Change In Output Voltage Research Articles

The Effect of Throttle Signal Output Voltage Variation and Load on Current Consumption

Many electric motorcycle users complain about the difficulty in controlling acceleration with precision, especially if they have never ridden a motorized vehicle before. This control difficulty is a result of the characteristics of BLDC motors, which have high torque instantly. While this characteristic is generally considered an advantage, in this discussion it is a disadvantage that can reduce rider comfort when operating an electric motorcycle. When the rider twists the throttle for the first time, the electric motor immediately spins at maximum power. The issues mentioned serve as the background for the this research entitled "The Effect of Throttle Signal Output Voltage Variations and Load on Current Consumption and BLDC Motor Speed in Electric Motorcycles."The method used in this research is an experimental method by varying the load at 60 kg, 70 kg, and 80 kg and three levels of throttle output voltage changes.The results of this study show that changes in load and throttle output voltage affect current consumption and BLDC motor speed. The highest current consumption is achieved when the vehicle is loaded with 80 kg and using mode 1 at 3.5309 A. The lowest current consumption is achieved when the vehicle is loaded with 60 kg and using mode 3 at 1.4403 A. The highest rotational speed is obtained in mode 1 with a 60 kg load at 219.341 rpm. The lowest rotational speed is obtained in mode 3 with an 80 kg load at 141.37 rpm.

Design of single-phase shifted full-bridge inverter voltage regulation system based on voltage-controlled closed-loop control and LLC resonant network

Abstract The phase-shifted full-bridge inverter is widely used in the field of power electronics technology, aiming to achieve precise regulation of the output voltage and improve the stability and efficiency of the power system. This paper proposes a single-phase phase-shift full-bridge inverter voltage regulation system and its parameter design method based on the LLC resonant network. Combined with voltage-controlled closed-loop control and APFC technology, the working mode of the system circuit is analyzed, and the system parameters are designed. The system simulation model is built in MATLAB/Simulink. The constant voltage output of the system is realized, the power factor is greater than 96%, and the relative error of the output voltage change is less than 2%.

Influence of Hydration and Temperature on the NaxCO2 Based Transducer Voltage.

This paper presents an experimental approach to maximizing the voltage generated by NaxCoO2 and improving the overall efficiency of the p-type thermoelectric leg by doping with Na up to x = 0.88. Two samples with different geometries were tested, each measured with and without an additional magnetic field applied in the direction of the temperature gradient. The properties of sodium cobaltite in response to hydration were explored, at temperatures between 300 and 380 K. Water injection boosted the current and power up to 75-100 µW at a temperature of 350-360 K. This power boost can be attributed to an electron-ion fluid flow pattern maintained by the longitudinal thermomagnetic effect and by water molecules forming hydrogen bonds with oxygen atoms in the CoO2 layers, inside the material. An electronic circuit was designed to boost the voltage to the desired level, for three or more sodium cobaltite samples mounted in parallel, and to store the energy in a supercapacitor. The output voltage and resistivity change of sodium cobaltite samples can be readily used as a humidity and temperature-sensing element in a transducer when paired with an appropriate electronic conditioning scheme.

High efficiency AOT-controlled boost converter with pseudo-constant switching frequency

An on-time generator for boost converters is proposed to achieve an adaptive on-time (AOT) control with pseudo-constant frequency in continuous conduction mode (CCM). Since the first-order parasitic effect of the components and devices is considered in the design of the on-time generator, the switching frequency (fsw) variation of the boost converter in CCM can be better suppressed with the load current (ILOAD), input voltage (VIN) and output voltage (VOUT) changes, which can effectively solve the EMI noise problem. In addition, the idea of capacitor pre-charging is applied to simplifying circuit complexity. Meanwhile, an on-demand modulation strategy is applied to improve the conversion efficiency. Simulation results show that the boost converter based on the proposed on-time generator can realize the fsw variation of 0.4 % in case of 200 mA ILOAD change. Moreover, the VIN may range from 0.8 to 1.5 V, the VOUT is set to 1.8 V, and the peak efficiency of the simulation is 96.9 %.

Non-volatile Fermi level tuning for the control of spin-charge conversion at room temperature

Current silicon-based CMOS devices face physical limitations in downscaling size and power loss, restricting their capability to meet the demands for data storage and information processing of emerging technologies. One possible alternative is to encode the information in a non-volatile magnetic state and manipulate this spin state electronically, as in spintronics. However, current spintronic devices rely on the current-driven control of magnetization, which involves Joule heating and power dissipation. This limitation has motivated intense research into the voltage-driven manipulation of spin signals to achieve energy-efficient device operation. Here, we show non-volatile control of spin-charge conversion at room temperature in graphene-based heterostructures through Fermi level tuning. We use a polymeric ferroelectric film to induce non-volatile charging in graphene. To demonstrate the switching of spin-to-charge conversion we perform ferromagnetic resonance and inverse Edelstein effect experiments. The sign change of output voltage is derived by the change of carrier type, which can be achieved solely by a voltage pulse. Our results provide an alternative approach for the electric-field control of spin-charge conversion, which constitutes a building block for the next generation of spin-orbitronic memory and logic devices.

Analysis of Control Strategy Based on P&G Algorithm for the Switching Component of Wireless Solar Power Transfer

Previous researchers have studied wireless power transfer (WPT), while the current study focused on converting DC voltage to AC voltage on the transmitting coil and transferring it to the receiving coil. Previous studies did not discuss the control technique to drive the switching component on the converter circuit, especially the change controller in DC voltage and current affecting the WPT performance. This paper discussed a control strategy based on the P&O algorithm for driving MOSFETs on the half H-bridge inverter of a wireless solar power transfer (WSPT) system. This system is constructed by PV modules as the main DC voltage source, a control strategy based on the perturb and observe (P&O) algorithm, a half H-bridge inverter, and a transmitting and receiving circuit. The WSPT system was modelled using MATLAB SIMULINK with various solar irradiance, and its performance was assessed. The results show that the change in the total output voltage and power of PV modules can be controlled by the P&O algorithm as the signal input of the PWM generator applied to drive the MOSFETs. There are no transient values of voltage waveform on the transmitting and receiving circuit when the transient total output voltage of PV modules occurs. It indicates that the P&O algorithm can effectively manage the PWM generator for its input signal, including the total output voltage and current produced by PV modules.

Study on the Design of Series-Type All-DC Wind Farms Based on Half-Bridge Voltage Balancing Circuits

Offshore wind farms connected in series, with each wind turbine connected in series with one another, enhance the coupling between them. Significant differences in wind speeds between neighboring DC wind turbines (DCWTs) might result in a substantial disparity in the output voltage, hence posing a risk of overvoltage. Nevertheless, implementing voltage-limiting configurations for DCWTs might lead to the dissipation of wind energy, thereby diminishing the wind farm’s capacity to deliver electricity. This work introduces a half-bridge voltage balancing circuit (HVBC) topology as a solution to the issue of DCWT output voltage changes affecting the stable operation of wind farms. The proposed HVBC topology is designed specifically for large-capacity series-connected all-DC wind farms where wind speed variations occur. This design achieves power decoupling for series-connected all-DC wind farms by providing current compensation to the series-connected DCWTs. A control strategy is devised by examining the decoupling principle and operational characteristics of the HVBC. A 60 kV/48 MW tandem-type all-DC wind farm model consisting of six DCWTs in series is built in Matlab/Simulink. The model is then simulated to evaluate its performance under conditions of unequal wind speed, rapid changes in wind speed, and wind turbine failure shutdown. This research verifies the feasibility of the HVBC topology and improves the stability of the series-type all-DC wind farm.

A wide-output buck DC-DC power management IC

-This article designs and develops a wide-input voltage, high-efficiency, small-size, and peak current-mode control step-down DC-DC converter. The Cadence Spectre simulation tool is used for system simulation to verify the performance of the chip. The overall research content of the article includes the function of the output under heavy load, light load and the stability of the output under transient load changes. The specific content of the research is buck synchronous step-down DC-DC converter chip with pulse modulated. It is provided with an input-voltage range of 6 V–80 V and maximum output-voltage range 72 V. The chip possesses wide operating temperature range of −20 °C to 130 °C. The 92 % high-efficiency can be achieved by using a PWM/PFM hybrid modulation method. When achieving transient load jump, the output voltage change shall not exceed 150 mV. The maximum load current of the chip is 1 A. Furthermore, the chip is packaged and samples can be obtained, and the output light load/heavy load, and other functions are tested through the circuit board. In addition, the chip achieved tape out by using 0.18 μm CMOS process with size of 2027 μm × 2020 μm. The converter features current mode control to simplify external compensation and optimize transient response through a wide range of inductors and output capacitors. It can be adopted user-programmable soft-start time to prevent inrush current during startup. It also includes thermal shutdown protection to provide safe and smooth operation in operating conditions.

Design of High-Reliability Low-Dropout Regulator Combined with Silicon Controlled Rectifier-Based Electrostatic Discharge Protection Circuit Using Dynamic Dual Buffer

Overshoot and undershoot caused by the current load impact the accuracy of the required output voltage and circuit performance. The transient response issue in existing low-dropout (LDO) regulators is a dynamic specification that must be addressed at the design stage. This transient response is influenced by system parameters such as stability and gain. The LDO regulator suggested in this study is designed to minimize the change in output voltage by considerably enhancing the gain using a dynamic dual buffer structure. A dynamic dual buffer is utilized to effectively control undershoot and overshoot. Under the conditions that the input voltage range is from 3.3 to 4.5 V, the maximum load current is 300 mA, the output voltage is 3 V, and the output of the proposed LDO regulator with the dynamic dual buffer structure has undershoot and overshoot voltages of 41 mV and 31 mV, respectively. That is, the output voltage of the proposed LDO regulator effectively provided and discharged an additional current suited for the undershoot/overshoot conditions to enhance the transient response characteristics. Furthermore, the electrostatic discharge (ESD) robustness characteristics of the proposed LDO regulator improved because of the silicon-controlled rectifier underlying the ESD protection device embedded in the output node and power line.

Advanced Multi-Sampling PWM Technique for Single-Inductor MIMO DC-DC Converter in Electric Vehicles

Amongst the various topologies of multi-input multi-output (MIMO) DC-DC converters, single-inductor MIMO (SI-MIMO) converters have the advantages of a reduced component count, a simpler structure, and low cost. These converters are suitable in electric vehicle (EV) applications involving variable ports, essential for performing different functions. Digital control in SI-MIMO converters is promising for enhancing transient performance due to its numerous benefits. However, delays in digital control, particularly computational and pulse width modulation (PWM) delays, can negatively impact the performance of DC-DC converters. Multi-sampling and double PWM update methods can mitigate these control delays, but they often necessitate complex control schemes, adding computational burden. In this work, an advanced multi-sampling PWM technique, integrating sample shift and multi-sampling, is proposed while employing a simple digital PID control scheme. The proposed method was tested for a shared-switch SI-MIMO converter with battery discharging and charging modes in the MATLAB/Simulink environment and compared with the conventional single- and multi-sampling PWM methods. The results demonstrated that the proposed method significantly improved the converter performance, surpassing the conventional single- and multi-sampling PWM methods. In the battery discharging mode, utilizing the proposed method, the output voltage achieved a settling time of 0.075 s in response to a step change in its reference, significantly outperforming multi-sampling, which yielded a settling time of 0.124 s, and single sampling, which exhibited an even longer settling time of 0.898 s. It also demonstrated a minimal overshoot of 0.06 volts compared to 1.5 volts with multi-sampling during the step change in the input voltage. Similarly, in the battery charging mode, upon a step change in the reference output voltage, the proposed method effectively minimized the overshoot of the output voltage to 0.845 volts compared to 1.175 volts with multi-sampling, and it decreased the inductor current settling time to 0.296 s from 0.330 s recorded under multi-sampling. These findings underscore the potential of the proposed method in enhancing the digital control performance of SI-MIMO DC-DC converters in electric vehicles.

ANFIS-based power management and islanding detection utilizing permeation rate(γ) and relaxation parameter(ζ) for optimal operation of multiple grid-connected microgrids

Microgrid(s) integration into distribution networks and the growing use of Distributed Generation Systems necessitate the switch from traditional fossil fuel-based power generation methods to renewable resource-based ones. To achieve optimal power delivery, an adaptive method for solving power quality delivery problems posed by this transition is required. Unexpected islanding is an important power security concern that can lead to equipment damage, electrical risks, and decrease in power quality delivery. To address this problem, ANFIS-Based power management and islanding detection utilizing permeation rate(γ) and relaxation parameter(ζ) is proposed in this paper based on a rate of change of output voltage(ROCOV) of power sources at the point of common coupling in a 34-bus distribution network. Modeling of the distribution network, distributed generators, ANFIS training, and simulations was done using MATLAB/Simulink software. Results show that a 0.3 and 1.01 value indicates permeation rate of Microgrid(s) in a grid-tied mode whereas a 0 value indicates relaxation parameter of Microgrid(s) disconnected from the main distribution network. Islanding detection time of 0.02 sec was recorded when all Microgrids were disconnected during disturbances, and a 0.04 sec islanding detection time for disconnecting individual power sources at a time was recorded respectively. In general, islanding causes a system nominal voltage(400 V) deviation of 7 %. However, this was quickly restored without causing network voltage fluctuations due to the adaptive nature of ANFIS. Comprehensive simulations were used to validate the suggested method. The outcomes demonstrated that the proposed approach effectively distinguishes between islanding and non-islanding events and can quickly and accurately identify islanding as compared to other related works.

Solar Panel Dirt Detection and Cleaning System

The proposed solar panel dirt detection and cleaning system improves the efficiency in generating output voltage that integrates Arduino micro-controller with voltage recognition technology to enhance the efficiency of solar energy harvesting. The system utilizes voltage divider circuit to identify dirt or debris on the solar panel surface by analyzing changes in output voltage produced by the solar panel. Along with voltage divider circuit, LDR (Light Dependent Resistor) sensor is utilized to enable the cleaning process only in day time when the intensity level of the LDR is more than threshold value. Upon detection, the Arduino micro-controller triggers a cleaning mechanism to remove the identified dirt. The cleaning mechanism can be designed using actuators, brushes and other appropriate tools. The Arduino's programmability allows for customization of cleaning intervals, ensuring timely maintenance.

CuO NWs boosted triboelectric microfluidic nanosensor functionalized by collagen-protein interactions for real-time platelet count monitoring

Blood platelet count significantly affects the development of severe conditions like myocardial infarction, peripheral arterial ischemia, respiratory compromise, stroke, diabetes, coronavirus disease 2019 (COVID-19), along with chemotherapy patients and those suffering cardiovascular diseases (CVDs). These conditions necessitate frequent monitoring of platelet counts to guide diagnostic and therapeutic decisions. However, existing techniques are relatively time-consuming, lack of accuracy and require precise operation. The emergence of these severe diseases underscored the need to develop advanced platelet count-monitoring techniques which are rapid, highly precise, and conveniently portable for point-of-care applications. In this study, we emphasized the development of a triboelectric microfluidic nanosensor (TMNS) for platelet quantification through the assessment of flow resistance. The functionality of TMNS device is based on immobilization of platelets on a collagen layer coated inside a microfluidic channel. The triboelectric voltage output is measured as a detection signal of the flow resistance and is enhanced by incorporating high surface area copper oxide nanowires (CuO NWs) on the interior of copper tubes. These copper tubes serve as terminal electrodes and for flow guiding. The flow resistance of plasma solutions is elevated when the platelet concentration increases due to heightened adherence of platelets onto the collagen layer. Variations in flow resistance induce alterations in contact electrification, causing changes in output voltage at load terminals. Fine-tuning of the TMNS device was achieved by optimizing the channel width and length, flowing liquid viscosity, and voltage measurement technique. Platelet quantification sensing data were acquired through the combination of platelet-rich plasma (PRP) and platelet-poor plasma (PPP) solutions. The described device exhibits promising capabilities for platelet-count monitoring in whole-blood samples collected from three distinct patient groups, showcasing its potential impact in precise point-of-care applications.

The Study on Single-Event Effects and Hardening Analysis of Frequency Divider Circuits Based on InP HBT Process.

The single-event effects (SEEs) of frequency divider circuits and the radiation tolerance of the hardened circuit are studied in this paper. Based on the experimental results of SEEs in InP HBTs, a transient current model for sensitive transistors is established, taking into account the influence of factors such as laser energy, base-collector junction voltage, and radiation position. Moreover, the SEEs of the (2:1) static frequency divider circuit with the InP DHBT process are simulated under different laser energies by adding the transient current model at sensitive nodes. The effect of the time relationship between the pulsed laser and clock signal are discussed. Changes in differential output voltage and the degradation mechanism of unhardened circuits are analyzed, which are mainly attributed to the cross-coupling effect between the transistors in the differential pair. Furthermore, the inverted output is directly connected to the input, leading to a feedback loop and causing significant logic upsets. Finally, an effective hardened method is proposed to provide redundancy and mitigate the impacts of SEEs on the divider. The simulation results demonstrate a notable improvement in the radiation tolerance of the divider.

LPG gas leakage detection using ESP32

This research paper presents the development of an LPG gas detection system utilizing the capabilities of the ESP32 microcontroller and email notification functionalities. Liquefied Petroleum Gas (LPG), a widely used fuel source, poses a significant threat due to potential fire and explosion hazards in case of leaks. This project addresses this concern by proposing a cost-effective and user-friendly solution for early leak detection. The system employs an MQ-series sensor specifically designed for LPG detection. The sensor's output voltage changes in response to LPG concentration in the surrounding air. This data is acquired by the ESP32 microcontroller and processed to trigger email notifications when gas levels exceed a pre-defined threshold indicative of a potential leak. This allows for remote monitoring and prompt intervention, potentially mitigating safety risks associated with LPG usage in homes and industries. The paper further discusses the system's functionality, development process, and potential applications, along with suggestions for future improvements. Keywords— LPG gas detection, ESP32, MQ-series sensor, email notification, leak detection, safety system, Internet of Things (IoT), microcontroller, sensor data acquisition

Development of method for frequency regulation of output current in high-voltage transformerless resonant chargers of capacitive energy storage devices

The object of research is high-voltage systems of electric discharge installations for various technological purposes. The work reports solving the problem of enabling the rate of charging of a capacitive energy storage, set by the requirements of a certain high-voltage technology. The quantitative characteristics of the deviation of the output current of the resonant inverter from the set stabilized value when changing the switching frequency of inverter switches in the range of output voltage change from 0 to 20 kV were determined. Using the Fourier transform of the rectangular input voltage, the frequency regulation possibility of the output current of the charger for capacitive energy storage devices was analyzed. Estimation dependences of the output current of resonant inverter on the load resistance and frequency deviation from resonant frequency were derived. These dependences could be used to implement frequency control over the switching inverter transistors, with the help of which the given effective value of the output current of the resonant inverter is obtained. A method of frequency regulation of the output current in high-voltage transformerless resonant charging devices of capacitive energy storage devices has been developed. Special feature of this method is that it is based on the frequency dependence of reactive resistances of the inductance and capacitance of the resonant circuit connected in series. Owing to that, it makes it possible to adjust the switching frequency of the inverter’s power switches depending on the relative resistance of the load and the specified growth rate of the capacitive energy storage voltage. The results reported here could be used in the design of benches for testing the electrical strength of high-voltage cables, as well as for the construction of high-voltage transformerless chargers in systems of electric discharge impulse processing of materials

Consensus based distributed secondary control for current sharing and voltage restoration considering local loads and constant power loads in dc microgrids

ABSTRACT Ensuring accurate current sharing and regulating output voltage is challenging in DC microgrids. Conventional droop control has limitations in achieving voltage regulation and accurate current sharing. Unequal transmission line resistances, local loads, and constant power load (CPL) add to the complexity. To tackle this issue, this paper presents a novel consensus based distributed secondary control that determines the resistance of transmission lines by injecting an external pulse to the reference voltage of each converter, and then measuring the resulting changes in output voltage and current. The proposed secondary control signal, denoted as ψi , enables simultaneous proportional current sharing and voltage restoration in the DC microgrid. To guarantee the stability of the proposed method, a comprehensive stability analysis of the system is performed. In contrast to similar methods, the proposed method enables achieving precise proportional current sharing and voltage restoration, even when faced with varying resistive loads and CPLs. Furthermore, the proposed method exhibits remarkable features including, high convergence speed, the capability to determine transmission line resistances instead of assuming them to be known, and robustness in plug-and-play scenarios and communication system failures. The proposed method is validated through simulations in MATLAB and experimental tests, affirming its effectiveness.

Modelling for Multiport Converter-based Hybrid Power supply for Renewable Energy Source Application

This research work deals with the design, modeling and technical evaluation of multiport modular converter based hybrid Power supply using solar PV for small village. The village’s maximum power demand is 50kvA, consisting of demands of twenty (20) households. The first converter in the proposed multiport system is a high frequency isolated DC-DC converter fed with HVDC link yielding an output voltage of 700vDC. The isolated DC-DC converter uses a medium frequency transformer with primary and secondary side converters in input-series output-parallel (ISOP) configuration. Also, the output of first converter is connected to a solar PV and battery system through a buck-boost converter. The second converter in the system is solar PV fed three phase modular inverter designed to have output AC line voltage of 0.415 kV. The three phase inverter is based on modular multilevel converter (MMC) with interleaved modulation techniques. A silicon carbide power MOSFETs, with model numbers CPM3-10000-0270(CREE) and SD11703 (Solitron) are used as a building blocks for isolated DC-DC converter. On the other hand, SiC -MOSFET with part number SCT3017AL (RHOM) is used as basic building block for modular inverter. A solar PV module with open circuit voltage of 85V and maximum power rating of 415W is used to feed the inverter. Different scenarios such as changes in load and changes in solar irradiance are used for critically evaluating the performances of the system under question. The output voltage THD, current distortions, changes in the converter output voltage, current magnitude and converter efficiency are used for performance evaluation of the system under consideration. Simulink/ PLECS (Piecewise Linear Electrical Circuit Simulation) combo simulation platform is used to model and simulate the system in question. Simulation results showed that the proposed multiport converter system can be a viable alternative to low frequency distribution transformer.
 Keywords: Multiport converter, MMC, DC-DC converter, Hybrid power Supply, Solar PV.

Current sharing and voltage restoration based on determination of transmission line resistance considering constant power loads in direct current microgrids

SummaryMaintaining proper current sharing among distributed generation (DG) units while regulating the output voltage is a challenging control issue in DC microgrids. The conventional droop control is widely used at the primary level of control to tackle this issue, but this method faces some limitations in voltage control and current sharing. To address this problem, this paper presents a new distributed secondary control method that determines the resistance of transmission lines by injecting an external pulse to the reference voltage of each converter and measuring output voltage and current changes. The proposed secondary control signal, denoted as , enables simultaneous proportional current sharing and voltage restoration in the DC microgrid by correcting the droop coefficients based on the determined resistances. In order to ensure the stability of the proposed method, the small signal stability analysis of the closed‐loop system is conducted, considering various parameter changes. In contrast to similar methods, the proposed method introduces a new hybrid technique of voltage setpoint shifting and droop parameter adjustment that achieves precise proportional current sharing and voltage restoration, even when faced with varying resistive loads and constant power loads (CPLs). Additionally, the proposed method demonstrates outstanding characteristics, such as high convergence speed, the ability to determine transmission line resistances instead of assuming them to be known, and robustness in plug‐and‐play scenarios and communication system failures. The simulation results in MATLAB and experimental tests confirm the effectiveness of the proposed method.

Frequency Tracking Method and Compensation Parameters Optimization to Improve Capacitor Deviation Tolerance of the Wireless Power Transfer System

Compensation capacitors are naturally susceptible to manufacturing defects and aging effects, leading to the degraded performance of a wireless power transfer (WPT) system. This paper focuses on the compensation parameters optimization during the design stage and control strategy during the operation phase to improve the inherent capacitor error tolerance of the WPT system. The Sobol sensitivity method is applied to rank the importance of deviations of three capacitors on the transfer characteristics, and then the method of tracking the secondary resonance frequency is proposed. The numerical method is applied to find the optimal compensation parameters, with the constraint that the output voltage change caused by the shift of the designed compensation condition is limited to be less than ±5%. Experimental results show that with the proposed frequency tracking method and compensation parameter optimization, the deviation tolerance index is decreased from 0.485 to 0.363, showing an improvement of 25.2%, and the minimum power factor is increased from 0.78 to 0.89. Besides, the characteristics of constant primary coil current and voltage gain are almost not affected.