Converter Circuit Research Articles

Active Equalization of Lithium Battery Pack with Adaptive Control based on DC Energy Conversion Circuit

Background:: How to solve the inconsistency of battery pack is a key point to ensure reliable operation of electric vehicles. Battery equalization is an effective measure to address the inconsistency. Passive equalization method has poor efficiency and thermal management problems. Average voltage equalization method is only suitable for situations where there is a significant voltage difference between batteries. The SOC-based equalization method is relatively difficult and may inevitably lead to the accumulation of errors during the process. Objective:: In order to avoid the disadvantages of traditional control methods, a new control method is proposed to improve the accuracy and self-adaptation of active equalization, which is easy to be realized without online calculation. Methods:: Cascaded bidirectional Buck-boost circuit is adopted as the novel equalization topology. Based on fuzzy PID theory, an adaptive digital-analog hybrid control strategy based on fuzzy PID is proposed in this paper. Parameter design of the fuzzy PID controller is carried out. A battery equalization system based on cascaded bidirectional Buck-boost circuit is designed and developed. Experimental verification is conducted on relevant hardware platforms. Results:: An adaptive digital-analog hybrid control strategy based on fuzzy PID is proposed. Compared to passive equalization, this proposed method provides high efficiency. Regarding traditional voltage control, the method improves control reliability and flexibility. Compared to the average voltage equalization method, the approach needs less convergence time. Moreover, the control method is much easier to realize than the SOC-based equalization method. Conclusion:: By using the presented adaptive control based on DC energy conversion circuit, the degree of self-adaptation of the equalization process has been obtained as higher and the inconsistency as smaller.

A bioinspired MXene-based flexible sensory neuron for tactile near-sensor computing

Multifunctional near-sensor computing sensory neurons based on the integration of flexible sensors and memristors hold promise to achieve unprecedented development in large-scale neuromorphic perception circuits and human-machine interaction systems. However, the traditional sensory-memory integrated systems are based on the integration of different device modules, which are subjected to redundant analog-to-digital conversion circuits and poor flexibility. Here, an all MXene-based flexible sensory neuron fabricated by a room temperature energy-efficient, and controllable oxidation preparation technique is reported. The near-sensor computing system is seamlessly integrated a MXene-based pressure sensor array for acquisition of tactile signals with a flexible MXene-based memristor array for simulating the implementation of perceived behavior. The tactile sensor array shows a wide range (0.1–100 kPa), high linear sensitivity (23.9 kPa−1), and the memristor array exhibits repeatable and stable bipolar resistive switching behavior (retention >100 cycles, endurance >103 s) and excellent flexibility (R=1.0 mm). As a conceptual demonstration, our devices realize high-precision recognition of handwritten digit recognition (93.21%) and human motion (97.96%), which demonstrate the feasibility for real-time health monitoring based on signals collected by sensors and artificial neural networks constructed by the memristors. The MXene-based sensor-memristor system offers a prominent contribution towards advanced application of intelligence in electronic skin and wearable electronic equipment.

Analysis, Design and Effectuation of a Tapped Inductor Current Converter with Fractional Output for Current Source Systems

This article proposes a new connection method of tapped inductors that works in the current source, which enables the current-mode power converter circuit to have a new topological relationship. Usually, in a switched-inductor circuit, a stable output multiple is obtained through the connection of the inductor and the switching devices. This is because the tapped point on the inductor varies, and the magnetomotive force (mmf) of inductance is adjusted. Thereby, the output current is controlled by the states of switching devices within a certain range. This optimized circuit structure can adjust the output current according to load changes in practical applications without changing the input power supply. The proposed method has been verified for its feasibility through detailed analysis and hardware work. The principal analysis based on the flux linkage and the PSIM simulation confirms that the theoretical circuit can be implemented. Finally, a hardware circuit is built to obtain real and feasible conclusions, and it is verified that the circuit can achieve a stable output and variable current within a specific range. The proposed work presents an alternative power conversion methodology using the active switching of mmf, and it is a stable and simple power conversion technique.

Expansion of Input Voltage Range and Signal Dynamic Range of Exponentiation Conversion Circuit

Expansion of Input Voltage Range and Signal Dynamic Range of Exponentiation Conversion Circuit

Active Filters for Standard-Compliant Power Quality in Electrical Networks

The article is devoted to the analysis of three circuits of modular multilevel converters (MMCS) with cascade connection of single-phase bridge and half-bridge voltage converters, each of which operates in pulse width modulation (PWM) mode. The main feature of active filters based on MMS is the possibility of selective high-speed harmonic filtering in on–line mode: AF allows the suppression of any given set of harmonics, including the negative harmonic of the fundamental frequency (reverse sequence), with a given degree of suppression - to zero or a normalized value - by an appropriate task in the control program. For the practical implementation of MMS in solving problems of normalization of electricity quality indicators, the so-called DSB control algorithm of MMS was developed, based on the traditional "classical" theory of automatic control and the theory of three-phase circuits. A comparative assessment of the use of various MMC schemes for symmetry and reactive power compensation has been carried out. It is shown that the problem of voltage symmetry using MMS is a special one, requiring the use of special algorithms to solve it, ensuring the reactive nature of branches of MMS circuits.

Development of modular dynamic code for steam power conversion system in sodium-cooled fast reactor

Sodium-cooled fast reactor (SFR) is one of the most promising Generation IV reactor types. To improve operational safety and economy, SFR requires accurate prediction of the steam power conversion system. Therefore, a one-dimensional thermal-hydraulic analysis code of the steam power conversion system of SFR is developed in this study where each equipment is packaged as a separate module with modular modeling method. JFNK is adopted to solve ODE in this code, which expand the universality of the code. The model is validated by comparing with design results from the Daya Bay nuclear power plant and the BN-600 steam generator. The maximum relative errors for pressure and temperature are 5.44% and 2.40%, respectively. After validation of the code, the steady-state analysis of the SFR steam power conversion circuit is carried out where the flow and heat transfer process of key equipment can be accurately simulated considering a complete steam power conversion cycle. This work provides reference value for the thermal-hydraulic characteristics of steam power conversion system in SFR.

A Precision Measurement System Design for Electrical Conductivity in the Low-Concentration TOC Analysis of the Ultra-pure Water

The concentration of total organic carbon (TOC) in water is an important key indicator of the quality of Ultra-pure water, which is useful in the semiconductor and pharmaceutical industries, among others. Therefore, as a technology to measure TOC, a technology that measures the amount of carbon dioxide (CO<sub>2</sub>) by electrical conductivity is being developed. This method uses ultraviolet light and an oxidizing agent to oxidize organic compounds to produce CO<sub>2</sub>, and measures the concentration of CO<sub>2</sub> by measuring the electrical conductivity based on the permeable membrane of the gas, and then converts it to the concentration of TOC in the organic compound. In this study, we presented the design conditions of the alternating current control circuit applied between the two electrodes of the electrical conductivity cell, the microcurrent signal detection, voltage conversion circuit, and the amplification and noise reduction circuit for measuring the low concentration of TOC required for ultrapure water. Based on the optimal design conditions, we have fabricated a PCB for ultra-precise electrical conductivity measurement for low concentration TOC analysis using membrane conductivity, and have compared the results with a commercial product.

Investigation on the Effect of Parasitic Elements on PID Control of DC-DC Buck Converter

DC-DC converter circuits are used in many electronic devices to adjust the voltage to a certain level such as Electric Vehicle. DC-DC Buck converters, which are the most used type of DC-DC converters, reduce the input voltage and keep the output voltage constant at a desired reference voltage value. In this study, the effect of parasitic elements in Buck DC-DC converters is examined on the PID controllers. Parasitic elements cause a non-linear effect on the Buck converter system model. Studies in the literature generally control the output voltage by designing controllers on the Buck converter model without parasitic elements. Alternatively, linear controllers such as PID are designed according to the linearizing model, taking into account the effect of parasitic elements. In addition, nonlinear controllers are designed on the full model with the effect of parasitic elements. In this study, the effect of parasitic elements on linear controllers, especially PID, is examined.

Cross-waveband optical computing imaging.

A novel, to the best of our knowledge, cross-spectral optical computing imaging experiment has been achieved through a single exposure of a charge-coupled device. The experimental setup integrates single-pixel imaging (SPI) with ghost imaging (GI) through a photoelectric conversion circuit and a synchronous modulation system. The experimental process involves modulation in one wavelength band (in SPI) and demodulation using the GI algorithm in another. Significantly, our approach utilizes optical computing demodulation, a departure from the conventional electronic demodulation in GI (SPI), which involves the convolution between the bucket optical signals and the modulated patterns on the digital micromirror device. A proof-of-concept cross-band imaging experiment from near-infrared to visible light has been carried out. The results highlight the system's ability to capture images at up to 20 frames per second using near-infrared illumination, which are then reconstructed in the visible light spectrum. This success not only validates the feasibility of our approach but also expands the potential applications in the SPI or GI fields, particularly in scenarios where two-dimensional detector arrays are either unavailable or prohibitively expensive in certain electromagnetic spectra such as x-ray and terahertz.

Enabling of CMOS Circuit using Dual Material Gate Germanium Pocket Induced FDSOI MOSFET

This research presents a comparison of the electrical performance of a double-side induced germanium-pocket (IGP) FD-SOI MOSFET and a dual material gate IGPFDSOI (DIGPFDSOI). The electrical performance is reviewed by comparing the device parameters like drain current, band diagram, lateral electric field, surface potential, and work function of the gate material. The proposed structure exhibits excellent characteristics compared to the IGPFDSOI MOSFET. The proposed structure has a greater Ion/Ioff ratio, a lower subthreshold slope, reduced capacitance, and an elevated cut-off frequency. The implementation of a dual metal gate is considered a superior method in comparison to FD-SOI technology because it effectively reduces the negative effects of scaling. A study is being done to analyze the differences in the work functions of metal gates to evaluate the effectiveness of the proposed construction. The comparison evaluation shows that the suggested design can be used for both digital and analog tasks because it has a higher switching frequency and a better cut-off frequency. Apart from this, the proposed structure can also be implemented without making substantial changes to the conventional FD-SOI MOSFET fabrication process flow. Here, we are using n-type and p-type DIGPFDSOI MOSFETs to make a CMOS converter circuit. Sentaurus TCAD is used to simulate and analyze the performance of the proposed structure.

Maximum Power Point Tracking Control Method of Photovoltaic Cell under Shadow Influence

In view of the poor effect of battery power tracking control in the current solar power generation system, the maximum power point tracking (MPPT) control method of photovoltaic cell under the influence of shadow is proposed. The MPPT control method of photovoltaic cell is optimized by using the influence of shadow, the structural characteristics of photovoltaic cell are optimized, and the voltage rise and fall DC / DC conversion circuit is adopted, The maximum power identification algorithm of photovoltaic cells is set, and the voltage disturbance method is used to realize the MPPT, so that the solar photovoltaic cells always maintain the maximum power output, so as to ensure the control effect. Finally, the experiment shows that the MPPT control method of photovoltaic cells has high practicability and fully meets the research requirements.

Realization of a Novel Artificial Intelligence Fuzzy Controller with Solar Irradiance-altered Maximum Power

This paper reports the realization of a novel artificial intelligence fuzzy Logic controller (AI-FLC) that attained the optimum power of the photovoltaic cell (PV array) with solar irradiance altered (from 300 to 1000 w/m2) using the boost-converter circuit. Experiments were conducted using the Simulink /MATLAB coding. The nonlinear current-voltage character of the PV array was observed to be affected by the weather conditions, solar irradiance level, and ambient temperature. In addition, unique maximum power point for each irradiance level was achieved which was ascribed to the rapid response of the FLC to the atmospheric changes without requiring any system parameters. The obtained accuracy was as much as 98.875%. The post converter circuit was connected to the buck converter for taking the advantage of the generated power, thereby stabilizing the synchronous generator-emanated voltage. The response of the proposed system was demonstrated to be better than the conventional PD control, wherein the output voltage was stable at 220 V even at low levels of the solar irradiance.

A 0.5–15 GHz reconfigurable IR-UWB receiver in 28 nm CMOS

A 0.5–15 GHz ultra-wideband (UWB) RF reconfigurable receiver in UMC 28 nm CMOS used for IR-UWB (impulse radio UWB) radar system is proposed in this paper. This receiver employs a 0.5–8 GHz path and an 8–15 GHz path to achieve the wide frequency band, and we proposed an RF channel select voltage-to-time converter (VTC) circuit. Two different low noise amplifiers (LNAs) are adopted in the two paths to obtain the high performance of noise figure (NF) and gain. The common drain stage and resistance negative feedback technology as well as the source degeneration inductive technology are introduced to achieve a high flat gain and fine input matching. The R-2R variable load network of a programable gain amplifier (PGA) gives it a nearly 24 dB dynamic range and approximately linear gain control. A 500MS/s time domain analog to digital converter (TD-ADC) with an equivalent sampling rate of 16GS/s is shared for the two paths which can realize the direct RF sampling. The input RF signal path selection is implemented by configuring the Band_sel signal. The receiver has reconfigurability of the RF front end and better power consumption and area. In the frequency of 0.5–8 GHz, the S11 is below −7.9 dB and the NF is smaller than 6 dB. In the frequency of 8–15 GHz, the S11 is below −8dB and the NF is smaller than 11 dB. The receiver dissipates 242.72mW with an area of 1.01 mm2

NÂNG CAO CHẤT LƯỢNG ĐIỆN ÁP RA NGHỊCH LƯU CẦU H NHỜ GIẢM TỔNG LƯỢNG SÓNG HÀI BẰNG CÁCH THAY ĐỔI THỜI GIAN PHÂN BỐ TRẠNG THÁI ĐIỆN ÁP 0 VÀ KHÁC 0

This article proposes a plan to improve the quality of the output AC voltage of the H-bridge inverter based on the change of the law of distribution of zero and non-zero voltage states of the inverter when controlling the H-bridge inverter. The results were surveyed, analyzed, compared, and evaluated by simulation model on Matlab-Simulink software. In which the fundamental harmonic level index and the total harmonic distortion (THD) are used to compare, analyze and evaluate the quality of H-bridge inverter output voltages in different switching modes such as pulse width modulation according to sine law (sinPWM), pulse width adjustment (SIR) and the proposed improved pulse width modulation law. The results show that the H-bridge inverter output voltage form with improved sequential switching law gives better quality than the original. This result has practical significance in the research and design of power conversion circuits for AC power transmission systems.

Modeling of memory effects in nanofluidic diodes

Nanofluidic diodes and ionic solutions find application in electrochemical circuits for information processing, controlled release, and signal conversion in hybrid devices. Here, we describe a physical model that accounts for the memory effects observed in conical nanopores in terms of the driving signal and ionic solution characteristics. The concepts invoked describe the device operation on the basis of the electrical interaction between the pore surface charges and the nanoconfined ionic solution. The physical insights provided can explain the experimental dependence of the nanofluidic tunability on the amplitude and frequency of the driving signal, the ionic concentration, and the solution pH. The model should also be useful for the design of electrochemical circuits based on ionic conduction in asymmetric memristors.

Design and implementation of a low-cost circuit for medium-speed flash analog to digital conversions

Despite the considerable advancements in analog-to-digital conversion (ADC) circuits, many papers neglect several crucial considerations: Firstly, it does not ensure that ADCs work well in the software or hardware. Secondly, it is not certain that ADCs have a wide range of amplitude responses for the input voltages to be convenient in many applications, especially in electronics, communications, computer vision, CubeSat circuits, and subsystems. Finally, many of these ADCs need to look at the suitability of the proposed circuit to the most extensive range of frequencies. In this paper, a design of a low-cost circuit is proposed for medium-speed flash ADCs. The proposed circuit is simulated based on a set of electronic components with specific values to achieve high stability operation for a wide range of frequencies and voltages, whether in software or hardware. This circuit is practically implemented and experimentally tested. The proposed design aims to achieve high efficiency in the sampling process over a range of amplitudes from 10 mV to 10 V. The proposed circuit operates at a bandwidth of frequencies from 0 Hz to greater than 10 kHz in the simulation and hardware implementation.

Dual Frequency Energy Harvesting System Based on Planar Inverted F-shaped Antenna

<p>With the expansion of Internet of things (IoT) scale and the extension of its application fields, node energy acquisition has become one of the constraints on the development and application of IoT technology. Wireless energy acquisition is faced with the challenge of how to enhance power conversion efficiency under low input power in the broadband range. This study aimed to improve the capability of energy collection and transmission in wireless communication, an efficient dual-frequency energy harvesting system was proposed, moreover a novel dual-frequency planar inverted-f antenna (PIFA) and its energy conversion circuit for Radio frequency (RF) energy harvesting were designed by studying the characteristics of ambient RF energy and antenna. The developed antenna is designed and manufactured for GSM 900mhz or DCS 1.8 GHz to harvest the ambient energy provided by nearby devices. It is proved that the new dual-frequency antenna still has high efficiency when the input power is less than -20 dbm, and can maximize the receiving energy. The system works with an energy conversion and storage module to convert weak signals into required voltages, the simulation and test results show that the maximum conversion efficiency of the prototype is about 65% at 920MHZ and 1.8GHz at -20 dBm input power.</p> <p> </p>

(MIMO Buck Converter) Multi-Input Multi-Output DC-DC Buck Converter

Abstract: Designs of the power electronics circuitry are nowadays reducing the size, space, and weight of converter and inverter circuits. This is possible because of the availability of new high-switching frequency devices. This paper presents a generalized model of buck converters that is multi-input multi-output(MIMO) fixed and variable. The converter used for stepping down the voltage is called a buck converter. The buck converter is designed, analyzed simulated & developed. The proposed model of this Buck converter consists of two parts: (a) Main converter circuits with the components like switch, inductor, diode, capacitor, and load, (b) A control circuit for controlling the operation of the switch using 10 10-turn potentiometer. This model can accurately give the power output voltage.

Анализ электромагнитных процессов блока возбуждения трехкаскадного стартер-генератора для авиационной энергосистемы

This article discusses the excitation system of a three-stage synchronous generator for aviation use in two distinctive modes of operation: as an electric power generator for an on-board power supply system and an electric starter for gas turbine engines of the aircraft. The article presents the calculation of the starter and generator operating modes of the excitation system. The basic design relations for the semiconductor converter circuit have been obtained and confirmed by simulation modeling in the PowerSIM environment. The problem of synthesizing an automatic control system for the TSG excitation unit operating as part of an on-board power supply system using a method for calculating the parameters of regulators based on the motion separation method has been solved. A two-circuit control system has been created for the generator mode of operation, including PI and PID regulators with output voltage regulation of the main generating stage. To control the excitation unit in the electric star¬ter mode of operation, a single-circuit control system for the current of the excitation winding with the addition of a resonant component has been designed. The evaluation of the efficiency of the designed control systems was carried out on the basis of simulation modeling using PowerSIM and MATLAB/Simulink application software packages for a generator feeding a three-phase AC network in accordance with the requirements of GOST R 54073-2017.The results of mathematical modeling formed the basis for the design of an experimental sample of the power unit in a hybrid integrated design for the TSG voltage regulation system.

PSO Training Neural Network MPPT with CUK Converter Topology for Stand-Alone PV Systems Under Varying Load and Climatic Conditions

Temperature and irradiance levels are two examples of environmental variables that affect the power value produced by photovoltaic panels. Therefore, in order to transfer the maximum power value from the PV panel to the load under varying climatic conditions, maximum power point tracking (MPPT) algorithms and DC-DC converter topologies are used. In this study, the performances of boost converter and CUK converter circuit topologies are investigated under variable irradiance and variable load conditions by using a neural network-based MPPT algorithm learning particle swarm optimization (PSO). As the first scenario, it is analyzed assuming that the temperature and irradiance values coming to the panel are constant. As the second scenario, the performance evaluation of the converter topologies according to the current, voltage and power parameters is made for the variable load situation. As the last scenario, the difference in the irradiance value coming to the panel depending on the sun's condition during the day has been examined. Canadian Solar CS6P-250P PV panel is used in the study. 50 kHz is selected as the switching frequency. According to the results obtained, it has been observed that the CUK converter circuit topology reaches the maximum power point faster than the boost converter circuit topology both in dynamic environmental conditions and load change, and the oscillation at this point is less. It is aimed to increase the performance of this method, which uses boost converter topology and MPPT in the literature, by applying CUK converter topology.