Capacitive Load Research Articles

Requirements for Standard and I/O Cell Library Domestic Characterization System Development

The article is devoted to define requirements and discover specific featuresfor domestic standard cell and I/O libraries characterization EDA tool. A general structure of the library characterization system is presented. The basic requirements indicted for the system are considered and analyzed in the article. A comparative analysis of correspondence to these requirements for domestic and foreign characterization tools is done. The specific features the domestic library characterization system should satisfy are formulated. Among the main features the following are outlined in the article: compatibility and support of domestic OS, support of well-known foreign and domestic Spice-simulators, Russian language support for documentation, scalability, ensuring confidence of the output data. A brief review of typical tasks, intrinsic for characterization tool development and corresponding algorithms, required for its resolving is given. The following issues along with appropriate proposals for its solution are mentioned: automated definition of optimal input waveforms for sequential cells initialization, searching for maximum capacitance load for the cell, setup and hold parameters calculation for sequential cells, method of optimal output current PWL approximation for CCS parameters calculation. As a conclusion of the investigation the current status of domestic characterization systems development is analyzed. In the outcome a problem of domestic library characterization tool that aligned with all the requirements and support the specific features defined above has been raised.

High‐speed, two‐stage operational transconductance amplifier without Miller capacitor, suitable for large capacitive load

AbstractA two‐stage Class A‐AB operational transconductance amplifier with low power consumption, high slew rate, and high bandwidth is introduced for handling large capacitive loads. Unlike the conventional two‐stage operational transconductance amplifiers that use a Miller capacitor, compensation is provided by the load capacitor (CL) at the output node. The proposed two‐stage amplifier maintains a 45° phase margin (PM) over any load capacitance. This is achieved through a MOSFET‐based RC network at the output node. Dual nMOS/pMOS differential stages drive output directly, improving both SR+ and SR−. Post‐layout simulation results with a capacitive load of 100 pF (CL) demonstrate that the proposed operational transconductance amplifier has a DC gain of 60.1 dB, an excellent average slew rate of 20.3 V/µs, a gain‐bandwidth product of 10.6 MHz, an average 1% settling time of 122.2 ns and a PM of 76.6°, while consuming only 103.5 µW. Reducing the CL to 10 pF reduces the PM to 47.6°, while increasing the gain‐bandwidth and average slew rate to 82.9 MHz and 142.6 V/µs respectively.

A Quantitative Analysis of Harmonic Effects on the Accuracy of Single-Phase kWh Meters in PT. PLN (Persero) ULP Kuta

The accurate measurement of electrical energy transactions using kWh meters is crucial to prevent losses for both consumers and utilities. However, the growing prevalence of nonlinear loads can introduce harmonics into the power system, potentially affecting the accuracy of kWh meter readings. This study aimed to investigate the impact of harmonics on the measurement accuracy of analog and electromechanical kWh meters. The results demonstrate that as the percentage of Total Harmonic Distortion (%THD) increases, due to the increased use of nonlinear loads, the measurement accuracy of both types of kWh meters decreases, potentially leading to financial losses for both consumers and the utility company. Based on the study, Simulation results demonstrate this impact, with analog and electromechanical kWh meters showing significantly different billing outcomes under resistive and capacitive loads. For example, a purely resistive 300-watt load resulted in a bill of Rp. 327,870 for the analog meter and Rp. 319,343 for the electromechanical meter. In contrast, a 300-watt capacitive load resulted in bills of Rp. 84,497 and Rp. 83,707, respectively.

Estimation of the Effect of Electric Vehicles on the Aging of Distribution Transformers Using Fuzzy Logic

Depending on industrialization and technological advancements worldwide, the demand for electrical energy, recognized as clean and dependable energy, is on the rise. Presently, electric energy consumption has notably increased alongside the rise in Electric Vehicles (EVs). The surge in EVs necessitates a thorough examination of the situation, anticipating the widespread adoption of Electric Vehicle Fast Charging Stations (EVFCS) in the near future and the subsequent escalation of their adverse impact on the grid. To mitigate these negative effects on the grid, proactive measures are essential. EVs function as capacitive loads due to their battery composition, and the harmonics produced during their grid connection detrimentally affect the quality of grid electricity, leading to constraints. Furthermore, the escalating EVFCS loads resulting from the rapid growth in EV numbers distribute the burden on distribution networks, posing a threat to network adequacy and reliability. Therefore, integrating EVFCS with distribution and generation units to minimize overloading, additional losses, and voltage fluctuations in the grid will enhance the efficiency of both systems. In addition, each EVFCS is only connected to the distribution transformer assigned to it or to the distribution transformers considered suitable in the city. Depending on the current drawn by one or more EVFCS linked to the feeder of each transformer, it can lead to overloading in transformers and chemical changes in windings and oils, resulting in the aging of transformers. In this context, a FL-based estimation is conducted to assess the impact of EVs' charging loads on transformer aging. The FL method utilizes transformer current load, EVFCS load, transformer temperature, and harmonic power quality data. The data utilized are derived from statistical information about a local distribution network and measured values from a feeder, and the aging effects on EVFCS distribution transformers are examined.

Ensuring the reliability of automated pulse electric spark control of pipe coatings in in-line production

The issues of ensuring the reliability of automated electric spark testing of the continuity of dielectric coatings on metal pipes with diameters up to 1.5 meters in the context of in-line manufacturing are addressed. A simulation of the “high-voltage pulse source – electrode – dielectric coating – metal substrate” system has been conducted. Experimental studies have been conducted to evaluate the load capacity and voltage stability of the Corona 2.2 holiday detector using an improved generator at high capacitive loads.

Pulse power supply for plasma aerodynamic actuators

The reduction of local heat load on the structural elements of aircraft or spacecraft vehicles due to the shock wave/boundary layer interaction can be successfully controlled in the future using a system of plasma actuators. The efficiency of plasma aerodynamic actuators operation is directly related to a power source. It determines a covered plasma area, an air flow speed and a thrust the actuator creates. The paper deals with the operation of a high-voltage source of sawtooth pulses with high efficiency for controlling plasma actuators. The pulse power source can be easily scaled for different nonlinear capacitive loads.

The Development of a Novel Transient Signal Analysis: A Wavelet Transform Approach

This paper presents a new method for the analysis of transient signals in the frequency domain based on the Continuous Wavelet Transform (CWT). The proposed case study involves test signals measured from an electronic switch considering open and close operations. The source is connected to inductive, resistive, and capacitive loads. Resonance behaviors are introduced and compared with the Discrete Fourier Transform (DFT). Multiple factors, such as reliability, repeatability, high noise attenuation, and the smoothing of the analyzed spectrum, are considered in this study. This proposed study highlights the effectiveness of CWT in signal processing, especially in obtaining a detailed spectrum that reveals the behavior of electrical circuits. Resonance behaviors were analyzed, demonstrating that the signal processing performed by CWT is better for spectrum analysis than DFT. This study shows the potential of CWT to analyze transient electrical signals, specifically for identifying and characterizing the behavior of load connections and disconnections.

Operator-Based Triboelectric Nanogenerator Power Management and Output Voltage Control.

In this paper, an operator-based voltage control method for TENGs is investigated, achieving output voltage tracking without compensators and uncertainty suppression using robust right coprime factorization. Initially, a comprehensive simulation-capable circuit model for TENGs is developed, integrating their open-circuit voltage and variable capacitance characteristics. This model is implemented to simulate the behavior of TENGs with a rectifier bridge and capacitive load. To address the high-voltage, low-current pulsating nature of TENG outputs, a storage capacitor switching model is designed to effectively transfer the pulsating energy. This switching model is directly connected to a buck converter and operates under a unified control strategy. A complete TENG power management system was established based on this model, incorporating an operator theory-based control strategy. This strategy ensures steady output voltage under varying load conditions without using compensators, thereby reducing disturbances. Simulation results validate the feasibility of the proposed TENG system and the efficacy of the control strategy, providing a robust framework for optimizing TENG energy harvesting and management systems with significant potential for practical applications.

ХАРАКТЕРИСТИКИ РЕЗОНАНСНИХ СИСТЕМ ДЛЯ ОТРИМАННЯ ВИСОКОЇ НАПРУГИ НА НАВАНТАЖЕННІ ЄМНІСНОГО ТИПУ

The work is devoted to the comparative analysis of currents in inverter circuits of transformerless resonant and transformer resonant and non-resonant systems of the same power for obtaining high voltage on a capacitive load. The purpose of the work is to determine the type of system characterized by the smallest average operating current of the inverter switches. The dependence of the currents in the circuits of the inverters on the parameters of the resonant circuits was obtained, the results of calculations according to which allow us to state that the use of a transformerless circuit to ensure the same power of systems for obtaining high voltage on a capacitive type load will allow to almost halve the average operating current in the inverter circuit. Simulation modeling of the processes in the studied schemes was carried out, which confirms the obtained theoretical results. The use of high-voltage transformerless resonant systems to obtain high voltage on a capacitive load will allow to halve the nominal and maximum permissible current characteristics of the power elements of the converters. Ref. 10, fig. 3.

An Ultra-Low-Voltage Transconductance Stable and Enhanced OTA for ECG Signal Processing.

In this paper, a rail-to-rail transconductance stable and enhanced ultra-low-voltage operational transconductance amplifier (OTA) is proposed for electrocardiogram (ECG) signal processing. The variation regularity of the bulk transconductance of pMOS and nMOS transistors and the cancellation mechanism of two types of transconductance variations are revealed. On this basis, a transconductance stabilization and enhancement technique is proposed. By using the "current-reused and transconductance-boosted complementary bulk-driven pseudo-differential pairs" structure, the bulk-driven pseudo-differential pair during the input common-mode range (ICMR) is stabilized and enhanced. The proposed OTA based on this technology is simulated using the TSMC 0.18 μm process in a Cadence environment. The proposed OTA consumes a power below 30 nW at a 0.4 V voltage supply with a DC gain of 54.9 dB and a gain-bandwidth product (GBW) of 14.4 kHz under a 15 pF capacitance load. The OTA has a high small signal figure-of-merit (FoM) of 7410 and excellent common-mode voltage (VCM) stability, with a transconductance variation of about 1.35%. Based on a current-scaling version of the proposed OTA, an OTA-C low-pass filter (LPF) for ECG signal processing with VCM stability is built and simulated. With a -3 dB bandwidth of 250 Hz and a power consumption of 20.23 nW, the filter achieves a FoM of 3.41 × 10-13, demonstrating good performance.

A gas spark switch electrode impact pressure test platform.

The discharge arc of a high-current gas spark switch has a strong mechanical effect on the electrode and adjacent objects. The measurement of this mechanical effect on the electrode plays a very important role in switch design and the theoretical study of spark discharge. However, in traditional stress measurement systems, the spatial electromagnetic interference caused by the discharge and the high electrode voltage affects the measurement accuracy and can even damage the experimental instrument. In this paper, an electrode impact stress measurement system based on PVDF piezoelectric film is designed to measure the electrode stress under a strong spatial electromagnetic field and high voltage. The experimental results show that the system can measure the impact pressure of high-voltage and high-current gas spark switch electrodes. The starting time of the stress measurement waveform shows that the shock to the electrode is formed in the initial stage of current buildup. The measured results clearly show the high magnetic field force component in the electrode impact pressure waveform. The shock waveforms induced by different pulse capacitor values, breakdown voltages, and loads are examined. It is found that the shock stress waveforms applied to the electrodes are affected by the peak value of the current, dI/dt, and the discharge duration.

Design and testing of a high power piezo pump for hydraulic actuation

Traditional valve-controlled hydraulic cylinders are usually very inefficient due to power loss through the control valve. An efficient alternative architecture is to distribute power electrically rather than hydraulically to a group of cylinders and drive each cylinder via individual servomotor-driven pumps. This arrangement is called electrohydrostatic actuation. Such actuators are currently available for power ratings of several hundred watts or greater, but not in the sub-100 W range. This paper details the design, simulation and testing of a piezopump which is intended to address this gap. The motivation is for aerospace applications, and in particular accessory actuators used in the landing gear system. The 10–100 W range is a high-power output for a piezopump, and to achieve this a novel design using disc-style reed valves was developed to allow pumping frequencies above 1 kHz. These high frequencies necessitated the development of custom power electronics capable of delivering 950 V peak-peak sine wave excitation to a largely capacitive load. Experimental results show that the piezopump is capable of delivering over 30 W of hydraulic power, and at no-load can deliver up to 2 L/min of flow at 1250 Hz. Future development includes a transition to multi-cylinder pumps, and improved reed-valve modelling to improve the accuracy of simulated performance.

A transient-enhanced output-capacitorless LDO regulator with non-inverting pull–push gain stage

A novel non-inverting pull–push gain stage output-capacitorless low-dropout regulator (OCL-LDO) is introduced, designed specifically for power management of system-on-chip (SoC). The incorporation of an innovative non-inverting gain stage (NIGS) serves to shift the non-dominant parasitic poles to higher frequencies, thereby enhancing the overall stability of the system. The proposed pull-push configuration markedly improves the slew rate limitation at the gate of the power transistor. Post-layout simulation outcomes, corroborated through a 180-nm CMOS fabrication process, indicate that the proposed LDO regulator maintains stability across a wide range of loading currents, from 0 mA to 100 mA, with a Miller compensation capacitance of only 3.5 pF. The circuit operates with a quiescent current of 143 μA when powered by a 1.5 V single supply. The LDO regulator boasts a dropout voltage of 300 mV, enabling it to deliver up to 100 mA of load current. Simulation results show that the undershoot voltage is only 63.7 mV when the load current jumps from 0 to 100 mA with edge of 100 ns, while employing a 100 pF capacitance load. The recovery time to return to equilibrium post this abrupt change is approximately 0.15 μs. The proposed OCL-LDO regulator exhibits a substantial enhancement in transient response compared to its predecessors, alongside a harmonized balance between line regulation and load regulation performance parameters.

Single and Double Stub Tuner Impedance Matching of Microwave Circuits Using Mathcad Software

In this paper impedance matching, using tuning stubs of different types and forms are designed and analyzed using Mathcad Software. The aim of this paper is impedance matching which is to connect an arbitrary complex-valued load impedance to a source with a given resistive internal impedance (Intrinsic Impedance Zo) without causing input reflection and to ensure transfer of maximum power from source to load (ZL). Smith chart is designed in this paper with a Mathcad software. This tool is considered as a very powerful tool to show the results on Smith chart. Single and double stub tuners are designed and analyzed with examples. The designed software is used in this paper for different cases, such as single stub and double stub tuners (open-ended and short-ended) for matching capacitive and inductive loads. The software designed in this paper is useful for designers working in this field as well as in education process.

Dual polarity open circuit voltage in triboelectric nanogenerators originated from two states series impedance

Experimental and simulation studies demonstrated that the initial voltage setting significantly influences the open-circuit voltage (VOC) in triboelectric nanogenerators (TENGs). Utilizing diode configurations, we consistently observed two distinct VOCs independent of the initial settings. A lower VOC corresponded to the surface voltage (VSurface), while a higher VOC was amplified by the product of the VSurface and the TENG's characteristic impedance ratio. Notably, a lower measurement system capacitance provided a more precise representation of the inherent characteristics of the TENG. Conversely, an increase in system impedance led to a convergence of the two VOCs and a reduction in their magnitudes relative to VSurface. These findings suggest that optimizing the initial/repeated charge balancing and minimizing capacitive loads are crucial for maximizing TENG output power in practical applications.

Enhanced Harmonic Suppression for a Miniaturized Hairpin-Line Bandpass Filter with Meander Spurline

The design of a fourth-order centrally corrugated double-folded hairpin line bandpass filter with a broad stopband and enhanced selectivity is demonstrated in this article. Initially, a double-folded hairpin-line bandpass filter (DFHLBF) is designed from a fourth-order conventional hairpin-line bandpass filter (CHLBF), which is centred at 2.5 GHz and has a fractional bandwidth of 3%. This results in a 68% size reduction. With this folding mechanism, the filter's skirt characteristic is only enhanced at the upper passband edge, resulting in an attenuation level of 40 dB at 2.65 GHz. The capacitive loading has then been incorporated by periodic rectangular corrugations that have disturbed the folded arms. Because of the high capacitive coupling between the folded arms, a symmetrical passband with an attenuation level better than 40 dB at both edges has been observed. Besides, a size reduction of 14% than that for the DFHLBF has been achieved. However, because of the imbalance of the modal phase velocities in the inhomogeneous microstrip filter construction, the stopband's attenuation level climbs to 8 dB. Rectangular meander spurlines have been added between the connected arms of the neighbouring centrally corrugated cells of the filters as a way to lower the attenuation levels of the harmonics. This creates a slow-wave effect between the odd- and even-modes of the propagating signals. This results in an overall size reduction of 81% over the standard hairpin-line filter and an enlarged stopband of up to 4.36f0 with a rejection level of 42 dB.

MCU-based Safer Coagulation Mode by Nonfixed Duty Cycle for an Electrosurgery Inverter.

The arcing-involved pulsating coagulation mode with both active and blank periods is essential for modern electrosurgery. This paper begins with a comprehensive introduction to such a pulsating mode, followed by its implementation challenges. Then, an industrial-scale low-speed microcontroller unit (MCU), TMS320F28379D, is utilized to exemplify the proposed output sampling and data-transferring strategy on a gallium nitride (GaN)-based high-frequency inverter that enables coagulation mode with interweaved active periods and blank periods. The inverter prototype fills the active period with 390 kHz sinusoids of amplitude ranging from hundreds to thousands of Volts, while maintaining null outputs during blank periods. The strategy of sampling the above-mentioned sinusoidal outputs, coupled with their data transfer facilitated by direct memory access (DMA), is also articulated for subsequential power computation. Besides that, a novel nonfixed duty cycle approach, featuring an alterable number of sinusoids as the active period, is proposed and integrated into the GaN-based inverter to enhance mode safety. Finally, the power tracking performance of the mode is evaluated initially on resistive load, secondarily on resistive plus capacitive load (R-C), and thirdly on fresh biotissue with the appearance of electrical arcing. The existing necessity of the null blank periods is examined at the end of the paper.

Conforming Capacitive Load Cells for Conical Pick Cutters.

In underground coal mining, machine operators put themselves at risk when getting close to the machine or cutting face to observe the process. To improve the safety and efficiency of machine operators, a cutting force sensor is proposed. A linear cutting machine is used to cut two separate coal samples cast in concrete with conical pick cutters to simulate mining with a continuous miner. Linear and neural network regression models are fit using 100 random 70:30 test/train splits. The normal force exceeds 60 kN during the rock-cutting tests, and it is averaged using a low pass filter with a 10 Hertz cutoff frequency. The sensor uses measurements of the resonant frequency of capacitive cells in a steel case to determine cutting forces. When used in the rock-cutting experiments, the sensor conforms to the tooling and the stiffness and sensitivity are increased compared to the initial configuration. The sensor is able to track the normal force on the conical picks with a mean absolute error less than 6 kN and an R2 score greater than 0.60 using linear regression. A small neural network with a second-order polynomial expansion is able to improve this to a mean absolute error of less than 4 kN and an R2 score of around 0.80. Filtering measurements before regression fitting is explored. This type of sensor could allow operators to assess tool wear and material type using objective force measurements while maintaining a greater distance from the cutting interface.

Switching and Frequency Response Assessment of Photovoltaic Drivers and Their Potential for Different Applications.

Newly introduced Photovoltaic (PV) devices, featuring a built-in chip with an illuminating Light Emitting Diode (LED), have emerged in the commercial market. These devices are touted for their utility as both low- and high-side power switch drivers and for data acquisition coupling. However, comprehensive knowledge and experimentation regarding the limitations of these Photovoltaic Drivers in both switching and signal processing applications remain underexplored. This paper presents a detailed characterization of a Photovoltaic Driver, focusing on its performance under resistive and capacitive loads. Additionally, it delineates the device's constraints when employed in signal processing. Through the analysis of switching losses across various power switches (Silicon and Silicon Carbide) in both series and parallel driver configurations, this study assesses the driver's efficacy in operating Junction Field-Effect Transistors (JFETs). Findings suggest that Photovoltaic Drivers offer a low-cost, compact solution for specific applications, such as high-voltage, low-bandwidth measurements, and low-speed turn-on with fast turn-off power switching scenarios, including solid-state switches and hot-swap circuits. Moreover, they present a straightforward, cost-effective method for driving JFETs, simplifying the circuit design and eliminating the need for an additional negative power source.

Designing a Dual-Feed Circular Polarization Antenna

This paper describes a novel dual-feed circularly polarized antenna, and the dual feeding mode is realized by grooving on the antenna radiator. The antenna utilizes air dielectric material to meet the requirements of low weight and cost. Test results demonstrate that the antenna exhibits capacitive loading between the metal antenna patch and the ground floor, allowing for adjustment of the working frequency of the dual-feed circularly polarized microstrip antenna. Specifically, the original center frequency of 2.264 GHz was reduced to 1.582 GHz, facilitating antenna miniaturization and broad bandwidth. With a return loss (S11) below -10 dB, a bandwidth of 72 MHz (1.552-1.624 GHz) was obtained. Additionally, the dual-feed microstrip antenna incorporates a 90° bridge, resulting in circular polarization gains of 2.26 dBi at 1.561 GHz and 2.45 dBi at 1.575 GHz. Overall, the antenna design offers a large working bandwidth and excellent circular polarization characteristics, making it suitable for a wide range of applications in satellite navigation and positioning terminals.