High-frequency DC-DC Converter Research Articles

Modelling and Simulation of Hybrid Electric Vehicle Based on MATLAB/ Simulink

Abstract: Due to the more vigorous regulations on carbon gas emissions and fuel economy, Fuel Cell Electric Vehicles (FCEV) are becoming more popular in the automobile industry. This paper presents a neural network based Maximum Power Point Tracking (MPPT) controller for 1.26 kW Proton Exchange Membrane Fuel Cell (PEMFC), supplying electric vehicle powertrain through a high voltage-gain DC-DC boost converter. The proposed neural network MPPT controller uses Radial Basis Function Network (RBFN) algorithm for tracking the Maximum Power Point (MPP) of the PEMFC. High switching frequency and high voltage gain DC-DC converters are essential for the propulsion of FCEV. In order to attain high voltage gain, a three-phase high voltage gain Interleaved Boost Converter (IBC) is also designed for FCEV system. The interleaving technique reduces the input current ripple and voltage stress on the power semiconductor devices. The performance analysis of the FCEV system with RBFN based MPPT controller is compared with the Fuzzy Logic Controller (FLC) in MATLAB/Simulink platform.

Design and Integration of Beyond-10MHz High Switching Frequency DC-DC Converter

There are continuous and strong demands for the DC-DC converter to reduce the size of passive components and increase the system power density. Advances in CMOS processes and GaN FETs enabled the switching frequency of DC-DC converters to be beyond 10MHz. The advancements of 3-D integrated magnetics will further reduce the footprint. In this paper, the overview of beyond-10MHz DC-DC converters will be provided first, and our recent achievements are introduced focusing on 3D-integration of Fe-based metal composite magnetic core inductor, and GaN FET control designs.

Design and Implementation of Two Hybrid High Frequency DPWMs Using Delay Blocks on FPGAs

The use of very high-resolution digital pulse width modulators (DPWMs) for high frequency dc-dc converters has been steadily increasing in recent years. However, the resolution of the DPWM formed by counters and comparators is limited when the switching frequency rise above MHz range. Given this limitation, new strategies for DPWM architectures are being designed to increase the resolution of the signals. This article proposes two new DPWMs architectures with the aim of increasing the resolution of trigger signals using field programmable gate arrays (FPGAs). The first proposed architecture is a hybrid DPWM, which integrates a clock manager and a delay line. For this architecture, the delay line is configured using FPGA intellectual properties (IP) blocks. This delay stage allows a fine resolution in the picosecond scale. In addition, an alternative solution has been implemented to generate two signals, the main signal and its complementary one, including high resolution for the dead time, which is also configurable. Both architectures have been tested through static and dynamic tests on two FPGAs of different costs, an Artix-7 (low-cost) and a Kintex-UltraScale 7 (high-cost) by Xilinx.

High Efficient Resonant DC-DC Converter for Automotive LED Driver Applications using Phase Shift Control Strategy

A high frequency DC-DC converter operating in the MHz range is proposed, which can achieve unbiased load current even while maintaining high performance over a wide range of load voltages. Due to these functions, the provided transformer is suitable for LED driver applications, which require different types of LEDs to operate with controlled current. The proposed transformer satisfies the uncontrolled load current using the LCL-T resonance community and achieves high efficiency using a predetermined switching frequency. The LCL-T resonance transformer also works effectively in controlling its output to the required rating using phase shift control. The overall performance of the LCL-T Echo transducer was evaluated and compared with the LC3L controlled echo transducer. Simulation work is done using the MATLAB / Simulink program.

Cybersecurity of Onboard Charging Systems for Electric Vehicles—Review, Challenges and Countermeasures

In this paper, the impacts of various data integrity attacks on the power electronic hardware present in an EV charger are comprehensively analyzed in order to provide necessary recommendations to defend against cyberattacks on electric vehicles and their onboard charging (OBC) systems. The adverse scenarios arising due to cyberattacks are carefully reviewed in this study, which includes (a) interfering with the main charger controller (FPGA) logic and its data, (b) establishing fake communication between the charging controller and other electronic control units (ECUs) connected over same controller area network (CAN) bus, and (c) interfering with the battery management system functionalities. A 6.6kW interleaved totem-pole PFC front-end followed by a high frequency DC-DC converter is used as our OBC representative system in this analysis. Possibilities and ways of potential cyberattacks on this model are investigated in detail. Effort is made towards providing software as well as hardware design-level protection mechanisms to mitigate the malicious effects of such cyberattacks on the OBC hardware. This system is simulated in MATLAB/Simulink to verify the fault occurrences under various data integrity attacks as well as to validate the effectiveness of our proposed countermeasure approaches. Quantitative analyses of the obtained results clearly demonstrate that if adequate precautionary measures are properly taken while designing the charging architecture (e.g., implementing intelligence to the main controller), any electrical hazard or deterioration of health of the components can be avoided to the maximum extent under the circumstances of a malicious cyberattack.

High frequency and high efficiency DC-DC converter with sensorless adaptive-sizing technique

High frequency and high efficiency DC-DC converter with sensorless adaptive-sizing technique

Analysis and Design of a Class E Type High Frequency DC–DC Converter Based on Resonant Driving Circuit

In this paper, a class E type high frequency DC-DC converter is proposed. The detailed analysis and parameter optimal design method are depicted in this paper. Based on optimal parameters, the switch can operate in ZVS condition. Also, to reduce the driving losses, a multistage resonant driving circuit is adopted and analyzed in this paper, which can utilize the energy stored in the switch input capacitance. The on/off control method is adopted to regulate output voltage and the enable signal frequency is 340 kHz. From the output side, the circuit can be seen as operating at enable signal frequency with high sampling frequency. A 20 MHz prototype is built in this paper, which verifies the feasibility of high frequency converter and control method.

Investigations on liquid immersion cooling in high frequency DC-DC Converter

Investigations on liquid immersion cooling in high frequency DC-DC Converter

Series-Loaded Resonant Converter DC-DC Buck Operating for Low Power

This paper presents the functions of Series-Loaded Resonant Converter (SLRC). Series Loaded Resonant DC-DC converter is a type of soft-switching topology widely known for providing improved efficiency. Zero voltage switching (ZVS) buck converter is more preferable over hard switched buck converter for low power, high frequency DC-DC conversion applications. Zero Voltage switching techniques will be used to improve the efficiency of current and voltage at the series loaded half-bridge rectifier. The results will be described from PSIM simulation, Programming of MATLAB calculation and hardware testing.

Implementation of Hybrid Photovoltaic/AC Grid System to a Micro Grid by Using MPPT

In recent days environmental pollution has become a severe problem for the mankind. Many of the scientists are conducting various researches to find out the possible measures for environment safety. Among the very serious problems growing rapidly along with the technology is the need of utilizing the solar energy before the fossil fuels get vanished. The main factors are considered as irradiance, temperature. Further a control method is surely needed for the solar energy conversion system as its efficiency changes rapidly with climate changes. In this paper the solar arrays are controlled by maximum power point tracking system (MPPT) along with the high frequency dc-dc converter.

A New Single Source Topology Four Quadrant DC-DC SEPIC Converter

The DC-DC converter find a wide scope in industries, telecommunication sectors, power electronics area, etc. Nowadays bi-directional converters have a higher end over them since the energy from the load during regenerative braking is fed back to the source, thus obtaining energy efficient system. A single topology that can provide Buck-Boost operation with positive output having four quadrant operations is not available in literature. A common limitation of power coupling effect in some known multiple-input dc-dc converters has been addressed in many literatures. In this paper, a new single-input DC-DC four quadrant Sepic converter has been developed to provide four quadrant operation of a high frequency dc-dc converter having one supply source and proper control of the converter. The combined topology has been analyzed and studied by spice simulation and Tecplot.

Optimization of Integrated Transistors for Very High Frequency DC–DC Converters

This paper presents a method to optimize integrated lateral double-diffused MOSFET transistors for use in very high frequency (VHF, 30-300 MHz) dc-dc converters. A transistor model valid at VHF switching frequencies is developed. Device parameters are related to layout geometry and the resulting layout versus loss tradeoffs are illustrated. A method of finding an optimal layout for a given converter application is developed and experimentally verified in a 50-MHz converter, resulting in a 54% reduction in power loss over a hand-optimized device. It is further demonstrated that hot-carrier limits on device safe operating area may be relaxed under soft switching, yielding significant further loss reduction. A device fabricated with 3-μm gate length in 20-V design rules is validated at 35 V, offering reduced parasitic resistance and capacitance, as compared to the 5.5-μm device. Compared to the original design, loss is up to 75% lower in the example application.

A 200-MHz Integrated Buck Converter With Resonant Gate Drivers for an RF Power Amplifier

High switching frequency dc-dc converters are present in many applications where wide regulation bandwidth and high efficiency are needed. A resonant gate driver is presented for improvement of efficiency at light-to-medium load conditions. Gate power losses that are a main contributor to total losses are reduced thanks to energy recovery. A testchip designed in 0.25- BiCMOS shows as much as a 30% decrease in power losses compared to a conventional driver at 200-MHz switching frequency. The proposed resonant gate driver is fully integrated with its inductor unlike earlier works. The limitation in the reduction of gate losses is detailed and confirmed experimentally.

Size and Performance Tradeoffs in Micro-Inductors for High Frequency DC-DC Conversion

This paper presents the design and measurement of optimized inductors-on-silicon (ldquomicro-inductorsrdquo) for use in high frequency DC-DC conversion applications. These ultra-compact low profile (< 70 mum) inductors range in area from 0.5-2.5 mm2 . The design process utilizes optimization software that finds the optimal physical dimensions, to maximize inductor efficiency, given certain technology constraints. Optimized micro-inductors achieve measured inductance densities of 66 nH/mm2 for a 2.5 mm2 area, 110 nH/mm2 for 1.3 mm2 device and 82 nH/mm2 for a 0.5 mm2 footprint area. Measured saturation currents range from 0.15-0.5 A for the optimized devices.

Continuous-Time Digital Controller for High-Frequency DC-DC Converters

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper introduces a voltage mode digital controller for low-power high-frequency dc-dc switch-mode power supplies (SMPS) that has fast transient response, approaching physical limitations of a given power stage. In steady state, the controller operates as a conventional pulsewidth modulation regulator and during transients it utilizes a novel fast voltage recovery mechanism, based on real-time processing of the output voltage in digital domain. This continuous-time digital signal processing mechanism is implemented with a very simple processor consisting of a set of asynchronous comparators, delay cells, and combinatorial logic. To eliminate the need for current measurement and calculate the optimal switching sequence of the power stage transistors, the processor performs a capacitor charge balance algorithm, which is based on the detection of the output voltage peak/valley point. The effectiveness of the controller is demonstrated on an experimental 5 W, 5 V to 1.8 V, 400 kHz buck converter. The converter recovers from load transients through a single on-off action of the power switch, virtually reaching the shortest possible time, limited by the values of the power stage filter components only. </para>

Design of a Soft-Switched 6-kW Battery Charger for Traction Applications

Auxiliary power converters for traction rolling stock applications have to operate under difficult conditions, including high-input voltages which are subject to wide fluctuations, high temperatures, and harsh environmental constraints. Additionally there is often a need for silent operation, which implies switching frequencies above 20 kHz. Increasingly, high-frequency DC-DC converters are being used for these applications, with their advantages of reduced size and weight. However, the requirement to accommodate high-input voltages and switch at high frequencies is challenging for a conventional hard-switched converter based on IGBTs, which makes soft-switching topologies an attractive alternative. This paper presents the design strategy for a zero-voltage switched (ZVS) 6-kW battery charger switching at 20 kHz using IGBTs. This paper illustrates how the design is a tradeoff between managing the hard-switch turn-on losses at light load, minimizing the duty cycle loss caused by soft-switching delays, and minimizing the effects of tail current-switching losses. These tradeoffs affect the selection of the ZVS capacitors, the determination of the series inductance value, the transformer turns ratio, and the selection of the IGBTs to be used. Design details, theoretical predictions, and experimental results are presented in this paper for the conversion system that was developed.

Low price Fuel Cell Inverter System for 3[KW] Residential Power

This study proposed a high efficiency DC-DC converter with a new current doubler rectifier for fuel-cell systems for use with the Nexa(310-0027) PEMFC from the Ballard Co. The proposed high efficiency DC-DC converter for the fuel-cell system generated ZVS by applying partial resonance and using a phase shift PWM control method. Constantly switching frequency, loss of switching, peak current, and peak voltage were reduced by this system. In addition to this system, two inductors were attached to a rectifier circuit allowing it to be able to provide the direct current(DC) and DC voltage safely to a load with reduced ripple components. Also, by using the newly proposed current doubler rectifier, the high frequency DC-DC converter for the fuel cell system was capable of reaching a highest efficiency of 92[%] as compared to 88.3[%] efficiency in previous results, which means that efficiency increased 3.7[%]. The overall results were confirmed by a simulation and laboratory experiment.

Comparison of Magnetic Materials for V-Groove Inductors in Optimized High-Frequency DC-DC Converters

The tradeoff between saturation flux density and resistivity in soft magnetic materials for thin film inductors is examined quantitatively. We use an optimization routine to evaluate the achievable efficiency and power density using designs individually optimized to make best use of particular materials. The optimization selects switching frequency, ripple ratio, inductor dimensions and MOSFET sizes. For the example application of a 3.3- to 1.1-V, 7-A output dc-to-dc converter, Co-Zr-O, Fe-Al-O and Co-Fe-B-Si-O materials are considered. Predicted efficiencies are in the range of 80% to 90% at power densities of 20 W/cm/sup 2/ to 1000 W/cm/sup 2/. Different materials show advantages in different power-density or efficiency ranges.

High-frequency flyback-type soft-switching PWM DC-DC power converter with energy recovery transformer and auxiliary passive lossless snubbers

A two-switch high-frequency flyback-type zero voltage soft-switching PWM DC-DC power converter for use in auxilary power supplies is proposed. Its basic building block is composed of two active power switches and a flyback high frequency transformer. In addition, two passive lossless snubbers with power regeneration loops for energy recovery that consist of a three-turn auxiliary high frequency transformer, auxiliary capacitors and diodes, are introduced to achieve zero voltage soft switching in the full range of light to full load conditions. The power converter has the advantages of a low cost circuit configuration, a simple control scheme and a high efficiency.The converter&apos;s operating principle is described and to in order determine circuit parameters, some practical design considerations are discussed. The effectiveness of the proposed power converter is evaluated and is compared to a hard-switching PWM DC-DC converter. The comparative electromagnetic conductive noise characteristics of both DC-DC power converter circuits are also investigated.

Design and analysis of automotive high intensity discharge lamp ballast using micro controller unit

A new scheme of the automotive high intensity discharge (HID) lamp ballast systems is proposed. The proposed scheme is consisted of the high frequency DC-DC converter and the low frequency DC-AC inverter as same as conventional HID ballast system. However this system separates the input voltage of the ignitor from DC link voltage using auxiliary winding, which results in the use of the lower voltage rating power devices for HID lamp ballast system compared with conventional system. As a result, proposed system has a lower cost or a higher efficiency. For the improvement of the efficiency, the proposed ballast controller using micro-controller unit (MCU), controls the frequency to operate the DC-DC converter in critical conduction mode. This paper presents the design and analysis of the proposed ballast and some experimental results.