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Full-Text Articles in Engineering
Investigation Of Variable Switching Frequency In Finite Control Set Model Predictive Control On Grid-Connected Inverters, Luocheng Wang, Tiefu Zhao, Jiangbiao He
Investigation Of Variable Switching Frequency In Finite Control Set Model Predictive Control On Grid-Connected Inverters, Luocheng Wang, Tiefu Zhao, Jiangbiao He
Electrical and Computer Engineering Faculty Publications
Finite control set model predictive control (FCS-MPC) has been widely studied and applied to the power converters and motor drives. It provides the power electronics system with fast dynamic response, nonlinear system formulation, and flexible objectives and constraints integration. However, its variable switching frequency feature also induces severe concerns on the power loss, the thermal profile, and the filter design. Stemming from these concerns, this article investigates the variable switching frequency characteristics of FCS-MPC on the grid-connected inverters. An intuitive relationship between the switching frequency and the magnitude of the converter output voltage is proposed through the geometry analysis, where …
Centralized Thermal Stress Oriented Dispatch Strategy For Paralleled Grid-Connected Inverters Considering Mission Profiles, Luocheng Wang, Tiefu Zhao, Jiangbiao He
Centralized Thermal Stress Oriented Dispatch Strategy For Paralleled Grid-Connected Inverters Considering Mission Profiles, Luocheng Wang, Tiefu Zhao, Jiangbiao He
Electrical and Computer Engineering Faculty Publications
One of the major failure causes in the power modules comes from the severe thermal stress in power semiconductor devices. Recently, some local control level methods have been developed to balance the power loss, dealing with the harsh mission profile, in order to reduce the thermal stress. However, there is not any specific system level strategy to leverage these local control level methods responding to the multiple inverters situation. Besides, the impacts of these methods on the thermal cycle and lifetime of the power modules in the long-term time scale have not been evaluated and compared yet. Hence, in this …
Electric Power System Studies For A Multi-Mw Pv Farm And Large Rural Community With Net Zero Energy And Microgrid Capabilities, Evan S. Jones, Oluwaseun M. Akeyo, Keith Waters, Dan M. Ionel
Electric Power System Studies For A Multi-Mw Pv Farm And Large Rural Community With Net Zero Energy And Microgrid Capabilities, Evan S. Jones, Oluwaseun M. Akeyo, Keith Waters, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
Solar photovoltaic (PV) systems are currently being deployed at an accelerated rate because of their cost-competitiveness and environmental benefits, which make them a prime candidate for local renewable energy generation in communities. Microgrids can help accommodate for the problems that accompany PV systems, such as intermittency due to weather, by coordinating different distributed energy resources (DERs), while islanded or by drawing power from the utility while in grid-connected mode. An islanding option is also important for resilience and grid fault mitigation, even if other DERs are not present within the system. This paper studies the potential benefits that a multi-MW …
Electric Drives With Wide Bandgap Devices For Two-Phase Very Low Inductance Machines, Yibin Zhang, Damien Lawhorn, Peng Han, Aaron M. Cramer, Dan M. Ionel
Electric Drives With Wide Bandgap Devices For Two-Phase Very Low Inductance Machines, Yibin Zhang, Damien Lawhorn, Peng Han, Aaron M. Cramer, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
Slotless and coreless machines with low inductance and low core losses are attractive for high speed and high power density applications. With the increase in fundamental frequency, typical drive implementations using conventional silicon-based devices are performance limited and also produce large current and torque ripples. This paper presents a systematic study of proposed drive configurations implemented with wide bandgap (WBG) devices in order to mitigate such issues for 2-phase very low inductance machines. Two inverter topologies, i.e., a dual H-bridge inverter with maximum redundancy and survivability and a 3-leg inverter for reduced cost, are considered. Feasible modulation schemes are derived …
A Comparative Study Of Constant Power Operation Techniques For Low Inductance Machines, Damien Lawhorn, Narges Taran, Vandana Rallabandi, Dan M. Ionel
A Comparative Study Of Constant Power Operation Techniques For Low Inductance Machines, Damien Lawhorn, Narges Taran, Vandana Rallabandi, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
In traditional electric machines, it is usually possible to achieve constant power high-speed operation by employing field weakening through the injection of a negative d-axis current component. However, in machines with low armature inductance, such as high power density permanent magnet synchronous machines, and more specifically, coreless machines, which are gaining increasing attention because of their high specific torque, the extended speed range obtained using this method is very narrow. This paper summarizes the performance characteristics of existing approaches for obtaining constant power operation and proposes two new techniques, specially applicable to coreless axial flux permanent magnet machine namely, current …
Modeling Of A Multi-Megawatt Grid Connected Pv System With Integrated Batteries, Vandana Rallabandi, Oluwaseun M. Akeyo, Dan M. Ionel
Modeling Of A Multi-Megawatt Grid Connected Pv System With Integrated Batteries, Vandana Rallabandi, Oluwaseun M. Akeyo, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
The multi-megawatt grid connected photovoltaic (PV) system studied in the paper includes parallel arrays and power electronic units, each with their own DC-DC and DC-AC converters. In one configuration, the DC-AC converters of adjacent parallel sections are connected in cascade, in order to effectively operate as a multilevel inverter, thereby reducing the filtering requirements. Grid voltage oriented control is employed for inverters and a battery is incorporated for energy storage and performance improvement. Modeling is performed with the PSCAD/EMTDC software, such that both the power electronics components, controls and subsystem aspects, and the electric grid power system issues, can be …