Showing papers by "Johann W. Kolar published in 2010"

Accurate Power Loss Model Derivation of a High-Current Dual Active Bridge Converter for an Automotive Application

Abstract: An accurate power loss model for a high-efficiency dual active bridge converter, which provides a bidirectional electrical interface between a 12-V battery and a high-voltage (HV) dc bus in a fuel cell car, is derived. The nominal power is 2 kW, the HV dc bus varies between 240 and 450 V, and the battery voltage range is between 11 and 16 V. Consequently, battery currents of up to 200 A occur at nominal power. In automotive applications, high converter efficiency and high power densities are required. Thus, it is necessary to accurately predict the dissipated power for each power component in order to identify and to properly design the heavily loaded parts of the converter. In combination with measured efficiency values, it is shown that conventional converter analysis predicts substantially inaccurate efficiencies for the given converter. This paper describes the main reasons why the conventional method fails and documents the different steps required to predict the power losses more accurately. With the presented converter prototype, an efficiency of more than 92% is achieved at an output power of 2 kW in a wide input/output voltage range.

1 Megawatt, 20 kHz, isolated, bidirectional 12kV to 1.2kV DC-DC converter for renewable energy applications

Abstract: The design of a 1 MW, 20 kHz, isolated, bidirectional 12kV to 1.2kV DC-DC converter for renewable energy applications is presented. The main topics addressed are: High-Voltage (HV) side switch, topology & modulation and Medium Frequency (MF) transformer. A study of the possible HV side switches, considering 4.5kV IGBTs is performed, fixing the requirements from the topology and modulation side in order to reach a highly efficient system. The studied topologies are the Dual Active Bridge (DAB) with triangular modulation and the Series Resonant Converter (SRC) with constant frequency operation. Both topologies are able to achieve Zero Current Switching (ZCS) in the HV side switches, reducing the switching losses in these devices, which contribute to a large share to the system losses. Efficiency curves are presented for different semiconductor technologies for the Low-Voltage (LV) side switch in order to study the trade-offs between the selected topologies. Three MF transformer concepts, namely core-type, shell-type and matrix transformer, are presented and compared in respect of winding arrangement, isolation mechanisms and thermal management. Power losses and volume are calculated in each case and used to compare the different transformer concepts.

Guideline for a Simplified Differential-Mode EMI Filter Design

Abstract: The design of electromagnetic interference (EMI) input filters, needed for switched power converters to fulfill the regulatory standards, is typically associated with high development effort. This paper presents a guideline for a simplified differential-mode (DM) filter design. First, a procedure to estimate the required filter attenuation based on the total input rms current using only a few equations is given. Second, a volume optimization of the needed DM filter based on the previously calculated filter attenuation and volumetric component parameters is introduced. It is shown that a minimal volume can be found for a certain optimal number of filter stages. The considerations are exemplified for two single-phase power factor correction converters operated in continuous and discontinuous conduction modes, respectively. Finally, EMI measurements done with a 300-W power converter prototype prove the proposed filter design method.

New physical model for lifetime estimation of power modules

Abstract: In this paper a physical model for lifetime estimation of standard power modules is proposed. The lifetime prediction is based on the assumption that the solder interconnections are the weakest part of the module assembly and that the failure cause is the inelastic deformation energy accumulated within the solder material. Unlike the well-known Coffin-Manson model, the proposed model can be used to physically explain the dependency of lifetime on the various properties of a temperature profile i.e. frequency, dwell-ramp time, minimum/maximum temperature. The model is based on Clech's algorithm for simulation of stress-strain solder response under cyclical thermal loading and on the solder deformation mechanism map used to define the dominant failure mechanism under observed stress-temperature conditions. Either accelerated cycling tests or existing field databases are needed to parameterize the model. To verify the approach, the results of power cycling tests for a high power IGBT module found in literature are applied and the impacts of two mission profiles on the module lifetime are examined.

Comparison of the chip area usage of 2-level and 3-level voltage source converter topologies

Abstract: In the low voltage converter range, 3-phase 3-level VSC topologies are not wide spread in industry because of the increased part count and higher costs, although they are more efficient for higher switching frequencies. In this paper an alternative 3-level topology referred to as T-type is presented, which is very high efficient for medium switching frequencies (4–20 kHz). Additionally, it is shown that the total silicon chip area of a 3-level topology can be lower than in a 2-level topology since the losses are distributed over more components leading to only a small increase in the junction temperature. This allows for the design of a chip area and cost optimized 3-level bridge leg module for the mass market.

Core losses under DC bias condition based on Steinmetz parameters

Abstract: When designing inductive components, calculating core losses is a difficult and not yet entirely solved problem. In particular it is impossible to predict the influence of a DC premagnetization on the losses without performing extensive measurements. For this work, different materials have been tested to gain information how core losses are influenced by a premagnetization. Measurements on molypermalloy powder, silicon steel, nanocrystalline material, and ferrite cores have been performed. Of the tested materials, a premagnetization mainly influences losses in ferrites and nanocrystalline materials, whereas the influence of a premagnetization in molypermalloy powder cores, and cores of silicon steel is negligible. The Steinmetz Premag-netization Graph (SPG) that shows the dependency of the Steinmetz parameters (α, β and k) on premagnetization is introduced. This permits the calculation of core losses under DC bias conditions. Such graphs are given for different materials and different operating temperatures. In addition, a detailed description of the test system is given, as high accuracy is crucial.

Optimized design of medium frequency transformers with high isolation requirements

Abstract: For future DC electric power systems, high-power DC-DC converters will play a major role as they will substitute today's bulky 50/60Hz transformers. One key component within this DC-DC converters is the medium frequency transformer that provides the isolation level and the step up/down of the different voltage levels. As a consequence, an optimized design methodology that considers this high isolation requirements is needed. This paper presents a step-by-step design for medium frequency transformers with high isolation requirements. Each step in the design is carefully discussed and the required design considerations, such as flux density limits, isolation and thermal management, are explained in detail. The proposed design procedure is applied to a core-type transformer analyzing the outcome of the optimization process.

Interleaved Triangular Current Mode (TCM) resonant transition, single phase PFC rectifier with high efficiency and high power density

Abstract: This paper presents a new topology for a highly compact and highly efficient single-phase Power Factor Corrected (PFC) rectifier system. The new topology consists of several interleaved boost stages which operate in a mode called Triangular Current Mode (TCM) in order to simultaneously achieve a high power density as well as a high efficiency. Applying TCM, ZVS is achieved over the full mains period by proper control of the power MOSFETs. The high TCM inductor current ripple is not transferred to the mains as the superposition of all boost cell input currents results in a smooth mains current waveform. Furthermore, one bridge leg operates synchronously to the mains frequency and connects the mains directly to an output rail. This results in very low common mode noise and only a small common mode filter has to be considered. The excellent behavior of this topology also applies to inverter operation.

Full-order averaging modelling of zero-voltage-switching phase-shift bidirectional DC-DC converters

Abstract: Full-order small-signal modelling and dynamic analysis of zero-voltage-switching (ZVS) phase-shift bidirectional DC-DC converters is studied. A general modelling method is proposed to develop the discrete-time average model. This full-order model takes into account the leakage inductance current and the resonant transition intervals in order to realise ZVS. Both the leakage inductance current and the resonant transition intervals are the key to accurately predict the dynamic behaviour of the converter. A control-to-output-voltage transfer function is derived for the dual active bridge DC-DC converter, which is taken as an example to illustrate the modelling procedure. Experimental results confirm that the new model correctly predicts the small-signal frequency response up to one-third of the switching frequency and is more accurate than the previously presented models.

Performance trends and limitations of power electronic systems

Abstract: In 2003 the Roadmapping Initiative of the European Center of Power Electronics (ECPE) has been started based on a future vision of society in 2020 in order to define the future role of power electronics, and to identify technological barriers and prepare new technologies well in time. In the framework of this initiative a new mathematically supported approach for the roadmapping in power electronics has been developed. As described in this paper the procedure relies on a comprehensive mathematical modeling and subsequent multi-objective optimization of a converter system. The relationship between the technological base and the performance of the system then exists as a mathematical representation, whose optimization assures the best possible exploitation of the available degrees of freedom and technologies. Thus an objective Technology Node of a system is obtained, whereby physical limits are implicitly taken into account. Furthermore, the sensitivity of the system performance with regard to the technological base can be calculated directly and the internal interdependence of Performance Indices directly studied. Accordingly, the improvement in performance achievable by improvements in the technology base can be tested and assessed in advance. Moreover, different system concepts, i.e. circuit topologies, control procedures, etc. can be evaluated and directly compared with regard to achievable efficiency, power density and costs in the form of the associated Pareto Front which defines the boundary of the Feasible Performance Space. If the target performance lies outside the Pareto Envelope of known system concepts and state-of-the-art technologies, a new technology must be employed. The necessity of a technological leap, i.e. the introduction of a Disruptive Technology can thus be recognized at an early stage. This offers an excellent basis for effective roadmapping for various main application areas in power electronics.

Calorimetric Power Loss Measurement for Highly Efficient Converters

Abstract: The electrical determination of power losses by measuring the input and output power can reach sufficient accuracy for DC-DC converter systems, if well calibrated voltage meters and shunt resistors are applied. However, it is difficult to determine the power in AC-systems, especially with harmonics, due to phase-errors in the electric measurement. In addition, the electromagnetic interference (EMI) of switched-mode power supplies can disturb the electric power measurement. In this paper, the calorimetric determination of power converter system losses resulting in a high accuracy and which is almost immune against EMI phase errors, is described. The closed-type calorimeter is realized with a double-jacketed chamber which enables the power loss measurement between 10W and 200W for power converter systems of several kW. The resulting deviation of the implemented measurement system is less than ±0.4W, or ±0.05% at full load conditions (several kW), respectively, over the entire measurement range.

Implementation of a Transformerless Common-Mode Active Filter for Offline Converter Systems

Abstract: This paper presents a study and practical implementation of an active filter employing a high-frequency (HF) power amplifier and passive-filter components to be connected to the ac power lines in order to mitigate common-mode conducted emissions of three-phase pulsewidth modulation converter systems. The filter topology is chosen from different possibilities listed in a literature survey and studied regarding practical implementation issues, where requirements for an HF power amplifier to be applied in active filtering are derived. Special attention is put on the stability analysis where the challenges for the feedback are discussed, and a simple feedback structure is proposed. Other feedback concepts are analyzed, and limitations posed by stability requirements are presented. A prototype is designed and built, from which mathematical and experimental results are obtained demonstrating the potential and limitations of such a system.

Optimal design of a 5kW/dm 3 / 98.3% efficient TCM resonant transition single-phase PFC rectifier

Abstract: In many applications single-phase PFC rectifiers should meet the demand for a high efficiency and a high power density at the same time. Depending on the weighting of these two design criteria, different topologies could be advantageous. As has been shown, with bridgeless PFC rectifiers an ultra high efficiency of 99.3% or a high power density of 5.6kW/dm3 could be realised. However, due to the hard switching operation it is not possible to achieve an exceptional efficiency and power density at the same time. Furthermore, SiC Schottky diodes are required for highly compact or highly efficient systems. Therefore, a triangular current mode (TCM), resonant-transition single phase PFC rectifier concept is presented in this paper, which overcomes both limitations. Besides a design procedure for optimising the chip area, also a simple and robust control concept, where a novel zero crossing detection concept is included, is explained and a prototype system as well as measurement results are presented for validating the concept and the design procedure.

Design of an 99%-efficient, 5kW, phase-shift PWM DC-DC converter for telecom applications

Abstract: In the last decade power electronic research focused on the power density maximization mainly to reduce initial systems costs [1]. In the field of data centers and telecom applications, the costs for powering and cooling exceed the purchasing cost in less than 2 years [2]. That causes the changing driving forces in the development of new power supplies to efficiency, while the power density should stay on a high level. The commonly used DC-DC converter in the power supply unit (PSU) for data centers and telecom applications are full bridge phase-shift converters since they meet the demands of high power and efficient power conversion, a compact design and the constant operation frequency allows a simple control and EMI design. The development of the converter with respect to high efficiency has a lot of degrees of freedom. An optimization procedure based on comprehensive analytical models leads to the optimal parameters (e.g. switching frequency, switching devices in parallel and transformer design) for the most efficient design. In this paper a 5kW, 400V–48⋖56V phase-shift PWM converter with LC-output filter is designed for highest efficiency (η ≥99%) with a volume limitation and the consideration of the part-load efficiency. The components dependency as well as the optimal design will be explained. The realized prototype design reaches a calculated efficiency of η = 99.2% under full load condition and a power density of ρ = 36W/in3 (2.2 kW/liter).

Comprehensive comparison of three-phase AC-AC Matrix Converter and Voltage DC-Link Back-to-Back Converter systems

Abstract: This paper provides a comprehensive comparison of a Direct Matrix Converter, an Indirect Matrix Converter, and a Voltage DC-Link Back-to-Back Converter for a 15 kW permanent magnet synchronous motor drive. The comparison involves the investigation of the passive components including the EMI input filter, the required silicon chip area for a defined maximum admissible thermal loading of the power semiconductors, the total losses and achievable efficiency, and a prediction of the resulting volume of the passive components. With this comparative evaluation a systematic procedure is presented that ultimately allows for determining the application area of the considered converter topologies.

Comparison and implementation of a 3-level NPC voltage link back-to-back converter with SiC and Si diodes

Abstract: This paper presents a high efficiency 10 kVA high-frequency input and output Si IGBT and SiC Schottky diode 3-level neutral point clamped voltage dc-link back-to-back converter (3LNPC-VLBBC). A switching frequency of 48 kHz makes the converter suitable for driving high-speed and low-inductive machines. A detailed loss analysis reveals that only four of the six diodes in a 3-level bridge-leg have to be replaced by SiC diodes to enable high efficiency operation if an appropriate modulation scheme is used. A comparison with an All-Si 3-level converter shows a reduction of the semiconductor losses by 10% at the nominal operating point. In addition, a semiconductor chip area based comparison is presented, showing the chip area partitioning of the individual semiconductor types and the corresponding costs for different implementations. The payback time for the additional costs resulting from replacing the Si diodes in the 3-level converter by SiC diodes due to energy savings is estimated. Finally, experimental results of the prototype are provided.

An optimized, 99% efficient, 5 kW, phase-shift PWM DC-DC converter for data centers and telecom applications

Abstract: The development of new power supply systems is increasingly focused on higher efficiency, while the power density should remain on a high level. This is especially true for data center and telecom application Power Supply Units (PSU). The commonly-used DC-DC converter in telecom and data center PSU's are full-bridge phase-shift PWM converter, which enables a high power and highly efficient conversion, compact design and simple control due to constant switching frequency. The component dimensioning of the converter system has many degrees of freedom, as the design parameters are interdependent from each other to some extend. An automatic optimization procedure based on comprehensive analytical models leads to the optimal design parameters, such as switching frequency and geometry of the magnetic components. In this paper, the development, optimization and design process for an efficiency-optimized 5kW, 400 V to 48..54 V phase-shift PWM DC-DC converter with LC-output filter and synchronous rectification is presented. The proposed optimization algorithm, which considers the part-load-efficiency as well, results directly in the component values for the realized prototype. The design of the converter is explained in detail and measurement results are presented and discussed.

Magnetically Levitated Homopolar Hollow-Shaft Motor

Abstract: This paper describes a novel and compact topology for contactless levitation and rotation of a wide annular rotor through the walls of a sealed process chamber. In the proposed setup, a homopolar magnetic bearing biased by permanent magnets is combined with a high-pole-number segment motor. The paper discusses the functional principle of the motor, and gives design and optimization guidelines for the bearing and the drive unit, respectively. An experimental system is presented along with a set of measurement results verifying the theoretical considerations.

A Miniature 500 000-r/min Electrically Driven Turbocompressor

Abstract: The trend in compressors for fuel cells, heat pumps, aerospace, and automotive heating, ventilation, and air-conditioning systems is toward ultracompact size and high efficiency. This can be achieved by using turbocompressors instead of scroll, lobe, or screw compressors, increasing the rotational speed and employing new electrical drive system technology and materials. This paper presents a miniature electrically driven two-stage turbocompressor system running at a rated speed of 500 000 r/min. The design includes the thermodynamic analysis, the electric motor, the inverter, the control, and the system integration with rotor dynamics and thermal considerations. Experimental measurements such as the compressor map are presented for air under laboratory conditions. The two-stage turbocompressor has been tested up to a speed of 600 000 r/min, where a maximal pressure ratio of 2.3 at a mass flow of 0.5 g/s has been reached. To the authors' knowledge, this is the highest rotational speed achieved with an electrically driven turbocompressor.

Optimal design of a compact 99.3% efficient single-phase PFC rectifier

Abstract: Due to rising energy costs the efficiency of power electronics converter systems is of higher and higher importance, especially for applications with continuous operation as e.g. server power supplies. For designing such supplies numerous parameters like the switching frequency and the characteristic values and the geometry of magnetic components must be determined. In this paper, an optimisation procedure, which automatically determines the parameter values of a single-phase bridgeless PFC rectifier for maximum efficiency is presented. There, continuous and discontinuous operation mode, as well as a concept for magnetic integration of the CM and DM filter inductors is included. For verifying the considerations, a prototype with 99.3% efficiency and a power density of 1.35kW/dm3 is presented.

Controllable dυ/dt behaviour of the SiC MOSFET/JFET cascode an alternative hard commutated switch for telecom applications

Abstract: Switching devices based on SiC offer outstanding performance with respect to operating frequency, junction temperature and conduction losses and enable a significant improvement of the system performance. There, the cascode consisting of a MOSFET and a JFET additionally has the advantage of being a normally off device and offering a simple control via the gate of the MOSFET. Without dv/dt control, however, the transients with hard commutation reach values of up to 45kV/µs, which could lead to EMC problems and especially in drive systems to problems related to earth currents (bearing currents) due to parasitic capacitances. Therefore, new dυ/dt control methods for the SiC MOSFET/JFET cascode as well as measurement results are presented in this paper. Based on this new concepts the outstanding performance of the SiC devices can be fully utilised without impairing EMC.

EMI Noise Prediction for Electronic Ballasts

Abstract: The design of electromagnetic (EM) interference filters for converter systems is usually based on measurements with a prototype during the final stages of the design process Predicting the conducted EM noise spectrum of a converter by simulation in an early stage has the potential to save time/cost and to investigate different noise reduction methods, which could, for example, influence the layout or the design of the control integrated circuit Therefore, the main sources of conducted differential-mode (DM) and common-mode (CM) noise of electronic ballasts for fluorescent lamps are identified in this paper For each source, the noise spectrum is calculated and a noise propagation model is presented The influence of the line impedance stabilizing network (LISN) and the test receiver is also included Based on the presented models, noise spectrums are calculated and validated by measurements

DC-DC converter for gate power supplies with an optimal air transformer

Abstract: Voltages in medium voltage (MV) systems as for example in MV drives, wind generation and smart grids are in the range of several kV. Hence, switches of medium power systems need gate drive power supplies which consider a galvanic isolation for safety reasons. In this paper a gate supply with a capacitive compensated air transformer for medium voltage systems is presented. This approach not only has the advantage of being capable in isolating almost arbitrarily high voltages but also is a compact, lightweight and cheap solution. The air transformer windings are realized as tracks on a circuit board (PCB). Furthermore, the air transformer has been optimized with respect to efficiency of the gate supply, which results in an optimal value of 85%. The optimization is accomplished by field simulation of the transformer and a circuit calculation to obtain the total losses. The simulation and optimization results are confirmed by a laboratory setup which is designed for an output voltage of 25V at 100 W.

Comparative evaluation of soft-switching concepts for bi-directional buck+boost dc-dc converters

Abstract: Soft-switching techniques are an enabling technology to further reduce the losses and the volume of automotive dc-dc converters, utilized to interconnect the high voltage battery or ultra-capacitor to the dc-link of a Hybrid Electrical Vehicle (HEV) or a Fuel Cell Vehicle (FCV). However, as the performance indices of a power electronics converter, such as efficiency and power density, are competing and moreover dependent on the underlying specifications and technology node, a comparison of different converter topologies naturally demands detailed analytical models. Therefore, to investigate the performance of the ARCP, CF-ZVS-M, SAZZ and ZCT-QZVT soft-switching converters, the paper discusses in detail the advantages and drawbacks of each concept, and the impact of the utilized semiconductor technology and silicon area on the converter efficiency. The proposed analytical models that correlate semiconductor, capacitor and inductor losses with the component volume furthermore allow for a comparison of power density and to find the η-ρ-Pareto-Front of the CF-ZVS-M converter.

SiC vs. Si - Evaluation of Potentials for Performance Improvement of Power Electronics Converter Systems by SiC Power Semiconductors

Abstract: Switching devices based on wide band gap materials as SiC o er a signi cant perfor- mance improvement on the switch level compared to Si devices. A well known example are SiC diodes employed e.g. in PFC converters. In this paper, the impact on the system level perfor- mance, i.e. eciency/power density, of a PFC and of a DC-DC converter resulting with the new SiC devices is evaluated based on analytical optimisation procedures and prototype systems. There, normally-on JFETs by SiCED and normally-off JFETs by SemiSouth are considered.

Shifting input filter resonances - An intelligent converter behavior for maintaining system stability

Abstract: Instead of just transforming energy, a modern power converter should incorporate enhanced features to adapt its behavior to its environment. Stability issues in 3-phase power systems with PFC rectifiers incorporating input filters have been a problem for a long time. In this paper a new concept is presented as to how the power converter can shift filter resonances into an unproblematic frequency range by simulating an additional inductivity or capacity. The concept is proved with an extensive stability analysis in the synchronous dq-reference frame. Simulations in the time domain demonstrate the positive impact of the proposed method.

Towards virtual prototyping and comprehensive multi-objective optimisation in power electronics

Abstract: The constant demand for higher efficiency and power density and lower costs of power electronics systems could be met by application of new topologies and/or modulation schemes and future wide-band gap semiconductor technology. However, the performance of state-of-the-art systems also could be improved significantly by multidomain/objective optimisation, i.e. by assigning overall optimal values to the design variables in the course of the design process. In order to perform such an optimisation first a comprehensive mathematical model of the main converter circuit has to be established, including thermal component models and the measures for DM and CM EMI filtering. Based on this model, an optimisation for multiple objectives, as e.g. efficiency and power density, can be performed. The optimisation makes best use of all degrees of freedom of a design and also allows to determine the sensitivity of the system performance on base technologies like Figures of Merit of the power semiconductors or properties of the magnetic core materials. Furthermore, different topologies can be easily compared and inherent performance limits can be identified. In the paper, analytical approaches for designing the main functional elements of a power electronics converter are described and arranged to a linear design process in a first step. Moreover, the linking of the component models, i.e. of the electric, magnetic, thermal and thermo-mechanic design domains and an overall optimisation of the respective design variables based on the linked models is discussed. Finally, the coupling of the different domains and for example the utilisation of electrical equivalent circuits for implementing these couplings are investigated.

Design procedure for compact pulse transformers with rectangular pulse shape and fast rise times

Abstract: Pulse modulators based on solid state technology and for pulses in the μs-range often utilize a pulse transformer, since it could offer an inherent current balancing for parallel connected power semiconductors and the turns ratio of the pulse transformer allows to adapt the modulator design to the available switch technology. The applications like radar systems, linear accelerators or klystron/magnetron modulators usually require a nearly rectangular pulse shape with a fast rise time and a as small as possible overshoot. In reality however, parasitic elements of the pulse transformer as leakage inductance and capacitances limit the achievable rise time and define the resulting overshoot. Therefore, in modulators based on pulse transformers, the design of the pulse transformer is crucial. In this paper, a step by step design procedure of a pulse transformer for rectangular pulse shape with fast rise time is presented. Different transformer topologies are compared with respect of the parasitic elements, which are then calculated analytically depending on the mechanical dimensions of the transformer. Additionally, the influence of the limited switching speed of semiconductors and the nonlinear impedance characteristic of a klystron is analyzed.

Novel AC coupled gate driver for ultra fast switching of normally-off SiC JFETs

Abstract: Over the last years, more and more SiC power semiconductor switches became available in low production volumes in order to prove their superior behavior with respect to fast switching speed, low on-resistance per chip area, high voltage range and high temperature operation. A very promising device among those introduced in numerous publications over the last years is the 1200 V 30 A JFET introduced by SemiSouth. It features a very low on-resistance (2.8m Ω cm2), switching operation within 20 ns, a normally-off characteristic and has already been commercialized in contrast to many other SiC switches. To fully exploit the potential of the SiC normally-off JFET, conventional gate drivers for unipolar devices must be adapted to this device due to its special requirements: During on-state the gate voltage must not exceed 3 V, while a current of around 300 mA must be fed into the gate, during switching operation the transient gate voltage should be around ±15 V and the low threshold voltage of 0.7 V requires a high noise immunity which is a severe challenge as the device has a comparably low gate-source but high gate-drain capacitance. To meet these requirements, several concepts have been published recently. They deal with the challenges mentioned, but they also note certain limitations (e. g. frequency and duty cycle limitations or need for additional cooling). In this paper, a novel gate driver consisting only of one standard gate driver IC, resistors, capacitors and diodes is designed and experimentally validated. It supplies enough gate current for minimum on-resistance, allows fast switching operation, features a high noise immunity and can be used for any duty cycle and usual switching frequencies without significant self-heating.

Advanced setup for thermal cycling of power modules following definable junction temperature profiles

Abstract: In this paper a setup for performing power cycling tests of IGBT modules for the purpose of reliability analysis is presented. The main purpose of the setup is to provide experimental data for the parameterization and verification of a newly developed physical model of solder deformation leading to the failure of power electronic devices. The design procedure, including considerations of reliability, measurement, and cooling, for a 5 kW flexible power cycling system is presented. Experimental results of a sub-1 kW prototype setup are shown, demonstrating the ability of the system to force the junction temperature of the device under test to follow an arbitrary temperature profile.