Download GR-17-01 - GRid-connected Advanced Power Electronics Systems

GRAPES Project Proposal
Award Year 2017
Executive Summary
Project Name: “GR-17-01 Power Devices and Module Needs Cuzner Ang SiC CSC AC to DC Converter”
Wide Band Gap (WBG) power semiconductors such as Silicon Carbide (SiC) MOSFETs enable Variable
Frequency Drives (VFDs), solar inverters, grid-tie wind power inverters and DC microgrid ac-to-dc converters
that operate with switching frequencies from 50-300kHz compared to their Silicon-based counterparts, which
operate from 5-30kHz. Increased switching frequency should enable significant reductions in passive component
sizes, such as differential mode (DM) and common mode (CM) filters, without significant impacts to heat losses
and efficiency and, ideally, will enable easily integrated, system compatible power converters fitting within
standard frame sizes. However, present research shows that the higher switching frequency of WBG devices in
the conventional Voltage Source Conversion (VSC) topology based power converters is accompanied by very
high pulsed voltage edge rates (high dv/dt) which impact the conducted electromagnetic interference (EMI). The
result is significantly increased content in both conducted and radiated EMI in the near radio frequency (nearRF) domain, i.e. from 1 to 30 MHz.
The connection of utility feeds to microgrids or electrical distribution networks involving meshes of power
electronic converter-fed loads must meet stringent power quality and electromagnetic compatibility (EMC)
requirements. Requirements vary between applications but, in all cases, as the number of grid connected
converters increases within a confined space or as grid connected converters are installed in close proximity to
other EMC sensitive equipment or share common bus interfaces with critical processes, the achievement of
simultaneous high power quality, EMC, efficiency and high power density are critical and demanding objectives.
The DM and CM switching frequency components of voltage and current are mitigated with passive filters that
must be effective over a wide frequency spectrum. Filter components and associated thermal management and
enclosures increase the equipment size and weight, reduce efficiency and usually lead to customization for each
installation, with increased programmatic cost and risk.
This project is collaborative effort between UWM (Cuzner) and UA (Ang) to develop and SiC MOSFET/diode
modules with reverse blocking capability and then integrate modules into a highly power dense, efficient,
optimally packaged bi-directional Current Source Converter (CSC). The CSC application will be as the ac-to-dc
interface to a 400V DC microgrid rated at 30kVA. Initially, topologies will be explored for a bi-directional single
stage ac-to-dc CSC and the decision on the module configuration will be finalized. The CSC requires switches
that can block voltage in both directions. The use of reverse blocking dual modules with unidirectional current
may be acceptable if the topology permits bi-directional power flow to and from the microgrid. Otherwise, a
standard CSC with common source dual parallel MOSFET/diode configurations performs the same function. The
SiC-based CSC ac-to-dc converter will meet demanding power quality and EMC requirements and has an
advantage over VSC because high dv/dt does not occur at the input interface. UA will develop and fabricate the
modules. UWM will be build the CSC hardware prototype using the modules, including controls, thermal
management system, enclosure, and construct a conducted EMI test fixture with Line Stabilization Networks
(LISNs) that are custom designed for un-filtered conducted emissions measurements over a broad frequency
spectrum. The EMI test fixture will be used to design optimal CM and DM filter designs and to identify excitation
of any parasitic resonant paths in the bus layout, gate drive design and heat sink design. Target switching
frequency is 100kHz. CM and DM filters will be designed to meet as IEC 61000-3-4 and FCC B standards—
which are appropriate for a residential DC microgrid application. The goal is to validate previous analytical work
demonstrating that CSC for this application meets power quality and EMC requirements with higher power density
and efficiency than an equivalently designed VSC because of reduced filter requirements. This project
demonstrates SiC MOSFET/diode modules in a topology that is different from conventional VSC topologies which
use parallel SiC MOSFET/diode half bridges. The objective of this project is to take advantage of the window of
opportunity to explore advantages of topologies enabled by different WBG module configurations before industry
massively commercializes one type of SiC module (i.e. a parallel SiC MOSFET/diode module to match the
ubiquitous IGBT half-bridge module). The focus is on the implementation of highly power dense, plug and play
grid-connected power converter systems that can be easily installed and integrated into applications with
demanding compatibility requirements.
For the DC microgrid application, the CSC has the additional benefit of being able block the flow of currents into
line-to-line faults, which can be advantages in coordinating converters with downstream fault behavior. A VSC
approach, on the other hand, loses current control when there is a line to line short circuit fault in the DC microgrid
and depends entirely on additional reverse blocking solid state switches to limit fault currents. The project will
also explore the interaction of the CSC and VSC with a DC microgrid during line to line and line to ground faults
and the impacts of DC side capacitances to ground on circuit CM and DM behavior.
GRAPES Project Proposal
Award Year 2017
Project Detail
Project Name: “GR-17-01” – “Power Devices and Module Needs Cuzner SiC CSC AC to DC Converter”
1. Project Description and Objectives:
This project proposes the development and packaging of bi-directional SiC MOSFET/diode modules or reverse
blocking series MOSFET/diode dual modules and the integration of these modules into a grid compatible, highly
power dense, packaged CSC-based bi-directional ac-to-dc converter interface to a 400V DC microgrid. The CSC
will rated at 30kVA with an input voltage of 480Vrms nominal. The project has the following objectives:
1. Explore advantages of topologies enabled by different WBG module configurations before industry massively
commercializes one type of SiC module (i.e. a parallel SiC MOSFET/diode module to match the ubiquitous
IGBT half-bridge module)
2. Develop a SiC/diode packaged dual module with reverse voltage blocking capability
3. Investigate the value proposition of WBG power semiconductor designs as a means of developing highly
power dense, plug and play grid-connected power converter systems that can be easily installed and
integrated into applications with demanding compatibility requirements
4. Explore the impacts of switching frequency, dv/dt and current edge rates (di/dt) on the frequency response
behavior of the module, module interconnections, gate drives, filter components and package structure of a
SiC MOSFET-based power converter operating at switching frequencies greater than 50kHz with signal edge
rates associated with a low switching loss design.
5. Develop a conducted EMI test environment, including LISNs, ground plane and interconnects, that can be
faithfully utilized to characterize DM and CM conducted emissions over a broad frequency spectrum (i.e. up
to 100MHz).
6. Use the EMI test environment to verify the fitness of the bus interconnect, gate drive and filter designs of a
converter that is designed to meet power quality and EMC standards (IEC 61000-3-4 and FCC B) and mitigate
any resonances that amplify EMI behavior at a particular frequency through design modifications.
7. Use the EMI test environment to demonstrate a previously proposed methodology for designing optimal DM
and CM filters to a given standard [1]-[5].
8. Develop the right topology for a CSC-based ac-to-dc converter interface to a DC microgrid as a platform for
testing the SiC/diode packaged module of (1.), (2.).
9. Validate previous analytical work that has shown that a CSC-based ac-to-dc converter interface to a DC
microgrid can meet power quality and EMC requirements with higher power density and efficiency than
equivalent VSC-based design. (Note that the hardware for the VSC-based design has been developed on a
prior project using commercially available SiC MOSFET dual modules. This project will be used to design
and build the filters for both controls and implement controls in order to perform a valid hardware comparison).
10. Explore issues associated with CSC and VSC ac-to-dc converter interfaces to a DC microgrid including: bidirectional power flow to and from the microgrid, steady state and transient operation over a wide DC load
range, behavior during line to line and line to ground short circuit faults and how fault mitigation is affected by
the converter topology choice, impacts of grounding structure and capacitance to ground in the installation
on system performance.
2. Background and Evaluation of State of the Art:
Recent studies have demonstrated higher power dense and efficiency with a Current Source Rectifier (CSR) for
power ranges below 30 kW [3], [5] when compared to the Voltage Source Rectifier (VSR). These improvements
are a result of the fact that, with the same switching frequency, the CSR requires smaller filter components than
the VSR to stay just below CM and DM emission requirements as reflected into a LISN (see Fig. 1, Fig. 2, Table
1). Although the CSR will have higher conduction losses than the VSR, both switching losses and filter losses
are lower.
WBG SiC MOSFETs enable higher switching frequency and, as a result, further reductions in filter sizes.
However, a prominent challenge in successful implementation of WBG-based converters is increased EMI that
results from resonances in parasitic impedances in (1.) multi-chip packaging structure and gate drive [6], [7]-[16],
in the grounding paths through heat sink [10], [12], [14], [17], chassis and external loads and within the EMI
mitigating components themselves [18]. These phenomena are a direct result of the both the higher switching
frequency capability of WBG devices and the higher signal edge rates, both of which have resulted in a movement
of generated spectral content into the “near-RF” domain where such parasitic effects are more likely to be excited
[19], [20].
GRAPES Project Proposal
Award Year 2017
Fig. 1 Spectrum of the input current and LISN current for the VSR
Fig. 2 Spectrum of the input current and LISN current for the CSR
Table 1 component values and calculated parameters of the rectifiers
VSR
CSR
Volume of filter, DC link and heat sink (Liter)
14.3
6.1
Filter Loss (W)
618
395.4
Switching loss (W)
480
523.4
Total loss (W)
Power Density (kW/L)
Efficiency
1098
2.2
96.5%
918.8
5.1
97%
Fig. 3 VSC test hardware and EMI test fixture
A SiC MOSFET based VSC was fabricated and unfiltered
conducted emissions were measured using custom design
LISNs that maintained their required impedance
characteristics up to 10MHz. The hardware is shown in Fig.
3 and Fig. 4. The LISNs were used to characterize the
parasitic impedance of the SiC MOSFET modules and
heat sink structure [21].
Fig. 4 Custom LISN
3. Proposed Novel Approach:
The novelty of the proposed approach is the development of a SiC MOSFET/diode module that is suitable for a
single stage CSC. Two potential bidirectional ac-to-dc converter CSC topologies are shown in Fig. 5 and Fig. 6.
The topology of Fig. 5 utilizes reverse blocking series SiC MOSFET/diode modules and the topology of Fig. 6
utilizes common source bidirectional parallel SiC MOSFET/diode modules. The two topologies and module
configurations will be studied in order to down-select which module to fabricate. The module will then be
integrated into the CSC topology and the surrounding interconnecting bus structure with integrated AC side
capacitors and gate drives will be designed and built. The optimal DC link inductor will be designed and
modulation approach of [22] will be incorporated into the controls in order to maximize power density. The high
frequency behaviors of the unfiltered CSR implementation will be characterized utilizing a similar test platform to
Fig. 3 and Fig. 4. Filter components will then be designed to meet power quality and EMC requirements using
the methodology of [5], which prevents filter over-design. The CSR system will then be constructed and tested
for conducted EMI compliance, power density and efficiency. The results will then be compared with a VSR
based system that is currently being designed and built using the same principles under a separate program.
Fig. 5 AC-to-DC CSC with reverse blocking switches
Fig. 6 AC-to-DC CSC with bi-directional switches
GRAPES Project Proposal
Award Year 2017
4. Upstream and Downstream Dependencies within GRAPES; How will they benefit if this project
is successful:
This project addresses the optimum design of a SiC power module for a CSC power converter in DC
microgrid. The knowledge gained will accelerate the adoption of SiC power modules in microgrid
applications
5. Potential Risks to Project Success:
None
6. Milestones for Mid-Project (Y1) and End of Project (Y2):
Mid-Project (Y1):
1. Explore topologies for a bi-directional single stage CSC-based ac-to-dc converter utilizing SiC MOSFET/diode
arrangements that can block voltage in both directions and therefore function as a buck rectifier when power
is flowing from ac to do or as a boost inverter when power is flowing from dc to ac.
2. Finalize on a SiC MOSFET/diode module that will be fabricated and tested in the circuit topology application.
The module will either be a reverse blocking SiC MOSFET/diode pair or bi-directional switch with two parallel
SiC MOSFET/diode switches connected in a common source configuration.
3. Construct LISNs and a conducted EMI test platform that is suitable for testing of un-filtered conducted
emissions over a broad frequency spectrum in order to develop optimal filter component designs and identify
and excitation any parasitic resonant paths in the bus layout, gate drive design and heat sink design with
switching frequency of 100kHz.
4. Incorporate SiC MOSFET/diode modules into a minimal, unfiltered configuration and perform conducted EMI
tests in order to determine the required attenuation vs. frequency in order to meet IEC 61000-3-4 and FCC B
standards
End of Project (Y2):
1. Design optimal CM and DM filters by decomposing the results of (4.) into CM and DM components
2. Perform simulation studies of CSR and VSR based ac-to-dc converters as part of a DC microgrid system.
Characterize responses to line to line and line to ground short circuit faults.
3. Using simulation, characterize the impacts of line to ground capacitance in the DC microgrid system on the
upstream CSR or VSR ac-to-dc converter.
4. Fabrication of SiC power modules based on optimum designs.
5. Implement the fully compatible CSC design, including thermal management and enclosure and re-test to IEC
61000-3-4 and FCC B standards —which are appropriate for a residential DC microgrid application.
6. Verify that the CSC for this application can meet power quality and EMC requirements with a higher power
density and higher efficiency than equivalently designed VSC.
7. References:
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
A. Nagel and R. W. De Doncker, "Systematic design of EMI-filters for power converters," in Conf. Rec. IEEE IAS Annu. Meeting, vol. 4, p.
2523–2525, Oct. 2000.
T. Nussbaumer, M. L. Heldwein, and J. W. Kolar, "Differential mode input filter design for a three-phase buck-type PWM rectifier based on
modeling of the EMC test receiver," IEEE Trans. Ind. Electron., Vols. 53, no. 5, p. 1649–1661, Oct. 2006.
Cuzner, R.; Drews, D.; Venkataramanan, G., "Power density and efficiency of system compatible, sine-wave input/output drives," Energy
Conversion Congress and Exposition (ECCE), 2012 IEEE , vol., no., pp.4561,4568, 15-20 Sept. 2012
Fu W.; Jiao, Q.; Hosseini, R.; Cuzner, R.; Lemmon, A., "Methodology for the volume minimization in non-isolated SiC based PV inverters,"
2015 International Conference on Renewable Energy Research and Applications (ICRERA), Palermo, Italy, 2015, pp. 1236-1242
Jiao, Q.; Hosseini, R.; Cuzner, R.;, " A Comparison between Silicon Carbide Based Current Source Rectifier and Voltage Source Rectifier
for Applications in Community DC Microgrid," 2016 International Conference on Renewable Energy Research and Applications (ICRERA),
Birmingham, U. K., 2016
Mantooth, H.A.; Glover, M.D.; Shepherd, P., "Wide Bandgap Technologies and Their Implications on Miniaturizing Power Electronic
Systems," in Emerging and Selected Topics in Power Electronics, IEEE Journal of , vol.2, no.3, pp.374-385, Sept. 2014
A. Dutta, S. Ang, “Electromagnetic interference simulations of power electronic modules,” IEEE International Workshop on Integrated Power
Packaging (IWIPP), 3-6 May 2015
Hazra, S.; Madhusoodhanan, S.; Bhattacharya, S.; Moghaddam, G.K.; Hatua, K., "Design considerations and performance evaluation of 1200
V, 100 a SiC MOSFET based converter for high power density application," in Energy Conversion Congress and Exposition (ECCE), 2013
IEEE , pp.4278-4285, 15-19 Sept. 2013
Lemmon, A.; Mazzola, M.; Gafford, J.; Parker, C., "Stability Considerations for Silicon Carbide Field-Effect Transistors," in Power
Electronics, IEEE Transactions on , vol.28, no.10, pp.4453-4459, Oct. 2013
GRAPES Project Proposal
Award Year 2017
[10] Gong, X; Ferreira, J.A., “Comparison and Reduction of Conducted EMI in SiC JFET and Si IGBT-Based Motor Drives,” IEEE Trans. Power
Electron., vol. 29, no. 4, pp. 1757–1767, Apr. 2014.
[11] Lemmon, A.; Mazzola, M.; Gafford, J.; Parker, C., "Instability in Half-Bridge Circuits Switched With Wide Band-Gap Transistors," in Power
Electronics, IEEE Transactions on , vol.29, no.5, pp.2380-2392, May 2014
[12] N. Oswald, P. Anthony, N. Mcneill, and B. H. Stark, “An Experimental Investigation of the Tradeoff between Switching Losses and EMI
Generation With Device Combinations,” IEEE Trans. Power Electron., vol. 29, no. 5, pp. 2393–2407, 2014
[13] Nayak, P.; Krishna, M.V.; Vasudevakrishna, K.; Hatua, K., "Study of the effects of parasitic inductances and device capacitances on 1200 V,
35 A SiC MOSFET based voltage source inverter design," in Power Electronics, Drives and Energy Systems (PEDES), 2014 IEEE
International Conference on , vol., no., pp.1-6, 16-19 Dec. 2014
[14] Scott, M.J.; Lixing Fu; Chengcheng Yao; Xuan Zhang; Longya Xu; Jin Wang; Zamora, R.D., "Design considerations for wide bandgap based
motor drive systems," in Electric Vehicle Conference (IEVC), 2014 IEEE International , vol., no., pp.1-6, 17-19 Dec. 2014
[15] Chen, H.; Divan, D., "High speed switching issues of high power rated silicon-carbide devices and the mitigation methods," in Energy
Conversion Congress and Exposition (ECCE), 2015 IEEE , vol., no., pp.2254-2260, 20-24 Sept. 2015
[16] A. Lemmon, R. Graves, and J. Gafford, “Evaluation of 1.2 kV, 100A SiC Modules for High-Frequency, High-Temperature Applications,”
Applied Power Electronics Conference and Exposition (APEC), 2015 IEEE , vol., no., pp.789-793, 15-19 March 2015
[17] Josifovic, I.; Popovic-Gerber, J.; Ferreira, J.A., "Improving SiC JFET Switching Behavior Under Influence of Circuit Parasitics," in Power
Electronics, IEEE Transactions on , vol.27, no.8, pp.3843-3854, Aug. 2012
[18] Gong, X.; Josifovic, I.; Ferreira, J.A., "Comprehensive CM filter design to suppress conducted EMI for SiC-JFET motor drives," Power
Electronics and ECCE Asia (ICPE & ECCE), 2011 IEEE 8th International Conference on , vol., no., pp.720,727, May 30 2011-June 3 2011
[19] A. Lemmon, R. Graves, and J. Gafford, “Evaluation of 1.2 kV, 100A SiC Modules for High-Frequency, High-Temperature Applications,”
Applied Power Electronics Conference and Exposition (APEC), 2015 IEEE , vol., no., pp.789-793, 15-19 March 2015
[20] A. Lemmon, R. Graves, “Parameter extraction for Silicon Carbide modules,” IEEE International Workshop on Integrated Power Packaging
(IWIPP), 3-6 May 2015
[21] R. Cuzner, R. Hosseini, A. Lemmon, J. Gafford, M. Mazzola, "Control and Characterization of Electromagnetic Emissions in Wide Band
Gap Based Converter Modules for Ungrounded Grid-Forming Applications," IEEE Applied Power Electronics Conference , pp. 1577-1584,
2016
[22] Cuzner, R; Venkataramanan, G., "Current source rectifiers in discontinuous conduction modes of operation”, Industry Applications, IEEE
Transactions on, vol.51, no.1, pp.470-478, Jan.-Feb. 2015
GRAPES Project Proposal
Award Year 2017
Relevant Data and Metrics for Project
A. Personnel
Project Leader
Other Faculty
Postdoctoral
Scholar
Graduate
Students
Undergraduate
Students
Rob Cuzner
Simon Ang
Mohammad Nasridi
Demographics
University
Title/Role
UWM
Ass. Prof./PI
UA
Prof./Co-PI
UA
PhD Student
Willy Sedano Balbin
UWM
PhD Student
B. Products (Note: include only those that explicitly acknowledge NSF support)
Journal Article 1
Journal Article 2
Conference Article 1
Conference Article 2
Patents filed/granted
Seminar
Curriculum development
BUDGET - GRAPES Center
Proposed Start & End Dates:
GRAPES Lead Investigator: Rob Cuzner
Project Campus: University of Wisconsin-Milwaukee and University of Arkansas
Project Number: GR-17-01
Salaries and Wages
# of mo/yr
Annual or
Summer?
Monthly Rate
Fringe Rate
Lead Investigator:
Name: Rob Cuzner
Co-PI:
Name: Simon Ang
Co-PI:
Name:
Co-PI:
Name:
Co-PI:
Name:
# of
students
# of mo/yr
Monthly Rate
Graduate Assistant (PhD)
# of hours/yr
Wage Rate
Hourly, non-student(s)
Hourly, enrolled student
Subtotal Salaries
Subtotal Fringes
Direct Costs:
Domestic Travel
Foreign Travel
Materials and Supplies
Services (Consultant/Computer/etc.)
Facilty Usage Fees
Subtotal Direct Costs
$ 11,778.00
$ 4,676.00
$ 8,806.00
$ 1,444.00
$
$
$
$
$
$
-
Salary
Fringes
Salary
Fringes
$ 15,327.00
$ 3,602.00
$ 18,000.00
$
120.50
Salary
Fringes
Salary
Fringes
$
$
$ 2,213.00
$
73.00
$ 56,124.00
$ 9,915.50
Fringe Rate
Graduate Assistant (Ph.D.)
# of
employees
Salary
Fringes
Salary
Fringes
Salary
Fringes
Salary
Fringes
Salary
Fringes
Fringe Rate
8500
25325
18122
12000
$ 63,947.00
Participant Costs:
Graduate Assistant Tuition (waiver or payment)
Participant Stipend (for example, for an REU student)
Participant Support (only to support students in Stipend category)
Subtotal Participant Costs
$
Total Project Cost
$ 139,968.50
9982
9,982.00