Direct Current To Direct Current Research Articles

An on-chip soft-start pseudo-current hysteresis-controlled buck converter for automotive applications

This paper introduces a novel direct current to direct current (DC-DC) buck converter that uses a pseudo-current hysteresis controller and an on-chip soft start circuit for improved transient performance in automotive applications. The proposed converter, implemented with Taiwan semiconductor manufacturing company (TSMC) 0.18 µm complementary metal oxide semiconductor (CMOS) one-poly-six-metal (1P6M) technology, includes a rail-to-rail current detection circuit and an on-chip soft start circuit to handle transient responses and improve efficiency. Transient response analysis shows fast settling times of 28 µs for both load current changes from 100 mA to 1 A and reversals with consistent transient voltages of approximately 190 mV and peak power efficiency of 99.32% at 5 V output voltage and 100 mA load current. Additionally, the converter maintains a constant output voltage of approximately 5 V across the entire load current range with an average accuracy of 90.41%. A comparative analysis with previous work shows superior performance in terms of figure of merit (FOM). Overall, the proposed pseudo-current hysteresis controlled buck converter exhibits remarkable transient response, load regulation and power efficiency, positioning it as a promising solution for demanding applications, particularly in automotive systems where precise voltage regulation is crucial.

Enhanced general conformable controller based on Lyapunov technique for DC-DC static converters: Application to a solar system

<abstract> <p>To synthesize the proper control signal while guaranteeing the necessary performance indices (speed, resilience, accuracy, etc.), mathematical models were frequently used to represent physical systems. These descriptions were utilized for control, monitoring, and detection in these kinds of systems. Quality and performance of the process may suffer if the model is inaccurate or incomplete. As a result, conformable systems (CS) may be used to make these mathematical models more near to the real world. However, non-power-electronics experts who need to model and simulate complex systems may find the task of modeling static converters to be rather challenging. Researchers have just recently outlined the properties of the general conformable systems (GCS). This innovative approach built upon the principle of the classical integer order systems, employing the same mathematical foundations for its derivation. With the introduction of this novel description of systems, a fresh array of differential equations emerged, specifically tailored for the realm of direct current to direct current (DC-DC) static converters. GCS has been proved to be more flexible and profitable than the traditional integer-order one for representing DC-DC static converters. This advancement paved the way for more effective control techniques based on the Lyapunov method, with practical applications in photovoltaic (PV) systems and beyond.</p> </abstract>

Design and implementation a novel single switch high gain DC-DC converter based on coupled inductor with low-ripple input current

A novel high-gain and high-efficiency direct current to direct current (DC-DC) converter is introduced in this paper. The presented converter is suitable for low-voltage renewable energy resources such as photovoltaic (PV) and fuel cell (FC). The existence of series inductance with the input source ensures continuous and low-ramp input current, which is important for extracting maximum power from resources. Using coupled inductor technology and an intermediate capacitor in the suggested converter leads to a high gain voltage. In the presented topology for recovering energy from the leakage inductor, reducing voltage stress on the power switch, and so decreasing overall converter losses, a passive clamp circuit is used. The suitable operation range of duty cycle in the converter, besides the leakage inductor, decreases the problem of reverse recovery in diodes. The low value of the leakage inductor and the low volume and cost of the proposed converter are due to the low turn ratio of the coupled inductor. Details of the operation principles of the proposed converter have been discussed in this paper. The presented simulation and laboratory prototype results verify the theoretical analysis and performance of the suggested topology.

Charging the battery via an electric machine fed by dual power source in fuel cell vehicles

In the powertrain of the available fuel cell vehicle, a direct current to direct current (DC/DC) converter is needed to solve the problem of voltage mismatch between the fuel cell and the battery. To cut down the cost and reduce the space occupation, the DC/DC converter is omitted from the powertrain in this study, where the electric machine has two sets of windings supplied by the fuel cell and the battery directly. This study aims to realize charging the battery through no DC/DC converters but only a dual winding electric machine in fuel cell vehicles. Four battery charging modes for the fuel cell vehicle are analyzed under different driving conditions. With a full consideration of the power source characteristic, a strategy based on a power distribution factor is proposed to charge the battery and satisfy the power demand of the vehicle simultaneously. To charge the battery without DC/DC converters when the vehicle is stopped, a method of changing d-axis flux linkage is proposed to make the electric machine perform like a transformer and conduct energy transfer between the fuel cell and the battery. The feasibility of the proposed charging method is verified by both simulations and experiments.

Application scenario evaluation of modified converter for quadratic Boost high gain DC-DC: taking the constant off time control mode as an example

Abstract In recent years, due to the energy crisis and serious environmental problems, the use and development of new energy has become the focus of research. Therefore, the application of new energy technologies has increased the demand for direct current to direct current (DC-DC) converters. The improvement of converter capability effectively enhances the functions of DC-DC converters, which makes it easy for secondary converters to meet the requirements of voltage gain, and expands the input voltage range of DC-DC converters, thereby having a good prospect in new energy applications. However, due to the many drawbacks of the quadratic Boost converter, such as pressure rise limitation, high switching stress, in order to reduce the working pressure of the improved quadratic Boost high gain converter and improve its operating performance, it is necessary to optimize it. Based on the application scenario of an modified converter for quadratic Boost high gain DC-DC, and taking the constant off time control method as an example, this paper conducted research to accurately recognize the current status of the converter and improve the utilization efficiency of the converter. In this paper, four groups of traditional converters and two types of improved quadratic Boost high gain DC-DC converters were selected as experimental objects for comparative analysis of images and data. The results showed that the conversion efficiency of the constant off time control method in the modified DC-DC converter based on quadratic high gain was 7.03 % higher than that of the traditional converter, while also improving the conversion efficiency of voltage gain and reducing switching stress, with higher safety. This indicated that the improved DC-DC converter with secondary high gain has better effects and wider application scenarios, thereby better serving new energy systems.

Design of a bidirectional converter for charging/discharging a supercapacitor

This article presents the analysis and design of a new converter that combines the current doubler topology and the parallel converter to achieve greater stability and effective reduction of ripple in both voltage and current parameters. Basically, the DC-DC (Direct Current to Direct Current) converter operates with pulse modulators to control the current in the desired charging or discharging direction. Extensive simulations were carried out at nominal values of 48 V and 8.5 A of output, and 100 V of input to confirm the performance of this converter. The approach used has benefits in terms of safety, reduced electrical noise, practical implementation for interconnecting energy sources with high voltage ratios, and increased lifespan of supercapacitors as well as batteries. Simulation results are presented and the advantages and applications of this new configuration are discussed.

Design and simulation of Arduino Nano controlled DC-DC converters for low and medium power applications

<p>This paper mainly focuses on the controller of portable direct current to direct current (DC-DC) converter which may be simple, low cost and efficient. Nowadays, proportional integral (PI) controller and opto-isolator based circuits are used for switching control. The switching control through the controller makes the DC-DC converter into larger circuit and less efficient. This problem will be rectified using the Arduino Nano controller which is small and low cost-effective controller. It is useful for low and medium power applications like residential solar power system, electronic gadgets, and academic laboratories. Arduino Nano-based DC chopper has been developed, and the Proteus software used for simulation. The different topologies of DC choppers like buck, boost, and buck-boost converter have been designed with mathematical calculations and simulated.</p>

A novel fuzzy logic control for a zero current switching-based buck converter to mitigate conducted electromagnetic interference

<span lang="EN-US">This research provides a new control technique for mitigating conducted electromagnetic interference (EMI) in a buck converter designed for solar applications. Indeed, hard-switching direct current to direct current (DC-DC) converters, commonly used in industrial applications, pose a significant risk to the surrounding environment regarding electromagnetic compatibility (EMC). Usually, the fast-switching phase induces abrupt changes in current and voltage, which adds to substantial electromagnetic interference in both conducted and radiated modes and excessive auditory noise. An architecture based on the duality of soft-switching topology and fuzzy logic control technology is developed to address these issues. On the one hand, resonant circuit topologies are used to induce switches to achieve soft switching conditions, which subsequently lessen the effects of EMI. On the other hand, the adoption of fuzzy logic control technology is interesting since it can reduce electrical stresses during switching. Furthermore, the simulation results show that zero current switching (ZCS) soft-switching closed-loop fuzzy logic converters outperform typical open-loop converters and soft-switching closed-loop converters with proportional integral (PI) control in terms of EMC requirements.</span>

FUZZY LOGIC CONTROL TO PROCESS CHANGE IRRADIATION AND TEMPERATURE IN THE SOLAR CELL BY CONTROLLING FOR MAXIMUM POWER POINT

This paper presents intelligent control methods to get the maximum power point (MPPT) to be a photovoltaic system that operates with high efficiency when weather conditions change as well as fluctuations in temperatures resulting from sunlight. The proposed method of controlling by fuzzy control techniques is applied with a Direct current to Direct current (DC-DC) converter device. The important steps of the control unit for integrated design. The photovoltaic system, which was designed by Matlab / Simulink, was implemented with simulations of autonomous water pumping techniques. Comparison of results with simulations without MPPT control. We have noticed that the system in the case of using the MPPT that was used in the fuzzy logic unit gave high efficiency for the energy production from the solar cell the crucial control unit steps for integrated design. Simulated autonomous water pumping methods were used to implement the Matlab/Simulink-designed photovoltaic system. Results comparison with simulations lacking MPPT control. We have observed that the system provided great efficiency for the energy generation from the solar cell in the event of using the MPPT that was used in the fuzzy logic unit.

Improved Performance in the Control of DC-DC Three-Phase Power Electronic Converter Using Fractional-Order SMC and Synergetic Controllers and RL-TD3 Agent

In this article, starting from a benchmark represented by a Direct Current-to-Direct Current (DC-DC) three-phase power electronic converter used as an interface and interconnection between the grid and a DC microgrid, we compare the performances of a series of control structures—starting with the classical proportional integrator (PI) type and continuing with more advanced ones, such as sliding mode control (SMC), integer-order synergetic, and fractional-order (FO) controllers—in terms of maintaining the constant DC voltage of the DC microgrid. We present the topology and the mathematical modeling using differential equations and transfer functions of the DC-DC three-phase power electronic converter that provides the interface between the grid and a DC microgrid. The main task of the presented control systems is to maintain the DC voltage supplied to the microgrid at an imposed constant value, regardless of the total value of the current absorbed by the consumers connected to the DC microgrid. We present the elements of fractional calculus that were used to synthesize a first set of FO PI, FO tilt-integral-derivative (TID), and FO lead-lag controllers with Matlab R2021b and the Fractional-order Modeling and Control (FOMCON) toolbox, and these controllers significantly improved the control system performance of the DC-DC three-phase power electronic converter compared to classical PI controllers. The next set of proposed and synthesized controllers were based on SMC, together with its more general and flexible synergetic control variant, and both integer-order and FO controllers were developed. The proposed control structures are cascade control structures combining the SMC properties of robustness and control over nonlinear systems for the outer voltage control loop with the use of properly tuned synergetic controllers to obtain faster response time for the inner current control loop. To achieve superior performance, this type of cascade control also used a properly trained reinforcement learning-twin delayed deep deterministic policy gradient (RL-TD3) agent, which provides correction signals overlapping with the command signals of the current and voltage controllers. We present the Matlab/Simulink R2021b implementations of the synthesized controllers and the RL-TD3 agent, along with the results of numerical simulations performed for the comparison of the performance of the control structures.

Direct-current electrical systems integration on a hybrid skidder using a parallelized step-down power converter array

This paper deals with the control of the direct-current to direct-current (DC/DC) energy conversion between high voltage and low voltage systems within a hybrid electric power-train structure intended to be used in articulated forestry tractor, also known as skidder. Electrical part of the hybrid power-train is modeled for the case of utilization of a parallel array of step-down (buck) DC/DC power converters as a bridge between the high and low voltage DC buses. Thus obtained models are used to derive the control laws for the primary-level (power converter voltage/current) control systems, and the secondary level (power allocation) control strategy, which are simulated within the MATLAB/SimulinkTM software environment, and subsequently verified by means of laboratory experiments. Final results are also used to gain insights about the efficiency of the DC/DC conversion process and to formulate practical rules for parallelized DC/DC converter operation aimed at maximization of overall DC-to-DC power conversion efficiency.

Buck-boost switched control without polarity reversal to regulate the production of direct current (DC-DC) in hybrid cars

The biggest problem that electric or hybrid vehicles present today are the amount of time required to recharge their energy, hence the importance of ensuring that the charge is not lost quickly and reducing the recharging time. We propose a more efficient energy production model to maintain the charge of the battery banks in hybrid and electric vehicles so that the autonomy time increases. A direct current to direct current (DC-DC) converter was modeled, in a buck-boost configuration that can keep the voltage constant of 50VDC powering the battery bank, with input voltages ranging between 35 and 70VDC with a fixed charging current of 4A. To automatically determine the values of the discrete components of the power filter, a MATLAB® script was developed. The transfer function of the power filter controller was calculated and simulated in open and closed loops to analyze the converter's stability. The complete circuit was tested for possible variations in voltage and load current using a Pulse-Width Modulation (PWM), with a time base of 2.4 kHz. To demonstrate the ability to perform the same function of the converter in a more stable way, digital control by PWM was implemented on a Nexys 4 development board (FPGA, Field Programmable Gate Arrays). In addition, with the advantage of reducing the variations inherent in using discrete components in an electronic circuit.Herein we disclose 1. a high-level language computer program to estimate the value of the components of the power filter that performs the energy conversion; 2. the transfer functions of the system modules; 3. the simulation of the buck-boost DC-DC converter control system without polarity inversion; and 4. the simulation of the system in digital form implemented on an FPGA.

Design Method of Double-Boost DC/DC Converter with High Voltage Gain for Electric Vehicles

Direct current to direct current (DC/DC) converters are required to have higher voltage gains in some applications for electric vehicles, high-voltage level charging systems and fuel cell electric vehicles. Therefore, it is greatly important to carry out research on high voltage gain DC/DC converters. To improve the efficiency of high voltage gain DC/DC converters and solve the problems of output voltage ripple and robustness, this paper proposes a double-boost DC/DC converter. Based on the small-signal model of the proposed converter, a double closed-loop controller with voltage–current feedback and input voltage feedforward is designed. The experimental results show that the maximum efficiency of the proposed converter exceeds 95%, and the output voltage ripple factor is 0.01. Compared with the traditional boost converter and multi-phase interleaved DC/DC converter, the proposed topology has certain advantages in terms of voltage gain, device stress, number of devices, and application of control algorithms.

Use of an in situ thermoelectric generator for electric field-assisted aerobic composting

Electric field-assisted aerobic composting (EAAC) is a simple and effective process. To further improve the EAAC process and make good use of waste heat during composting, in this study, we designed an in situ thermoelectric generator using thermoelectric sheets and applied it for EAAC. The findings show that the voltage generated was 8.8–18.6 V, and the maximum power was over 7 W. A direct current-to-direct current (DC-DC) voltage converter was used to stabilize the output at 6.0 V. Self-powered EAAC (sp-EAAC) enhanced compost maturity compared to conventional aerobic composting (CAC). The germination index reached 118% and 88% in sp-EAAC and CAC, respectively, at the end of composting. This work verified that the temperature gap between compost and the environment could be used for the EAAC process, opening a new way to recover waste heat during aerobic composting and accelerate compost maturity.

Study on structure optimization of a dual IGBT module heat sink in a DC–DC converter under natural convection based on field synergy theory

Aiming at the heat sink with dual insulated gate bipolar transistor (IGBT) modules in a direct current to direct current (DC‐DC) converter, the calculation of the temperature field of the cooling structure with low power consumption is completed by using Icepak simulation software, and analysis of the influence of the two IGBT module installation distance on the maximum temperature. The simulation results show that the maximum temperature of two heat sources decreases with the installation distance, but the maximum decline is not more than 0.5 °C. Based on field synergy theory, it is found that the local structure of the heat sink is not conducive to the natural convection heat transfer. Therefore, the improved measures of slotting the plate are proposed, and the effectiveness of this measure to reduce the heat source temperature is verified by simulation analysis and experiment. The influence of slot size on the maximum temperature of heat source is analyzed: the maximum temperature of heat source decreases with the increase of slot size. When the slot size is 16 mm, the cooling effect is obvious, and the maximum temperature drop is up to 6 °C compared with that before the slotting. Besides, the slot processing can also reduce the heat sink material and reduce the weight. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Power Sharing and Voltage Vector Distribution Model of a Dual Inverter Open-End Winding Motor Drive System for Electric Vehicles

A drive system with an open-end winding permanent magnet synchronous motor (OW-PMSM) fed by a dual inverter and powered by two independent power sources is suitable for electric vehicles. By using an energy conversion device as primary power source and an energy storage element as secondary power source, this configuration can not only lower the DC-bus voltage and extend the driving range, but also handle the power sharing between two power sources without a DC/DC (direct current to direct current) converter. Based on a drive system model with voltage vector distribution, this paper proposes a desired power sharing calculation method and three different voltage vector distribution methods. By their selection strategy the optimal voltage vector distribution method can be selected according to the operating conditions. On the basis of the integral synthesizing of the desired voltage vector, the proposed voltage vector distribution method can reduce the inverter switching frequency while making the primary power source follow its desired output power. Simulation results confirm the validity of the proposed methods, which improve the primary power source’s energy efficiency by regulating its output power and lessen inverter switching loss by reducing the switching frequency. This system also provides an approach to the energy management function of electric vehicles.

Thermal energy harvesting circuit with maximum power point tracking control for self-powered sensor node applications

We present a simple implementation of a thermal energy harvesting circuit with the maximum power point tracking (MPPT) control for self-powered miniature-sized sensor nodes. Complex start-up circuitry and direct current to direct current (DC-DC) boost converters are not required, because the output voltage of targeted thermoelectric generator (TEG) devices is high enough to drive the load applications directly. The circuit operates in the active/asleep mode to overcome the power mismatch between TEG devices and load applications. The proposed circuit was implemented using a 0.35-μm complementary metal-oxide semiconductor (CMOS) process. Experimental results confirmed correct circuit operation and demonstrated the performance of the MPPT scheme. The circuit achieved a peak power efficiency of 95.5% and an MPPT accuracy of higher than 99%.

An Improved Current-Doubler Rectifier for the Marine Controlled Source Electromagnetic Transmitter

High power marine controlled source electromagnetic transmitters have gained interest with applications in marine geological survey and mineral resources exploration. The direct current to direct current (DC-DC) converter that is typically used in marine transmitters has some issues, as the insulated-gate bipolar transistor (IGBT) tube cannot achieve zero-voltage switching (ZVS). In particular, lagging-leg switching cannot easily achieve ZVS. The conversion efficiency of the heat converter requires improvement. This paper proposes an improved current-doubler rectifier for the marine controlled source electromagnetic transmitter (ICDR-MCSET). Resonant inductance is increased and a blocking capacitor is added to the converter (DC-DC) circuit, where the converter can achieve ZVS in a wide load range. This results in the effective decrease of the heating temperature and the improvement of transformation efficiency. Saber software simulation and a 20 KW electromagnetic transmitter are used to verify the results, which show that the method is feasible and effective.

Development of Sliding Mode Controller for a Modified Boost Ćuk Converter Configuration

This paper introduces a sliding mode control (SMC)-based equivalent control method to a novel high output gain Ćuk converter. An additional inductor and capacitor improves the efficiency and output gain of the classical Ćuk converter. Classical proportional integral (PI) controllers are widely used in direct current to direct current (DC-DC) converters. However, it is a very challenging task to design a single PI controller operating in different loads and disturbances. An SMC-based equivalent control method which achieves a robust operation in a wide operation range is also proposed. Switching frequency is kept constant in appropriate intervals at different loading and disturbance conditions by implementing a dynamic hysteresis control method. Numerical simulations conducted in MATLAB/Simulink confirm the accuracy of analysis of high output gain modified Ćuk converter. In addition, the proposed equivalent control method is validated in different perturbations to demonstrate robust operation in wide operation range.

On Control of a Boost DC-DC Power Converter under Constrained Input

In this paper, a new controller for a boost DC-DC (direct current to direct current) power converter is proposed. The discussed DC-DC boost converter model considers the losses coming from the inductor and capacitor. The novel control scheme takes into account that the duty cycle is constrained to physically admissible values. The analysis of the closed-loop trajectories provides the conclusion that output voltage regulation is achieved in asymptotic form. In addition, the problem of uncertain supply voltage and unmeasurable inductor current is also addressed by using an observer together with the proposed control law. Our theoretical results are supported by using numerical simulations and experimental tests. Comparisons with respect to known approaches are presented.