Wide Input Voltage Range Research Articles

Three-Level Double LLC Resonant Converter with Ripple-Free Input Current for DC Microgrid Application

DC distribution systems have garnered interest in recent years due to their advantages over AC distribution systems, such as their high power conversion efficiency and lack of harmonic issues. An isolated DC-DC converter with low-input noise, high efficiency, and high-power density is required for DC microgrids within DC distribution systems. Although existing DC to DC converters have high efficiency and high power density, they still have input noise problems due to pulsating input currents. Thus, a large input filter should be inserted, which increases the cost and degrades the power density. In this study, a novel three-level double LLC resonant converter with zero-input-current ripple is presented for DC microgrid application with a high-voltage DC bus. The input-current ripple of the proposed converter theoretically decreases to zero without adding large input filters. Moreover, the voltage stress on each main switch is only half of the input voltage when using the modified three-level structure, which enables the use of low-voltage-rated power switches for high-voltage input applications. In addition, all the primary switches and secondary diodes are softly switched over a wide input voltage range. The experimental results of the prototype are presented to verify the performance of the proposed converter.

Real-time monitoring and control of a PV-fed enhanced cubic voltage gain converter for DC microgrid

In this manuscript, a novel high-gain DC-DC converter with an ultra-step-up voltage gain value of 22.2 is introduced along with a custom-developed web application for remotely monitoring and controlling the power converter. The proposed converter is synthesized using two stages – stage 1 yields a cubic voltage gain and stage employs a diode-capacitor gain cell (DCGC) to reduce the voltage stress on the switch. The proposed gain extension hypothesis is experimentally validated through an 18 V to 400 V, 175 W prototype converter which delivers 175 W to the load at a 93.5% efficiency. The proposed converter exhibits excellent dynamic response when regulating the output voltage to 400 V over a wide range of input voltage and load current variations; the overshoots and undershoots are also negligible. Further, the maximum voltage stress on the switch is only 37.5% of the output voltage. For remotely controlling and monitoring the converter under real-time conditions with a high sampling rate, a web application is developed using React.js. The STM32 microcontroller is programmed to transmit data serially to the server, which then interacts with the web application using hypertext transfer protocol (HTTP) and WebSockets. The effectiveness of the developed interface is also practically verified by controlling the proposed converter in various modes viz., open-loop, soft-start, constant voltage, constant current, soft-stop, load regulation and overvoltage protection modes. Based on the comparison with several converters the proposed converter possesses unique advantages. Additionally, its web-based remote monitoring and control features are preferable for DC microgrid application.

An Input-Coupling LLC Converter With Wide Input Voltage Range and High Efficiency

An Input-Coupling <i>LLC</i> Converter With Wide Input Voltage Range and High Efficiency

Minimizing conduction losses in multiple active bridge converters across wide voltage ranges using advanced dual‐duty modulation

AbstractMultiple port DC/DC converters have applications in many fields: hybrid energy storage systems where batteries are combined with supercapacitors, multi‐level and multi‐modular inverters that need multiple DC sources, and DC microgrids. Among these converters, the Multiple Active Bridge (MAB) is particularly attractive due to its high power ratings and galvanic isolation capabilities. This paper introduces an advanced dual‐duty modulation technique for MAB converters designed to significantly reduce conduction losses over a wide range of input voltages by minimizing the harmonics’ reactive power on the AC stage. Consequently, it can improve the converter's efficiency when dealing with non‐constant voltage sources such as batteries and supercapacitors. The overall control technique is based on the dq‐frame control method under the first harmonic approach (FHA). This method is verified through simulations and implemented in a 1000 W triple‐port prototype. In the simulation, conductive and switching losses are modelled, and the trade‐off between these loss types is discussed. The experimental results affirm an overall improvement in efficiency for certain scenarios involving non‐unit voltage conversion ratios.

Continuous Input Current Isolated Resonant LED Driver With Wide Input Voltage Range

Continuous Input Current Isolated Resonant LED Driver With Wide Input Voltage Range

Design of wide input voltage range and low quiescent current LDO

Design of wide input voltage range and low quiescent current LDO

Power converters design and experimental verification for electromagnetic contactors to reduce the impact of the voltage sag in the power system

This research aims to offer a power supply system based on power converters to supply electromagnetic contactors from the power distribution grid. Its primary purpose is to minimise the voltage sag impact on the contactor, eliminating the possibility of contacts tripping or excessive vibration. In addition to this, the contactor's inherent low power factor must be compensated, reducing the contactor's impact on the power grid. To complete these requirements, the power supply system comprises a Totem-pole PFC converter, a Buck converter stabilising the supplied voltage, and an H-Bridge, decreasing the switch-off commutation time. The research focuses on the converters' design methodology, supported by a case study and experimental verification. Considering the electromagnetic contactor characteristics, the system design requirements are systemised. The analytically and experimentally obtained data shows that based on the chosen converters' topologies, the suggested power supply system provides contactor stable operation in a wide input voltage range, acceptable power losses and high efficiency.

Design and optimization of 30 kW CLLLC resonant converter for vehicle‐to‐grid applications

AbstractThe CLLLC resonant converter is a promising technology for electric vehicles and microgrids due to its ability to operate bidirectionally. This article presents a design of a bidirectional CLLLC resonant converter that is applied in the vehicle‐to‐grid (V2G). The battery side of the converter uses a two‐channel parallel structure to enhance its efficiency and reliability. In contrast, the DC‐bus side uses a transformer series structure to obtain the benefits of passive current sharing on the secondary side and reduce the transformer turns ratio. By utilizing the proposed design method, the converter can achieve a wide input and output voltage range, high efficiency, and high power density. The article analyzes the working principle of the converter and explains the design process, which includes the transformer turns ratio, magnetizing inductance, and resonance parameters. Finally, an experimental prototype is produced to verify the theory's validity and the design's feasibility. The prototype has a DC‐bus side voltage of 660–860 V, a battery side voltage of 250–500 V, and a maximum power output of 30 kW. The peak efficiency of the prototype is 98.2%, and its power density can reach up to 8 kW/L.

A modified two-stage isolated bidirectional buck-DAB converter with a full-load ZVS range

A modified two-stage buck-DAB (MBDAB) converter is proposed to improve the performance of the traditional two-stage buck-DAB (TSBDAB) converter. In the MBDAB converter, the DAB can work with fixed voltage gain and voltage-matched condition under a wide input voltage range. The voltage gain of the converter is adjusted through the added front-end stage, which is similar to a buck converter. Compared with the TSBDAB converter, only part of the transmitted power flows through the front-end stage, so the loss of the buck stage and the burden of zero-voltage switching (ZVS) can be reduced. Detailed analysis of the working principle, partial power characteristics, and the full-load ZVS range design are presented. To verify the effectiveness of the proposed MBDAB converter, experimental results are obtained from a prototype with a rated power of 1 kW.

A wide input voltage range DC-DC Buck converter with dynamically modified ZCD circuit

A wide input voltage range DC-DC Buck converter with dynamically modified ZCD circuit

Boost DC-DC converter with regenerative snubber

To accommodate the wide range of input voltages supplied by redundant batteries and ensure an adequate hold-up time for communication systems during utility power failures, power supplies used in 5 G base stations typically include a front-end boost converter as the first stage and a second-stage isolated converter. In this paper, a new topology for a regenerative snubber in boost converters is proposed. Compared to traditional active or passive snubber topologies, the proposed snubber offers the advantages of having fewer components and occupying less space. Moreover, it does not require additional active devices and can be driven by widely-used commercial PWM control integrated circuits, achieving a higher level of cost-effectiveness and offering increased industrial applications. The final prototype of a power supply for a networking switch hub (as used in 5 G base stations) is fabricated to demonstrate the feasibility of the proposed method.

A dual-mode buck converter with dynamic sawtooth voltage for wide input voltage range application

A dual-mode buck converter with dynamic sawtooth voltage for wide input voltage range application

Optimization of Ultrasonic Motor Control Based on NARX Neural Network

Abstract Compared with traditional motors, ultrasonic motors have the advantages of small size and no noise and are widely used in modern technological fields. This article proposes a neural network-based ultrasonic motor control method and optimizes it to address the difficulty of controlling ultrasonic motors. Firstly, the principle and equivalent circuit of ultrasonic motors are studied, and a phase-shifted PWM method suitable for driving ultrasonic motors is proposed. Secondly, to meet the nonlinear characteristics of ultrasonic motors, a NARX neural network that can be used for nonlinear systems is adopted for optimization control. Finally, an experimental platform was built for the experiment, and the results showed that the proposed H-bridge driving circuit has a wide input voltage range. After using the NARX neural network, the output voltage of the H-bridge circuit is more stable, which can provide a stable driving voltage for the ultrasonic motor. It can provide a certain reference value for the application of ultrasonic motors in modern technology.

Hybrid PFM and PWM Modulation Strategy for Stacked Structure LLC Resonant Converter With Wide Input Voltage Range Application

Hybrid PFM and PWM Modulation Strategy for Stacked Structure LLC Resonant Converter With Wide Input Voltage Range Application

Monolithic design of self-adaptive CMOS converter and robust event-triggered consensus control for integration of multi-renewable energy sources with battery storage system

Recently, integrating renewable energy sources (RESs) has been one of the most effective ways to overcome the power shortage problems due to the cumulative load demand, which cannot be covered using conventional power production. DC-DC converters with a wide voltage conversion range are highly important when integrating RESs to achieve voltage matching. In recent years, many large-scale improvements have been made to the DC-DC converters to improve reliability, effectiveness, flexibility, modularity, and cost-effectiveness. This study investigates the feasibility of integrating RESs and designing the most effective structure using complementary metal-oxide semiconductors (CMOS) for DC-DC converters. A novel monolithic CMOS buck converter with an adaptive sensing feedback system (ASFS) circuit is proposed for renewable integrated systems. The proposed converter based on ASFS provides a wide range of conversion voltages, low cost, and reliability. It depends on the pulse-width modulation (PWM) technique with a voltage-control duty-cycle (VCDC) circuit. The proposed multi-input DC-DC converter is tested to integrate three RESs to form an integrated hybrid system. The proposed converter is built to integrate the PV, wind turbine (WT), wave energy source, and battery energy storage system (BESS). The proposed DC-DC converter is tested to adjust the output voltage of the RESs at 12 V with a load current of 2.4 A to facilitate the integration process. The results show the success of the proposed converter in maintaining the output voltage at 12 V, with maximum efficiency of the CMOS buck DC-DC converter reaching 96.25 % over a wide input voltage range from 15 V to 35 V. Moreover, the maximum peak-peak ripple over the output voltage reaches 600 mV at the maximum input voltage of 35 V. A control method-based event-triggered consensus algorithm has been proposed to regulate the system voltage and ensure active power sharing in the microgrid system. The controller's settling time and rise time have been measured, and a robustness analysis has been performed based on the connections and disconnections of DGs and the impact of faults.

Optimal Design of LCC Resonant Converter With Phase Shift Control for Wide Input/Output Voltage Ranges in Fuel Cell System

This paper proposes an optimal design of an LCC resonant converter with a phase shift control for a fuel cell system which has wide input and output voltage ranges. The proposed optimal design focuses on the circulating energy minimization by adjusting the transformer turns ratio according to the maximum gain of resonant tank. This makes the root mean square (RMS) value of resonant current and turn-off current stationary even though the resonant tank change. Thus, designers can select resonant tank optimized for the converter specifications without considering the conduction and switching losses. By the proposed optimal design, the efficiency degradation at worst case, which is a significant issue of the fuel cell system with wide output voltage range, can be minimized. In addition, for the fuel cell converter with wide input voltage range, a phase shift control which operates the full-bridge inverter with a constant effective duty cycle according to the fuel cell voltage is proposed. This control scheme improves the light-load efficiency without deteriorating the rated-load efficiency by reducing the circulating current and switching frequency. The validity of the proposed works is confirmed by experimental results of the 30kW LCC resonant converter.

A 96 dB DR Second-Order CIFF Delta-Sigma Modulator with Rail-to-Rail Input Voltage Range

A second-order delta-sigma modulator (DSM) is proposed for readout integrated circuits of sensor applications requiring a small area and low-power consumption. The proposed second-order CIFF DSM with the architecture of cascaded-of-integrator feedforward (CIFF) basically consists of two integrators, a 3-bit quantizer, data-weighted averaging (DWA) circuit, and clock generator. The use of the 3-bit quantizer instead of the single-bit quantizer reduces the size of the feedback capacitor in the first integrator. The 3-bit quantizer is designed based on a successive approximation register analog-to-digital converter for small area and low power implementation. Furthermore, the proposed second-order CIFF DSM has a single supply without an additional reference driver while having a wide analog input voltage range with rail to rail. The proposed second-order CIFF DSM, implemented using a 130 nm 1-poly 6-metal CMOS process with a supply of 1.5 V, has an area of 0.096 mm2. It has a sampling frequency of 500 kHz for the implementation of an input bandwidth of 2 kHz and an oversampling ratio of 125. The measured peak signal-to-noise and distortion ratio is approximately 90 dB when the differential analog input signal has a frequency of 353 Hz and an amplitude of 1.2 Vpp. The measured dynamic range is approximately 96.3 dB.

Analysis and Optimization of a Regenerative Snubber for a GaN-Based USB-PD Flyback Converters

This paper presents a high-efficiency GaN-based 65 W Quasi-Resonant (QR) Flyback converter. The converter is characterized by a wide input voltage range and a variable output voltage, and it is designed as a Switch Mode Power Supply (SMPS) for high power density USP-Power Delivery (USB-PD) applications. To increase the efficiency and power density, a regenerative snubber clamp solution has been used to limit the excursion of the drain voltage during the power switch turn-off. The activity involved the modeling of the converter, the sizing of the regenerative snubber, and the design of the flyback transformer. Furthermore, a dedicated test application board was used to verify the effectiveness of the solution. The results were compared with those obtained using a flyback converter with an RCD snubber.

A Novel Modular Sigma DC/DC Converter with a Wide Input Voltage Range

A modular Sigma DC/DC converter with wide input voltage range is proposed in this paper. The proposed converter is combined with a traditional LLC converter and two multi-resonant converters via Sigma architecture. Among them, the traditional LLC converter operates as a DC transformer (DCX) at resonant frequency to achieve maximum efficiency. Meanwhile, one of the multi-resonant converters, the DC to DC (D2D) part of the Sigma structure, is responsible for voltage regulation over a wide input voltage range. In addition, the other multi-resonant converter has two operation modes, including DCX and D2D. When it operates in the DCX mode, the Sigma converter has better performance and higher efficiency. When it operates in the D2D mode, the Sigma converter can handle a wider input voltage range. For each submodule, the operation principle and characteristics of the proposed Sigma converter are analyzed in detail. In addition, some key points of the parameter design for each part are also demonstrated. Finally, an experimental prototype with an input voltage of 540~1100 V is built to verify the effectiveness of the proposed converter.

Converter with Wide Input Voltage Range Applied to Solid State Lighting Based on HV9930

Currently research has pointed to LEDs as the technology more efficient and durable to be used in lighting, however, it requires a static converter in order to control the electrical current flowing through the LED lamp. In this context, this paper describes the implementation of a DC/DC converter with wide input voltage range called Boost-Buck Quadratic, with simple control strategy, driving a LED lamp. The converter can be powered from 12 VDC (battery voltage) to the universal AC input voltage (90 to 240 VAC). Theoretical analysis, design guidelines and experimental results from a prototype of the proposed Boost-Buck Quadratic converter driving a 12 W LED lamp are shown in this paper.