A5101426580- Advanced DC-DC Converters
- Microgrid Control and Optimization
- Advanced Battery Technologies Research
- Photovoltaic System Optimization Techniques
- Silicon Carbide Semiconductor Technologies
- Multilevel Inverters and Converters
- Power Systems and Renewable Energy
- Semiconductor materials and devices
- Electric Vehicles and Infrastructure
- Advancements in Semiconductor Devices and Circuit Design
- Real-time simulation and control systems
- Electric and Hybrid Vehicle Technologies
- High voltage insulation and dielectric phenomena
- Wind Turbine Control Systems
- Smart Grid Energy Management
- Experimental Learning in Engineering
- HVDC Systems and Fault Protection
- Electromagnetic Compatibility and Noise Suppression
- Power Transformer Diagnostics and Insulation
- Radiation Effects in Electronics
- Power Systems Fault Detection
- Electric Power Systems and Control
- Power Quality and Harmonics
- CCD and CMOS Imaging Sensors
- Analog and Mixed-Signal Circuit Design
University of North Carolina at Charlotte
2017-2024
Oak Ridge National Laboratory
2022-2024
Epic Systems (United States)
2021
Changwon National University
2010-2011
For the first time, we have demonstrated a 32nm high-k/metal gate (HK-MG) low power CMOS platform technology with standby leakage transistors and functional high-density SRAM cell size of 0.157 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Record NMOS/PMOS drive currents 1000/575 μA/μm, respectively, been achieved at 1 nA/μm off-current 1.1V V <inf xmlns:xlink="http://www.w3.org/1999/xlink">dd</inf> cost process. With this high...
This paper presents system architecture and control scheme of a photovoltaic (PV) string inverter allowing seamless battery integration with the dc-series method. The uses partial-power processing universal dc-dc optimizer to have flexible power by regulating T-node compensation current. is configured dual active bridge converter bidirectional flow galvanic isolation. Three operation modes are proposed depending on input sources connected. Based mode, dc-ac switch their reference deliver...
Grid background harmonics cause harmonic distortion on the output current of grid-tied inverters, and they require inverter to have mitigation control. The main object this paper is propose a decentralized control strategy for impact distorted grid ac-stacked photovoltaic architecture. Two schemes architecture are proposed analyzed in mitigate caused by voltage without any handshaking among members supervisory center. method improves reliability increasing operating margin it power quality...
This letter presents a control scheme to operate battery-integrated ac-stacked photovoltaic (PV) inverter architecture and its operating range analysis. The main operation strategy is the combination of decentralized controls individual members; PV battery. In ac-series integration, battery charging discharging operations affect margins members. interactive needs be analyzed identify system under different conditions. A ramp-rate control, which mitigates output variations improves grid...
The main objective of this paper is to analyze the feasibility decentralized control approach in providing smart inverter functions for grid-tied AC-stacked PV architecture. Decentralized controller allows fully distributed architecture both terms and physical implementation a system, resulting higher reliability potentially lower cost. In paper, Relative Gain Array concept has been used determine best locally measured input-output pairing sets designing proposed controller. Proposed by...
This letter presents a control scheme to operate boost converter in boundary conduction mode (BCM). In the proposed method, it is assumed that zero-current information not available for controlling operation mode. Therefore, cursor identified detect mode, i.e., continuous mode/BCM. Details of and associated method will be discussed this letter. We demonstrate experimentally effectiveness on GaN whose active switch current monitored through current-mirroring technique.
There is no doubt that in the future, a need for higher switching frequency inevitable to extract full benefits of reliable Gallium Nitride (GaN) device characteristics. Along with reliability enhancement GaN-based power converters, it essential monitor precursor signature identification diagnostics/prognostics techniques. With availability most granular information deduced from advanced devices, new data-driven scheme proposed system monitoring and possible lifetime extension 400W GaN...
Reliability and operation of high-frequency Gallium Nitride (GaN) power converters are yet to be discovered. Coming with the reliability assessment improving life extension converters, approach is monitor semiconductor on-resistor changes as a precursor signature for diagnostic/prognostic. This paper presents novel hybrid condition-based prognostic monitoring GaN devices. The proposed offers multi-physics co-simulations solution degradation fatigue modeling With availability most granular...
In order to improve the efficiency of wind power generation system (WPGS), many researchers have tried develop a larger WPGS and superconducting synchronous generator (SCSG) has been suggested over 5 MW class WPGS. There are two expected types drive-train, geared gearless. The structure electrical parameters SCSG depend on type drive-train used. This paper deals with comparative analysis 10 gearless for Three drive-trains designed SCSGs using finite elements method tool. PSCAD/EMTDC is...
Unbalanced operation between panel-level modular inverters constrains the operating range of grid-tied cascaded H-bridge Photovoltaic (PV) inverter system when active and reactive power architecture changes. The main objective this paper is to propose a distributed control approach for balancing among inverters. controller allows fully decentralized in terms physical implementation PV system, resulting higher reliability potentially lower cost. proposed autonomously compensates contents...
This paper presents the challenges of implementing in-situ prognostics to practical power converters and proposes a new on-state voltage (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DSON</inf> ) monitoring circuit for high-side transistors. The proposed approach references drain transistors their V measurement. allows measurement not only multiple but also low-side at same time. measured is used calculate resistance (R in real-time using...
Current prognostics for life expectancy of power semiconductors utilize off-line measurements the on-state resistance. Presented is a half-bridge (HB) voltage (VON) sensor capable being utilized in-situ enabling continuous and real-time monitoring The design provides single VON measurement output that contains independent information both high low side devices in HB leg. referenced from middle point combines two complementary sensing outputs. This system reduces number components, required...
Ramp-rate control smooths out sudden photovoltaic (PV) output variations by charging and discharging electricity through an energy storage system (ESS). This paper describes the ramp-rate strategy adapted to new modular panel-level grid-connected single-phase PV inverter architecture, distributed PV-ESS AC-stacked inverter, its capability. The members including inverters ESS are connected in series regulating each member's decentralized manner. To minimize communication requirements between...
Integration of energy storage with a grid-tied photovoltaic (PV) generation system in conventional residential and commercial applications uses legacy PV power electronics topologies. This paper presents novel solar which allows seamless integration partial processing technique. In the proposed topology, dual active bridge DC-DC converter is applied to configure partially-rated bi-directional flow, galvanic isolation, high voltage boosting gain, results conversion efficiency. The topology...
This paper presents the development of a power electronics teaching lab to prepare students for next generation engineering using wide bandgap (WBG) semiconductor devices. The objectives are expedite transfer theoretical knowledge practical experience on WBG devices, and at same time provide hands-on understanding comprehensive systems. To incorporate different types especially switches, perform various experiments from an investigation component switching characteristics construction...
This paper presents a novel short circuit protection strategy for wide-band gap power electronics converter composed of multiple half-bridge legs. The main approaches the proposed are single point monitoring (SPM) indicating events occurred in switching legs and non-invasive implementation an ultra-fast current detection strategy. Ultra-high frequency (UHF) AC current, tens or hundreds MHz, flowing through decoupling capacitor represents To capture UHF noninvasive MHz bandwidth magnetic...
A seamless battery integration with higher power conversion efficiency and lower system rating can be achieved by adopting the DC-series topology into a photovoltaic (PV) string inverter system, PV-battery series inverter. The uses partial-power processing technique to achieve flexible current control between PV battery. In process of designing DC-DC optimizer, different types converters size batteries considered, vary based on design. This paper presents comparative analysis type optimizers...
This paper presents the development of a plug-and-play (P&P) power electronics education board designed to build hands-on lab incorporating wide-bandgap (WBG) semiconductor switches and circuits. The developed adopts modular architecture P&P concept allow students construct various experiment setups handle different devices such as Si-based WBG devices. By inserting daughter boards completing system connections on motherboard, experiments can be conducted; from switching characteristic...
Grid-tied Photovoltaic (PV) inverters are required to have harmonics mitigation control reduce distortion on the output current caused by impact of grid background harmonics. In this paper, a decentralized strategy for reduction distorted voltage AC-stacked PV inverter architecture is proposed. Two schemes with selective and without any handshaking among proposed analyzed present improvement power quality as well operating margin architecture. The methods impedance analysis verified their...
This paper presents the development of a multi-purpose generic board for hands-on power electronics education lab session focusing on Photovoltaic (PV) applications. The presented work tries to apply advanced methods circuit designs and firmware developments DC/DC converter DC/AC helping students get familiar with system/subsystem level learning. developed converters can be used interconnection low voltage PV systems. Besides, objective is expedite transferring theory practical purposes,...
This paper presents the design of Isolated SenseGaN (Iso-SenseGaN) current sensing technique using Gallium Nitride (GaN) transistors. The isolation for brings an opportunity integration element with power modules, and enables many control schemes in converters. could effectively open broader area smart device monitoring, implementation controlling techniques at high frequency, proper feedback diagnostics/prognostics developments. In this work, focus is on practical challenges presenting...