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1.
Control of an inductive power transfer system using a double coil structure
Nataša Prosen, Mitja Truntič, Jure Domajnko, 2022, original scientific article

Abstract: This paper presents the design of the control of the system using a double DD coil structure. The double DD coil is a layered coil structure that consists of two single DD coils, rotated to each other by 90◦. A large-signal and small-signal model of the proposed IPT system are designed for control synthesis. The small-signal model is derived from the large-signal using harmonic approximation and the extended describing functions (EDF). For the small-signal model, voltage and current control schemes were proposed for the purpose of wireless battery charging. The robustness of the control is tested on a small-scale IPT system using double DD coils and resistive load. The results are evaluated at different reference voltages, currents, loads and coupling coefficients.
Keywords: wireless power transfer, double DD coil structure, voltage control, IPT with multiple coils
Published in DKUM: 28.03.2025; Views: 0; Downloads: 2
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2.
Control of a modified switched-capacitor boost converter
Benjamin Ošlaj, Mitja Truntič, 2022, original scientific article

Abstract: Switched-capacitor converters and their alternatives have been shown to provide high efficiency with high power densities on smaller volumes, and can thereby be a suitable choice for energy harvesting. This paper proposes a hybrid power architecture based on a switched-capacitor topology and a boost converter that can be used for such purposes. A switching capacitor circuit can achieve any voltage ratio, allowing a boost converter to increase the input voltage to higher voltage levels. The first stage is unregulated with high-efficiency voltage conversion. The boost stage provides a regulated voltage output on such a converter. Rather than cascading two converters, their operation is integrated for the output voltage regulation. One major problem of switched-capacitor converters is output voltage regulation, which is solved by the interconnection of the power stages. The simplicity and robustness of the solution provide the possibility to achieve higher voltage ratios than cascading boost converters and provide higher efficiency. The converter’s size and cost can be improved with the integration of switching capacitors in DC-DC converter structures. A converter prototype has been designed, modelled, and built for the input voltage level of 2 V and power level of 5 W.
Keywords: SC-BC, cascade control, low power, low voltage
Published in DKUM: 28.03.2025; Views: 0; Downloads: 2
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3.
The development of ARM-based portable and adaptable power supply : magistrsko delo
Tomislav Brlek, 2019, master's thesis

Abstract: This master’s thesis describes a development of a portable and adjustable power supply. The first part of the thesis introduces us to the working principle of power supplies in general. Next, we present a functional design of a portable and adjustable power supply and a list of its required functionalities. Chapter “switched-mode power supplies” introduces us to the theoretical basics of the said power supplies, while chapter “linear regulators” introduces us to different types of linear regulators and tells us more about how they work. Everything regarding which microcontroller was used and why it was used is described in the “ARM microcontroller” chapter. Besides microcontrollers, it also talks about which integrated development environment is used and how the microcontroller is programmed. A full and detailed description of each part of the analog circuitry can be found in the chapter “describing the development of the portable and adjustable power supply”. Lastly, the user interface is described in detail.
Keywords: portable power supply, ARM processor, variable laboratory bench power supply, LCD touchscreen, energy efficient, lithium battery, battery charger, voltage control
Published in DKUM: 13.11.2019; Views: 1164; Downloads: 151
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4.
SOFT SWITCHING FOR IMPROVING THE EFFICIENCY AND POWER DENSITY OF A SINGLE-PHASE CONVERTER WITH POWER FACTOR CORRECTION
Tine Konjedic, 2015, doctoral dissertation

Abstract: This thesis investigates the possibilities for increasing the power conversion efficiency and power density of a single-phase single-stage AC-DC converter with power factor correction capability. Initially, the limitations are investigated for simultaneous increase of power density and efficiency in hard switched bidirectional converters. The switching frequency dependent turn-on losses of the transistors have been identified as the main limiting factor. In order to avoid the increase in total power losses with increasing the switching frequency, a control approach is proposed for achieving zero voltage switching transitions within the entire operating range of a bidirectional converter that utilizes power transistors in a bridge structure. This approach is based on operation in the discontinuous conduction mode with a variable switching frequency. Operation in the discontinuous conduction mode ensures the necessary reversed current that naturally discharges the parasitic output capacitance of the transistor and thus allows this transistor to be turned on at zero voltage. On the other hand, the varying switching frequency ensures that the converter operates close to the zero voltage switching boundary, which is defined as the minimum required current ripple at which zero voltage switching can be maintained. Operation with the minimum required current ripple is desirable as it generates the lowest magnetic core losses and conduction losses within the power circuit. The performance and effectiveness of the investigated approach were initially verified in a bidirectional DC-DC converter. A reliable zero voltage switching was confirmed over the entire operating range of a bidirectional DC-DC converter, as well as the absence of the reverse recovery effect and the unwanted turn-on of the synchronous transistor. In order to justify its usage and demonstrate its superior performance, the proposed zero voltage switching technique was compared with a conventional continuous conduction mode operation which is characterized by hard switching commutations. After successful verification and implementation in a bidirectional DC-DC converter, the investigated zero voltage switching approach was adapted for usage in an interleaved DC-AC converter with power factor correction capability. Comprehensive analysis of the converter's operation in discontinuous conduction mode with a variable switching frequency was performed in order to derive its power loss model. The latter facilitated the design process of the converter's power circuit. A systematic approach for selecting the converter's power components has been used while targeting for an extremely high power conversion efficiency over a wide operating range and a low volume design of the converter. The final result of the investigations performed within the scope of this thesis is the interleaved AC-DC converter with power factor correction capability. Utilization of interleaving allows for increasing the converter's power processing capability, reduces the conducted differential mode noise and shrinks the range within which the switching frequency has to vary. The proposed zero voltage switching control approach was entirely implemented within a digital signal controller and does not require any additional components within the converter's circuit. The experimental results have confirmed highly efficient operation over a wide range of operating powers. A peak efficiency of 98.4 % has been achieved at the output power of 1100 W, while the efficiency is maintained above 97 % over the entire range of output powers between 200 W and 3050 W.
Keywords: zero-voltage switching, power factor correction, variable switching frequency, discontinuous conduction mode, reverse recovery, unwanted turn-on, bidirectional DC-DC converter, bidirectional AC-DC converter, control of switching power converters
Published in DKUM: 13.10.2015; Views: 2269; Downloads: 245
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5.
Adaptive control for power system stability improvement
Jožef Ritonja, 2010, independent scientific component part or a chapter in a monograph

Keywords: synchronous generator, control functions, mathematical model, voltage control
Published in DKUM: 31.05.2012; Views: 4088; Downloads: 108
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