Varentec, Inc.

Apple Inc.

Georgia Tech Research Corporation

Anish Prasai

Deepakraj M Divan

Brandon Pierquet

Ashish K Sahoo

Jie Lu

Rohit Moghe

Rajendra Prasad Kandula

Andrew Dillon

Hao Chen

Amrit Iyer

Jorge Hernendez

An isolated switching converter can include an inverting bridge, a transformer, a rectifying bridge, and control circuitry. The inverting bridge can receive an input voltage and deliver an output voltage to the transformer primary windings. The inverting bridge can include a plurality of half bridges cascaded across the input voltage. Each half bridge can include an input capacitor; upper and lower switches coupled across the input capacitor and connected at a switch node; and a DC blocking capacitor coupled between the switch node and a primary winding terminal. The rectifying bridge can have an input coupled to the secondary windings of the transformer and can deliver an output voltage of the isolated switching converter. The control circuitry can monitor inverter feedback signal(s) and generate phase staggered inverter drive signal(s). The control circuitry can also monitor rectifier feedback signal(s) and generate rectifier drive signals that operate the rectifying bridge.

Multi-phase cascaded bridge for DC/DC, AC/DC, and DC/AC applications

An electrical system can include an isolated bidirectional converter (having an input couplable to a grid connection and an output couplable to a battery) and an isolated converter (having an input coupled to the input of the isolated bidirectional converter and couplable to the grid connection, with an AC output coupled to a convenience outlet). The electrical system can further include a controller that controls operation of the converters to operate in one of a plurality of modes including a charging mode in which the isolated bidirectional converter operates in a forward direction to charge the battery and the non-isolated converter powers the convenience outlet from the grid connection, and a non-charging mode in which the isolated bidirectional converter operates in a reverse direction to power the non-isolated converter from the battery and the non-isolated converter powers the convenience outlet.

Hybrid charger and inverter system

An electrical system can include a first bidirectional AC-DC converter having an input couplable to a grid connection and an output couplable to a battery and a second bidirectional AC-DC converter having an input couplable to the grid connection or a convenience outlet and an output couplable to the battery. The electrical system can further include a controller that controls the first and second converters to operate in a plurality of modes including a two-stage charging mode in which the first and second converters operate in a forward direction to charge the battery, a single-stage charging mode in which the first converter operates in a forward direction to charge the battery and the second converter operates in a reverse direction to power the convenience outlet, and a non-charging mode in which the first converter is idle and the second converter operates in a reverse direction to power the convenience outlet.

An AC-AC converter can include a stack of four switches. An input of the converter can be coupled across the stack of four switches, and an output of the converter can be taken from first terminal coupled to a connection point of first and second switches of the stack and a second terminal coupled to a connection point of third and fourth switches of the stack. The converter can further include a controller that operates the switches such that during a positive half cycle of an AC input voltage, the first and second switches are operated with an alternating 50% duty cycle and the third and fourth switches are constantly on, and during the negative half cycle of the AC input voltage, the third and fourth switches are operated with an alternating 50% duty cycle and the first and second switches are constantly on.

Systems and methods for an edge of network voltage control of a power grid are described. A system includes a distribution power network, a plurality of loads (at or near an edge of the distribution power network), and a plurality of shunt-connected, switch-controlled volt ampere reactive (VAR) sources also located at the edge or near the edge of the distribution power network where they may each detect a proximate voltage. The VAR source can determine whether to enable a VAR compensation component therein based on the proximate voltage and adjust network VAR by controlling a switch to enable the VAR compensation component. Further still, each of the VAR sources may be integrated within a customer-located asset, such as a smart meter, and a multitude of such VAR sources can be used to effectuate a distributed controllable VAR source (DCVS) cloud network.

Systems and methods for edge of network voltage control of a power grid

Methods and systems of network voltage regulating transformers are provided. A network voltage regulating transformer (NVRT) may provide voltage transformation, isolation, and regulation. A NVRT may further provide power factor corrections. Multiple NVRTs may operate autonomously and collectively thereby achieving an edge of network voltage control when installed to a power system. A NVRT comprises a transformer, a VAR source, and a control module. The input current (i.e., the current through the primary side of the transformer), the output current (i.e., the current through the secondary side of the transformer), and/or the output voltage (i.e., the voltage across the secondary side of the transformer) may be monitored.

Methods and systems of network voltage regulating transformers

Dynamic power flow controllers are provided. A dynamic power flow controller may comprise a transformer and a power converter. The power converter is subject to low voltage stresses and not floated at line voltage. In addition, the power converter is rated at a fraction of the total power controlled. A dynamic power flow controller controls both the real and the reactive power flow between two AC sources having the same frequency. A dynamic power flow controller inserts a voltage with controllable magnitude and phase between two AC sources; thereby effecting control of active and reactive power flows between two AC sources.

Dynamic power flow controllers

Power flow controllers based on Imputed DC Link (IDCL) cells are provided. The IDCL cell is a self-contained power electronic building block (PEBB). The IDCL cell may be stacked in series and parallel to achieve power flow control at higher voltage and current levels. Each IDCL cell may comprise a gate drive, a voltage sharing module, and a thermal management component in order to facilitate easy integration of the cell into a variety of applications. By providing direct AC conversion, the IDCL cell based AC/AC converters reduce device count, eliminate the use of electrolytic capacitors that have life and reliability issues, and improve system efficiency compared with similarly rated back-to-back inverter system.

Impute DC link (IDCL) cell based power converters and control thereof

Systems and methods for dynamic AC line voltage regulation are provided. A simple and cost-effective method for achieving AC line voltage regulation in AC systems including split-phase systems, of which the voltage for each voltage line may be regulated over a specified range, is provided. Buck and boost regulation is achieved for lowering or increasing the line voltage, respectively, with reference to the incoming grid voltage. Systems for dynamic AC line voltage regulation may comprise an AC/AC converter which uses fractionally rated switches and magnetics that handle only a fraction of the load current, resulting in lower costs. The use of an AC snubber further provides safe and robust switching of the main switching devices by eliminating failure prone switching sequences that are dependent on accurate assessment of voltage and/or current polarity for AC or bi-directional switches.

Systems and methods for dynamic AC line voltage regulation with energy saving tracking

A power flow controller with a fractionally rated back-to-back (BTB) converter is provided. The power flow controller provide dynamic control of both active and reactive power of a power system. The power flow controller inserts a voltage with controllable magnitude and phase between two AC sources at the same frequency; thereby effecting control of active and reactive power flows between the two AC sources. A transformer may be augmented with a fractionally rated bi-directional Back to Back (BTB) converter. The fractionally rated BTB converter comprises a transformer side converter (TSC), a direct-current (DC) link, and a line side converter (LSC). By controlling the switches of the BTB converter, the effective phase angle between the two AC source voltages may be regulated, and the amplitude of the voltage inserted by the power flow controller may be adjusted with respect to the AC source voltages.

Power flow controller with a fractionally rated back-to-back converter

Compact dynamic Phase Angle Regulators (CD-PARs) are provided. A Compact Dynamic Phase Angle Regulator (CD-PAR) is a stand-alone device that regulates phase angle through a single transformer. A CD-PAR has no external energy source, uses low-rating devices, and can be isolated from a fault in the grid. A CD-PAR may be implemented in a single-phase or in a three-phase configuration, but the operation of a CD-PAR cross-couples all three phases. A CD-PAR controls both the real and the reactive power flow between two AC sources having the same frequency by inserting a voltage with controllable magnitude and phase. A CD-PAR may be implemented in either a buck configuration or a boost configuration.

Compact dynamic phase angle regulators

Multi-level rectifiers are provided. A multi-level rectifier may convert a medium AC voltage to a medium DC voltage. A multi-level rectifier may comprise an input inductor, a set of diodes, a set of switches, and a DC link comprising a set of capacitors. One end of the input inductor is coupled to the input AC voltage and the other end of the input inductor is coupled to a pair of diodes that are series connected. The set of switches may be regulated such that the inductor may be coupled to a DC voltage point of the DC link. A multi-level rectifier may operate under a set of operation modes. Each operation mode may be determined from the input voltage and the inductor current. Accordingly, a sinusoidal voltage at the fundamental frequency of the input voltage may be synthesized by selectively switching between adjacent operation modes of the set of operation modes. A multi-level rectifier may be used in connection with a medium voltage to low voltage DC/DC converter to form a power conversion system that converts a medium AC voltage to a low DC voltage.

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San Jose, CA, United States of America

Anish Prasai