skip to main content

Explore Research Products in the NSF-PAR

Title: Review of Standards on Insulation Coordination for Medium Voltage Power Converters
The increasing viability of wide band gap power semiconductors, widespread use of distributed power generations, and rise in power levels of these applications have increased interest and need for medium voltage converters. Understanding the definitions of insulation coordination and their relationship to applications and methodologies used in the test environment allows system engineers to select the correct insulation materials for the design and to calculate the required distances between the conductive surfaces, accessible parts and ground accurately. Although, design guidelines are well established for low voltage systems, there are some deficiencies in understanding and meeting the insulation coordination requirements in medium voltage, medium frequency applications. In this study, an overview on standards for insulation coordination and safety requirements is presented to guide researchers in the development of medium voltage power electronic converters and systems. In addition, an insulation coordination study is performed as a case study for a medium frequency isolated DC/DC converter that provides conversion from a 13.8kV AC system to a 4.16kV AC system.  more » « less
Award ID(s):
1939124
NSF-PAR ID:
10221367
Author(s) / Creator(s):
; ; ;
Date Published:
Journal Name:
IEEE Open Journal of Power Electronics
ISSN:
2644-1314
Page Range / eLocation ID:
1 to 1
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ( , 2021 IEEE Energy Conversion Congress and Exposition (ECCE))
    This paper presents a unique Virtual Prototyping Process (VPP) that allows for metaheuristic optimization of the building block based Power Electronic Converter systems. The VPP allows for exploration of a range of design space variables, including voltage levels, power semiconductor device technology and thermal management approach against competing objectives such as power density, efficiency and specific cost given electrical and environmental constraints. A unique feature of proposed VPP is compilation of lower voltage building blocks into a much higher voltage rated system and inclusion of allocations for insulation systems, thermal management, accessibility, busing/interconnections and frame/structure/chassis. This approach enables understanding of these practical considerations on power density. This paper presents a use case of a Medium Voltage ac (MVac) to Low Voltage dc (LVdc) solid state transformer. 
    more » « less
  2. ; ; ( , Energies)
    AC/DC hybrid microgrids are becoming potentially more attractive due to the proliferation of renewable energy sources, such as photovoltaic generation, battery energy storage systems, and wind turbines. The collaboration of AC sub-microgrids and DC sub-microgrids improves operational efficiency when multiple types of power generators and loads coexist at the power distribution level. However, the voltage stability analysis and software validation of AC/DC hybrid microgrids is a critical concern, especially with the increasing adoption of power electronic devices and various types of power generation. In this manuscript, we investigate the modeling of AC/DC hybrid microgrids with grid-forming and grid-following power converters. We propose a rapid simulation technique to reduce the simulation runtime with acceptable errors. Moreover, we discuss the stability of hybrid microgrids with different types of faults and power mismatches. In particular, we examine the voltage nadir to evaluate the transient stability of the hybrid microgrid. We also design a droop controller to regulate the power flow and alleviate voltage instability. During our study, we establish a Simulink-based simulation platform for operational analysis of the microgrid. 
    more » « less
  3. ; ( , 2020 First International Conference on Power, Control and Computing Technologies (ICPC2T))
    This paper proposes a combination of cell-level energy processing and a Cascaded H-Bridge Multilevel Inverter (CHBMLI) for medium voltage, grid connected, battery energy storage systems. One isolated converter (Dual Active Bridge DC-DC Converter) manages each cell in the Battery Module, and the combination of Battery module and converter modules are cascaded to get the multi-level ac output voltage. The operating principle and control design of cell level isolated converter with double frequency ripple power, and the control strategy of the CHBMLI are presented. The performance of the battery cell level CHBMLI system with a 9-level inverter at small scale power level is validated through the simulations in MATLAB ® /SIMULINK ® software. The configuration holds promise for improving the performance and reliability of the battery modules at the cell level while also providing cell level galvanic isolation and high ac voltage. 
    more » « less
  4. ; ; ( , 2021 6th IEEE Workshop on the Electronic Grid (eGRID))
    MMC-based back-to-back (B2B) converters are promising for hybrid AC/DC transmission systems when integrating large scale PV sources. This paper proposes a novel configuration for hybrid AC transmission systems with B2B converters and multi-terminal direct current (MTDC) operation which facilitates the integration of PV energy and enhances the system stability and reliability. This is achieved by an advanced interconnection with two operation modes: 1-A bi-directional power flow via AC connections, and 2- Direct active power injection to the MTDC from PV source. Conventional outer, inner and capacitor voltage balancing control systems are utilized in this study for regulating the currents and voltages of B2B converter. Also, The Perturb and observe (P and O) technique is implemented for obtaining maximum power point tracking (MPPT) of the PV generation considering a dc-dc boost converter. The efficacy of this proposed configuration is verified through time-domain simulations carried out by MATLAB/SIMULINK. 
    more » « less
  5. ; ; ; ; ( , 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA))
    null (Ed.)
    In this paper, design of a compact high frequency four-port transformer for a Solid-State Transformer (SST) arrangement is presented. Unlike other SSTs, the four-port system integrates three active sources and a load port with galvanic isolation via a single transformer core. In addition to this feature, one of the three source ports is designed to operate at Medium Voltage (MV) 7.2kV for direct connection to 4.16kV AC grid, while other ports nominal voltages are rated at 400V. The transformer is designed to operate at 50kHz and to supply 25kW/port. Thus, the proposed system connects the MV grid, Energy Storage System (ESS), PV, and DC load to each other on a single common transformer core. Based on the system power demand and availability of renewable energy resources, utility and energy storage ports can either supply or draw power, while PV port can only supply power, maintaining the required demand for the load. This work focuses mainly on the High Frequency Transformer (HFT) design. An extensive study is carried out to obtain the optimal, compact, cost effective, and high efficiency model. Modeling, mathematical, and simulation results are derived and presented to demonstrate the viability of this design. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email