Publicaties
Direct Torque Controlled Space Vector Modulated Induction Motor Fed by a Z-source Inverter for Electric Vehicles Vrije Universiteit Brussel
This paper proposes a new closed loop speed control of an induction motor fed by a high performance Z-source inverter (ZSI), the speed control is based on direct torque control space vector modulation (DTC-SVM) control strategy. The modified space vector modulation (MSVM) is used to insert the shoot-through state within the switching signals for the ZSI. A dual loop controller is designed to control the peak dc link voltage of the ZSI, where the ...
Evidence of oxygen-dependent modulation in $LuFe_{2}O_{4}$ Universiteit Antwerpen
A polycrystalline sample of LuFe2O4 has been investigated by means of powder synchrotron x-ray and neutron diffraction and transmission electron microscopy (TEM), along with Mössbauer spectroscopy and transport and magnetic properties. A monoclinic distortion is unambiguously evidenced, and the crystal structure is refined in the monoclinic C2/m space group [aM = 5.9563(1) Å, bM = 3.4372(1) Å, cM = 8.6431(1) Å, β = 103.24(1)°]. Along with the ...
$LiZnNb_{4}O_{11.5}$ Universiteit Antwerpen
A novel lithium zinc niobium oxide LiZnNb(4)O(11.5) (LZNO) has been found in the Nb-rich part of Li(2)O-ZnO-Nb(2)O(5) system. LZNO, with an original alpha-PbO(2) related structure, has been synthesized by the routine ceramic technique and characterized by X-ray diffraction and transmission electron microscopy (TEM). Reflections belonging to the LZNO phase, observed in X-ray powder diffraction (XRPD) and electron diffraction, have been indexed as ...
K₅Eu(MoO₄)₄ red phosphor for solid state lighting applications, prepared by different techniques Universiteit Antwerpen
The influence of preparation techniques on the structure and luminescent properties of K5Eu(MoO4)(4) (KEMO) was investigated. KEMO phosphors were synthesized by three different techniques: solid state and sol-gel (sg) methods as well as the Czochralski (CZ) crystal growth technique. Laboratory powder X-ray diffraction (PXRD) studies revealed that all KEMO samples had a structure analogous to that of other high temperature alpha-K5R(MoO4)(4) ...
Experimental Study of the Shoot-Through Boost Control Methods for the Z-Source Inverter Vrije Universiteit Brussel
This paper presents a simulation and experimental comparative analysis of the Z-source inverter (ZSI) with four different shoot-through (ST) control methods, namely: the simple boost control, the maximum boost control, the maximum constant boost control and the modified space vector modulation boost control methods. A review of these methods is presented with a summary of all expressions. A prototype of a 30 kW ZSI is designed and implemented. ...
Competing magnetic structures and the evolution of copper ion/vacancy ordering with composition in the manganite oxide chalcogenides $Sr_{2}MnO_{2}Cu_{1.5}(S_{1-x}Se_{x})_{2}$ Universiteit Antwerpen
The series Sr2MnO2Cu1.5(S1-xSex)(2) (0 <= x <= 1) contains mixed-valent Mn ions (Mn2+/Mn3+) in MnO2 sheets which are separated by copper-deficient antifluorite-type Cu(2-delta)Ch(2) layers with delta similar to 0.5. The compounds crystallize in the structure type first described for Sr2Mn3Sb2O2 and are described in the I4/mmm space group at ambient temperatures. Below about 250 K, ordering between Cu+ ions and tetrahedral vacancies occurs ...
Improving performance of three-phase slim DC-link drives utilizing virtual positive impedance-based active damping control Vrije Universiteit Brussel
In this paper, a virtual positive impedance (VPI) based active damping control for a slim DC-link motor drive with 24 section space vector pulse width modulation (SVPWM) is proposed. Utilizing the proposed control and modulation strategy can improve the input of current total harmonic distortion (THD) while maintaining the cogging torque of the motor. The proposed system is expected to reduce the front-end current THD according to ...
A layered iron-rich 2234-type with a mixed valence of iron: the ferrimagnetic Tl-doped $Fe_{2}(Sr_{2-\varepsilon}Tl_{\varepsilon})Sr_{3}Fe_{4}O_{14.65}$ Universiteit Antwerpen
A new Tl-doped strontium ferrite Fe2(Sr2-Tl)Sr3Fe4O14.65, with an original structure, has been synthesized and structurally characterized by powder X-ray diffraction and transmission electron microscopy. The TGA and Mssbauer studies evidence a mixed valence of iron. The structure exhibits a commensurate modulation, with a F-type subcell a ≈ b ≈ 5.4 Å (≈ ap√2), c ≈ 42 Å with a modulation vector q = αa* with α = 0.4. The supercell parameters have ...
Smart grid integration of micro hybrid power system using 6-switched 3-level inverter Vrije Universiteit Brussel
A hybrid power system modeled in Matlab/Simulink environment is presented in this study. This model includes a hybrid system consisting of wind and solar panels and it is connected to the smart grid through a 6-switched 3-level inverter. A 6-switched 3-level inverter is preferred in this study as an inverter due to its success in minimizing the harmonics. The signals required for the operation of the semiconductor switches within the inverter ...