The University of North Carolina at Charlotte

Sinewatts, Inc.

Babak Parkhideh

Shibashis Bhowmik

Chondon Roy

Mehrdad Biglarbegian

Neel Mayur Shah

Iman Mazhari

Robert W Cox

Namwon Kim

Hamidreza Jafarian

Andreas Lauer

James Gafford

Shahriar Jalal Nibir

Various examples are provided for on-state voltage sensing for in-situ monitoring and prognostics. In one example, an on-state monitoring circuit includes clamping circuitry including high-side and low-side voltage clamping circuits associated with high-side and low-side switching devices of a half-bridge (HB) leg of an converter, on-state voltage circuitry including high-side and low-side voltage measurement circuits, the high-side and low-side circuits referenced to the positive and negative buses of the converter respectively, and output circuitry including high-side and low-side isolation circuits that provide isolated outputs referenced to a control ground of the converter. In another example, an on-state voltage measurement circuit includes clamping circuitry including high-side and low-side voltage clamping circuits referenced to a common point between high-side and low-side switching devices of a HB leg, on-state voltage circuitry including high-side and low-side voltage measurement circuits and a voltage merger circuit, and output circuitry including an isolation circuit providing a single output containing both high-side on-state voltage and low-side on-state voltage.

On-state voltage measurement of high-side and low-side power transistors in a half-bridge for in-situ prognostics

Apparatuses and methods of the present disclosure integrate a non-intrusive current sensor in the form of a current mismatch sensor into a power module having paralleled semiconductor structures or components. The current mismatch can be detected by the current sensor by monitoring a magnetic flux density between the paralleled components or devices.

Systems and methods to detect and measure the current mismatch among parallel semiconductor devices

In preferred embodiments, a short circuit protection system for a wide-band gap power electronics converter composed of multiple half-bridge legs is presented. The main approaches of the system are a single point of monitoring (SPM) for multiple switching legs, and non-invasive implementation and fast speed of the short circuit current detection. Ultra-high frequency (UHF) AC current, tens or hundreds of MHz, flowing through the DC-link capacitors represents the short circuit current occurred at the multiple switching legs. To capture the UHF AC current, a non-invasive MHz bandwidth magnetic current sensor is applied to the PCB conduction path of the converter. In this digest, simulation results of the short circuit current representation through the DC-link network and the magnetic field distribution in PCB layout for the selection of the proper location of the detection, and experimental results showing the UHF AC current sensing performance are presented.

Systems and methods to measure changing electric current

A circuit for a smart photovoltaic (PV) inverter system and the smart PV inverter system are described. The circuit includes one or more strings coupled to an electrical load. Each of the one or more strings further includes one or more string members coupled in series, where each of the one or more string members comprises a voltage source and an inverter. The circuit also includes a controller to receive an output from an operator controller and control the strings, where the controller is configured to control the strings by providing a function command to a first string member of each of the one or more strings based on the output from the operator controller. The voltage source may also receive an output from an energy output device. Further, the inverter may be configured to convert the output of energy output device into an energy source of electrical load.

Systems and methods for advanced grid integration of distributed generators and energy resources

Various examples are provided for contactless wideband current sensing. A combination of magnetoresistive (MR) sensor and Rogowski coil outputs can be combined to provide current sensing from DC to 10 MHZ or more. In one example, a system includes a MR sensor that can provide an MR output voltage corresponding to a magnitude of the current through a trace; a Rogowski coil sensor that can provide a Rogowski output voltage corresponding to a magnitude of the current; and processing circuitry configured to generate an output current signal by aggregating the MR and Rogowski output voltages. In another example, a method includes conditioning an output from a MR sensor disposed adjacent to a trace carrying a current; conditioning an output from a Rogowski coil disposed adjacent to the trace; and aggregating the first and second conditioned signals to provide an output current signal corresponding to the current passing through the trace.

Wideband contactless magnetoresistive-rogowski current sensing

Various examples are directed to electrical converters and systems for operating the same. An electrical converter may comprise a first converter module configured to receive a first direct current (DC) input and provide a first output. The first converter module may comprise a first switch modulated according to a first switch control signal. A second converter module may be configured to receive a second DC input and provide a second output. The second converter module may be connected in series with the first converter module. The second converter module may comprise a second switch modulated according to a second switch control signal. A phase of the first switch control signal may be offset from a phase of the second switch control signal by a first phase offset.

Converter with phase-offset switching

Devices, systems, and methods of manufacture relating to PCB embedded inductors are described in the present disclosure. Namely, an example device includes a substrate having an upper surface and an opposing lower surface. The device also includes a plurality of upper conductors disposed along the upper surface and a plurality of lower conductors disposed along the lower surface. The upper conductors and the lower conductors are radially disposed about a central axis. Each of the upper conductors and the lower conductors includes a petal shape. A distance between adjacent upper conductors is less than a width of each upper conductor and a distance between adjacent lower conductors is less than a width of each lower conductor. The device also includes a plurality of through-substrate conductors connecting respective upper conductors to respective lower conductors so as to form a series electrical connection. The series electrical connection includes a toroid configuration.

High power density printed circuit board (PCB) embedded inductors

A method for detecting and preventing islanding includes issuing a command to an inverter connected to a power source, where the inverter is coupled to a power grid and supplies power to the power grid, the command causes a frequency of a waveform output by the inverter to vary, and the frequency of the waveform output by the inverter is a command frequency, determining that a amount of change of the command frequency is a constant value for a predetermined amount of time, removing the power supplied by the inverter from the power grid, and determining whether the power grid is valid.

System and method for islanding detection and prevention in distributed generation

Various examples are directed to systems and methods for detecting an islanding condition at an inverter configured to couple a distributed generation system to an electrical grid network. A controller may determine a command frequency and a command frequency variation. The controller may determine that the command frequency variation indicates a potential islanding condition and send to the inverter an instruction to disconnect the distributed generation system from the electrical grid network. When the distributed generation system is disconnected from the electrical grid network, the controller may determine whether the grid network is valid.

Growing community of inventors

Charlotte, NC, United States of America

Babak Parkhideh