includes obtaining an input from a first sensor measuring characteristics at an electrical conductor connecting a main power source to a load, comparing the input to one or more thresholds, cycling a first switch between an OFF and ON position for one or more cycles, determining the input exceeds the one or more thresholds when the first switch is cycled ON, and connecting the load to the main power source with the first switch in response to the input being within the one or more thresholds, or connecting the load to a second power source with a second switch in response to determining the input exceeds the one or more thresholds after the one or more cycles. The input may include a source voltage and the one or more thresholds may include an upper and lower voltage threshold.

Abstract: A static transfer switch includes first and second inputs, an output, first and second bypass breakers, first and second power stages, first and second contactors, a load switch, and a controller. The first and second inputs are configured to selectively couple with a first power source via a first circuit breaker and a second power source via a second circuit breaker, respectively. The first and second bypass breakers are configured to selectively couple the first and second input with the output, respectively. The first and second contactors are configured to selectively couple the first input with the first power stage and the second input with the second power stage, respectively. The load switch is configured to selectively couple the first and second power stages with the output, and the controller is configured to modify an operating state of the first and second contactors and the first and second power stages.

Abstract: In one aspect, a controller for managing electrical faults in a microgrid is provided. The microgrid includes electrical loads, electrical sources, and circuit protection devices that selectively couple the electrical loads and the electrical sources with each other. The controller comprises at least one processor configured to direct a grid tie switch to open to electrically isolate the microgrid from an electric grid, determine, in response to directing the grid tie switch to open, that an electrical fault exits in the microgrid, and determine whether a fault current of the electrical fault is less than a threshold value. The at least one processor is further configured to direct the grid tie switch to close to electrically connect the microgrid to the electric grid and increase the fault current above the threshold value in response to determining that the fault current is less than the threshold value.