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An investigation of the voltage imbalance of the two capacitors of the semi-full-bridge submodule is performed. Since the capacitances are not exactly the same, there may be a difference between the capacitor voltages. The resulting current-spike when they are connected in parallel has been analyzed in a full-scale laboratory experiment.
Recently introduced Bi-directional Z-Source breakers [1] are capable of clearing the short circuit fault within a few microseconds. In this paper, various applications and protection requirements for Bidirectional Z-Source breakers are discussed. Detailed comparison between de-rated AC breakers and Z-Source breakers is discussed. Breaker design criteria are explained with the help of simulation results...
This paper extensively analyzes the operation limits, system stability and disturbance rejection capability of the voltage control loops used in master-slave AC and DC Microgrids (MGs). Two different control schemes are studied analytically, simulated and experimentally tested, focusing on Constant Power Loads (CPL). Additionally, the use of the virtual capacitance (VC) as a tool for response enhancement...
A new single-stage three-phase resonant ac-dc matrix-based converter is proposed. It uses a new modulation scheme designed for use with a tuned LCL resonant network that achieves unity power factor at both network ports, which leads to reduction in rms bridge currents and conduction loss. The line-frequency phase currents are controllable by modulating the ac-side and dc-side switches according to...
This paper presents the evaluation of a 650 V GaN transistor which is used for a motor drive application. The influence of parasitic effects, e.g. cross conduction and stray inductances, in a GaN phase-leg configuration are analyzed by means of simulation. Additionally, experimental results of the switching transients are shown. Furthermore, measurement issues and other practical challenges are discussed.
An electric motor is more effective and flexible when supplied by a frequency converter. The frequency converter not only produces the fundamental voltage but also a set of higher harmonics which cause additional losses in the motor. Losses in the frequency converter are normally neglected in the drive dimensioning due to insufficient data available from manufacturers. Motor's losses can be reduced...
Recent development renewable energy increases the requirement in constructing multi-terminal HVDC systems or HVDC grids. To increase the system reliability, an HVDC circuit breaker will be required. However the existing HVDC breakers developed in recent years use large amount of IGBTs. Considering the cost reduction in real HVDC grids, this paper presents a novel hybrid HVDC circuit breaker. The proposed...
Development and technology maturation of Silicon Carbide (SiC) power transistors over the last 15 years has motivated its study in aerospace systems. When compared with Si devices, superior voltage blocking capacity and the capability of operation at higher temperatures, give important advantages in space power electronics applications, similar to what happens in terrestrial electronics. This paper...
The transient performance of a DC power supply strongly depends on the loop design and output filter sizing. Most of the time, the finite loop bandwidth imposes the need of a large output filter capacitor in order to comply with the required regulation performance and stability margins. In space applications the linear conductance control principle has been used for a long time. It reduces the voltage...
The application of Gallium Nitride (GaN) power transistors in a single phase inverter for photovoltaic (PV) systems is presented inverter. The power of the system is 2 kW. For both stages (DC boost stage and inverter stage), a very high switching frequency of 250 kHz is used. By this, a highly compact design for the inverter (200 × 150 × 80 mm3 / 2.4 l) was reached. The power to weight ratio corresponds...
Dielectric Barrier Discharge (DBD) reactors are widely used for industrial ozone generation. Paper presents impact of voltage shape of different power supply topologies for DBD on ozone efficiency production. Results of five voltage shapes of three different power supply topologies were presented and discussed. Investigation shows that selection of voltage shape and as a result power supply topology...
Input-series-output-series (ISOS) inverter system is very suitable for high input voltage and high output voltage power conversion applications. If the inverter system topology is applied to the grid-connected application, a large-capacity inverter system can be built with multiple small-capacity standardized inverter modules, which will improve system reliability and simplify system design. For the...
Packages of commercial Gallium-Nitride power semiconductors present increasingly small dimensions to enable low parasitic inductance, increasing the heat flux density of the package and the challenges associated with their thermal management. This paper compares between Printed Circuit Boards and Direct Copper Bonded as substrates for a Gallium Nitride based half-bridge from a thermal and reliability...
This paper is focused on the analysis of voltage source inverter (VSI) loss model for automotive applications. The converter is generally integrated in a thermally challenging environment and requires therefore a reliable, modular and accurate model for their evaluation. This work analyses first the current methods for the evaluation and the calculation of the losses and then present different solutions...
The Self Turn-ON influences the turn-ON and short-circuit behaviour of the IGBT. This is a positive feedback by the IGBT on itself and increases its turn-ON speed. The strength of the effect depends on the gate structure's design. Therefore, IGBTs with different gate structures are investigated with TCAD simulations. Additionally, its influence during Fault under Load is investigated.
This paper is focused on the analysis of the geometrical deviation of a variable reluctance (VR) resolver and its impact to the inverter losses for automotive applications. Therefore a VR resolver model is introduced, verified with measurements at a sensor test bench and the additional inverter losses are investigated.
A control algorithm for an integrated power factor correction (PFC) and series resonant converter (SRC) using only two switches is presented, allowing to open loop control the AC input current and the DC output current independently. The theory for this approach is analyzed in time domain and a novel approach for open loop regulation is presented and verified. The software defined power (SDF) control...
In this paper a control scheme for a PMSM drive that keeps the torque ripple within predefined limits is presented. The electromagnetic torque is assumed to be proportional to i1q, which is measured by using Sigma-Delta Analog to Digital Converters (ΣΔ-ADCs) with a very high sampling rate, so the actual ripple of the torque can be obtained and controlled in an enhanced way. The measurement results...
This paper presents the critical design aspects addressed during the development of a 100 kW, 12.5 kV, 22 kHz, and 30 kV insulated medium frequency transformer used in a power converter. The transformers are used in a resonant multilevel converter topology producing HV DC voltage from a three phase 400 V AC industrial grid. The power converter is used to supply radio frequency systems in particle...
This paper deals with a synchronous demodulation scheme to be used to obtain the speed and position from resolver position sensor. Proposed algorithm is intended to be implemented on a FPGA to provide the elaborated information for very low latency control loops. Moreover, resolver excitation circuit has been simplified working directly with a square wave signal. Resolver frequency behavior has been...
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