Small-signal model of the two-phase interleaved coupled-inductor boost converter

A coupled-inductor dc-dc converter has several modes of operation in continuous-conduction mode (CCM) and discontinuous-conduction mode (DCM), and is quite complex. This paper presents the derivation of the complete small-signal model of a two-phase interleaved dc-dc boost converter utilizing a single-core coupled-inductor operating in both CCM and DCM. Several small-signal models are required to fully model the converter due to the complexity of the converter operating in DCM. The transfer functions are then derived from these small-signal models. The theoretical analysis is validated experimentally using frequency sweeps from a 1-kW prototype

T-NPC Soft-Commutated Inverter Based on Reverse Blocking IGBTs with the Novel Concept of a DESAT Control Circuit in the Gate Driver

This article presents the concept of switching and conduction loss reduction in a T-NPC inverter based on IGBT transistors. The method of limiting switching losses involves the connection of an LC circuit designed to cause transistors in vertical branches to shut down under zero voltage conditions. In order to reduce conduction losses, it was proposed to use two reverse blocking transistors connected anti-parallel in the horizontal branch of the inverter. To ensure safe operation of the transistors, a gate driver proposal for controlling the IGBT reverse blocking transistor is presented. The solution is characterized by a changed part of the driver, responsible for short-circuit protection. It eliminates excessive, destructive currents that can potentially flow through the driver circuit under the influence of the power supply voltage of the power circuit connected backwards to the controlled transistor. Examples of applications and benefits of the proposed solution are presented and verified with laboratory tests

A photovoltaic source I/U model suitable for hardware in the loop application

This paper presents a novel, low-complexity method of simulating PV source characteristics suitable for real-time modeling and hardware implementation. The application of the suitable model of the PV source as well as the model of all the PV system components in a real-time hardware gives a safe, fast and low cost method of testing PV systems. The paper demonstrates the concept of the PV array model and the hardware implementation in FPGAs of the system which combines two PV arrays. The obtained results confirm that the proposed model is of low complexity and can be suitable for hardware in the loop (HIL) tests of the complex PV system control, with various arrays operating under different conditions

GaN-Based DC-DC Resonant Boost Converter with Very High Efficiency and Voltage Gain Control

This paper presents a concept for the operation of a resonant DC–DC switched-capacitor converter with very high efficiency and output voltage regulation. In its basic concept, such a converter operates as a switched-capacitor voltage doubler (SCVD) in the Zero Current Switching (ZCS) mode with a constant output voltage. The proposed methods of switching allow for the switched-capacitor (SC) converter output voltage regulation, and improve its efficiency by the operation with Zero Voltage Switching (ZVS). In this paper, various switching patterns are proposed to achieve high efficiency and the output voltage control by frequency or duty cycle regulation. Some examples of the application of the proposed switching patterns are presented: in current control at the start-up of the converter, in a bi-directional converter, and in a modular cascaded system. The paper also presents an analytical model as well as the relationships between the switching frequency, voltage ratio and efficiency. Further, it demonstrates the experimental verification of the waveforms, voltage ratios, as well as efficiency. The proposed experimental setup achieved a maximum efficiency of 99.228%. The implementation of the proposed switching patterns with the ZVS operation along with the GaN-based (Gallium Nitride) design, with a planar choke, leads to a high-efficiency and low-volume solution for the SCVD converter and is competitive with the switch-mode step-up converters

All-Bootstrap Gate-Driver Supply System for a High-Voltage-Gain Resonant DC-DC Converter with Seven Switches

This paper presents the concept and implementation of an electronic system for a switched-capacitor DC-DC converter with high voltage gain. The converter consists of seven switches, five of which being controlled like high-side type. This paper presents a non-typical bootstrap-based gate-driver system so that the converter can run using a single voltage source. The converter requires a special switching pattern to drive seven switches in a steady state and also during the start-up of the converter and the regulation of the output voltage. Therefore, an FPGA-based digital control system is used with various switching algorithms and protection functions implemented. The presented converter is an autonomic device that taps the energy from the main input. Therefore, the electronic system of the converter is equipped with a self-supply system with a wide range of the input voltage. The parameters of the converter such as voltage gain, voltages and power ranges can be scalable for prospective applications with the proposed control system

A Cost-Effective Resonant Switched-Capacitor DC-DC Boost Converter – Experimental Results and Feasibility Model

This paper presents the results of experimental research of a resonant switched capacitor voltage multiplier in a cost-effective topology (CESCVM) with a limited number of active switches. In the charging mode of the switched capacitors, the converter utilizes only one active switch and a required number of diodes. Therefore, the cost of the converter is decreased as compared with that of a classical SCVM converter, owing to a lower number of switches and gate driver circuits, as well as a smaller PCB area. Moreover, the CESCVM has simpler control circuits and higher reliability. This paper presents the original experimental results of the operation of the CESCVM converter. A concept of the bootstrap supply of gate drivers of the flying switches is also examined

Single-source three-phase switched-capacitor-based MLI

This article proposes a novel three-phase inverter based on the concept of switched capacitors (SCs), which uses a single DC source. A three-phase, seven-level line-to-line output voltage waveform is synthesised by the proposed topology, which includes eight switches, two capacitors, and one diode per phase leg. The proposed topology offers advantages in terms of inherent voltage gain, lower voltage stresses on power switches, and a reduced number of switching components. Additionally, the switched capacitors are self-balanced, thereby eliminating the need for a separate balancing circuit. The proposed structure and its operating principle, the self-balancing mechanism of the capacitors, and the control strategy are all thoroughly explained in the article. The proposed topology has also been compared with some recent SC topologies. Lastly, the proposed topology has been shown to be feasible through simulation and experimentation