| EPE 2015 - DS1a: Advanced Power Converter Topologies |
| You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2015 ECCE Europe - Conference > EPE 2015 - Topic 02: Power Converter Topologies and Design > EPE 2015 - DS1a: Advanced Power Converter Topologies |
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 | A 3.6kW Single-ended Resonant Inverter for Induction Heating Applications
By Jaeeul YEON | [View]
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Abstract: The single-ended (SE) resonant inverter is a type of class E parallel resonant inverter and popularly used in many IH applications due to its lower cost structure and relatively high efficiency. However its maximum power rating should be limited because the resonant voltage of SE resonant inverter increases as its power increases. Consequently the maximum power rating of SE resonant inverter should be limited up to around 2kW. This paper proposes an interleaved single-ended resonant inverter for the induction heating applications. The proposed inverter can provide two times higher output power than the conventional single-ended resonant inverter by the alternative operation of two inverters. A burst mode control enhances the power control range from very light load to full load and can improve efficiency.
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| | A Highly Efficient 2kW 3-Level Full-MOSFET Inverter
By Guillaume LEFEVRE | [View]
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Abstract: This paper investigates an improved 3-level flying capacitor inverter topology allowing a drastic reduction of reverse recovery related losses. It benefits from the latest superjunction (SJ) MOSFET devices. The presented 2kW inverter was designed for Japanese PV market (200Vrms). It allows non unitary power factor operations with peak and European efficiency of 98.0\% and 97.6\% respectively. Thanks to SJ MOSFET implementation, it outperforms state-of-art configuration using IGBTs and SiC diodes in terms of efficiency.
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| | A Multilevel Five-phase Open-end Winding Drive with Unequal DC-link Voltages
By Milan DARIJEVIC | [View]
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Abstract: A new multilevel five-phase open-end winding drive topology is proposed and analysed in this paper. The topology consists of an induction machine with open-end windings, supplied with one three-level and one two-level voltage source inverters (VSIs). The two inverters are fully isolated with dc-link voltages in a ratio 2:1, which results in performance equivalent to that of a four-level five-phase single-sided topology. In addition to four-level operation, two- and three-level operating modes are also possible, depending on the modulation algorithm. This feature can be used in order to reduce switching losses and improve harmonic performance. Two carrier-based pulse width modulation (CB PWM) strategies are evaluated using detailed numerical simulations.
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| | A New High-Power High-Voltage Isolated DC-DC Converter using an NPC Balanced Capacitive Divider
By Alfred RUFER | [View]
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Abstract: A new isolated DC-DC converter is presented suited for high voltage applications. It is based on theseries connection of NPC inverter cells, using semiconductor devices with lower voltage blockingcapability than the total input voltage. The galvanic isolation is realized using multiple MFtransformers, each designed for a fraction of the global power. The output comprises multiple dioderectifiers connected in series. The circuit uses a capacitive voltage divider at its input, allowing anactive balancing of the intermediate levels according the principle of the current diverter. Thebalancing half bridges allow an N-1 mode of operation in case of a fault or disconnection of one of theseries connected cells.The used 3-Level NPC topology for the half bridges allows in addition the continuous variability ofthe total voltage transformation ratio. The operation principle is verified by simulation, completed by asmall scale experimental set-up. Three- and four-stage topologies are used in the study, but theprinciple can be extended to a high number of modules, making the topology suitable for very highvoltage levels, where structures with redundancy (N-1) can be designed.
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| | A New Hybrid Seven Level Inverter Topology with a Single DC Supply and Reduced Switch Count
By Arun Rahul S | [View]
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Abstract: In this paper, a new three-phase hybrid seven level inverter topology with a single DC supply is proposed for the first time. The proposed inverter is realized by cascading two three level flying capacitor inverters with a half bridge module. The inverter topology is having multiple switching state redundancies for each of the pole voltage levels. By using these switching state redundancies, capacitor charging can be controlled in every PWM switching cycle. This feature is advantageous for reducing the capacitor sizing. Another advantage of the proposed inverter is that the charge balancing of each capacitor can be controlled irrespective of modulation index and load power factor. A hysteresis controller based capacitor charge control algorithm is implemented for the proposed inverter. Furthermore, the proposed topology uses lesser number of semiconductor devices, capacitors and DC power supplies compared to conventional seven level inverter topologies. The proposed topology is tested with open loop V/f control scheme in an induction motor drive. Inverter is tested for entire modulation range, and experimental results for steady-state operation are presented for various fundamental frequencies. Experimental results showing the effectiveness of capacitor charge control for both steady state and transient operating conditions are presented.
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| | A Passive Three-Phase Rectifier Enhanced by a DC-Side High Switching Frequency Add-On SiC-Converter Stage for Unity Power Factor Applications
By Markus MAKOSCHITZ | [View]
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Abstract: Recent developments showed that existing passive three-phase rectifier circuits with DC-side located smoothing inductor can be extended to a low harmonic input stage by adding an additional converter stage on the DC-side of the passive rectifier system. In this paper an implementation of this converter stage using reduced number of semiconductors (only two half-bridges) is proposed. The system shows input current distortions which can be reduced considerably to values below 1\% if switching frequencies of 72kHz or above are used. A proper design of the injection chokes is thereto required and several operating modes and optimization possibilities are discussed. Design guidelines are verified by simulation results and a laboratory prototype based on a 10kW/72kHz rectifier system using SiC-MOSFETs.
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| | A power electronics controlled current source based on a multi-converter topology
By Michal GWOZDZ | [View]
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Abstract: The paper presents a conception of power electronics voltage controlled current source (VCCS) which is able much more precise mapping of its an output current in a reference signal, compared to a typical converter solution. It can be achieved by means of such interconnection of two separate converters that one of them corrects a total output current towards a reference signal. An output power of auxiliary converter is much smaller than an output power of main one. Thanks to continuous work of this converter also pulse modulation components in this current are minimized. The typical application of a VCCS can be e.g. an execution block in Active Power Filter.
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| | A Soft Switching Bidirectional DC-DC Converter based onThree-State Switching Cell to Photovoltaic Systems Applications
By Luan C. S. MAZZA | [View]
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Abstract: This paper presents a new three-port soft switching dc-dc converter topology based on thebidirectional version of the three-state switching cell, feasible to interconnect battery banks with a dclink and photovoltaic panels. All active switches are designed to operate in Zero Voltage Switching(ZVS). The theoretical analysis and experimental results for a 2 kW laboratory prototype are presented.
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| | AC-side parallel-series active filter with DC-voltage control capability of a diode rectifier
By Andreas REINHOLD | [View]
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Abstract: This paper discusses a parallel-series active power filter (APF) for a three-phase diode rectifier. In addition to power quality improvement, the proposed APF can control the DC voltage of the diode rectifier. A new control strategy by the series APF generates an adjustable constant DC voltage. The simulation results show that the DC voltage can be decreased or increased.
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| | AC/DC reversible mixed inverter with built-in Inrush-Current limitation and cut-off stand-by losses
By Laurent GONTHIER | [View]
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Abstract: A new inverter using two thyristors in place of two freewheeling diodes is presented. This inverter allows a reversible DC/AC converter to be implemented. This converter can control the inrush-current and allow bridge full-disconnection at stand-by to suppress undesired losses. This is achieved by a full-silicon solution without the need of any inrush-current limiting resistor and or mechanical relays.In this paper, PSPICE simulation results are presented to validate the converter operation. Experimental results are given to discuss the on-state threshold voltage difference between a slow diode, using in a classic inverter, and a thyristor used in this new topology.
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| | An FPGA-based Real-time HIL Test Bench for Full-Bridge Modular Multilevel STATCOM Controller
By Wei LI | [View]
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Abstract: The modular multilevel converter (MMC) STATCOM removes the need for AC filter and transformer, has no DC bus fault hazard, and thus becomes a better option than a 2-level voltage source converter (VSC) STATCOM. An MMC can have hundreds of submodules (SM). The switches in the SM are controlled individually and the capacitor voltages have to be balanced. Therefore, the control and protection system is sophisticated and has to be validated for different scenarios preferably by hardware-in-the-Loop (HIL) tests. Modeling MMC in detail and simulating it in real time has two main challenges: solving the large circuit containing numerous switches and handling numerous inputs and outputs (IO) in very small time steps. This paper presents a real time test bench, which implements the detailed MMC valve models in field programmable gate array (FPGA) boards and enables connecting to external controllers through high speed protocols used by MMC manufacturers. It can simulate very large systems, e.g. multiple MMC STATCOM and high voltage direct current (HVDC) systems with up to 1000 SM per valve, at multiple sampling rates in real time: the MMC valve is simulated in FPGA with a time step of 250 ns and the rest of the power system is simulated in central processing unit (CPU) cores with a time step of tens of microseconds. The detailed MMC model in the test bench is able to accurately reproduce system behaviors in steady state, transients and faults, which facilitate HIL tests of actual MMC controller for all scenarios in a close-to-reality environment.
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| | Analysis of Hybrid Thirteen Level Cascaded H-Bridge Inverter Operated Under Different PWM Methods
By Dmitry BAIMEL | [View]
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Abstract: The paper presents an extended analysis of a hybrid 13-level inverter operated under different modulation methods and different conditions. The proposed approach can be extended to any desired number of levels. Extensive simulation results of the proposed inverter are presented. The simulations are validated by hardware-in-the-loop experimental results.
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| | Analysis of Output Capacitor Voltage Ripple of the Three-Phase Transformer-Linked Boost Converter
By Wilmar MARTINEZ | [View]
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Abstract: The techniques of interleaving phases and magnetic coupling in power converters are effective downsizing the capacitive components as well as the inductive components in certain configurations. These techniques help tackle the problem of large mass and volume in autonomous electric vehicles as the use of the transformer-linked method in interleaved converters facilitates the miniaturization of the inductor, the output capacitor and the cooling system. Consequently, the analysis of all the characteristics of each component in the converter should be taken into account. This study presents the analysis of the output capacitor voltage ripple in the three-phase interleaved boost converter with coupled inductor (Transformer-linked). In this paper, the operating principle of the three-phase interleaved boost converter with coupled inductor is presented, then the output voltage ripple analysis is conducted for each mode of the operating principle, and finally the voltage ripple analysis is validated by experimental tests of a 1kW prototype.
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| | Analysis of the Power Semiconductor Design Rating for Three-level Neutral-Point-Clamped Inverter based on Datasheet Parameters
By Stephan BRUESKE | [View]
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Abstract: This paper presents a method for the calculation of the power semiconductor rating based on data sheet parameters of the three-level Neutral-Point-Clamped (NPC) inverter. Beside the basic equations for calculating the turn-on and turn-off losses for Insulated Gate Bipolar Transistors (IGBT) and diodes, the electrical inverter topology, the different current paths for the commutations and the critical operation points are shown. The power semiconductor ratingisinvestigatedfordifferentoperationconditionsandshowstheinfluenceofthereverse-recoveryperformance of the commutation diode on the IGBT behaviour. The method works in this way, that 'virtual' (interpolated) power semiconductors are selected in an optimization program to reach in one of possible operation points the maximum junction temperature. The design calculations and analysis are exemplarily carried out for a low power 20kW electrical drive inverter for an electric vehicle and a high power 1MVA wind inverter system. This method can well be applied to accurately compare the design rating of power semiconductor topologies.
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| | Comparison of Basic Power Cells for Quad-Active-Bridge DC-DC Converter in Smart Transformer
By Levy COSTA | [View]
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Abstract: Smart Transformer (ST) is a promising technology, which usually requires a high frequency high voltagedc-dc converter. This paper investigates the application of a Quad-Active-Bridges (QAB) converter usingmultilevel bridges as a solution for the dc-dc stage of Smart Transformer. The focus of this work is tocompare in terms of efficiency 2-level and 3-levels bridges in a QAB converter for ST applications. Theconsidered power cell topologies are: H-bridge, Neutral-Point-Clamped (NPC), Flying-Capacitor (FC)and T-type (TT). The NPC and FC show as main advantage reduced voltage over their semiconductors,which allow the utilization of IGBT and diodes with lower forward drop voltage. Meanwhile, the HBtopology shows as advantage reduced current through its device. Thus, a comparative study is performedin order to find out the most suitable topology for this application. Two scenarios are defined and thecomparison and final results are presented for both scenarios.
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| | Coupling L-CL Filters and Active Damping Method for Interleaved Three-Phase Voltage Source Inverters
By Dongsul SHIN | [View]
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Abstract: The combination of coupled inductors (CIs) and LCL filters can be a filter configuration to achieve highpower density for high current applications. Frequency characteristics (i.e., resonance phenomenon)are changed according to the filter configuration and feedback currents (i.e., inverter-side or grid-sidecurrent) for current control loops. Therefore, stability analysis should be performed to guarantee thestable operation. In this paper, through stability analysis of three possible candidates for coupling L-CL filters, a most promising configuration is suggested, and an active damping method is proposedin consideration of lossless and costless. Finally, for the verification, simulation and experiment areperformed.
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| | Design of Dynamic Voltage Restorer for Voltage Sag and Swell Compensation using High Frequency Isolated Direct AC-AC Converter without Commutation Problem
By Hafiz Furqan AHMED | [View]
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Abstract: In this paper, a dynamic voltage restorer (DVR) is presented based on a novel buck type PWMdirect ac-ac converter topology. The ac-ac converter used in proposed DVR has no commutationproblem because of using switch cell structure and coupled inductors, and therefore, it does not needto sense the input voltage polarity for safe commutation, which saves the cost of input voltage sensor.The proposed DVR also utilizes high-frequency-isolation in the direct ac-ac converter, to avoid theneed of the bulky line frequency (60 Hz) transformer. Although the proposed converter adds twocoupled inductors to solve the commutation problem, however, the size of the transformer and outputinductor can be reduced significantly. All the passive components in proposed DVR also experiencetwice the switching frequency, and the use of external fast recovery diodes allow to further increasethe switching frequency, which can significantly reduce the passive component sizes. Moreover, theac-ac converter used in proposed DVR has both inverting and non-inverting operation and therefore,can compensate both voltage sags and swells. A detailed analysis of the proposed DVR is given,followed by the experimental results.
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| | Dimensioning of a Transformerless Photovoltaic Inverter Circuit for Thin-Film or Back-Side Contacted Solar Modules
By Mario GOMMERINGER | [View]
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Abstract: This paper deals with the dimensioning of a single-phase transformerless photovoltaic inverter circuit. The circuit contains a flying capacitor and allows the connection of one pole of the solar generator to the neutral conductor. The intended purpose of the design guidelines is the minimization of size and costs and the increasing of lifetime. A prototype inverter with silicon carbide MOSFETs is built up. It reaches a very high efficiency of up to 98.8 percent and is used to verify mathematical models.
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| | Effect of Dead-Time in Interleaved PWM for Two Parallel-Connected Inverters
By Ramkrishan MAHESHWARI | [View]
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Abstract: Parallel-connected inverters are used for high power application. Due to the parallel-connection, there exists a circulating current which does not contribute to the ac side current. The analysis presented in the paper shows that the circulating current is affected by the dead-time. The effect of the dead time on the circulating current for the space vector pulse width modulation (PWM) and a discontinuous PWM is analyzed. The dead-time causes a dc value of the circulating current for the discontinuous PWM. A dead-time compensation technique is used for eliminating the dc component of the circulating current. Experimental results are presented to verify that.
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| | Evaluate Solid State Transformer and Low-Frequency Distribution Transformer under the Daily Loading Profile
By TAO YANG | [View]
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Abstract: The effect of several modular approaches to the design, on the efficiency and size of a Solid State transformer (SST) are investigated. The modular approaches are evaluated for the case of 400 kVA, 10 kV/0.4 kV solid state transformers, considering the daily loading profile of the distribution network. The SST is compared to an equally rated low-frequency transformer (LFT) in terms of efficiency, volume and weight. It is shown that advantage can be taken of the modular approach to improve the light load efficiency of the SST, while at peak loading the SST's efficiency is 3\% lower than that of the LFT. By increasing the number of modules and the switching frequency of the DC-DC converter stage, the weight of the SST can be reduced to 50\% and its volume reduced to 33\% that of the LFT.
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| | High Efficiency Buck and Boost Type AC-AC Converters
By ASHRAF ALI KHAN | [View]
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Abstract: In this paper, buck and boost type AC-AC converters are proposed which are derived from the recently developed switching cell (SC) AC-AC converters. The volume of magnetic components of the SC AC-AC converters is large, and they are also associated with circulating current. The proposed AC-AC converters are free of circulating current and have smaller magnetic volume, therefore they can realize high efficiency. In addition, the proposed converters can effectively eliminate the loss due to revere recovery of body diode of MOSFETs, therefore they can make best use of power MOSFETs and fast freewheeling diodes which allow the proposed converters to get higher efficiency by reducing losses. The proposed converters are free of commutation problem, because the dead and overlap time cannot damage its switching devices. Furthermore, the proposed converters are not require to use sensing modules or resistive snubbers for commutation, and therefore they can be adopted with highly distorted input voltage and inductive load. A 250 W prototype of proposed boost type converter is tested to verify the analysis and operation of the proposed converters. It is found from the experimental results that the proposed boost type converter can get 97.7\% efficiency for 50 kHz switching frequency.
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| | Integrated current-energy modeling and control for Modular Multilevel Matrix Converter
By Yun WAN | [View]
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Abstract: This paper presents a layered and structured analytical method to develop the state-space model of a modular multilevel matrix converter (M3C) system. This method firstly divides the modeling task into the current modeling layer and the energy modeling layer and then decomposes each layer to the corresponding terminal and internal dynamics. The terminal currents of an M3C are applied to control the terminal power and the sum branch energy, while the generally-defined circulating currents (CC) inside the M3C are manipulated to realize the internal branch energy balancing (IBEB). A multivariable controller is designed based on the obtained mathematical model and then verified by a hybrid switched M3C model established in Simulink/SimPowerSystems.
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| | Investigation on the commutation process of 20MVA IGCT-Based NPC\_H-bridge inverter
By Pei YANG | [View]
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Abstract: This paper investigates the topology of 20MVA IGCT-based high power NPC/H-bridge inverter. The detailed structure design is presented. The commutation processes of IGCT equivalent circuit and NPC leg are analyzed, which are influenced by the snubber circuit and the characteristic of diode and IGCT. The system simulation model is built in PSIM. The simulation and experimental results validate the correctness of theoretical analysis.
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| | Modular multilevel converter electrical circuit model for HVdc applications
By Abel FERREIRA | [View]
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Abstract: Several MMC models are present in the literature. The suitable converter model used depends on thestudies that must be performed. The work presents a simplified electrical equivalent model for the ModularMultilevel Converter (MMC) which can be used for ac power flow and fault studies.The total energy that is stored in the MMC submodules is modelled as an equivalent capacitor. Also,decouples the converter DC link from the equivalent arm capacitors voltages and allows the MMC arm'senergy balance.The proposed electrical model was tested and compared with the existent literature data equivalent model(DEM) under different operating conditions. The mean percentage deviations between the signals retrievedby both models shows the higher deviation less than 1.1\%. Besides very accurate, the presentedmodel reveals to save around 72\% of computational time leading to a faster model.
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| | Power Loss and Efficiency Analysis of a Four-level p-type Converter
By Bosen JIN | [View]
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Abstract: In this paper, an analytical model has been developed to analyze the device power loss and the efficiency of a new four-level p-type converter. The efficiency of the p-type converter has been evaluated against a conventional two-level converter, three-level T-type converter as well as the three-level NPC converter. It has been found out that the four-level p-type converter has a higher efficiency when switching frequency is above 5 kHz. It can achieve 97\% efficiency at 50 kHz switching frequency under the rated current. An experimental four-level p-type inverter topology has been built and the efficiency has been validated.
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| | Quasi Y-Source Boost DC-DC Converter
By Yam SIWAKOTI | [View]
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Abstract: A new topology called 'quasi-Y-source impedance network' is presented in this paper. It inherits all the advantages of the original Y-source network. In addition, the new topology draws continuous current from the source which is required for many renewable sources. It also has dc-current-blocking capacitors, which avoids saturation in the transformer core. Theoretical analysis and experimental results confirm the superiority of the proposed converter.
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| | Soft-Switched Quasi-Z-Source Inverter Topology for Variable Speed Electric Drives
By Alexandre BATTISTON | [View]
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Abstract: A novel bidirectional soft switched quasi-Z-source inverter is presented in this paper. By using a resonantcapacitor and coupled inductors, the proposed quasi-Z-source inverter topology provides a solution to hard-switching problems for hybrid electric applications. The presented topology allows soft switching operations which aims at reducing the inverter's active devices switching stresses as well as mastering the slew rate dv/dt that have a negative effect over the motor windings. The effectiveness of the proposed topology has been analytically studied and simulated in Matlab/Simulink and the results have been validated by experiment for both motoring and generating modes.
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| | Stability of DC/DC three terminal converter using Modular Multilevel Converters for HVDC systems.
By Miguel JIMENEZ CARRIZOSA | [View]
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Abstract: This paper presents the modelling and control of a DC/DC bidirectional converter with 3 terminals based on Modular Multilevel Converter (MMC) suitable for high voltage and power applications in multi-terminals high voltage direct current (MT-HVDC) grids. A proof is given in order to guarantee the global stability of the system by means of Lyapunov theory and switching control theory. In addition, a study on how to improve the generated harmonics is shown.
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| | State-Space Modeling of Modular Multilevel Converters Including Line Frequency Transformer
By Alexandre CHRISTE | [View]
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Abstract: This paper presents a detailed state-space modeling of a Modular Multilevel Converter (MMC) in combination with line frequency transformer (LFT). The classical MMC topology is compared with the recently proposed Open-End Winding MMC (OEWMMC) topology, which integrates the LFT in the converter arm. The line frequency transformer parameters are added in the model, some of which are often neglected in the available literature. Both models are verified and compared by means of numerical simulations in open-loop. Despite integration attractiveness offered by the OEWMMC topology, there are also some inherent drawbacks affecting the overall system sizing that are discussed in the paper.
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| | The Controlled Transition Bridge
By Colin OATES | [View]
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Abstract: The Controlled Transition Bridge (CTB) is a converter topology that combines series connected semiconductor 'director switches' with chains of switched capacitor modules, 'chainlink circuits', in such a way that the director switches carry the main current for a significant portion of the AC power frequency period and the chainlink elements provide a controlled traverse of voltage between different director switches conducting. The simplest example of this is where the director switches form a six pulse bridge and the chainlink circuits traverse at a constant voltage rate between the upper director switch conducting and the lower director switch conduction etc., so that the output AC waveform is a trapezoid. A modified form of trapezoid waveform has been used to give both AC voltage magnitude control and reduced harmonic level. The paper presents the method of circulating the current through the bridge to give full control over power and reactive power while minimizing the power loss within the chainlink circuits. Aspects of the control of the converter are discussed including the sizing of the submodule capacitors within the chainlink circuits and the method of energy balance. Finally results are presented from a model of a full converter illustrating the different ways in which the current circulates through the converter bridge during the power ramp up
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| | Understanding the Contribution of Switch Input Connection Geometry to Overall DC Link Inductance
By Edward SAWYER | [View]
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Abstract: Minimizing equivalent series inductance (ESL) seen by inverter switches is critical to limit voltage overshoot at turn-off. The DC link capacitor and bus structure are traditionally viewed as dominant contributions to the ESL. Results are presented to demonstrate that the IGBT module connections actually have a significant effect on ESL.
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| | Voltage Balancing Control for Reduced Flying Capacitor Converters using Hybrid Phase-Shifted Carrier Phase-Disposition PWM
By ZIYOU LIM | [View]
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Abstract: This paper proposes a new approach of modular cell converter with reduced flying capacitors (RFCC) using hybrid phase-shifted carrier phase-disposition PWM (PSC-PD-PWM). The proposed topological design is achieved by clamping a series of modular cell onto a low operational frequency cell. By doing so, the transformerless RFCC significantly reduces the component counts, cost and size. The voltage balancing of the flying capacitors are importantly concerned which may affect both reliability and stability of the system. Thus, a closed-loop flying capacitor voltage balancing control is proposed as well. The hardware prototype is also developed to prove the feasibility of the proposed RFCC and the voltage balancing control based on the seven-level (7L) pole voltage waveforms under various dynamic operating conditions.
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| | Voltage control of common flying capacitors in 5-level converter with capacitor current estimation
By Hasegawa ISAMU | [View]
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Abstract: In this paper, a new flying capacitor (FC) voltage control method that is suitable for a 5-level converter with common FCs is proposed. The proposed method can control voltage of FCs using the estimated capacitor current and control FC voltage more steadily compared with previous method. The current is calculated from detected phase current and phase voltage reference. This method can be applied to a FC shared with any number of phases without violating the limitation of the switching pattern. An experiment was conducted to verify the control method using 400V, 6 kW downscaled model.
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