North Carolina State University

The University of Texas System

Electric Power Research Institute Incorporated

Tennessee Valley Authority

Qin Huang

Yu Du

Wu Chen

Iqbal Husain

Abdel-Aty Edris

Michael R Ingram

Qingyun Huang

Wenxi Yao

Chang Peng

Landon K Mackey

Siriroj Sirisukprasert

Various examples are provided related to direct current circuit breakers and their control methods. In one example, among others, a hybrid direct current circuit breaker (DCCB) includes an ultrafast mechanical switch (UFMS) connected in series with a commutating switch (CS) or auxiliary circuit breaker (ACB); a main breaker (MB) including a series of &#x3b7; semiconductor switching stages in parallel with the UFMS and CS or ACB; and control circuitry that can turn off individual switching stages in a defined order in response to opening contacts of the UFMS. The switching stages can be turned off based upon a dielectric strength across the contacts as they open. In another example, a method includes opening contacts of an UFMS connected in series with a CS or ACB; and turning off individual switching stages of a series of &#x3b7; semiconductor switching stages connected across the UFMS and the CS or ACB.

Control of direct current circuit breakers with series semiconductor switches

A method and apparatus include a primary transformer coil, a secondary transformer coil, and a center tapped inductor coupled to the secondary transformer coil. A first switch may be in electrical communication with the center tapped inductor and may be configured to affect the first output voltage. A second switch may be in electrical communication with the center tapped inductor and may be configured to affect the second output voltage. In a particular example with an analog current (AC) output voltage, the two output voltages are out of phase to each other. In a direct current (DC) implementation, the transformer may be operated to output a positive and a negative output voltage. The apparatus may function as a resonant converter, or may operate in non-resonant mode. In one implementation, an H bridge may provide reactive power support. An inductor filter may be in electrical communication with the secondary transformer coil. Where desired, a diode bridge may be in electrical communication with the primary transformer coil.

Transformer converter with center tap inductance

Method and apparatus include a circuit having a duty cycle and interleaving modulation configured to realize high density and efficient energy transfer. The circuit may efficiently achieve higher step-down voltage ratios with fewer electrical components. For example, as few as seven electrical devices, such as switches and diodes, may be used to realize at least a four-to-one conversion ratio. The high density of the circuit is advantageous to meet shrinking space demands A modulator may interleave signals sent to the electrical components (e.g., switching devices via driver circuitry). The driver signals may include a duty cycle of 1/(nc+1), where nc is (n&#x2212;1)/3, and n is the number of devices.

Modular high step-down DC/DC converter

A method and apparatus include an n-doped layer having a first applied charge, and a p-doped layer having a second applied charge. The p-doped layer may be positioned below the n-doped layer. A p-doped buffer layer may have a third applied charge and be positioned below the p-doped layer. The respective charges at each layer may be determined based on a dopant level and a physical dimension of the layer. In one example, the n-doped layer, the p-doped layer, and the p-doped buffer layer comprise a lateral semiconductor manufactured from silicon carbide (SiC).

Lateral semiconductor device and method of manufacture

An energy storage system is provided. The system includes a plurality of energy storage modules connected in parallel. Each energy storage module has an energy storage source, a bidirectional current converter configured for supplying charge to the energy storage source from a power source and for discharging current for use by an electrical device, a monitoring module for monitoring the energy storage source and the current converter, and a controller configured to control the current converter based upon monitored characteristics of the storage source and the current converter to produce a respective output signal for each module. A communications module is in connection with each output signal of the energy storage modules and configured for communicating a combined output signal with one of the power source and the electrical device.

Intelligent integrated battery module

A high power density switched-capacitor DC-DC converter is disclosed. According to one aspect, the subject matter described herein includes a high power-density switched-capacitor DC-DC converter that includes: first and second voltage summing circuits, each voltage summing circuit producing an output voltage that is substantially equal to an input voltage; and a switching circuit connected between the first and second voltage summing circuits and configured to provide a DC voltage source as an input to the first and second voltage summing circuits, wherein the converter produces an output voltage that is the sum of the voltage produced by the first voltage summing circuit, the voltage provided by the DC voltage source, and the voltage produced by the second voltage summing circuit.

Switched-capacitor DC-DC converter

Static synchronous compensator (STATCOM) systems and methods are disclosed. An example STATCOM system includes a reactive component configured for electrical connection to a power network. For example, the reactive component may be a capacitor bank. The system also includes an inductor electrically connected in series with the reactive component. Further, the system includes a converter electrically connected in series with the reactive component and the inductor. A method may include using the static synchronous compensator system to provide one of reactive power and active power to the power network.

Static synchronous compensator systems and related methods

An alternating current-to-direct current (AC-DC) converter is provided. The converter may include a transformer having a primary side and a secondary side. A first bi-directional switch and a first inductor may be connected in series between a positive terminal of an AC source and a first terminal of the primary side of the transformer. A second bi-directional switch and a second inductor may be connected between the positive terminal of the AC source and a second terminal of the primary side of the transformer and connected in parallel with the first bi-directional switch.

Isolated soft-switch single-stage AC-DC converter

A method of balancing the voltage of DC links in a cascaded multi-level converter (CMC) semiconductor circuit, including the steps of providing a plurality of H-bridge converters per phase in the CMC circuit and utilizing a three phase duty cycle value from the main controller to determine a normalized duty cycle value, a ceiling duty cycle value and a floor duty cycle value. The normalized duty cycle value and an output current of the CMC is used to determine the direction and polarity of a capacitor current, and utilizing the capacitor current to determine a plurality of output capacitor voltages. A voltage summation result and direction is obtained from a ceiling index pointer and a floor index pointer and the voltage summation result, direction from the ceiling index pointer and a floor index pointer are used to create a combined switching table for the H-bridge converters. A pulse width modulator is utilized to balance the voltage of the DC links and thereby eliminate DC-capacitor voltage imbalance.

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Cary, NC, United States of America

Qin Huang