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The DC-link capacitor in power electronic systems is one of the most vulnerable components in terms of reliability. Since a reliable design of the DC-link capacitor depends on an accurate estimation of its current ripple, this paper proposes analytical equations to model the influence of dead-time on the input current ripple of a three-phase voltage source inverter. The effect of dead-time is modeled as a delay in the rising edges of the input current waveform. The proposed analytical equations are derived and then verified by simulations and experiments. The proposed equations generally provide better accuracy in predicting the input current ripple value compared to the benchmark equations. From the simulation and experimental results, the proposed equations are optimized for dead-time values more than 0.7 μs and modulation indices less than or equal to 0.7. Limitations of the proposed equations are also discussed. For small phase displacements and high modulation indices (0.8 to 1), the accuracy decreases because of the influence of AC output current ripple. For small modulation indices (less than 0.2) and a high value of dead-time (2 μs), the accuracy also decreases due to distortion in the phase current waveforms.

This paper provides analytical equations to model the influence of dead-time and diode's reverse recovery on the input current ripple of a three-phase voltage source inverter. Analytical equations are derived and then verified by simulation and experiments. The influence of dead-time is also modeled heuristically as a linear relationship between the dead-time and the input current ripple values. A comparative analysis shows that the analytical equations proposed here are more accurate in predicting the input current ripple value than the heuristic method.

This paper discusses the analytical expressions for the input current ripple of several six-phase full-bridge inverter topologies and their carrier-based PWM techniques. The analytical expressions are verified by simulation to prove their validity. A comparative analysis is performed to determine the effect of topologies and carrier-based PWM techniques on the input current ripple of the inverters.

This paper proposes a heuristic method to improve power cycling related lifetime in series connectable modular full-bridge inverters by means of load sharing. The load sharing scheme is realized by continuous alternation between two possible series configurations of the circuit at a heuristically-determined changeover frequency. Simulation results in the single-phase circuit are included, and the switches lifetime performance are compared with the reference cases. It is evident from the results that this method yields increased switches lifetime. Alternatively, it allows more current to be applied to the circuit for the same switches average junction temperature.

This paper proposes the fault-tolerant control of a series connectable modular full-bridge inverter in case of an open switch fault. The faulty main switch is detected and identified by comparing the value of the measured phase node output voltage with the PWM signal generated for the respective phase leg. The series switch fault is detected and identified by comparing the measured output voltage of the phase legs connected by the series switch with a reference value. The post-fault control following an open main/series switch fault is realized by modifying several reference values in the healthy control system and is validated for several fault scenarios.

The notion that technology is value-free is becoming a prevalent view amongst the technology practitioners, as depicted in the phrase “guns don’t kill people, people do”. This is inseparable from the definition of technology which has been narrowed down to a mere tools/artifacts and the shortcomings inherent in the existing human-technology interaction model. This paper aims to re-discuss to which extent the value-free argument of technology holds true. Based on the worldview analysis, it is evident that technology is in fact value-laden. A more comprehensive human-technology interaction model is additionally proposed to overcome the shortcomings of the previous models. Having proven that technology is in fact value-laden, this paper then examines how the comprehensive teaching of Islam as a worldview can provide as a basis for the discipline of Islamic technology, i.e. a discipline of knowledge which aims to formulate how the worldview of Islam serves as the foundation for the technological development and (contemporary) technology evaluation. Some topics on the worldview of Islam that are relevant to the inventor and user of technology as well as its implementation on the practical level are addressed to show the wide-ranging scope of the discipline of Islamic technology.

This paper evaluates the losses of multi-phase asymmetrical bridge dc-dc boost converter. Expressions concerning its losses for general n-phase case will be derived and verified by simulation and experimental results. Total and each component losses reduction due to number of phase increase will be plotted and analysed. Optimum number of phase which resulted in most significant losses reduction will also be determined for the sake of design.

A highly integrated electric drivetrain module with 157 kW peak power is presented, which incorporates novel technologies in the field of electric machines, power electronics and transmissions: 1. High-speed electric machine with six phases and injection mould polymer-bonded magnets, 2. High-ratio dual-speed transmission with double planetary gear set (Ravigneaux gear set), 3. Gallium nitride (GaN) power electronics with winding reconfiguration feature.The combination of these components in one single housing makes the drive module flexible to integrate and to combine with conventional or alternative propulsion technologies, thus allowing various hybrid and electric drivetrain topologies. All technologies are selected in accordance with mass production potential and can therefore have a high impact on the automotive market in the future. Currently, the drive module is under development, the first models will be assembled in winter 2019. The integration into a demonstrator vehicle in 2020 will prove the potential of many new technologies and the suitability for the automotive market.

Within the H2020 ModulED project, a highly integrated electric powertrain is developed. One of the main challenges was the development of a performant and simultaneously efficient cooling system. This was due to the compactness of the module and the dense packaging of subsystems such as motor, inverter and transmission. While keeping flow and pressure drop within limits to reduce required auxiliary power, the cooling system must be capable of dissipating the generated heat at maximum powertrain power and under most extreme ambient temperatures. Development experience from prior projects provided an initial layout concept of the coolant routing within the drivetrain module. The concept was further developed and adapted to the available space in the ModulED integrated powertrain. Threedimensional conjugate heat transfer (3D-CHT) simulations were applied to investigate the effect of various influencing parameters on the system's hydraulic and thermal performance. The cooling system's performance was improved considering several limiting factors within the design space. The objectives were reached by hydraulically connecting inverter and motor cooling in series. The option of a parallel connection was also considered and will be assessed in the hardware prototype. At maximum powertrain power, the required coolant flow rate and the resulting pressure drop remain within the predefined limits, increasing overall module efficiency. At lower power levels with lower cooling demand, the flow rate will be adjusted accordingly. This paper covers several aspects of the inverter and motor cooling that were investigated in the project as well as the final performance of the cooling subsystem. A design approach of a highly efficient and performant cooling system for electric vehicle drivetrain modules is presented, which also considers restrictions such as integration space and costs.

This paper compares several carrier-based PWM techniques to see their influence on the common-mode voltage (CMV) and common-mode current (CMC) of a six-phase full-bridge inverters. Fast Fourier Transform (FFT) analysis displays the dominant harmonics spectrum of the CMV and CMC of each carrier-based PWM techniques. The influence of dead-time on the CMV and CMC is also addressed. Simulation and experimental results are included to see which carrier-based PWM techniques induce the most rms value of common-mode current to the six-phase full-bridge inverters.