Georgia Tech Research Corporation

Deepak M Divan

Rajendra Prasad Kandula

Mickael J Mauger

Shreyas Bhalchandra Kulkarni

Aniruddh Marellapudi

Mohammadreza Miranbeigi

Ruomu Hao

Pranjal M Gajare

A universal control (UniCon) scheme for grid-connected converters is presented herein that allows operation automatically in grid-following, grid-firming, and grid-forming modes. The converter does not need information on the grid or connected sources and loads. The converter can set its own operating point based on local measurements. The converter can operate over a wide range of typically encountered steady-state, transient, and fault conditions. UniCon realizes a universal control strategy for converters on the grid, allowing operation in distinct modes, including dispatch in grid connected mode, and automatic load sharing in islanded or microgrid mode. Under transient conditions, the converters provide inertial support and improve damping to stabilize and reduce disturbances. Multiple converters on the system do not require detailed system knowledge or low-latency communications for fast coordination, using communications when available for slow coordination and system level optimization.

Unified control strategies for grid-connected converters

An exemplary embodiment of the present disclosure provides a resonant module and sensing circuits for use with a soft-switching current source converter. The resonant module comprises a resonant switch, a resonant inductor, and a resonant capacitor. The resonant inductor is connected in electrical series with the resonant switch. The resonant capacitor is connected in parallel with the serially connected resonant switch and resonant capacitor. The resonant module further comprises first and second sensing circuits. The first sensing circuit is configured to generate a first sensing signal indicative of when the time derivative of a voltage across the resonant capacitor is negative. The second sensing circuit is configured to generate a second sensing signal indicative of when a voltage across the resonant capacitor is less than or equal to a predetermined threshold value.

Systems and methods for controlling soft-switching current source converters

An exemplary embodiment of the present disclosure provides a current sensor comprising a current input, a current output, a first current path, and a second current path parallel to the first current path, a Rogowski coil current sensor, and a controller. The first current path can comprise a first switch. When the first switch is in a closed position, current can flow along the first current path between the current input and the current output. The second current path can comprise a second switch. When the second switch is in a closed position, current can flow along the second current path between the current input and the current output. At least one of the first current path and the second current path can pass through an aperture of the Rogowski coil. The controller can be configured to control the first and second switches.

Universal AC/DC current sensor and isolator

An embodiment of the disclosure provides a flexible multiport energy routing system comprising a first port configured to connect to an AC grid, a plurality of second ports configured to connect to a plurality of devices, a step-down transformer, a power converter stack, and a third port. The step-down transformer can a high voltage side electrically coupled to the first port and a low voltage side. The power converter stack can comprise a plurality of power converter modules each having a first converter bridge connected to the low voltage side of the step-down transformer and a second converter bridge connected to one or more of the plurality of second ports. Each of the power converter modules can have a converter transformer connected between the first and second converter bridges. The first and second converter bridges can bidirectionally manage AC and DC power flows between the first, second, and third ports.

Multiport energy routing systems

An exemplary embodiment of the present disclosure provides an energy meter comprising a current sensor and an interchangeable voltage sensor. The current sensor can be configured to measure an electrical current flowing through a conductor. The interchangeable voltage sensor detachably can be connected to the current sensor and configured to measure an electrical voltage carried by the conductor.

Energy meters and energy monitoring systems and methods

An exemplary embodiment provides a power conversion system comprising a first battery module, a second battery module, first and second transformers, and first, second, and third current source converter bridges. The transformers can have low voltage sides and high voltage sides. The first bridge can be configured to connect the battery modules and the low voltage sides of the transformers. A mid-point of the serial connection of the battery modules can be connected to a mid-point of the series connection of the transformers. The second bridge can connect to the high voltage side of the first transformer and one or more ports configured to transmit electrical power to and/or receive electrical power from an electrical load and/or source. The third bridge can be configured to connect to the high voltage side of the second transformer and the one and one or more ports.

Modular multiport ac battery power converter systems and methods of using same

The present disclosure relates to current source inverters (CSIs), and in particular to soft-switching current source inverters (SSCSIs). An exemplary CSI comprises a first CSI bridge, a second CSI bridge, a DC-link inductor, and a resonant tank. The first CSI bridge can be operatively connected to a first power bank. The second CSI bridge can be operatively connected to a second power bank. The DC-link inductor can be connected in series between the first and second CSI bridges. The resonant tank can be connected in parallel with the DC-link inductor.

Growing community of inventors

Atlanta, GA, United States of America

Deepak M Divan