Sinusoidal Voltage Excitation Research Articles

Design of an Electromagnetic Micro Mirror Driving System for LiDAR.

Electromagnetic micro mirrors are in great demand for light detection and ranging (LiDAR) applications due to their light weight and low power consumption. The driven frequency of electromagnetic micro mirrors is very important to their performance and consumption. An electromagnetic micro mirror system is proposed in this paper. The model of the system was composed of a micro mirror, an integrated piezoresistive (PR) sensor, and a driving circuit was developed. The twisting angle of the mirror edge was monitored by an integrated PR sensor, which provides frequency feedback signals, and the PR sensor has good sensitivity and linearity in testing, with a maximum of 24.45 mV/deg. Stable sinusoidal voltage excitation and frequency tracking was realized via a phase-locked loop (PLL) in the driving circuit, with a frequency error within 10 Hz. Compared with other high-cost solutions using PLL circuits, it has greater advantages in power consumption, cost, and occupied area. The mechanical and piezoresistive properties of micro mirrors were performed in ANSYS 19.2 software. The behavior-level models of devices, circuits, and systems were validated by MATLAB R2023a Simulink, which contributes to the research on the large-angle deflection and low-power-consumption drive of the electromagnetic micro mirror. The maximum optical scan angle reached 37.6° at 4 kHz in the behavior-level model of the micro mirror.

Composition Regulation of Potassium Sodium Niobate Thin Films through Post-Annealing under Alkali Element Atmospheres

Amorphous potassium sodium niobate (KNN) films were synthesized at 300 °C through the radio frequency magnetron sputtering method and subsequently crystallized by post-annealing at 700 °C in various alkali element atmospheres (Na and K). The as-deposited film is notably deficient in alkali metal elements, particularly K, whereas the loss of alkali elements in the films can be replenished through annealing in an alkali element atmosphere. By adjusting the molar ratio of Na and K in the annealing atmosphere, the ratio of Na/K in the resultant film varied, consequently suggesting the efficiency of this method on composition regulation of KNN films. Meanwhile, we also found that the physical characteristics of the films also underwent differences with the change of an annealing atmosphere. The films annealed in a high Na atmosphere exhibit large dielectric losses with limited piezoelectric vibration behavior, while annealing in a high K atmosphere reduces the dielectric losses and enhances the piezoelectric behavior. Furthermore, the results of vibration measurement demonstrated that the film annealed in a mixed powder of 25% Na2CO3 and 75% K2CO3 exhibits an optimal vibration displacement of ~400 pm under the sinusoidal excitation voltage of 8 V. This approach of altering the composition of KNN films through post-annealing may introduce the new concept of property design of KNN as well as other similar films.

Effect of Plasma-Activated Time for Ozone Generation in SDBD System Under Pulse and Sinusoidal Excitation

In the surface dielectric barrier discharge (SDBD) excitation schema, different power source topologies, such as the pulse and sinusoidal voltage inverters, are used to obtain the plasma. The inverter design is a critical element for consumer applications. However, some works in the literature have explained plasma properties and high-voltage excitation, but no clear definition has been identified to select a plasma property for a particular application. In general, SDBD is used for nonthermal plasma applications such as air purification and sterilization. Plasma generates reactive species that can react with target substances. Therefore, the reactive species generation rate greatly affects the plasma reaction performance. In addition, some researchers compare the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathrm{O}_3$</tex-math> </inline-formula> generation rate with sinusoidal and pulse power supply, but they do not focus enough on the plasma which determines the electrical properties. In this study, the plasma-activated time (PAT) is introduced to link the plasma properties and electrical parameters. Sinusoidal and pulse voltage excitation characteristics and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathrm{O}_3$</tex-math> </inline-formula> generation rates are used to experiment with this concept. The generation of reactive species is tested by measuring the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathrm{O}_3$</tex-math> </inline-formula> generation rate under fixed electrical and environmental conditions such as voltage, temperature, humidity, frequency, and PAT.

Numerical Simulation Research on Partial Discharge of Particle Defects at Epoxy Interface Excited by High-Frequency Sinusoidal Voltage.

In order to improve the effectiveness of partial discharge detection in attached metal particle insulators, this paper proposes a partial discharge detection method for particle defects in insulators under high-frequency sinusoidal voltage excitation. In order to study the development process of partial discharge under high-frequency electrical stress, a two-dimensional plasma simulation model of partial discharge with particle defects at the epoxy interface is established under plate-plate electrode structure, which realizes the dynamic simulation of particulate defect partial discharge. By studying the microscopic mechanism of partial discharge, the spatial and temporal distribution characteristics of microscopic parameters such as electron density, electron temperature, and surface charge density are obtained. Based on this simulation model, this paper further studies the partial discharge characteristics of epoxy interface particle defects at different frequencies, and verifies the accuracy of the model from two aspects of discharge intensity and surface damages through experimental means. The results show that with the increase in the frequency of applied voltage, the amplitude of electron temperature shows an increasing trend. However, the surface charge density gradually decreases with the increase in frequency. These two factors make partial discharge severest when the frequency of the applied voltage is 15 kHz.

Correction to: Optimization of the Parameters of a Cold Plasma Jet Produced by Sinusoidal Voltage Excitation for Effective Suppression of Cancer Cell Viability

Correction to: Optimization of the Parameters of a Cold Plasma Jet Produced by Sinusoidal Voltage Excitation for Effective Suppression of Cancer Cell Viability

Optimization of the Parameters of a Cold Plasma Jet Produced by Sinusoidal Voltage Excitation for Effective Suppression of Cancer Cell Viability

Optimization of the Parameters of a Cold Plasma Jet Produced by Sinusoidal Voltage Excitation for Effective Suppression of Cancer Cell Viability

Application Status and Prospect of Impedance Spectroscopy in Agricultural Product Quality Detection

The nondestructive testing of agricultural products has always been a key technology for the modernization of agriculture and food. By applying a sinusoidal voltage (current) excitation signal of variable frequency, the relationship between the amplitude, frequency and phase of the response signal is obtained, and the measured response function in a certain frequency range is obtained, constructing the correlation between impedance spectroscopy and matter properties. Electrical impedance spectroscopy (EIS) is a widely used method for the nondestructive characterization of agricultural products, and its applications in the agricultural field has attracted increasing attention. This paper summarizes the research of electrical impedance spectroscopy (EIS) in the detection of grain quality, fruit and vegetable quality, meat quality and food quality from 2005 to 2022. The potential and development direction of electrical impedance spectroscopy in the nondestructive testing of agricultural product quality are prospected, which provides a reference for scientific researchers who applied electrical impedance spectroscopy in agricultural product quality detection.

Electromagnetic Interference Effects of Continuous Waves on Memristors: A Simulation Study.

As two-terminal passive fundamental circuit elements with memory characteristics, memristors are promising devices for applications such as neuromorphic systems, in-memory computing, and tunable RF/microwave circuits. The increasingly complex electromagnetic interference (EMI) environment threatens the reliability of memristor systems. However, various EMI signals’ effects on memristors are still unclear. This paper selects continuous waves (CWs) as EMI signals. It provides a deeper insight into the interference effect of CWs on the memristor driven by a sinusoidal excitation voltage, as well as a method for investigating the EMI effect of memristors. The optimal memristor model is obtained by the exhaustive traversing of the possible model parameters, and the interference effect of CWs on memristors is quantified based on this model and the proposed evaluation metrics. Simulation results indicate that CW interference may affect the switching time, dynamic range, nonlinearity, symmetry, time to the boundary, and variation of memristance. The specific interference effect depends on the operating mode of the memristor, the amplitude, and the frequency of the CW. This research provides a foundation for evaluating EMI effects and designing electromagnetic protection for memristive neuromorphic systems.

Performance Analysis of Acceleration and Inertial Force of Electromagnetic Suspension Inertial Stabilizer

In this paper, the structural characteristics of electromagnetic suspension (EMS) inertial stabilizers are analyzed firstly, and then a mechanical analysis of a single mass block and double mass block is carried out. The relationship model between the inertial anti-rolling mass block and inertial force transmitted to the ship is established. The inertial force is determined by the number of coil turns, coil current, mass block, mass of the ship, electromagnet current, rate of change of the electromagnet current, air gap between the electromagnet and inertial mass block, and rotational angular speed. Through theoretical analysis, it is found that the response speed of inertia force is directly related to the electromagnetic coil current, the voltage at both ends of the electromagnetic coil, the coil resistance and the air gap. It is concluded that the response speed of the inertia force can be controlled by controlling the coil current, adjusting the voltage at both ends of the coil and adjusting the air gap. The inductance of the electromagnetic coil will also increase the nonlinearity of the inertial anti-roll system. On the basis of theoretical analysis, a digital simulation of EMS inertial stabilizer is carried out by MATLAB and ANSYS MAXWELL2D. Finally, a single mass block system of EMS inertial stabilizer is designed and tested. During the test, a 1.5 V sinusoidal excitation voltage is added to the electromagnetic coil after the mass block is suspended stably, and the maximum acceleration values of the inertial anti-rolling mass block and hull are 10.29 m/s2 and 1.27 m/s2. Finally, the theoretical analysis results, digital simulation results and experimental results are analyzed, which verifies the correctness of the acceleration and inertia force performance analysis of the EMS inertial stabilizer.

Influence of De-Trapped Charge Polarity in Sensing Health of Power Transformer Insulation

Assessment of insulation condition by sensing and subsequent analysis of oil-impregnated paper response at periodic intervals is necessary for reliable operation of transformers. Sensing frequency domain insulation response requires the application of either a sinusoidal excitation voltage (over a wide range) or a custom excitation waveform. This not only requires a specially designed variable-frequency variable-amplitude excitation voltage source but also makes measurement practically problematic. Measurement of low-frequency data is time-consuming and the data tends to get affected by field noise. In comparison, a simpler and cheaper alternative is the analysis of time-domain insulation response. This involves the measurement of low amplitude polarization and depolarization current. A pico-ammeter or Electrometer is generally used for this purpose. The available interpretation scheme of time domain response sensed using Electrometer does not consider the de-trapping charge’s polarity. The result presented in the paper shows that such an assumption inadvertently leads to inaccurate diagnosis. This, in turn, generates doubt regarding the current sensing capability of the Electrometer involved. In the present work, a better interpretation scheme of the data sensed by the Electrometer is discussed. The significance and influence of de-trapped charge polarity on polarization and depolarization currents are investigated. The analysis is tested on data collected from real-life in-service power transformers.

Gas Temperature Effect in Methane DBD Reactor for Hydrogen Production

Numerical investigation of gas temperature distribution in a dielectric barrier discharge (DBD) for plasma reactor in pure methane gas (CH&lt;sub&gt;4&lt;/sub&gt;) were carried out by using one-dimensional fluid model. This physical approach was based essentially on electrons and ions transport equation resolution coupled with Poisson's equation for two parallel electrodes plates. In the present work, the heat transport equation was solved in order to determine the gas heating behavior in the discharge DBD. The numerical model was applied in the case of a gas pressure of 350 torr and sinusoidal voltage excitation at period frequency of 50 kHz. The results obtained by this model show the time variations of charged particles, the electric field, and the electrical characteristics of CH&lt;sub&gt;4&lt;/sub&gt; DBD. The gas heating development in the discharge reactor becomes important in the vicinity of the dielectrics. The effect of operation discharge parameters such as the applied voltage, the secondary electron-emission coefficient (&amp;gamma;) as well as the gas pressure have been analyzed and discussed. The findings suggest that the increase of gas temperature in CH&lt;sub&gt;4&lt;/sub&gt; DBD reactor affects the improvement of discharge behavior and consequently the hydrogen production.

Inductance Measurement Methods for Surface-Mount Permanent Magnet Machines

Analytical performance estimation of a permanent magnet (PM) motor requires an accurate equivalent circuit model. In a lumped electrical model of a PM motor, resistance and inductances appear as passive elements, which are used to represent the phase winding resistance, inductance, core loss, etc. There is currently no available standard for parameter measurement of permanent magnet (PM) motors. In the literature, there are many studies on inductance measurement. However, they are applied to different types of motors. The purpose of this study is to evaluate those different inductance measurement methods, on the same motors, to identify whether they lead to the same result. Also, it was aimed to find out the difficulties involved in the measurement process. This study concentrates on determining the d-axis and q-axis inductances of two different surface-mount PM motors at standstill and under running conditions. The standstill measurement methods evaluated include the “current decay” method and the “DC inductance bridge” method as well as more common methods. The dependence of the inductances on the current magnitude, frequency, and excitation signal waveform is investigated. Measurements with PWM and sinusoidal AC voltage excitation are found to give similar results. The tests indicated that the “current decay” method is prone to measurement errors especially when the phase resistance is low. It is discovered that inductance measurements from standstill tests are independent of frequency for all practical purposes. Next, the same inductances are measured, while the test motors are running. The methods considered include; inductance measurement from no-load test, zero power factor load test, and unity power factor load test; while the machine is in generating mode. Furthermore, a new inductance measurement method is introduced where the measurement is made while the test motor is driven with a vector-controlled drive. Finally, inductance measurement results from different standstill tests and running tests are compared and evaluated.

Experimental comparison of localised magnetostriction difference under sinusoidal and PWM excitations

The majority of power transformers are usually energized by sinusoidal excitation. However, there is a growing demand for using PWM excitation on power electronics devices for energy savings. As awareness of the environment also increases, the importance of noise and vibration issues becomes more significant. Increasing non-linear loads over time affect the ageing and lifetime of transformers. Such cases also cause to change the nominal values ​​of transformers. It is important that mechanical parameters such as vibration and noise can be accurately measured and examined so that all necessary functions can be entirely performed as other electromagnetic performances. For this reason, it is necessary to analyse the vibration movements of transformers and determine their characteristics, especially locally under changing operating conditions. Magnetostrictive is known as the main source of vibration and noiseof the transformer core. This paper presents localized magnetostriction of transformer core measured by strain gauges under sine and PWM voltage excitations. For validation of the study in this paper, a no-load strain measurement was performed experimentally on a real 20kVA three-phase three-limb T-joint transformer assembled in a laboratory.Localized magnetostriction in the rolling and transverse directions of the lamination under sinusoidal and PWM voltage excitations was carried out. The results of the experiment were compared with each other in terms of the location of the sensors.The Finite Element Analysis (FEA) was used to simulate the magnetic behavior of the transformer based on time-dependent analysis of magnetic field density, force, e.t. distributions under no-load conditions, respectively.In conclusion, evaluating the localized magnetostriction characteristic, especially under PWM voltage excitation, is essential for interlamination electromagnetic and electromechanical behaviors.

Research on numerical simulation for partial discharge of epoxy interface excited by high‐frequency sinusoidal voltage

High-frequency sinusoidal voltage excitation is proposed as a feasible method to solve the difficulty of partial discharge detection at the epoxy interface. In order to study the development process of partial discharge under high-frequency stress, a two-dimensional plasma simulation model of partial discharge for a needle-plate electrode structure is established by coupling particle transport equation, Poisson equation and plasma chemical reaction. The model adopts a reaction set to reduce the difficulty of modelling generation, transport and disappearance of charged particles. It realises dynamic simulation of the partial discharge at the epoxy interface. The spatial–temporal distribution characteristics of microscopic parameters such as electron density, electron temperature and surface charge are obtained. Based on this simulation model, the partial discharge characteristics of the epoxy interface at different frequencies are further studied in this work. The results show that with the increase of applied voltage frequency, the electron temperature shows an increasing trend, but its increasing rate gradually slows down; while surface charge accumulation decreases uniformly with the increase of applied voltage frequency. These two factors make the partial discharge severest under the frequency of 10 kHz. The results of the model are verified from two aspects of discharge form and discharge intensity by experimental means.

Design and experimental study of longitudinal-torsional ultrasonic transducer with helical slots considering the stiffness variation

The ultrasonic transducer employing helical slots to generate longitudinal-torsional (L&T) ultrasonic vibration is popular in the field of hard and brittle material machining. However, the design approach for this type of L&T ultrasonic transducer is not well established. An improved design model combining equivalent circuit theory and material parameter equivalent method based on stiffness variation was proposed in this study. The structure parameters of the transducer can be obtained according to given resonance frequency and nodal position. The model can further predict electrical characteristics and mechanical responses under specific excitation. For the preliminary verification of this theoretical model and the optimization of the transducer, finite element analyses were carried out to investigate the influences of slot structure parameters on dynamic performances in terms of resonance frequency, frequency separation, and amplitude of L&T vibration. After that, a prototype was manufactured according to the design results, and the measurements of impedance curve and vibration amplitude were conducted. The experimental results indicate that this prototype resonates at 24,920 Hz with an effective electromechanical coupling coefficient of 0.19. Meanwhile, the vibration amplitude in longitudinal direction is 8.1 μm and that in tangential direction is 5.6 μm under 70-V sinusoidal voltage excitation, which are consistent with the theoretical design and simulation results. Furthermore, machining tests demonstrate that surface roughness reduction and surface quality improvement can be gained by adopting this L&T ultrasonic transducer, compared to using the longitudinal vibration transducer. The proposed design approach was validated and this study can provide guidelines for the design of L&T ultrasonic transducer for rotary ultrasonic machining (RUM).

A Fourier Transform-Induced Data Process for Label-Free Selective Nanopore Analysis under Sinusoidal Voltage Excitations.

Nanopore analysis based on a resistive-pulse technique is an attractive tool for single-molecule detection in different fields, but it suffers a great drawback in selectivity. A common solution to this challenge is to add extra sensing aptamers and labels to analytes by improving the sensitivity of their pulses for distinguishing. Compared to the labeling methods, we alternatively develop and demonstrate a novel data process for label-free nanopore analysis that enables the conversion of resistive current signals to more specific frequency domain phase angle features with the contribution from both sinusoidal voltage excitation and Fourier transform. In particular, we find that the transmural capacitance induced by nanoparticle translocations under a sinusoidal voltage plays an important role in this process, making phase angle features more pronounced. In practical applications, the method is successfully applied to directly distinguish the translocation events through a nanopipette by their unique phase angles for similarly sized SiO2, Ag, and Au nanoparticles and soft living organisms of HeLa and LoVo and even in a more complicated case of a SiO2, Ag, and Au nanoparticle mixture.

Excitation and characteristics of electrostatic ion-cyclotron waves launched by a grid

Previous experimental studies on electrostatic ion-cyclotron waves (EICWs) and their instability were often performed in a narrow plasma column in Q-machines, in which the wave was conventionally generated via the instability driven by an electron current parallel to a magnetic field. The propagation characteristics of wave patterns have seldom been studied, especially the different characteristics in pulse and continuous wave patterns. In this paper, we present the experimental launching of the EICW via a grid applied with either a pulsed or a sinusoidal external excitation voltage in a magnetized plasma device. Either pulsed or continuous EICWs were excited, and the wave pattern trajectories were observed. Using the time-of-flight method, both phase and pulse (group) velocities of the wave signals were directly measured. It was shown that for the continuous EICW excitation, the measured dispersion relation is in agreement with the result from the kinetic theory in some range of parameters in the fundamental and harmonic frequency bands. The dependence of the measured pulse and phase velocities on the magnetic field shows agreement with the fluid theory only in the low field strength case but is closer to the result from the kinetic theory in the high field strength case.

Vibration and noise characteristics of high-frequency amorphous transformer under sinusoidal and non-sinusoidal voltage excitation

The vibration test of silicon steel, amorphous and nanocrystalline magnetic rings shows that the magnetostriction of amorphous materials is much larger than that of silicon steel and nanocrystalline. This paper focuses on the measurement and analysis of the vibration and noise of a 5kVA/4.5 kHz amorphous high-frequency transformer (HFT) under sinusoidal and non-sinusoidal excitation. Comparing and analyzing the measured data of vibration and noise, the results show that the vibration of HFT under the non-sinusoidal excitation is much larger than that of the sinusoidal excitation. The vibration excited by sinusoidal excitation basically concentrates on the double frequency of the excitation. Most of the vibration under non-sinusoidal excitation is also on the double frequency, but contains many harmonics. The influences are analyzed of duty cycle of rectangular excitation and the natural frequency of HFT on the vibration and noise.

Core loss calculation for power electronics converter excitation from a sinusoidal excited core loss data

The authors propose a core loss calculation method for power electronics converter excitation from sinusoidal excited core loss data. This method is based on Brockmeyer’s theory and adapts to calculate core loss under DC-bias excitation conditions. Furthermore, the number of core loss test conditions are reduced as this method only requires the addition of DC-bias characteristics to the sinusoidal excitation core loss data provided by the core manufacturers. To validate the proposed method, the core losses under sinusoidal and square voltage excitations are first measured by a BH analyzer with a DC-bias excitation unit. Then, the measured values under a square voltage excitation and the calculated values from a sinusoidal excited core loss data are compared.

Investigation of Core Loss Calculation Methods for Nanocrystalline Core in Medium Frequency Range

Nanocrystalline core is often adopted in high-power medium-frequency transformer, whose excitation voltage is usually a rectangular wave with an adjustable duty ratio. In this paper, several kinds of methods are proposed for core loss calculation under non-sinusoidal voltage excitation by modifying the original Steinmetz equation (OSE). Firstly, these correction methods are compared in theory, and their analytical equations under rectangular voltage with an adjustable duty ratio are deduced. Then, a hysteresis loop measurement system is established to measure the core loss density of a nanocrystalline core. Based on the measured results of the core loss density under sinusoidal voltage excitation, the coefficients of OSE for the core are fitted. Finally, core loss calculation results using the proposed correction methods under different amplitudes and duty ratios are analyzed and compared with the measured values. The results verify the correctness of the theoretical analysis, that waveform-coefficient Steinmetz equation is the most suitable method for loss calculation of nanocrystalline core in medium frequency range when the excitation voltage is a rectangular wave with an adjustable duty ratio.