Florida State University Research Foundation, Inc.

Hui Li

Mischa Steurer

Passinam Tatcho

Yanjun Shi

Fang Peng

Yan Zhou

Liming Liu

Da Zhang

Emmanuel Collins

Rui Li

Zhehui Guo

Yuxiang Shi

Ran Mo

Yu Zhang

Xiaohu Liu

Zhan Wang

Zhong Du

The disclosure relates to devices, systems and methods implementing a charge pump gate driver (CPGD) that offers adjustable pump voltage, enabling online and active dv/dt and di/dt control for power devices, including the wide bandgap devices, such as SiC MOSFETs and GaN HEMTs. The disclosed CPGD allows a flexible pump voltage adjustment through the pre-charging interval control. Both the turn-on and turn-off switching speed (both dv/dt and di/dt) of power devices can be online regulated rapidly within each switching cycle, without interrupting the power converter operation. The disclosed CPGD has a simple structure and eliminates the extra power supplies to reduce circuit cost and footprint.

Charge pump gate driver circuit with an adjustable pump voltage for active DV/DT control

The disclosure relates to a devices, systems and methods implementing a single transformer-based gate driver. In one embodiment, single transformer-based gate driver includes an RF source; a PWM controller; an edge detector and pulse generating circuit operably connected to the RF source and PWM controller; a transformer comprising a primary side and a secondary side, the primary side of the transformer operably connected to an output of the edge detector and pulse generating circuit, the secondary side of the transformer operably connected to a rectifier circuit and a signal recovery circuit; and a drive circuit operably connected to the rectifier circuit and the signal recovery circuit.

Single transformer-based gate driver

An active reflected wave canceller (ARWC, or RWC) can attached to each phase at the output of a motor drive (i.e., inverter). The reflected wave canceller is generally comprised of a pulse generator and a power inductor. The power inductor is used to by-pass the load current, so it doesn't flow through the pulse generator. The pulse generator injects an accurately controlled nanoseconds narrow-width pulse into the system. The injected narrow pulse breaks the rising and falling edge of the inverter output voltage into two steps, which generates two traveling waves along the cable that cancel each other at the motor terminals.

System, method and device for reflected wave cancellation

A gate driver for power semiconductors is disclosed. The gate driver includes modulation to modulate signals from a controller to a radio frequency (RF) range that is much higher than frequencies associated with conducted EMI. The gate driver also includes RF transformer and tank circuit to that couples the modulated signals, filters EMI, and provides galvanic isolation. The gate driver further includes a RF demodulator and unfolder circuit for converting the RF signal into a signal appropriate for controlling the gate of a power semiconductor for switching. Additionally, the disclosed gate driver provides active gate control using programmable waveforms with values that can range over a continuous range of voltages.

Radio-frequency isolated gate driver for power semiconductors

Disclosed is a phase-shifted square wave modulation technique for single-phase and three-phase IM2DC applications in HVDC/MVDC systems. A square wave based modulation waveform is applied to each cell of IM2DC and compared to the phase-shifted carrier waveforms to generate device gate signals. As a result, a higher equivalent switching frequency can be achieved, and square wave based arm and AC link waveforms will be generated. In addition, power flow of IM2DC can be controlled by a phase shift angle of the square modulation waveforms between HVS and LVS. The converter cell capacitors can be reduced in size because they are only required to smooth high switching frequency ripple components. In addition, lower TDR can be achieved due to the higher power transferring capability of square waves.

Modulation method for DC to DC converters

A three-port bidirectional DC-DC converter for grid-interactive renewable energy source system applications. The three-phase topology is suitable for residential power requirements. The control of the backup battery system and the renewable energy source system are naturally decoupled. In addition, the port interface with the renewable energy is current type, which can implement maximum power point tracking (MPPT) and soft switching under wide variations in the renewable energy source terminal voltage.

Integrated three-port bidirectional DC-DC converter for renewable energy sources

This invention presents a family of isolated BESS topologies with multiple functions, which are suitable for high voltage and high power DC grid application. A battery energy storage system (BESS) for direct current (DC) grid applications is provided, including an alternating current (AC) transformer having a primary side and a secondary side, at least one primary side arm coupled to the primary side of the AC transformer, the at least one primary side arm comprising a plurality of cascade connected voltage source converter sub-modules and a plurality of energy storage battery units and at least one secondary side arm coupled between the secondary side of the AC transformer and a DC grid voltage bus, the at least one secondary side arm comprising a plurality of cascade connected voltage source converter sub-modules. Modulation and control strategies for the various topologies are also provided.

Family of isolated battery energy storage system (BESS) with multiple functions for DC grid application

In one embodiment, a current-fed modular multilevel dual active-bridge DC-DC converter suitable for medium voltage direct current (MVDC) grid or high voltage direct current (HVDC) grid integration is described. The DAB modular converter and the current-fed DAB converter are soft-switched modular multilevel dual-active-bridge (DAB) converters having DC fault ride-through capability. In an additional embodiment a voltage-fed isolated modular dual active-bridge DC-DC converter for medium voltage direct current (MVDC) or high voltage direct current (HVDC) grids or systems is described. In specific embodiments, the converters may be coupled to a battery energy storage system (BESS), wherein the BESS comprises split-battery units and the interface of the isolated DC-DC converter connects the split-battery units to the MVDC or HVDC system. The converters can be implemented in single-phase or poly-phase configurations and can be controlled to maintain a desired DC output current under both normal and DC grid fault condition.

Modular multilevel DC-DC converter and associated method of use

A self-balanced modulation method and a closed-loop magnetic flux rebalancing control method for parallel multilevel inverters. The combination of the two methods provides for balancing of the magnetic flux of the inter-cell transformers (ICTs) of the parallel multilevel inverters without deteriorating the quality of the output voltage. In various embodiments a parallel multi-level inverter modulator is provide including a multi-channel comparator to generate a multiplexed digitized ideal waveform for a parallel multi-level inverter and a finite state machine (FSM) module coupled to the parallel multi-channel comparator, the FSM module to receive the multiplexed digitized ideal waveform and to generate a pulse width modulated gate-drive signal for each switching device of the parallel multi-level inverter. The system and method provides for optimization of the output voltage spectrum without influence the magnetic balancing.

Self-balanced modulation and magnetic rebalancing method for parallel multilevel inverters

The cascaded multilevel inverter is considered to be a promising topology alternative for low-cost and high-efficiency photovoltaic (PV) systems. However, the leakage current issue, resulting from the stray capacitances between the PV panels and the earth, remains a challenge in the photovoltaic cascaded multilevel inverter application. The present invention presents leakage current suppression solutions for the PV cascaded multilevel inverter by introducing properly arranged and designed passive filters. The embodiments of the invention do not include an active semiconductor device, and as such, the leakage current suppression techniques of the present invention retain the simple structure of the cascaded inverter and do not complicate the associated control system.

System and method for leakage current suppression in a low switching frequency photovoltaic cascaded multilevel inverter

The scalable cascaded Z-source inverter is able to interface flexibly different distributed renewable energy sources or storages in wide voltage change range, such as wind power, solar power, battery, fuel cell, Ultra-capacitor and so on. The invention facilitates the AC 1 MHz frequency output; therefore high power density can be reached. Z-source network is integrated in each inverter module to wide system operation range, improve high system efficiency, and enhance high system reliability. The invention is applied for PV system to verify the performance.

1MHz scalable cascaded Z-source inverter using gallium nitride (GAN) device

The present invention provides a system to ensure that distributed resources of a power distribution system remain connected to the circuitry of the power distribution system when a fault occurs at a distributed resource node to assist in identifying the location of the fault by continuing to inject current from the distributed resources into the distribution system, wherein at least one of the distributed resources comprises a controllable voltage source converter.

System for locating a fault in a power distribution system comprising at least one distributed resource having a controllable voltage source converter

System and method for leakage current suppression in a photovoltaic cascaded multilevel inverter

The present invention provides a method to ensure that distributed resources of a power distribution system remain connected to the circuitry of the power distribution system when a fault occurs at a distributed resource node to assist in identifying the location of the fault by continuing to inject a direct current (DC) signal from the controllable voltage source converter of at least one DC voltage distributed resource into the distribution system and modulating an alternating current (AC) signal on top of the direct current (DC) signal.

Method of locating a fault in a power distribution system using a direct current signal of a distributed resource modulated by an alternating current signal

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Tallahassee, FL, United States of America

Hui Li