Output Voltage Amplitude Research Articles

Structural Design of MEMS Acceleration Sensor Based on PZT Plate Capacitance Detection.

The problem that the fuze overload signal sticks and is not easily identified by the counting layer during the high-speed intrusion of the projectile is an important factor affecting the explosion of the projectile in the specified layer. A three-pole plate dual-capacitance acceleration sensor based on the capacitive sensor principle is constructed in this paper. The modal simulation of the sensor structure is carried out using COMSOL 6.1 simulation software, the structural parameters of the sensor are derived from the mechanical properties of the model, and finally the physical sensor is processed and fabricated using the derived structural parameters. The mechanical impact characteristics of the model under different overloads were investigated using ANSYS/LS-DYNA, and the numerical simulation of the projectile intrusion into the three-layer concrete slab was carried out using LS-DYNA. Under different overload conditions, the sensor was tested using the Machette's hammer test and the output signal of the sensor was obtained. The output signal was analyzed. Finally, a sensor with self-powered output, high output voltage amplitude, and low spurious interference was obtained. The results show that the ceramic capacitive sensor has a reasonable structure, can reliably receive vibration signals, and has certain engineering applications in the intrusion meter layer.

All-Solid-State Nanosecond Pulse Power Supply Based on BLTs and Pulse Transformer for DBD Application

Nanosecond(ns) pulses have been proven to drive DBD more efficiently. However, since the DBD device is a capacitive load, which will cause distortions in the pulse waveform of the power supply. To maintain the ns pulse waveform, a parallel resistor is normally set to overcome the influence of DBD loads in the traditional methods, which will cause extra energy loss. This paper proposed a bipolar ns pulse power supply for DBD based on Blumlein transmission lines (BLTs) and pulse transformer. It does not need to set a parallel resistor and can adapt well to the load characteristics of DBD. This topology can output bipolar ns pulses on DBD loads with a rise time of 100 ns, a pulse width of 300 ns, an adjustable amplitude of 0-5 kV, and a maximum repetition frequency of 20 kHz. In this context, the operating characteristics of the circuit are derived based on the lossless transmission line model and Laplace transform, and then the correctness of the theoretical derivation is verified by the prototype. The results showed that the proposed ns power supply can drive DBD loads with adjustable output voltage amplitude and frequency.

Analysis and Design of a Duty-Cycle-Controlled Amplitude Shift Keying Class-E Power Amplifier

This paper presents a method for implementing amplitude modulation in class-E power amplifiers (PA). The output voltage amplitude of a class-E PA is proportional to the input signal duty cycle. The proposed method exploits this feature in order to implement amplitude shift keying (ASK) modulation in the standard class-E power amplifier. The conditions for the optimum operation of a class-E PA while using two different input duty cycles are analyzed. The desired conditions are derived at the same time to reduce differences between optimum circuit elements while using different input duty cycles. The resulting class-E PA satisfies both zero voltage switching (ZVS) and zero derivatives of voltage at switching (ZDVS) conditions by changing only one capacitor. This method neither degrades the efficiency nor needs many changes in circuit components. A step-by-step design procedure based on the proposed method is introduced. The simulations and measurement results verify the accuracy of the proposed method. The fabricated PA is designed to operate at 1MHz frequency with V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DD</sub> = 2V and 50Ω load. The input duty cycle is changed from 25% to 49%, resulting in output amplitudes of 1.2Vpp and 3.68Vpp, and efficiencies of 88% and 94%, respectively.

Electrical Response Estimation of Vibratory Energy Harvesters via Hilbert Transform Based Stochastic Averaging

Abstract Converting mechanical vibrations into electrical power with vibratory energy harvesters can ensure the portability, efficiency, and sustainability of electronic devices and batteries. Vibratory energy harvesters are typically modeled as nonlinear oscillators subject to random excitation, and their design requires a complete characterization of their probabilistic responses. However, simulation techniques such as Monte Carlo are computationally prohibitive when the accurate estimation of the response probability distribution is needed. Alternatively, approximate methods such as stochastic averaging can estimate the probabilistic response of such systems at a reduced computational cost. In this paper, the Hilbert transform based stochastic averaging is used to model the output voltage amplitude as a Markovian stochastic process with dynamics governed by a stochastic differential equation with nonlinear drift and diffusion terms. Moreover, the voltage amplitude dependent damping and stiffness terms are determined via an appropriate equivalent linearization, and the stationary probability distribution of the output voltage amplitude is obtained analytically by solving the corresponding Fokker–Plank equation. Two examples are used to demonstrate the accuracy of the obtained analytical probability distributions via comparisons with Monte Carlo simulation data.

Exploring the Potential of Flow-Induced Vibration Energy Harvesting Using a Corrugated Hyperstructure Bluff Body.

Fluid-induced vibration is a common phenomenon in fluid-structure interaction. A flow-induced vibrational energy harvester based on a corrugated hyperstructure bluff body which can improve energy collection efficiency under low wind speeds is proposed in this paper. CFD simulation of the proposed energy harvester was carried out with COMSOL Multiphysics. The flow field around the harvester and the output voltage in different flow velocities is discussed and validated with experiments. Simulation results show that the proposed harvester has an improved harvesting efficiency and higher output voltage. Experimental results show that the output voltage amplitude of the harvester increased by 189% under 2 m/s wind speed.

Design of magnetostrictive tactile sensor for depth detection

PurposeThis paper aims to design a magnetostrictive tactile sensor for surface depth detection. Unlike the human finger, although most tactile sensors have high sensitivity to pressure, they cannot detect millimeter-level depth information on the surface of objects precisely. To enhance the ability to detect surface depth information, a piezomagnetic sensor combining inverse magnetostrictive effect and bionic structure is developed in this paper.Design/methodology/approachA magnetostrictive tactile sensor based on Galfenol [(Fe83Ga17)99.4B0.6] is designed and studied for surface depth measurement. The optimal structure of the sensor is determined by experiment and theory. The test platforms for static and dynamic characteristics are set up. The static and the dynamic sensing performance of the sensor are studied experimentally.FindingsThe sensor can detect 0–2 mm depth change with a sensitivity of 91.5 mV/mm. A resolution of 50 µm can be achieved in the depth direction. In 50 cycles of loading and unloading tests, the maximum error of the sensor output voltage amplitude is only 2.23%.Originality/valueThe sensor can measure the depth information of object surface precisely with good repeatability through sliding motion and provide reference for object surface topography detection.

Modelling and control of current full compensation system‐based controllable voltage source

AbstractCurrent active suppression technology of arc overvoltage in distribution network has small capacity of controllable voltage source and complex control and cannot flexibly adjust the zero‐sequence voltage of neutral point. This study proposes a controllable voltage source system to fully compensate the arc current of ground fault for solving these problems. A controllable voltage source model based on passive supply voltage converter is established, utilising Dyn transformer to carry unbalanced load for a long time. The model output voltage is the same amplitude and frequency as that of single‐phase ground fault phase, but opposite phase. The compensation switch is operated when a ground fault occurs. The output voltage amplitude of the controllable voltage source is controlled, the fault phase voltage is controlled to be 0 in the closed loop, the grounding fault arc current is eliminated and the arc grounding overvoltage is suppressed. The control strategy was verified by the PSCAD/EMTDC simulation model of single‐phase grounding fault arc in 10 kV distribution network and the real single‐phase fault experiment platform of 0.4 kV distribution network. Results proved the model and strategy's accuracy and effectiveness. It provides an engineering practical method for active suppression of arc grounding overvoltage in distribution network.

Harmonic-Reduced Bias Circuit for Ultrasound Transducers.

The gain of class-C power amplifiers is generally lower than that of class-A power amplifiers. Thus, higher-amplitude input voltage signals for class-C power amplifiers are required. However, high-amplitude input signals generate unwanted harmonic signals. Therefore, a novel bias circuit was proposed to suppress the harmonic signals generated by class-C power amplifiers, which improves the output voltage amplitudes. To verify the proposed idea, the input harmonic signals when using a harmonic-reduced bias circuit (-61.31 dB, -89.092 dB, -90.53 dB, and -90.32 dB) were measured and were found to be much lower than those when using the voltage divider bias circuit (-57.19 dB, -73.49 dB, -70.97 dB, and -73.61 dB) at 25 MHz, 50 MHz, 75 MHz, and 100 MHz, respectively. To further validate the proposed idea, the pulse-echo measurements were compared using the bias circuits. The peak-to-peak echo amplitude and bandwidth of the piezoelectric transducer, measured when using a harmonic-reduced bias circuit (27.07 mV and 37.19%), were higher than those achieved with a voltage divider circuit (18.55 mV and 22.71%). Therefore, the proposed scheme may be useful for ultrasound instruments with low sensitivity.

APPLICATION OF STATIC SYNCHRONOUS COMPENSATOR (STATCOM) AS REACTIVE POWER CONTROL IN DFIG WIND FARM AND GRID INTERCONNECTION SYSTEMS

The most difficult aspect of optimizing a wind farm is creating an accurate wind farm model, especially if the farm is connected to the grid. The inconsistency and unpredictability of wind speeds exacerbates this issue. When dealing with wind farms, it is possible that the reactive power addition capabilities of individual wind turbines are insufficient to meet network requirements. This is due to cable losses and line losses between the wind farm and PCC. This study employs a doubly fed induction generator (DFIG) and a Static Synchronous Compensator (STATCOM) compensator to keep the output voltage amplitude more constant. Using two PI controller loops, the STATCOM will generate reactive (capacitive) power if the DFIG voltage is lower. The STATCOM will then absorb reactive (inductive) electricity if the DFIG system voltage is greater. STATCOM's ability to regulate the flow of reactive power can increase the network's stability. By optimizing the network's reactive power, the power factor is increased and stabilized up to 0.99. In addition, the system's harmonics never exceed the 5% limit specified by the IEEE 519-1992 standard.

Energy harvesting of nanofluid-conveying axially moving cylindrical composite nanoshells of integrated CNT and piezoelectric layers with magnetorheological elastomer core under external fluid vortex-induced vibration

This paper deals with the renewable energy that can be harvested as electrical voltage due to the vibrations of an axially moving composite nanoshell conveying nanofluid. The significance of the study and its main innovation is the investigation of the possibility of yielding electrical energy caused by natural mechanical vibrations in a smart dynamic composite nanostructure, which can have potential applications in the nano industry. To this end, oscillations of nanocomposite interacting with the internal nanofluids are investigated under both non-periodic and the harmonic excitations of an external vortex fluid flow colliding with the outer layer, as a natural phenomenon. The considered composite nanoshell consists of three integrated layers of piezoelectric, magnetorheological elastomer, and carbon nanotube. As a theoretical methodology, using the Navier-Stokes equations and energy method, the governing coupled mechanical–electrical equations of dynamic composite nanoshells are derived based on the Euler-Bernoulli beam theory applying nonlocal-piezo-elasticity theory utilizing the van der Pol equation for the external vortex shedding flow. The vortex fluid flow leads to the appearance of the added mass and damping terms in the motion equations. The effects of velocities of moving nanocomposite, passing internal nanofluid, and external vortex fluid, the effects of nano-scale structure and aspect ratio, the effect of applied magnetic field intensity on the smart middle layer, the internal and external fluid densities effects (gas/liquid), and the effect of electrical resistive load on the frequency response and the output voltage amplitude of the dynamic nanosystem are also studied. As one of the significant obtained results, it is revealed that the output voltage due to the vortex-induced vibration (VIV) of the nanosystem will significantly increase as the densities of both internal fluid flow and external vortex fluid flow decrease. In addition, the extractable voltage can be increased or decreased by controlling the intensity of the magnetic field through its effect on the magnetorheological layer.

Low temperature plasma ablation device for minimally invasive surgery.

This study introduces the design principle of a high-frequency square wave power supply, as well as the simulation and design process of a minimally invasive electrosurgical scalpel, which formed the low temperature plasma in saline solution. In order to verify the performance of the device, saline discharge experiments and pork ablation experiments were performed. An alternating high-frequency square-wave voltage was applied between coaxial double-layer electrodes with a spacing of 400 µm. The waveforms and amplitude of output voltage and current, conductance between electrodes, and output power were measured in saline discharge experiments. The results of pork ablation experiments with different power sources demonstrate that the device can generate low-temperature plasma for ablation rather than relying on thermal effects. The device can ablate pork under the driving of a 10V, 100kHz square wave voltage. In addition, the ablation speed and area will be greater with an increase in voltage or frequency.

Novel RDD Pulse Shaping Method for High-Power High-Voltage Pulse Current Power Supply in DBD Application

High-voltage pulse power supplies are key power input devices for the study and application of discharge plasma. A high-voltage pulse current power supply (HV-PCPS) with an energy storage pulse transformer based on flyback topology can output microsecond pulsewidths with high-power, ultrahigh voltage, and high reliability, which are suitable for most dielectric barrier discharge (DBD) plasma applications. However, during the process of DBD driven by an HV-PCPS based on an energy storage pulse transformer, the output pulse voltage waveform quality is poor, making it not suitable for stable discharge long-term operation. This article aims to solve the aforementioned problem and proposes a novel resistor–diode–diode (RDD) shaping method. Not only can this novel method solve the problem of poor quality of the output pulse power from the HV-PCPS, guaranteeing stable discharge for various DBD electrodes, it can also limit the maximum output voltage amplitude. This prevents overvoltage breakdown when the output terminal is in an open state or a light load state because the HV-PCPS is acting as a current source. This article also analyzes the effectiveness of an RDD branch when solving the problem in theory, and gives a detailed parameter design method. Finally, a 30-kV HV-PCPS prototype is built to verify the effectiveness of the proposed RDD pulse shaping method. The average pulse power output of the whole prototype is greatly improved, and it can achieve an average pulse power output of 1 kW. Furthermore, the electrode loads of different DBD reactors can be driven by this technology.

Dual-mode acceleration sensor of downhole drilling tools based on triboelectric nanogenerator.

Downhole vibration is important for the judgment of the drilling tool conditions and the formulation of drilling technology. To meet the demand of downhole drilling tools acceleration measurement, this research proposes a self-powered acceleration sensor with two working modes based on the triboelectric nanogenerator, namely, mode A, which is based on the voltage response acceleration trend and mode B, which judges the acceleration based on the output pulses. Test results show that the acceleration measurement range is 0-11m/s2, the maximum output voltage amplitude can reach 15.3V, the working environment temperature is less than 250°C, the working environment humidity is less than 90%, and long-time working has almost no effect on the output voltage of the sensor. In addition, since the sensor will generate electrical energy during the vibration process, the power generation performance of the sensor has been tested. And the results show that the maximum output power of the sensor is 0.18 µW when a 1000 MΩ load is connected in series. Compared to traditional downhole sensors, the sensor is more flexible, because it can work normally at high temperatures and has the potential for being self-powered.

Threshold Voltage Cancellation For Low Input Voltage of 65nm CMOS Rectifier of Energy Harvesting For Implantable Medical Devices in Telemedicine Embedded System

Telemedicine applications run at very low voltages, necessitating the use of a Great Precision Rectifier with high sensitivity to function at low input voltages. In this study, we used a 65 nm CMOS rectifier to achieve a 0.2V input voltage for Energy Harvesting Telemedicine application. The suggested rectifier, which has two-stage structure and operates at frequency of 2.4GHz, has been found to perform better in cases where the minimum operating voltage is lower than previously published papers, and the rectifier can operate over a wide range of low input voltage amplitudes. Full-Wave Fully gate cross-coupled Rectifiers (FWFR) CMOS Rectifier Efficiency at Freq of 2.4 GHz: With an input voltage amplitude of 2V, the minimum and maximum output voltages are 0.49V and 1.997V, respectively, with a peak VCE of 99.85 percent and a peak PCE of 46.86 percent. This enables the suggested rectifier to be used in a variety of vibration energy collecting systems, including electrostatic, electromagnetic, and piezoelectric energy harvesters. The proposed rectifier, which is built at 2.4GHz and has a two-stage structure, performs better in the event of low input voltage amplitude and has a lower minimum operation voltage than previously published papers. Full-wave fully gate cross-coupled rectifiers (FWFR) CMOS Rectifier Performance Summary at Freq of 2.4 GHz: With a 2V input voltage amplitude, the minimum and maximum output voltages are 0.49V and 1.997V, respectively, with a maximum VCE of 99.85% and a maximum PCE of 46.86%.

High Precision Low Input Voltage of 65nm CMOS Rectifier for Energy Harvesting using Threshold Voltage Minimization in Telemedicine Embedded System

Telemedicine applications run at very low input voltages, necessitating the use of Great Precision Rectifier with high sensitivity to function at low input voltages. In this study, we used a 65 nm CMOS rectifier to achieve a 0.2V input voltage for Energy Harvesting Telemedicine application. The suggested rectifier, which has two-stage structure and operates at frequency of 2.4GHz, has been found to perform better in cases where the minimum operating voltage is lower than previously published papers, and the rectifier can operate over a wide range of low input voltage amplitudes. Full-Wave Fully gate cross-coupled Rectifiers (FWFR) CMOS Rectifier Efficiency at Freq of 2.4 GHz: With an input voltage amplitude of 2V, the minimum and maximum output voltages are 0.49V and 1.997V, respectively, with a peak VCE of 99.85 percent and a peak PCE of 46.86 percent. This enables the suggested rectifier to be used in a variety of vibration energy collecting systems, including electrostatic, electromagnetic, and piezoelectric energy harvesters. The proposed rectifier, which is built at 2.4GHz and has a two-stage structure, performs better in the event of low input voltage amplitude and has lower minimum operation voltage than previously published papers. Full-wave fully gate cross-coupled rectifiers (FWFR) CMOS Rectifier Performance Summary at Freq of 2.4 GHz: With a 2V input voltage amplitude, the minimum and maximum output voltages are 0.49V and 1.997V, respectively, with a maximum VCE of 99.85% and a maximum PCE of 46.86%.

A Novel Pre-Synchronization Control Method Based on Open-Loop Phase Detection for the Maritime VSC-HVDC System

Maritime island grids based on renewable energy are being rapidly developed, which poses a new challenge to the traditional pre-synchronization process of grid connection. Aiming at the problems of impulse current out of limit and long steady-state regulation time, a novel pre-synchronization control method is provided based on open-loop phase detection, which is realized by replacing the frequency detection method of the difference judgment part. The open-loop detection model of voltage phase and amplitude based on the synchronous rotating coordinate system is established first. Then the voltage phase is linearized to control the output frequency and finally reduces the voltage deviation through the compensation of virtual power to achieve the effect of a smooth grid connection. The novel pre-synchronization method has a fast response speed and no regulator effect, which can synchronize the actual values of output voltage amplitude, phase, and frequency. Simulation results verify the excellent performance of the proposed method in island stable operation and grid connection under disturbance.

Pulsating heat pipe and thermo-electric generator jointly applied in renewable energy exploitation: Analytical and experimental investigations

In order to effectively harvest solar energy and waste thermal, pulsating heat pipes (PHPs) could be utilized to promote the hot end temperature of the thermoelectric modules (TEMs) and thus enhance its conversion efficiency. This paper explored a novel approach of recovering low grade energy and conversion to electricity utilizing PHP assisted with TEG. This research fully analyzed the effects of various working fluids, input powers, filling ratios, inclination angles and air velocities on the thermo-hydrodynamic and electricity conversion performance of PHP-TEG hybrid system. Our results demonstrated that the peak-to-peak amplitude of output voltage mainly depends on heat inputs and working fluids, and independent of the filling ratios; the inclination angle (from 30° to 90°) has slight effects on the heat transfer performance and thermoelectric generation of PHP-TEG system, due to the advantages of surface tension. In addition, the inlet temperature and flow velocity of cooling water on the thermal recovery efficiency and thermo-electricity conversion performance were further investigated. These results indicated the best heat recovery performance of 80.12% and the maximum thermoelectric conversion efficiency of 1.22% were achieved simultaneously at the situation of 10 °C and 600 mL/min of cooling water. Present investigation could contribute to waste thermal recovery and electronic cooling applications.

Frequency response analysis of piezoelectric resonance of poly-lactic acid film for bending angle detection

The relationship between the output voltage from a poly-lactic acid piezoelectric film sensor and the bending angle of it can be derived by analyzing the resonance frequency of the sensor changes with the bending angle using the finite element method. The proposed sensor was excited and its oscillation was observed using the piezoelectricity of poly-lactic acid. The output voltage was amplified by resonating a brass plate with a slit. The frequency changes significantly with bending because the change in frequency of resonance of the metal substrate with high mechanical Q was measured. The resonance frequency increased linearly when the bending angle ranged from 0° to 5°. It was also confirmed that the correspondence between the frequency and the bending angle is uniquely determined because there was only one peak of the output voltage amplitude for inputs of multiple frequencies.

A single‐phase p‐type ac–ac converter with reduced components count and high boost factor

AbstractThis paper proposes a new single‐phase direct step‐up ac–ac converter by modifying the p‐type impedance source. It provides a high boost factor as well as high efficiency, while only six parts are required to design it, involving just two bidirectional power switches. A safe commutation method has been applied to power switches to make the converter snubber‐free and high efficient. Input and output harmonic filters are no longer required since input and output currents variate continuously with small ripple and low total harmonic distortion (THD). The proposed topology only modulates the output voltage amplitude, not the phase and frequency, so the output frequency is identical to the input frequency and constant. Thus, it can be utilized in step‐up conversion applications, like inductive power transmission from low ac voltage sources. Input and output have the same ground, which is a good protective feature. In this paper, the operating principle of the converter is demonstrated. Experimental results have been represented to evaluate the performance of the converter. For this purpose, an experimental prototype has been fabricated. Results are investigated and compared with other previous step‐up ac–ac converters. Results confirm the theory, operating principle, and performance of the converter.

AC Power Flow Analysis for Inverters in Microgrid Application

In a microgrid system, proper current distribution and load sharing strategies are essential to achieve reliable parallel operation. Line impedance is an important factor when implementing a control technique for an inverter for microgrid operation, whether it is operating in grid connected or island mode. It is sometime difficult to visualize the impact of different line impedance to the power flow in AC microgrid. In this paper, AC power flow of an inverter-based system connected to a common ac bus through purely resistive, inductive or complex line impedances is investigated. For each line impedance case, the effect of an inverter’s output voltage power angle and amplitude on the active and reactive power flow are studied. Several active and reactive powers plots are generated in 3D surf plots to visualize the impact of line impedance on the power flow in an AC system.