Abb Schweiz Ag

Thomas Anthony Kendzia, Iii

Christopher Alan Belcastro

Veerakumar Bose

Yu Du

Harshang Shah

Xiaoqing Song

Yuzhi Zhang

Gilbert Taylor Miller

Taylor Miller

Harish Suryanarayana

Rebecca Ann Waddell

Zachary Wade Smith

Frank Allen Cowan

Liju Kallarackal

Hany Fawzy Kamel Habib

Hany Habib

Paul Thomas Yerly

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.

Systems and a method for fault protection of selectively islanded microgrids

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.

Hybrid bridge transfer switch system and methods

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.

Active pre-load resistor

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.

Static transfer switches with intelligent bypass and removable power stages

An electrical distribution enclosure includes an electrically insulated panel defining an access portion of the enclosure and a load portion of the enclosure; at least one electrically insulated compartment panel positioned within the access portion; and two or more compartments within the access portion, each compartment separated from an adjacent compartment by an electrically insulated compartment panel, each of the two or more compartments having a front-accessible neutral connection, at least one front-accessible phase connection and a at least rear phase connection.

Isolated load electrical distribution enclosure

A system and a method for connecting electrical load(s) to a first power source and a second power source including a switching device and a controller. The switching device includes a first semiconductor device pair and a second semiconductor device pair. The controller configured to receive a first set of electronic signals corresponding to a condition of the first power source and the second power source, isolate the first power source or the second power source from the one or more loads by transmitting a first set of control signals to the switching device, receive a second set of electronic signals corresponding to the condition of the first power source and the second power source, and connect the first power source or the second power source to the one or more loads by transmitting a second set of control signals to the switching device.

Convertible transfer switch

A ground fault protection system includes a power switch including a source-side and a load-side. The power switch is structured to receive a load current from a power source at the source-side and selectively output the load current from the load-side to a load. A first voltage measuring device is structured to measure a first voltage of the source-side while the power switch is not conducting the load current. A second voltage measuring device is structured to measure a second voltage of the load-side while the power switch is not conducting the load current. A controller is structured to determine a source-side-to-ground voltage based on the first voltage, determine a load-side-to-ground voltage based on the second voltage, determine a ground fault is occurring, and determine a direction of the ground fault relative to the power switch.

Ground fault protection in a high resistance grounding system

A cooling system for power semiconductor switches is provided. The cooling system includes a heat sink that is pressed against the power semiconductor switch. A plenum is also provided with an opening through a wall thereof which is aligned with the heat sink. A fan draws air through or around the heat sink and through the plenum wall opening and the plenum in order to cool the power semiconductor switch.

Power semiconductor cooling system

A method of operating a static transfer switch is provided. The method includes monitoring a voltage waveform for each phase of first and second power sources, and calculating flux for each phase of the power sources. The method also includes determining (i) a first flux difference between the respective flux of the first phases of the first and second power sources, (ii) a second flux difference between the respective flux of the second phases of the first and second power sources, and (iii) a third flux difference between the respective flux of the third phases of the first and second power sources. The method further includes turning off a third solid-state switch to disconnect the third phase of the first power source from a load, in response to the controller determining that the third flux difference is greater the first and second flux differences.

Systems and methods of accelerating transfer in a static transfer switch

In one aspect, a solid-state switching apparatus is provided that includes a pair of anti-parallel thyristors, a quasi-resonant turn-off circuit, a sensor, and a control circuit. The turn-off circuit is coupled in parallel with the pair of anti-parallel thyristors and includes a first selectively conductive path and a second selectively conductive path. The sensor is configured to sense a thyristor current conducted by at least one of the pair of anti-parallel thyristors. The control circuit is configured to receive the sensed thyristor current from the sensor and determine a magnitude of the sensed thyristor current and a polarity of the sensed thyristor current. The control circuit is further configured to activate, in response to determining that the magnitude is greater than a threshold value, one of the first selectively conductive path and the second selectively conductive path based on the polarity to commutate and interrupt the thyristor current.

Thyristor current interrupter

A press-pack semiconductor fixtureincludes a housing defining an interior passage. A first conductor and a second conductor are mechanically coupled with the housing. The mechanical coupling of the first conductor and the second conductor with the housing is effective to apply a clamping force to a press pack semiconductor. A number of apertures or openings are provided in the housing, the first conductor, and the second conductor to permit fluidic flowbetween the interior passageand spaces or structures exterior to the housing.

Press-pack semiconductor fixtures

High amperage static transfer switch

Systems, methods, techniques and apparatuses of ground fault protection are disclosed. One exemplary embodiment is a power switch being structured to receive a load current from a power source at a source-side and selectively output the load current from a load-side to a load; a first voltage measuring device structured to measure a first voltage of the source-side while the power switch is conducting the load current; a second voltage measuring device structured to measure a second voltage of the load-side while the first voltage measuring device is measuring the first voltage; and a controller structured to determine a source-side-to-ground voltage based on the first voltage, determine a load-side-to-ground voltage based on the second voltage, determine a ground fault is occurring, and determine a direction of the ground fault relative to the power switch by comparing the source-side-to-ground voltage and the load-side-to-ground voltage.

A static transfer switch is provided for supplying power to a load alternately from two different power sources. Switching between the two power sources may occur within a fraction of one electrical cycle. In response to sensing degraded performance in the power source supplying the load, a main circuit is turned off with a resonant turn off circuit. The resonant turn off circuit is shared between the main circuits of two different power sources such that the resonant turn off circuit is connected to the main circuit of whichever power source is currently supply power to the load.

Shared resonant turn off circuit

A static transfer switch is provided for supplying power to a load alternately from two different power sources. Switching between the two power sources may occur within a fraction of one electrical cycle. In response to sensing degraded performance in the power source supplying the load, resonant turn off circuits connected directly to the main switches of two phases of the power source are actuated to commutate the respective main switches. The main switch of the third phase is commutated with one or more of the resonant turn off circuits through the delta side of a transformer connected to the three phases of the power source.

Growing community of inventors

Richmond, VA, United States of America

Thomas Anthony Kendzia, Iii