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EPE 2013 - DS1b: Hard Switching Converters and Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 05: Hard switching converters and control > EPE 2013 - DS1b: Hard Switching Converters and Control
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	5 level cross connected cell for cascaded converters   By Frans DIJKHUIZEN, Alireza NAMI, Liwei WANG, Anshuman SHUKLA	[View]   [Download]
Abstract: Proposed here is an alternate Five-level four-quadrant cascaded multilevel converter cell configurationthat compared to the other cell configurations, for dc fault current limitation, will be more compactand avoid the external dc breaker. Loss comparison on cells with dc fault blocking capability for thecascaded converter is also presented.
	A Modified LLCL-filter with the Reduced Conducted EMI Noise   By Weimin WU, Yunjie SUN, Zhe LIN, Frede BLAABJERG, Shu Hung Henry CHUNG, Min HUANG	[View]   [Download]
Abstract: For a transformerless grid-tied converter using Pulse Width Modulation (PWM), the harmonics of grid-injected current, the leakage current and the Electromagnetic Interference (EMI) noise are three important issues during design of the output filter. In this paper, the Common-Mode (CM) and the Differential-Mode (DM) EMI noises are investigated for the LCL- and LLCL-filters based single-phase full-bridge grid-tied inverter. Based on this, a modified LLCL-filter topology is proposed to provide enough attenuation on the conducted EMI noise as well as to reduce the DC-side leakage current. The parameter design method of the filter is also developed. The comparative analysis and discussion on four filter cases (the conventional LCL-filter, the conventional LLCL-filter, the modified LCL-filter, and the modified LLCL-filter) are carried out and verified through simulations and experiments on a 0.5 kW, 110 V / 50 Hz single-phase full-bridge grid-tied inverter prototype.
	A multilevel inverter topology for the generation of dodecagonal space vectors for Medium voltage induction motor drives   By Najath ABDUL AZEEZ, Rajeevan PUTHANPURAYIL, Jaison MATHEW, Gopakumar K, Mathew K	[View]   [Download]
Abstract: In this paper, a hybrid multilevel inverter topology for the generation of dodecagonal space vectors is presented which eliminates all (6n±1), n=odd harmonics from the motor phase currents in the entire range of modulation with an increase in the range of linear modulation. The topology is a hybrid of flying capacitor, H-bridge and conventional two-level inverter cells. With this topology, any standard induction motor can now be used as the load thus avoiding the requirement of open end winding induction motors for the generation of dodecagonal voltage space vectors. A strategic variation in the PWM switching scheme, which is valid for two-level as well as multilevel inverters, is also proposed that reduces the current THD compared to conventional space vector PWM schemes.
	A New Isolated, Output Filter Free DC-AC Converter Topology   By Luyu WANG, Per KARLSSON, Hans BANGTSSON	[View]   [Download]
Abstract: In this paper, a new isolated DC-AC converter with ‘‘sinusoidal shape’’ output voltage is analyzed, simulated and verified with a scaled prototype. Design expressions for selection of passive component values and design requirements of power semiconductor devices are given. The control algorithm is thoroughly investigated. The converter losses based on the commercially available semiconductors are calculated with different load conditions. The output waveform is measured.
	A NEW N-LEVEL SPACE VECTOR MODULATOR FOR CASCADED MULTILEVEL CONVERTERS    By Mario MARCHESONI, Gianmarco MARAGLIANO, Luis VACCARO	[View]   [Download]
Abstract: A new generalized space vector modulator for cascaded multilevel converters is presented, featuring centralized control, fault tolerant and common mode voltage reduction capabilities. The SVPWM technique is based on the redundancy properties inherent in multilevel modulation schemes and is validated through a case study. Simulation and experimental results are presented.
	A Novel Space Vector Modulation Strategy for Thyristor Matrix Converters   By Michael LONNEKER, Joachim BOCKER	[View]   [Download]
Abstract: A novel modulation strategy for matrix converters based on space vector representation is outlined in this contribution. In particular, the method is applied to a thyristor matrix converter connecting a multi-phase generator of varying frequency with the fixed-frequency three-phase grid. Compared with the well-known space vector modulation for a three-phase voltage source inverter, the elementary output voltage vectors are no longer constant but varying themselves in time. Additionally, not every transition between the switching states is possible at any time as an appropriate external commutation voltage is needed. Goal of the proposed control approach is get by with only a small number of commutations per fundamental in order to keep the switching losses low while ensuring a reasonable harmonic distortion.
	A Submodule Implementation for Parallel Connection of Capacitors in Modular Multilevel Converters   By Kalle ILVES, Franz TAFFNER, Staffan NORRGA, Antonios ANTONOPOULOS, Lennart HARNEFORS, Hans-Peter NEE	[View]   [Download]
Abstract: The modular multilevel converter is a suitable converter topology for high-voltage high-power applicationsand consists of series-connected submodules. Typically, these submodules are half-bridges withdc capacitors. A voltage ripple in the submodule capacitors is inevitable due to the current flowing inthe arms. The converter should therefore be controlled in such a way that the capacitor voltages arekept balanced and close to their nominal values over time. This paper presents a new submodule circuitwhich alleviates the balancing of the capacitor voltages. The proposed submodule circuit consists of twocapacitors and eight switches, forming a three-level submodule. Ideally, the voltage and current ratingof the switches can be chosen such that the combined power rating of the semiconductors is the sameas for equivalent half-bridge submodules. The proposed submodule circuit provides the possibility ofconnecting the two capacitors in parallel when the intermediate voltage level is used. This will reducethe capacitor voltage ripple, especially at low switching frequencies and thus allow for a reduction of thesize, weight, and cost of the submodule capacitors. The proposed submodule circuit is validated by bothsimulation results and experiments on a laboratory prototype. It is found that the parallel connection ofthe submodule capacitors will, in fact, significantly improve the balancing of the capacitor voltages.
	AN EFFICIENT HIGH CURRENT, LOW VOLTAGE MULTI-CELL BUCK CONVERTER USING INTERCELL TRANSFORMER, Modeling and Implementation of 12-phases prototype   By Thierry MARTIRE, Philippe ENRICI, Jean-Jacques HUSELSTEIN, Petru NOTINGHER, Abdallah DARKAWI	[View]   [Download]
Abstract: This paper deals with the design of high power density DC/DC buck converter for portable bench space charge measurements in full-size HVDC cables. The design of a coupled interleaved buck converter used for delivering the necessary regulated high transient current (up to 1200A during one or two seconds) is presented. The structure is original regarding its compacity and the use of an innovative, small and compact structure of magnetic coupling called InterCell transformer (ICT) which guarantees an excellent filtering of the output current. Experimental results are included in order to confirm the effectiveness and the advantages of the proposed structure. Thermal step current measurements are included in order to validate the application principle on aged power cable loops.
	An Overview of Multilevel Converter Topologies for Grid Connected Applications   By Ehsan BEHROUZIAN, Massimo BONGIORNO, Hector ZELAYA	[View]   [Download]
Abstract: This paper provides an overview of multilevel converter topologies for grid connected applications. Different converter topologies such as Diode Clamp Converter (DCC), Capacitor Clamp Converter (CCC) and Chain Link Converter (CLC) are considered and compared from different aspects such as component sizing, complexity, efficiency and reliability. Thanks to its modular structure, the CLC appears as the most attractive topology for high power and high voltage applications. Single-Star Bridge-Cell (SSBC), Single-Delta Bridge-cell (SDBC), Double-Star Bridge-Cell (DSBC) and Double-Star Chopper-Cell (DSCC) are four basic subset topologies of CLC. A comprehensive comparison of these subset topologies for the CLC is provided for the particular application of grid connected converters. The problem of operation under unbalance grid conditions and the ability of this converter topology to inject negative sequence into the grid are discussed. It will be shown that due to the lack of a common DC link between phases, this converter topology presents limited negative sequence injection capability when the phase legs are connected in delta, while in case of star connection voltage balancing between the different cells of the converter becomes problematic due to the uneven current distribution among phases. This represents the main limitation of this converter topology, especially when used for load balancing and active filter applications.
	Analysis and Design of a Parallel-Connected Single Active Bridge DC-DC Converter for High-Power Wind Farm Applications   By Kiwoo PARK, Zhe CHEN	[View]   [Download]
Abstract: This paper presents a parallel-connected Single Active Bridge (SAB) dc-dc converter for high-powerapplications. Paralleling lower-power converters can lower the current rating of each modular converterand interleaving the outputs can significantly reduce the magnitudes of input and output current rippleswithout increasing switching losses or device stresses. Analysis of both the input and output currentcharacteristics and design aspects of the transformer, the filter inductor, and the input and output filtercapacitors will be presented. Considering the high maintenance cost and fault tolerant requirements,this modular converter concept is expected to be highly beneficial especially for the offshore wind farmapplication.
	Comparison of Multilevel PWM versus Interleaved Based Sinewave Shaping for Two-Stage Current Source Inverters Used in PV Applications   By Savvas PAPADOPOULOS, Christian KLUMPNER	[View]   [Download]
Abstract: This paper investigates the advantages of using interleaved based direct sinusoidal current shaping techniques as alternative to 5-level Pulse Width Modulation (PWM) when used in conjunction to a two stage Current Source Inverter (CSI) in PV applications. By using simulation based modelling it is proven that; in combination with switching harmonic cancellation techniques; for a given output power, direct shaping allows for better utilization of devices and subsequently the minimization of losses without sacrificing power quality.
	Comparison of Peak-To-Peak Current Ripple Amplitude in Multiphase PWM Voltage Source Inverters   By Jelena LONCARSKI, Claudio ROSSI, Gabriele GRANDI	[View]   [Download]
Abstract: Multiphase systems are nowadays consid¬ered for various industrial applications. Numerous PWM schemes for multi¬phase voltage source inverters with sinusoidal outputs have been developed, but just recently the im¬pact of these modulation schemes on the output peak-to-peak cur¬rent ripple am¬plitude has been consid¬ered. Determination of cur¬rent ripple in multiphase PWM voltage source inverters is important for both de¬sign and control purposes. This paper gives the comparison of the peak-to-peak cur¬rent ripple dis¬tribution over a fundamen¬tal period for multiphase VSIs, starting from three-phase and extended to the multiphase inverters, with emphasis on five and seven phases. Simplified expres¬sions to get maxi¬mum val¬ue of the rip¬ple are carried out and compared among inverters with different phase number. Although refer¬ence is made to the centered symmet¬rical PWM, being the most simple and effective solution to maximize the dc bus utili¬zation, leading to a nearly-optimal modulation to minimize the rms of the current ripple, the analysis can be readily extended to ei¬ther discontinu¬ous or asymmetrical modula¬tions, both carrier-based and space vector PWM. The results obtained by the proposed analytical approach are backed with the numeri¬cal simulations of the peak-to-peak ripple for inverters with different phase numbers and in case of different modulation indexes to prove the effec¬tiveness of mathe¬matical developments.
	Energetic Macroscopic Representation and Inversion Based Control of a Modular Multilevel Converter   By Philippe DELARUE, Francois GRUSON, Xavier GUILLAUD	[View]   [Download]
Abstract: This papers deals with the Modular Multilevel Converter (MMC). This structure is a real breakthroughwhich allows transmitting huge amount of power in DC link. In the last ten years, lots of papers havebeen written but most of them study some intuitive control algorithms. This paper proposes a formalanalysis of MMC model which leads to the design of a control algorithm thanks to the inversion of themodel. The Energetic Macroscopic Representation is used for achieving this goal. All the statesvariables are controlled to manage the energy of the system, avoid some instable operational pointsand determine clearly all the dynamics of the different loops of the system.
	Experimental Studies on a Single-Phase Improved Switched Inductor Z-Source Inverter   By Mohamed ISMEIL, Ralph KENNEL, Mohamed ORABI, Ayman AYAD	[View]   [Download]
Abstract: This paper presents an experimental work on improved SL Z-source inverter topology. Because of the limitations of classical Z-source inverter, the SL Z-source inverter has been proposed to increase the voltage gain and to reduce the voltage stress on the capacitors of the Z-network. The simulation and experimental results show that the improved SL Z-source inverter increases the boost factor, improves the voltage stress across the capacitors, and reduces the inrush current.
	Fault tolerant operation of single-ended non-isolated DC-DC converters under open and short-circuit switch faults   By Ehsan JAMSHIDPOUR, Mahmoud SHAHBAZI, Philippe POURE, Eskandar GHOLIPOUR, Shahrokh SAADATE	[View]   [Download]
Abstract: Fault tolerant operation of single-ended non-isolated DC-DC converters used in embedded and safety critical applications is mandatory to guaranty service continuity. This paper proposes a new, fast and efficient FPGA-based open and short-circuit switch fault diagnosis asssociated to fault tolerant converter topology. The results of Hardware-In-the-Loop and experimental tests are presented and discussed.
	High Precision Switched Mode Amplifier with an Auxiliary Bias Circuit   By Jan SCHELLEKENS, Jorge DUARTE, Henk HUISMAN, Marcel HENDRIX, Elena LOMONOVA, Mark CARIS	[View]   [Download]
Abstract: Blanking time, also referred to as dead-time, is one of the dominant sources of output current and voltagedistortion in pulse-width modulated power amplifiers. Extensive studies are known on elimination,minimization, and compensation of the effect. Most techniques achieve a reduction of the distortion butare not capable of completely removing it. Topologies like the opposed current converter do not requiredead-time and therefore do not suffer from this nonlinear effect.In order to ensure continuous conduction mode, opposed current converters require bias current thatnormally flows through the output filter inductors. This paper presents an alternative approach wherethe bias current is supplied from additional current controlled switching legs. A modulation strategyis proposed and guidelines are given for the design of the inductive components. Finally the inductorvolume of the proposed topology is compared to the opposed current converter equal showing that bothtopologies are comparable with respect to volume of the passive components.
	On the Impedance Modeling of Switched Capacitor Converters with Arbitrary Output Nodes    By Julia DELOS, Marcel HENDRIX, Eduard ALARCON, Toni LOPEZ, Elena LOMONOVA	[View]   [Download]
Abstract: Demand for high power density and miniaturization are pushing the application limits of Switched Capacitor Converters (SCCs) to new areas. Their benefit has up to now been used only in low power application ICs such as memories, or mobile phone backlighting where efficiency is not critical and magnetic components are not available. Recently, research in SCCs is demonstrating that their benefits can be extended to high power density systems, achieving efficiency levels comparable to classical inductive SMPS. These new concepts consider advanced control schemes or hybrid combinations of SCCs and inductive switching, and require better understandings of the SCC and its appropriate models. This work presents a new methodology to model hybrid combinations of SCCs and inductors. The well-known vector charge flow analysis for Switched Capacitor Converters is reviewed and extended in order to accurately model the behavior of a SCC when any of the internal nodes is loaded and controlled by PulseWidth-Modulation. Results of the analysis compare favorably to behavioral simulations.
	Practical verification of topology for a high voltage pulse converter for non-thermal plasma generation   By Michal BALCERAK, Marcin HOLUB, Stanislaw KALISIAK, Michael SCHMIDT	[View]   [Download]
Abstract: This paper presents the topology of the high voltage, pulsed converter using transformer parasitic parameters. The converter uses solid-state switches and generates (in no load conditions) a voltage pulse with an amplitude of 20 kV with 5kV supply. The steepness of the voltage rise without load is 1.36 kV/ns and the pulse duration is less than 100ns.
	Semiconductor Component Reduction in AC-DC Converters with Transmission Lines   By Andreas KARVONEN, Sverker SANDER	[View]   [Download]
Abstract: By replacing the power inductor in a traditional converter topology with a transmission line, new functions such as inverting and non-inverting output voltage polarity from the same converter will arise. In this paper, the proposed technology was investigated in an AC/DC converter where the traditional topology (diode bridge and secondary DC/DC converter) was replaced with a single converter with a transmission line as an energy storage device. The transmission line was realized with lumped elements and the major benefit was found to be a reduced number of semiconductors; the same functionality could be achieved with only half the original amount. Due to practical reasons, the operating principle was verified in a DC/AC-circuit which was simulated in LTspice. The simulations showed that a switch mode converter with transmission line is possible to use for the suggested application with a power stage efficiency of ηPwSt=87\%. To verify the simulations, a prototype was built and tested which showed that the principle works in practice with a measured power stage efficiency of ηPwSt=85\%.
	Study on the Over-current Protection Method of the Large Power Inverter with IGCTs   By Chengsheng WANG, Chongjian LI, Zhiming LAN, Wei DUAN, Qiongtao YANG	[View]   [Download]
Abstract: Large power three-level voltage source inverters with IGCTs are widely used in medium and large power drive systems now and have prospective future. Measures should be carefully taken to protect the inverter when over-current occurs due to every reason, especially that due to short circuit in the load or in the inverter itself. The short circuit process of the inverter with IGCTs is analyzed. With software simulation and experiment, the influence of some circuit parameters on the short circuit process is investigated. Then the schematic diagram of the inverter with over-current protection function is designed. System experiments show the inverter has excellent performance.
	Three-Level NPC-based Bidirectional PWM Converter Operation for High Availability/Power Quality Bipolar Dc Distribution Networks   By Joabel MOIA, Marcelo HELDWEIN	[View]   [Download]
Abstract: This work proposes an operation strategy for a four-legs neutral point clamped converter (NPC) to beused in future bipolar dc distribution networks. The operation of the fourth leg with a three-level modulationis proposed to reduce the required inductance and switching losses. In addition, a proper controlscheme based on a state space averaged model for the fourth NPC leg is introduced. This provides ripplefree and balanced NPC partial dc-link voltages. The system is able to provide increased redundancy andimproved dc voltage quality. Simulation and experimental results are presented to illustrate the operationof the 4-legs NPC with the proposed control and modulation scheme
	Three-Phase Unidirectional Modular Multilevel Converter   By Gean Jacques MAIA DE SOUSA, Marcelo HELDWEIN	[View]   [Download]
Abstract: Unidirectional power flow voltage source converter high voltage direct current (VSC-HVDC) systemscan be advantageously used in future dc subsea electric transmission and distribution systems (DC-SETDS) in order to reduce cost, increase efficiency and reliability. This work proposes a unidirectionalmodular multilevel converter (uMMC) suitable for VSC-HVDC systems used in DC-SETDS. The mainadvantage of the proposal is the reduced number of active switches, lowering costs and increasing relia-bility. Suitable currents and voltages control strategies are presented, as well as simulation results.
	Transformer-Based Asymmetrical Embedded Z-source Neutral Point Clamped Inverters with Continuous Input Current and Enhanced Voltage Boost Capability   By Wei MO, Poh Chiang LOH, Frede BLAABJERG	[View]   [Download]
Abstract: Z-source Neutral Point Clamped (NPC) inverters were introduced to integrate both the advantages of Z-source inverters and NPC inverters. However, traditional Z-source inverters suffer from high voltage stress and chopping input current. This paper proposes six types transformer-based impedance-source NPC inverters which have enhanced voltage boost capability and continuous input current by utilizing of transformer and embedded dc source configuration. Experimental results are presented to verify the theory validation.
	TRANSFORMER-BASED MULTILEVEL INVERTER TOPOLOGY FOR STAND-ALONE PHOTOVOLTAIC SYSTEM   By Saad MEKHILEF	[View]   [Download]
Abstract: A proposed hybrid multilevel inverter topology is derived from the multiple-transformer invertertopology by integrating the flying capacitor asymmetric H-Bridge inverter into the multiple transformer inverter topology to improve the performance of a multilevel inverter. The Proposedhybrid multilevel inverter topology reduces amount of THD in the output voltage of the multilevel inverter by increasing the number of output voltage levels of the multilevel inverter and reduces the amount of power losses in the power semiconductor switches by using appropriate power semiconductor switches in different switching conditions. The performance of the proposed hybrid multilevel inverter is verified through simulation of the proposed hybrid multilevel inverter topology and comparison of the result from the simulation of the hybrid multilevel inverter topology with the result from the simulation of other multilevel inverter topologies.
	Unified Analysis Technique for Energy Quality Factors Estimation of NPC Multilevel VSC for Energy Storage Systems   By Gennadiy ZINOVIEV, Maxim DYBKO, Sergey BROVANOV, Sergey KHARITONOV	[View]   [Download]
Abstract: The paper presents an analysis of the energy quality factors such as voltage and current spectra, THD, WTHD of any order, efficiency, for an energy storage system based on a diode-clamped multilevel VSC. The analysis technique includes two key parts: mathematical simulation and analytical research. The main advantages of the analysis technique are the possibility to apply it to any m-leg n-level converter and any SPWM or SVPWM modulation strategy. An experimental verification of the results obtained is given
	Voltage Balancing Control of A Four-level Hybrid-Clamped Inverter Using Modified Phase-Shifted PWM   By Kui WANG, Yongdong LI, Zedong ZHENG, Lie XU, Jing SHANG	[View]   [Download]
Abstract: This paper presents a voltage balancing method for a four-level hybrid-clamped inverter. The relationship between the capacitor currents and switching functions is studied. A modified phaseshiftedPWM method is used to regulate the capacitor currents by adjusting the start and end time ofthe PWM signals slightly according to the capacitor voltages and the polarity of the output current.Experimental results are presented to verify this method.