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This paper presents a test bench for lifetime investigation of 10 kV silicon carbide power modules. The test bench subjects high voltage switching operation to the modules while power cycling. Thus both a thermal and electrical operating point is emulated. The power cycling setup features offline measurement of on-state voltages and direct real-time measurement of die surface temperatures, enabled...
Multi-converter systems composed of series or parallel connected modular multilevel converters (MMCs) require a means to manage power sharing between the MMCs by balancing the load during operation. Series connected MMCs require proper voltage balancing while parallel connected MMCs require proper current balancing. The paper describes this imbalance phenomenon, illustrates the solution via simulation...
Current controlled inverters need to be dynamic and robust even under grid disturbances and different grid faults. Besides a robust control method the requirements for synchronization of the system become more and more important especially when multilevel inverter topologies are used. The combination of direct current control methods and advanced grid synchronization techniques promise excellent working...
The Press-pack IGBTs is ideally suited to applications where series operation is required; this quality is of particular interest for HVDC applications where several 100 devices may be required in a single switch. To ensure continued operation between maintenance cycles it is essential that the device fails to a stable short circuit. An experiment has been conducted and is reported in this paper to...
In this article a new method to characterize magnetic components is presented. This method is based on the φ(i) loop measurement for any running conditions. This method is suitable for planar magnetic components and does not need any modification of the component.
Power converters represent one of the highest failure rates in the wind turbine. Therefore converter manufacturers perform burn-in tests to prevent shipping of faulty converters. Recent developments in junction temperature estimation, based on accurate online IGBT collector-emitter voltage measurements, allow for thermal stress estimation of the IGBT modules. This is utilized to detect infant mortalities...
The gate-emitter voltage VGE affects the on-state characteristics of the BIGT in diode forward-conduction mode. While for conventional IGBT with antiparallel free-wheeling diode VGE is at 15 V regardless of current direction, it has to be adapted for the BIGT. The gate-emitter voltage VGE has to be below threshold voltage, in order to operate at low static losses in diode forward-conduction mode....
A floating capacitor H-Bridge converter is proposed to stabilize the automotive energy net against undesired voltage spikes and to limit the voltage range for the electrical loads. In comparison to classical converter topologies the proposed floating H-Bridge converter with integrated energy storage device provides lower switch-voltage stress and allows therefore the implementation of high-current...
In this paper, an FPGA-based on-line switching loss measurement system for an advanced condition monitoring system is presented. For this purpose, an on-line measurement system for the semiconductor voltage and current transients integrated at the gate-driver voltage level is proposed. This system and the switching loss calculations are verified by experimental results.
In this contribution, the switching frequency based active power will be presented as a new power definition. It combines the information of the instantaneous power, as product of voltage and current, and the conventional active power representing the mean value of the instantaneous power over the fundamental period. Under several theoretical conditions the switching frequency based active power is...
This paper presents the control method of an LCL filter implemented for a three-phase, voltage-source, grid-connected inverter for not only offering better attenuation of switching harmonics but also for highly damping the resonance. A discrete-time deadbeat current controller with tuned state-feedback gains is proposed to realize the time optimum responses with high control accuracy. In addition,...
This paper analyzes the influence of the threshold voltage on the parallel connection of three phases of a high power SiC MOSFET module. The current mismatch and the resulting switching loss distribution between paralleled phases will be investigated. Two different gate-drive circuit concepts will be tested. The influence of the choice of the gate-resistor arrangement will be presented regarding the...
The performance versus cost tradeoffs of a fully electric, hybrid energy storage system (HESS), using lithium-ion (LI) and lead-acid (PbA) batteries, are explored in this work for a light electric vehicle (LEV). While LI batteries typically have higher energy density, lower internal resistance and longer lifetime than PbA batteries, the module cost of LI batteries are typically three to five times...
This paper presents an improved Simulated Annealing (SA) based Maximum Power Point Tracking (MPPT) technique designed for photovoltaic (PV) systems under partial shading conditions (PSC). Compared with existing SA MPPT algorithms, the proposed method performs faster convergence speed, higher tracking accuracy and continuously tracking of the global Maximum Power Point (GMPP) under climate changes...
Chaotic detection is presented to deal with the problem that the weak electrical signals of a stator are difficult to measure when a motor is at a low speed. In practice, traditional chaotic method will take a long time, and it is not accurate enough, so cell mapping theory is introduced, and this approach is faster and more accurate compared with the traditional chaotic method.
This paper includes a look into the resonant phenomena of the Multistage Stacked Boost Architecture and a dedicated control method for the MSBA converter to handle these resonances. A linearized fast feed-forward control relying on the feedback of the output current was implemented for the boost stage and the MSBA stages. This was verified by simulations as well as measurements with a low voltage...
An increasing number of sensorless control methods are being developed for a recently rediscovered machine type: synchronous reluctance machines (SynRMs). The advantage of sensorless control methods is that the position sensor can be omitted. Many alternative methods are conceivable, but in all of them, it is impossible to observe and estimate the electrical rotor position at standstill and at low...
A linear-quadratic controller of a single-phase converter with LCL filter is designed. Since the full state is not directly observed, we design several observation models of the system and apply the Kalman filtering theory to obtain observes. In the tested configuration, we obtained good performance of the controller even with one voltage and one current sensor.
Power GaN HEMT components offer very interesting performances (high voltage, high current, low on-resistance, fast switching), but the GaN material has some “defects” that can lead to carrier trapping, which induces dynamic electrical phenomena. Thereby, static measurement of the GaN HEMT components requires some reconsideration. In this work, we analyze how the typical static electrical parameters...
This paper introduces usage of Volt-sec. sensing in back-EMF-based self-sensing (sensorless) induction machine drives. In practice, both inverter nonlinearity and dc bus voltage affect back-EMF estimation accuracy, and therefore self-sensing performance. A real-time Volt-sec. sensing scheme to measure the terminal Volt-sec. vector for each switching period is introduced in the paper. The measured...
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