Output Voltage Characteristics Research Articles

A Single-Channel, 600-MS/s, 12-b, Ringamp-Based Pipelined ADC in 28-nm CMOS

Achieving high linearity and bandwidth with good power efficiency makes the design of ADCs in deep nanoscale CMOS processes very challenging, as the constraints of low-voltage operation and limited intrinsic gain often dictate the use of power-consuming analog circuits and intensive digital calibration. This paper addresses these problems by introducing a pipelined ADC that exploits the low but very constant open-loop gain versus output voltage characteristic of the ring amplifier (ringamp) to achieve both high speed and linearity in low-voltage nanoscale CMOS designs. A tunable ringamp biasing scheme using an anti-parallel arrangement of CMOS transistors and an active ringamp-based common-mode feedback are also introduced. A single-channel prototype ADC is implemented in a standard 28-nm CMOS process, achieving 58.7-dB SNDR and 72.4-dB SFDR at 600 MS/s while consuming 14.5 mW from a single 0.9-V supply, resulting in Walden and Schreier figure-of-merit (FoM) values of 34.4 fJ/conv.-step and 161.9 dB, respectively.

Research of control strategies of MMC based on full bridge sub‐modules

Although full bridge sub-module topologies require more power devices than half bridge topology, it can offer flexible control of positive, negative, and zero voltage output characteristics. Here, full-bridge MMC with three kinds of operating modes as positive, negative voltage output with low voltage operation, and DC-link fault current suppression with zero voltage output are studied. To deal with the problem of insulation reduction when long-distance overhead line is applied and reduced DC voltage operation is required when LCC is connected with MMC, the effect of constant power and reduced power transmission on the storage capacitor voltage balance are studied. What is more, the zero voltage output characteristic is also studied not only to avoid the problem that the sub-module capacitor voltage may diverge due to long time blocking converter during DC line fault but also to supply reactive power for AC grid. Control strategies are designed under different operating modes to achieve full bridge MMC flexible operation. Finally, a simulation model is built in PSCAD/EMTDC to simulate the output characteristics of full-bridge MMC in different operation modes.

Fabrication and impact output voltage characteristics of carbon fiber reinforced polymer composites with lead-free piezoelectric nano-particles

Fabrication and impact output voltage characteristics of carbon fiber reinforced polymer composites with lead-free piezoelectric nano-particles

Effects analysis of bias and excitation conditions on power output of an environmental vibration energy harvesting device using Fe-Ga slice

With the advent of low power VLSI designs and the mass manufacture of CMOS, the power consumption of wireless sensor nodes has been significantly reduced from mW to μW. This opens up a new and interesting research field, that is, the possibility of converting environmental vibration energy to electrical energy for supplying power to the sensors. In this paper, using magnetostrictive materials slice, that is Fe-Ga alloy, a device for harvesting environmental vibration energy is designed and tested. Compared with piezoelectric materials and Terfenal-D alloy, Fe-Ga alloy offers excellent properties for surviving in tough ambient vibration conditions, including higher energy conversion efficiency, longer life cycles, excellent toughness, reduced depolarization and higher flexibility, etc. The designing of vibration energy harvesting process is based on the coupling characteristics of magnetostrictive inverse effect and Faraday electromagnetic induction. The device consists of a Fe-Ga alloy cantilever beam with a magnetostrictive direction throughout the length. It has magnetostrictive inverse effect during vibration and the internal magnetization state will change. A cantilever beam is surrounded by a pickup coil and voltage is induced due to the magnetic field according to Faraday's law. The energy conversion principle among mechanical, magnetic and electric energy is described through a dynamic equation of motion and in conjunction with an electromagnetic conversion equation. The influence law of bias and excitation conditions on output voltage, power and other characteristics of device are investigated in comprehensive experiments. By knowing these influence laws, it is possible to choose an appropriate number of pick up coil for a definite load resistance, to set an appropriate working frequency range, pre-tightening force and pre-magnetized magnetic field such that a maximum power can be harvested. The results derived here can be used as a design guideline for future studies in optimal design and the modeling of vibration energy harvester and force sensor.

Fabrication and impact output voltage characteristics of carbon fiber reinforced polymer composites with lead-free piezoelectric nano-particles

Wearable Internet of Things (IoT) devices for sports require an innovative design of a self-powered technology that is able to wirelessly transmit and receive the signal (force, ambient condition) forms a body wearing item, relying upon the vibration/impact energy harvesting materials that possess lightweight but excellent resistance to intense exercise. In this study, piezoelectric hybrid carbon fiber reinforced polymer (CFRP) composite laminates are developed by embedding potassium sodium niobate (KNN) nano-particle filled epoxy interlayer, and the composite samples are successfully polarized. The output voltage of the samples due to impact load is then measured. The results show that a voltage higher than 50 mV is generated. Our work represents an important step forward in the development of piezoelectric CFRP composite materials for energy harvesting applications and opens the door for further development of lightweight, robust and efficient energy harvesting sport equipment.

Analysis of broadband characteristics of two degree of freedom bistable piezoelectric energy harvester

In order to broaden the working frequency band of the piezoelectric energy harvester and improve the energy harvesting efficiency, a new two degree of freedom bistable piezoelectric vibration energy harvester is designed in this paper. It consists of a basic cantilever beam, a mass, a piezoelectric cantilever beam and magnets. The equivalent model of the system is established using lumped parameter method, and the two degree of freedom bistable motion equation is established considering the influence of electromechanical coupling. Using Matlab, the motion equation is calculated, and the curve of the system voltage with time and frequency is obtained. The voltage output characteristics of the system under bistable vibration and the influence of the stiffness and the mass of the basic cantilever beam on the output performance of the system are analyzed. Under the excitation of 0.3 g simple harmonics, the two degree of freedom bistable piezoelectric energy harvester is experimented using one-way frequency-increasing sweep. The results show that the maximum output voltage of the two resonance band of the energy harvester is 26 V and 13 V. Compared with the single degree of freedom bistable structure, the frequency band is widened by 10 Hz. In addition, reducing the stiffness of the basic cantilever beam and increasing the mass of mass block are all beneficial to broadening the working band of the harvester.

A Coupled Inductor and Switched Capacitor Non-isolated DC/DC Converter

Due to the output voltage characteristics of the photovoltaic cell and other renewable energy generation systems, DC/DC converter with high step-up ratio is commonly needed to raise the voltage. The high gain Boost converter based on coupled inductor with switch capacitor network is presented in this paper. The proposed converter avoid the ultimate duty cycle by designing the ratio of the coupling inductor. As the energy of leakage inductor in the input side can be transferred to the output side, the loss of leakage inductor is reduced. The voltage peak of the switch is inhibited by the switching capacitor, which greatly reduces the voltage stress of the switch, thus the converter improves the transfer efficiency. The working state of the converter is analyzed in detail, the theoretical formula is derived, and the stress of the converter is analyzed in the paper. A simulation circuit is built to verify the theoretical analysis.

Analysis and Design of Load-Independent Output Current or Output Voltage of a Three-Coil Wireless Power Transfer System

The design of operating frequencies and compensation topologies for load-independent output current or output voltage in two-coil wireless power transfer (WPT) system has been widely studied. The three-coil WPT system has been proven to be more efficient and shows a better performance compared to the two-coil WPT system with an increasing transmission distance. However, the research on load-independent output voltage or output current of the three-coil WPT system is still at pilot stage. This paper systematically investigates the load-independent output voltage and output current characteristics of a three-coil WPT system to achieve a constant output voltage (CV) and constant output current (CC) with near zero reactive power, which can simplify the control. The CV and CC characteristics are achieved by well-designed passive parameters of the receiver side compensation. Additionally, a hybrid receiver side compensation with two additional switches for the three-coil WPT system is developed to charge the electric vehicle battery by combining the CC and CV characteristics. Finally, a scaled-down experimental setup with 4-A charging current and 96-V cell voltage is constructed to verify the proposed approach. The experimental results agree well with the theoretical analysis.

An improved harmonic injection PWM-frequency modulated triangular carrier method with multiobjective optimizations for inverters

This paper proposes a new optimized switching method to improve the output voltage quality of the inverter. This proposed method has called Improved Harmonic Injection Pulse Width Modulation-Frequency Modulated Triangular Carrier (IHIPWM-FMTC). The purpose of this study is to describe the features of the line-to-line output voltage in a three-phase three-level inverter. Some controllable parameters in both the reference and carrier waves are defined to improve the output voltage characteristics such as THD, LOH, and DF. To obtain better results, multiobjective optimizations are used. These algorithms lead to more controllability and conclude multiple responses with different properties. Optimizations are performed by four useful intelligent algorithms. The simulation results of the proposed method were compared with SPWM and the conventional HIPWM-FMTC methods in the output voltage characteristics, rotor speed, and torque ripple. The optimization results determine the desired magnitude of the reference and carrier wave parameters. Finally, the practicality of switching method was experimentally validated.

Improved transient characteristics of output voltage of marine synchronous generator

Improved transient characteristics of output voltage of marine synchronous generator

Time‐domain characterisation of multicarrier‐based digital SPWM of multilevel VSI

The effect of sampling frequency on digital sinusoidal pulse width modulated (SPWM) output of phase-shifted carrier-based multilevel voltage source inverter (VSI) and the characteristics of output voltage and load current has been discussed here. The generalised equation of digitally controlled phase-shifted carrier-based multilevel VSI output voltage is derived using double Fourier integral solution. The Jacobi–Anger expansion has been used to obtain the integral solution. Time-domain analysis has been used to establish the relation between sampling frequency, carrier frequency, and fundamental frequency, at different modulation indices for n-level VSI. The load current of VSI is stepped in nature due to stepped variation in the output of the digital SPWM. Therefore, the low-frequency harmonic components closer to the fundamental frequency appear in the frequency spectrum. The variation of total harmonic distortion with respect to multisampling factor (sampling to carrier frequency ratio) has been discussed at different modulation indices for multicarrier-based multilevel inverter. The analytical results are verified through simulation and laboratory experimental results.

Output voltage characteristic of heat pipe sink thermoelectric generator with exhaust heat utilization of motorcycles

Nowadays the great challenge to energy engineers is how to develop new and renewable energy sources to reduce the use of fossil fuels. In this direction, the research focuses on the recycle of wasted heat energy on a motorcycle exhaust gas into electrical energy using the concept of seed back. Recycle energy using this concept on a motorcycle is done because the bike has the energy efficiency of ± 35 – 40 % while the rest were dumped unceremoniously in the form of heat energy that is issued through the exhaust. This research aims to know the characteristics of the output voltage heat pipe sink thermoelectric generator utilizing waste heat of the motorcycle. This research has been done on the measurement of the output voltage is generated by the thermoelectric module series TECI-12706B type SP1848-27145 SA as a heat pipe sink thermoelectric generator to produce electrical energy. This research was conducted to know the output voltage from 4 thermoelectric modules arranged in series or parallel. furthermore this thermoelectric generator will be the main energy source for SSUPER-BT devices. Stages of the research done by performing laboratory and road testing. In laboratory testing, simulation of thermoelectric generator made using aluminium rods contain Heater. two sides of the aluminium coupled to thermoelectric modules, heat pipe and CPU fan. in each experiment, the thermoelectric modules strung together in series or in parallel. The results showed on the TEGs with 4 thermoelectric modules in series were able to produce higher output voltage and current compared to TEGs with 2 thermoelectric modules with output voltage reaching 15.7 volts and 7.7 volts respectively. The TEGs circuit with 4 thermoelectric modules produces 72.6% greater power than TEGs with 2 thermoelectric modules.

Evaluation of output voltage characteristics by impact test of piezoelectric PVDF film

Evaluation of output voltage characteristics by impact test of piezoelectric PVDF film

A Three-Phase Dynamic Wireless Charging System with Constant Output Voltage

A dynamic wireless power transfer (WPT) system is an effective method, which can reduce charging time and extend the driving range of the electric vehicles. In the dynamic WPT systems, the output voltage may fluctuate when the receiver moves along the transmitter coils. This paper proposes a three-phase dynamic WPT charging system with overlapped three-phase transmitter coils. The overlap length is optimized to depress the fluctuation of the output voltage. These coils are powered by a three-phase inverter to generate an even magnetic field, and a unipolar coil is employed as a receiver to simplify the coil structure of the secondary side. Based on the proposed three-phase coil structure, the output voltage characteristics of the system are analyzed in detail. A 500 W dynamic charging prototype is established to validate the proposed dynamic charging system. Experimental results show that the output voltage fluctuation is within ±3.05%. The maximum system efficiency reaches 89.94%.

Study of the Phase Shift Plus PWM Control Strategy Based on a Resonant Bridge Modular Switched-Capacitor Converter

Bridge modular switched-capacitor converter (BMSCC) has been reported with symmetric and modular structure, and featured less output voltage ripple, less components cost, and convenient voltage extension but weak output voltage regulation. This paper presents a phase shift plus pulse width modulation (PWM) control strategy for the novel resonant BMSCC. With this control method, output voltage regulation and the limitation of the loop peak current to a proper range are implemented. Also, output voltage ripple could be effectively controlled as well through the voltage ripple characteristics analysis in different cases. Detailed analyses of the relationships between the switching phases of MOSFETs and the output voltage, the switching-phases of MOSFETs and the loop peak current are performed. Meanwhile, through optimal switching sequence, the proposed control method ensures that almost all switching devices maintain zero current switching or zero voltage switching operation, which results in high system efficiency. Using simulation software of the saber and hardware platform, the soft switching, output voltage, and peak current characteristics are verified.

Space-Vector Overmodulation Strategy for Ultrasparse Matrix Converter Based on the Maximum Output Voltage Vector

In this paper, a space-vector overmodulation strategy for an ultrasparse matrix converter (USMC) is proposed. The maximum output voltage vector, which has the same phase as reference voltage, is derived accurately in space-vector modulation. According to the maximum output voltage vector, the overmodulation mode I and mode II are re-divided, the boundary voltage transfer ratio (VTR) of which is extended to 0.954, whereas the maximum VTR of USMC remains 1, and the low-order harmonic components are reduced effectively. The overmodulation strategies in both modes are realized, respectively, by the linear superimposed principle. In addition, the harmonic characteristics of output voltage in overmodulation mode are analyzed by the double Fourier integral transform method. It is shown that the output voltage contains not only $({\rm 6} z_{1}\pm 1) f_{\rm{out}}$ harmonics, but also ${\rm{\vert }} f_{\rm{out}} \pm 6 z_{2}f_{\rm{in}}{\rm{\vert }}$ and $\vert (6z_{1}\pm 1) f_{\rm{out}} \pm 6 z_{2}f_{\rm{in}}{\rm{\vert }}$ harmonics. The effectiveness of the proposed overmodulation strategy and the correctness of harmonic analysis method are verified by experiments.

Dynamic modeling of a microbial fuel cell considering anodic electron flow and electrical charge storage

To describe the anodic electron flow and electric charge storage behavior of an MFC system from an electrical perspective, a dynamic model based on a novel electrical equivalent circuit is developed. Conventional equivalent circuits typically have series impedances to model the system from the standpoint of terminal quantities: output voltage and current. However, the conventional approaches do not properly explain internal anodic electron flow and double-layer charge storage characteristics of MFCs. The proposed model uses an equivalent capacitance in parallel and series resistances to accurately model and characterize the anodic electron flow, electrical charge storage, and the dynamic characteristics of both output voltage and current. Two straightforward test methods are proposed to determine the equivalent circuit parameters. Experimental results showed the validity of proposed MFC model.

A New Improved Variable Frequency Triangular Carrier-PWM with MOPSO Algorithm for Carrier Based PWM Techniques in Inverters

This paper investigates multi-carrier PWM methods in multi-level inverters. Two new MCPWM methods are introduced. This study proposes a new optimized MCPWM method to improve the output voltage characteristics like THD and LOH. The proposed method is based on variable frequency with a specific range. It means each carrier wave has a determined frequency. It is calling Variable Frequency Triangular Carrier-PWM. MOPSO algorithm is used to optimize the answers. This work considers some different levels of inverters like five, seven and nine levels. The results are compared with SPWM method.

Improved power efficiency in phosphorus doped n-a-SiNxOy/p-Si heterojunction light emitting diode

The higher up to 60% internal quantum efficiency of photoluminescence (PL) from amorphous silicon oxynitride (a-SiNxOy) films has been reported in our previous work. In present work, the improved power efficiency visible light emitting diode (LED) has been realized based on phosphorus doped n-a-SiNxOy/p-Si heterojunction structure, which is at least three times higher than that of ITO/a-SiNxOy/p-Si (called MIS) LED. The n-a-SiNxOy films were doped by using phosphine (PH3) gas during the deposition by plasma enhanced chemical vapor deposition technique and the electron concentration is about 2.4 × 1015 cm−3 at room temperature obtained from Hall-effect measurements. The light emitting (electroluminescence (EL)) peak energy is coincided with that of PL of a-SiNxOy, which suggests that the EL emission is also originated from the radiative recombination via N-Si-O bonding defect states in n-a-SiNxOy layers. The transport mechanism and optical performance of the device have been investigated with the characteristics of current-voltage (I-V) and light output-voltage (L-V), in terms of the energy band diagram of n-a-SiNxOy/p-Si heterojunction structure. The power law like L ∼ Im of light output-current (L ∼ I) characteristic in n-a-SiNxOy/p-Si heterojunction has also been observed, which exhibits a superlinear behaviour with a slope of 1.35 in the low current range and becomes almost linear with a slope of 1.05 in the high current range, due to the saturation of nonradiative recombination centers.

Quick Response Wide Input Range DC-DC Converter for Renewable Energy System

The switching power supply must deal with much more tasks than ever in the renewable energy system whose implementation is being promoted. For that reason, the digital control switching power supply is recognized as a solution in such a complex system. Although the digital control can realize a higher performance than the analog control, there is the room to be improved for further development. The delay time caused by the A-D conversion and processing time influences the dynamic characteristics and transient response. Also, the control precision depending on the quantization error leads to the limit cycle oscillation. These issues must be improved in the digital control. In this paper, the quick response wide input range dc-dc converter is presented, which meets the demand on the control precision of output voltage, transient response, and dynamic characteristics that are required for the renewable energy system. The proportional gain is changed to a high value at the beginning of the transient state. It is attenuated smoothly to an initial value which is set to a low value for steady state. A high proportional gain is used for short time in the transient state. In brief, the proposed method can utilize the feedback gain according to the situation and can meet the demand simultaneously. Therefore, the proposed method is effective in such a complex condition occurring in the renewable energy system.