Table of contents monday, September 9, 1: 30pm-4: 00pm modular Multi-Level Converters, hvdc, and dc grids I 3
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- Bu səhifədəki naviqasiya:
- Wireless Power Transfer I
- Monday, September 19, 5:30PM-7:00PM Poster Session: Renewable and Sustainable Energy Applications
- Poster Session: Smart Grid Utility Applications
| 2:20PM Optimized Power Modules for Silicon Carbide MOSFET [#924]
Guillaume Regnat, Pierre-Olivier Jeannin, Jeffrey Ewanchuk, David Frey, Stefan Mollov and Jean-Paul Ferrieux, G2ELAB, France; Mitsubishi Electric RandD Centre Europe, France An Integrated Power Board technology was used to construct a 3D power module. This packaging is suitable for use of WBG devices as it reduces the inductive parasitics to the strict minimum, with a 2nH loop inductance in our 1.2kV/80A SiC prototype using SiC MOSFETs. The packaging presents virtually no parasitics or necessity for slowing down the commutation, which is oscillation-free. The conducted emissions of the 3D module are more than halved in comparison to those of a bespoke wire-bonded, EMI-optimised module. 2:45PM An Improved Wire-bonded Power Module with Double-End Sourced Structure [#1151]
This paper proposes a wire-bonded design with a unique double-end sourced structure for multi-chip paralleled SiC power modules. The proposed design achieved a reduced power-loop inductance of 7.2 nH, while inheriting the advantages of the conventional wire-bond technology. More importantly, the symmetrical structure of the proposed design brought consistent performances to the paralleled devices. A 1200 V, 60 A SiC MOSFET half-bridge module (3 devices in parallel) was fabricated and tested for verification. It demonstrated suppressed voltage overshoot and improved current-sharing among the devices. In addition, the proposed layout exhibited lower radiation noises, which will cause less interference to the sensitive electronic devices. A converter level design is also presented to accommodate this unique module structure. 3:10PM An Initial Consideration of Silicon Carbide Devices in Pressure-Packages [#204]
Fast switching SiC Schottky diodes are known to exhibit significant output oscillations and electromagnetic emissions in the presence of parasitic inductance from the package/module connections. Furthermore, solder pad delamination and wirebond lift-off are common failure modes in high temperature applications. To this end, pressure packages, which obviate the need for wire- bonds and solder/die attach, have been developed for high power applications where reliability is critical like thyristor valves in HVDC line commutated converters. In this paper, SiC Schottky diodes in pressure-packages (press- pack) have been designed, developed and tested. The electrothermal properties of the SiC diode in press-pack have been tested as a function of the clamping force using different thermal contacts, namely molybdenum and Aluminum Graphite. Finite Element Simulations have been used to support the analysis. 3:35PM Effect of Junction Temperature Swing Durations on a Lifetime of a Transfer Molded IGBT Module [#139]
In this paper, the effect of junction temperature swing duration on the lifetime of a transfer molded Intelligent Power IGBT Module is studied and a relevant lifetime factor is modeled. A temperature swing duration dependent lifetime factor is defined based on 38 accelerated power cycling test results under 6 different conditions and it may improve a lifetime model for lifetime prediction of IGBT modules under various mission profiles of converters. The power cycling tests are performed by an advanced power cycling test setup which enables tested modules to be operated under more realistic electrical conditions during the power cycling test. The analysis of the test results and the temperature swing duration dependent lifetime factor under different definitions and confidence levels are presented. Wireless Power Transfer I Monday, September 19, 1:30PM-4:00PM, Room: 202B, Chair: Yaow-Ming Chen, Oscar Lucia 1:30PM An Inductive and Capacitive Integrated Couper and Its LCL Compensation Circuit Design for Wireless Power Transfer [#47] Fei Lu, Hua Zhang, Heath Hofmann and Chris Mi, University of Michigan, United States; Northwestern Polytechnical University, China; San Diego State University, United States This paper proposes a novel coupler structure for wireless power transfer, which takes advantage of both magnetic and electric fields. The coupler contains four metal structures, two each at the primary and secondary sides, which are capacitively coupled. Each structure consists of long strips of metal sheet to increase its self-inductance, which is then inductively coupled with the other three structures. The structures are vertically arranged, and the outer structures are larger than the inner ones to maintain the capacitive couplings. An external LCL compensation network is proposed to resonate with the coupler. The resonance provides conduction current flowing through each plate to establish magnetic fields, and displacement current flowing between different plates corresponding to electric fields. A 100W output power prototype is designed and implemented to operate at 1 MHz, and it achieves 73.6% efficiency from dc source to dc load at an air-gap distance of 18 mm. The contribution of this paper is to propose a concept to transfer power using magnetic and electric fields simultaneously. The potential application of this system is the charging of low power portable devices, such as laptops. After the coupler structure is optimized, it can be extended to higher power applications, such as vehicle charging. 1:55PM Design Procedure of Optimum Self-Inductances of Magnetic Pads in Inductive Power Transfer (IPT) for Electric Vehicles [#380]
This paper presents a design process of inducing self-inductances for the lowest power losses of magnetic pads in inductive power transfer (IPT) system. The total losses of the magnetic pads caused by winding coil, ferrite core, and aluminum shield are numerically calculated and achieved by finite element analysis (FEA) simulation. By plotting the total power losses depending on the coil turns of each magnetic pad, the optimum primary and secondary inductances with the minimum power loss are derived. The validity of the design process is verified through the experimental results provided by a 3.3 kW laboratory prototype. 2:20PM Design high power and high efficiency inverter operating at 13.56MHz for wireless power transfer systems [#954]
This paper presents the proposed design of high power and high efficiency inverter for wireless power transfer systems operating at 13.56 MHz using multiphase resonant inverter and GaN HEMT devices. The high efficiency and the stable of inverter are the main targets of the design. The module design, the power loss analysis and the drive circuit design have been addressed. In experiment, a 3 kW inverter with the efficiency of 96.1% is achieved that significantly improves the efficiency of 13.56 MHz inverter. In near future, a 10 kW inverter with the efficiency of over 95% can be realizable by following this design concept. 2:45PM Improved Design Optimization Approach for High Efficiency Matching Networks [#1446]
Multistage matching networks are often utilized to provide voltage or current gains in applications such as wireless power transfer. Usually, each stage of a multistage matching network is designed to have a purely resistive input impedance and assumed to be loaded by a purely resistive load. This paper introduces an improved design optimization approach for multistage matching networks comprising L-section stages. The proposed design optimization approach explores the possibility of improvement in efficiency of the network by allowing intermediate stages to have complex input and load impedances. A new analytical framework is developed to determine the effective transformation ratio and efficiency of each stage for the case when input and load impedances may be complex. The method of Lagrange multipliers is used to determine the gain and impedance characteristics of each stage in the matching network that maximize overall efficiency. Compared with the conventional design approach for matching networks, the proposed approach achieves higher efficiency, resulting in loss reduction of up to 35% for a three-stage L-section matching network. The theoretical predictions are validated experimentally using a three-stage matching network designed for 10 MHz and 10 W operation. 3:10PM Efficiency Optimization Method of Wireless Power Transfer System with Multiple Transmitters and Single Receiver [#344]
In this paper, an analysis into the wireless power transfer system using inductive coupling with multiple transmitters and single receiver is presented. It is proved that, with certain total amount of input power from all of the transmitters, there is a maximal output power that can be delivered to the receiver. To achieve this optimal result, the electrical currents in all the transmitters shall be in-phase or 180-degree-out-of-phase. The magnitudes of the currents shall be controlled to match certain ratios. These ratios can be calculated from measurements in any known system. Experiments have been conducted to verify the theory in a wireless power transfer system with four transmitters and one receiver. The practical results match the simulated ones very well. 3:35PM Maximum Efficiency Tracking in Wireless Power Transfer for Battery Charger: Phase Shift and Frequency Control [#1071]
This paper presents a maximum efficiency point tracking algorithm for Wireless Power Transfer (WPT) to match the load impedance to that of the source impedance. Conventionally, the load is considered only resistive in the literature. In most of the applications the battery is the end load and the equivalent circuit of battery consists of resistive and reactive elements. Therefore, to improve the overall efficiency of the system, load impedance has to be matched with source impedance. In this paper, a maximum efficiency power tracking (MEPT) algorithm is presented to match source impedance to load impedance. Proposed algorithm varies both frequency and phase shift of the inverter output voltage to minimize input power, whereas output power is kept constant by a dc-dc converter. Battery voltage and current regulation are maintained by the output side dc-dc converter. A brief mathematical analysis is provided to verify the proposed concept. Further, a laboratory prototype with a power rating of 600W is developed, and results are provided to verify the effectiveness of the concept. Monday, September 19, 5:30PM-7:00PM Poster Session: Renewable and Sustainable Energy Applications Monday, September 19, 5:30PM-7:00PM, Room: Exhibit Hall, Chair: Euzeli Santos Jr., Johan Enslin
P101 Modeling, Parameterization, and Benchmarking of a Lithium Ion Electric Bicycle Battery [#495] Weizhong Wang, Pawel Malysz, Khalid Khan, Lucia Gauchia and Ali Emadi, ECE department, McMaster University, Canada; ECE department, Michigan Tech University, United States A lithium-ion battery from an electric bicycle conversion kit is tested and modeled using electrochemical impedance spectroscopy, and the hybrid pulse power characterization test (HPPC). Equivalent circuit model parameterizations are obtained from both time and frequency domain fitting and compared. Parameterization methods are described and a novel quadratic programmed-based two stage parameter fitting algorithm is presented to process and generate model parameters. Experimental data is applied to the proposed algorithm to assess fitting performance. The battery model is validated by real-life riding cycles. Additional electric bicycle benchmarking tests are performed to assess real-world battery performance under a variety of riding conditions and at different assistance levels. The brief correlation between tiredness and assistance levels is investigated. P102 Performance evaluation of a hybrid thermal-photovoltaic panel [#745]
A theoretical and experimental analysis of a thermal-photovoltaic panel, whose purpose is to produce both electrical and thermal energy, has been performed. In order to achieve the main objective, the different components that constitute the thermal-photovoltaic panel have been studied and a simulation model of the proposed thermal-photovoltaic panel has been developed; then, the simulated values, based on the solar irradiance, the ambient temperature and the wind speed, have been compared with experimental data. The results are analyzed and discussed in the paper. In particular, such a validated model can be used to establish if and when it is more convenient to use a hybrid structure rather than two separate devices (PV only and thermal collector only). P103 On-line Wind Speed Estimation in IM Wind Generation Systems by Using Adaptive Direct and Inverse Modelling of the Wind Turbine [#1508]
This paper presents a neural network (NN) based wind estimator and related Maximum Power Point Tracking (MPPT) technique for high performance wind generator with induction machine. The target is to develop an MPPT system, embedding an adaptive virtual anemometer which is able to correctly estimate the wind speed even in presence of variations of the wind turbine characteristic, caused by aging or even damages. This paper proposes the use of the adaptive properties of feed- forward neural networks to address the on-line estimation of the wind speed even in case of slowly time- varying wind-turbine parameters. The method is inspired to the inverse adaptive control but it is used for parameter estimation and not for control purposes. Once the wind speed is estimated, the machine reference speed is then computed by the optimal tip speed ratio. For the experimental application, a suitably developed test set- up has been used, with a back-to-back configuration with two voltage source converters, one on the machine side and the other on the grid side. P104 Passivity-Based and Standard PI Controls Application To Wind Energy Conversion System [#1701]
The controller design for wind energy conversion systems (WECS) is complicated considering the highly nonlinear properties of electric machines and power converters. Targeting at a controller for WECS, this article adopts a passivity based PI control (PI-PBC) method, to which the stability can be analytically guaranteed. Then, a comparative study between the proposed method and a standard PI is provided. The wind energy system consists of a wind turbine, a Permanent Magnet Synchronous Generator (PMSG), a pulse width modulation (PWM) rectifier, a dc load and an equivalent distributed energy storage device, which is formed with a dc source with internal resistor. The generator rotational velocity is regulated at maximum power point (MPPT) for the investigated wind turbine. P105 Evaluation of Circulating Current Suppression Methods for Parallel Interleaved Inverters [#760]
Two-level Voltage Source Converters (VSCs) are often connected in parallel to achieve desired current rating in multi-megawatt Wind Energy Conversion System (WECS). A multi-level converter can be realized by interleaving the carrier signals of the parallel VSCs. As a result, the harmonic performance of the WECS can be significantly improved. However, the interleaving of the carrier signals may lead to the flow of circulating current between parallel VSCs and it is highly desirable to avoid/suppress this unwanted circulating current. A comparative evaluation of the different methods to avoid/suppress the circulating current between the parallel interleaved VSCs is presented in this paper. The losses and the volume of the inductive components and the semiconductor losses are evaluated for the WECS with different circulating current suppression methods. Multi-objective optimizations of the inductive components have been also carried out. The design solutions, that are obtained using the optimization, have been compared on the basis of the volume of the inductive components and yearly energy loss for a given mission profile. Poster Session: Smart Grid & Utility Applications Monday, September 19, 5:30PM-7:00PM, Room: Exhibit Hall, Chair: Johan Enslin, Euzeli Santos Jr. P301 A Fast Dynamic Unipolar Switching Control Scheme for Single Phase Inverters in DC Microgrids [#692] Nicolai Hildebrandt, Mandip Pokharel, Carl Ngai-Man Ho and Yuanbin He, Fraunhofer-Institut fur Solare Energiesysteme, Germany; University of Manitoba, Canada; City University of Hong Kong, Hong Kong This paper presents the digital implementation of a boundary controller with unipolar switching characteristic for single phase voltage source full bridge inverters, which will be used as an interface between a low voltage DC microgrid and AC loads. This paper expands the second order switching surface control method for single phase inverters by unipolar switching with the use of a finite-state machine. Compared to bipolar switching, unipolar switching has the advantage of lower switching losses and filter size. Besides, the switching losses can be equally distributed among semiconductor switches compared to conventional three-level inverter switching scheme. The operating principles of proposed control scheme and mathematical derivation of the switching functions will be given. A 550 VA, 120 V, 60 Hz voltage source inverter (VSI) with a digital signal processor has been implemented to verify the theoretical predictions. Experimental results for steady state operation at different loading conditions show a tightly regulated output voltage, for large-signal disturbances the control is fast and precise. P302 A Novel Method of Optimizing Efficiency in Hybrid Photovoltaic-Grid Power System [#1598]
In this paper, a method of optimizing efficiency of hybrid photovoltaic-grid power system by changing dc bus voltage is introduced. The hybrid photovoltaic-grid power system composed of a solar cell, grid, DC bus, solar cell interface converter (Boost + full-bridge LLC resonant converter), grid interface converter (single-phase PWM rectifier) and load interface converter (half-bridge LLC resonant converter). By analyzing the loss of every interface converters in hybrid photovoltaic-grid power system, the relationship between the bus voltage and the efficiency of the whole system can be found out. To verify the loss analysis and the efficiency optimization method, 1kW hybrid photovoltaic-grid power system hardware was built in the lab. The experimental results verify the feasibility of the efficiency optimization method. P303 A Novel Autonomous Control Scheme for Parallel, LCL-Based UPS Systems [#404]
This paper proposes a novel autonomous control scheme for equal load current distribution between n parallel-connected, LCL-based, three phase UPS units. The control is based on varying the capacitor reference voltage of each inverter as a function of its own output current, without exchanging information between the inverters. The load voltage is maintained fixed at the specified reference value. The control method is fast, precise and robust against load variations. Capacitor voltage and capacitor current are used in a dual-loop control at each inverter. The validity of the proposed method is verified by simulation and experiments on a system of two 5-kVA parallel inverters. P304 Harmonic Components Based Protection Strategy for Inverter-Interfaced AC Microgrid [#571]
In the inverter-interfaced AC microgrid (IIAM), when a short-circuit fault occurs at the distribution line, the output fault current of inverter is commonly limited to two times over its rated current due to the limited overcurrent capacity of power electronic device. Therefore, the conventional overcurrent protection principle cannot be applied to IIAM. Aiming at addressing this issue, a new protection method based on the low harmonics components is proposed in this paper. Through injecting a certain proportion of fifth harmonics to the fault current, the protection device can detect the fault according to the low harmonics components extracted by the digital relay (DR). This scheme does not rely on the large fault current. Therefore, some limitations of the traditional overcurrent protection are avoided. The corresponding experiments were carried out with two 10kVA parallel-connected inverters supply system, and the results proved the feasibility of this approach. P305 Adaptive Virtual Inertia Control of Distributed Generator for Dynamic Frequency Support in Microgrid [#732]
The distributed generator based on power electronic converters has no inherent inertial response like that from the rotating mass of the conventional synchronous generator. The control scheme of Virtual Synchronous Generator (VSG) is anticipated to improve the distributed generator system stability by imitating the behavior of the synchronous generator including the system inertia. Unlike a real synchronous generator, the equivalent inertia of the distributed generator using VSG can be controlled in a wide range with the system frequency variation. In order to explore this feature for providing a fast and smooth inertial response, a flexible virtual synchronous generator control (FVSG) strategy with adaptive inertia is proposed. By fully considering the relationship between system inertia and frequency fluctuation rate, a calculation method adopting a function of the frequency change rate to achieve an adaptive inertia coefficient is presented and introduced to the VSG control. A simulation system using Matlab/Simulink is implemented to validate the proposed FVSG control strategy on improving the system dynamic frequency performances.
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