Voltage Detection Research Articles

A multisource energy harvesting circuit for vibration and light energy with MPPT

SummaryThe article presents a multisource energy harvesting circuit (MEHC) for vibration and light energy with maximum power point tracking (MPPT). The MEHC has a cold start capability and extracts energy from piezoelectric transducers (PZTs) and photovoltaic cells (PVs) simultaneously when the multi PZTs reach their peak open‐circuit (OC) voltage, detected by the peak voltage detector and the PV1 cell voltage exceeds the MPP voltage (MPP voltage is approximately 0.7 times the PV cell's OC voltage) during the off‐peak time of the PZTs. The experimental results indicate that the output power of the MEHC is 2.8 mW under certain conditions, and the maximum energy extraction efficiency of the PVs is about 75%. The output power of the MEHC is 4.59 times of that without PVs.

Photovoltaic charging multi-station with modular architecture for Light Electric Vehicles

This paper deals with a modular architecture for recharging the batteries of light electric vehicles (LEVs) using a photovoltaic (PV) generator. The architecture is organized into two hierarchical levels. At the top level (master), a microcontroller tracks the maximum power point of the PV generator. This microcontroller executes a proportional-integral-derivative (PID) control algorithm whose output is the setpoint of the microcontrollers of the lower level. At the lower level (slaves), there is a microcontroller for each vehicle charging station. Each microcontroller controls the recharge current of the vehicle battery connected to the station by executing another PID control algorithm. Modular architecture allows the number of charging stations to be extended up to 112. Other characteristics of the system are the automatic detection of the nominal voltage of the battery (it allows to recharge batteries of 24V, 36V or 48V) and the inclusion of protection functions as battery overload or detection of not allowed batteries.

Optimum PI controllers of active power filters for harmonic voltage mitigation in multibus industrial power systems.

The bus voltage and branch current detection control strategies of the active power filters used in multibus power systems for harmonic voltage mitigation are analysed in terms of the optimum gains of PI controllers

Connection of Shunt Active Power Filters in Multibus Industrial Power Systems for Harmonic Voltage Mitigation.

The bus voltage and branch current detection control strategies of the active power filters used in multibus power systems for harmonic voltage mitigation are analysed in terms of the harmonic bus voltage mitigation and of the demanded current spectrum injected by the active power filters.

Novel voltage Multiplier/Divider-based active square law detector for heartbeat measurement

This paper describes a novel active voltage detector that is capable of processing analog signals with levels from units of mV up to 250 mV. An advantage of the proposed circuit is that the relationship between output voltage and input level is not linear but quadratic, which increases the sensitivity when processing low-level signals. The presented solution has tuning parameters for correction or intentional shift of internal DC offset and electronic control of the output signal gain level. The application example presents detection of beats per minute (BPM) in the range of 6–300 BPM, which corresponds to a frequency range of 0.1–5 Hz. The advantage of the presented solution is that the output of the circuit is directly a digital signal compatible with TTL levels, so there is no need for any analog to digital converter to produce a digital signal for further processing.

Beyond helium: hydrogen as a carrier gas in multiresidue pesticide analysis in fruits and vegetables by GC-MS/MS.

In this comprehensive study, we evaluated the feasibility of using hydrogen instead of helium as a carrier gas in a GC-MS/MS system for pesticide residue analysis, spanning three matrices: pepper, tomato, and zucchini. Initial assessments focused on the ion source's chemical inertness, employing nitrobenzene as a benchmark to monitor the hydrogenation process. A method with a duration of less than 12 minutes was developed, achieving good chromatographic peak resolution attributable to the enhanced chromatographic performance of hydrogen as a carrier gas. The study emphasized the optimization of system parameters, testing various ion source temperatures, detector voltages, and injection volumes. Sensitivity assessments, based on the DG-SANTE criteria, indicated that the majority of compounds were identifiable at a concentration of 5 μg kg-1 (81% in tomato, 84% in pepper and 73% in zucchini). Detailed validation for reproducibility, matrix effects, and linearity across 150 pesticides unveiled generally favorable outcomes, with a notable majority of compounds displaying low matrix effects, satisfactory linearity ranges and good reproducibility with most compounds returning a relative standard deviation (RSD) below 10%. When applied to 15 real samples, the hydrogen-based system's performance was juxtaposed against a helium-based counterpart, revealing that results are very comparable between both systems. This comparative approach highlights hydrogen's potential as a reliable and efficient carrier gas in pesticide residue analysis for routine food control laboratories, overcoming difficulties resulting from the lack of helium supplies.

An Online Monitoring Method for Capacitor Condition of Cascaded H-Bridge STATCOM Based on Sensorless Capacitor Voltage Detection

An Online Monitoring Method for Capacitor Condition of Cascaded H-Bridge STATCOM Based on Sensorless Capacitor Voltage Detection

Towards Sustainable Smart Living: Cloud-Based IoT Solutions for Home Automation

In recent times, the realm of home automation systems has garnered significant attention, thanks to the ever-evolving landscape of communication technology. The concept of a smart home, essentially an application of the Internet of Things (IoT), leverages the power of the internet to oversee and employ household appliances through a sophisticated automation infrastructure. Nevertheless, challenges persist within the existing home automation systems, such as constrained wireless transmission reach, a deficiency in backup power management, and the substantial financial outlay involved. Addressing these limitations, our study introduces an economical and resilient solution that combines cloud based IoT with an uninterrupted power management system, making a cutting-edge home automation prototype. This system relies on a microcontroller unit, specifically the ESP-32, which functions as a Wi-Fi-enabled gateway for connecting a variety of sensors and transmitting their data to the Blynk IoT cloud server. The data assembled from a multitude of sensors, including vibration sensors and voltage detectors, becomes readily accessible on users' devices, be it smartphones or laptops, irrespective of their geographical location. The system is further strengthened by a set of relays that link the ESP-32 with household appliances, allowing for centralized control. Structurally, the design uses a control box that can be seamlessly integrated into a real home environment, offering the means to both monitor and govern an array of household devices. This IoT-based home automation solution not only efficiently manages internet-connected appliances but also provides an effective emergency power management system, enabling remote initiation and deactivation of backup generators. It represents a innovative leap in the evolution of home automation systems, steering in convenience, efficiency, and cost-effectiveness.

Sensorless Capacitor Voltage Detection Method of Cascaded H-Bridge STATCOM Based on Special Switching Mode Identification

The cascaded H-bridge (CHB) static synchronous compensator (STATCOM) has been widely used in wind farm and conflux station. As the grid-connected voltage increases, the number of cascaded CHB proportionately increases. In order to achieve the capacitor voltage balance, it is necessary to independently detect the capacitor voltage of all H-bridge cells, which raises the cost of capacitor voltage detection. To solve this problem, the mapping relationship is studied between the converter output voltage and capacitor voltages by analyzing carrier phase-shifted sinusoidal pulse width modulation technique (CPS-SPWM), and special switching mode is firstly found. Based on the above finding, without changing the conventional CHB topology, an improved sensorless detection method is proposed to solve the problems of detection error, large computation burden and the application limitation in existing sensorless detection methods. Compared with conventional sensor detection, this method not only saves DC voltage sensors and data transmission channels but also suppress the third harmonics in the converter current. Finally, the effectiveness of the detection method applied on CHB STATCOM is proved by simulation and experiment.

Abstract 16984: A Wearable Device Reproducibly Identifies Premature Ventricular Contractions and Tachyarrhythmias in Heart Failure Patients

Introduction: occurrence of ventricular arrhythmias (VAs) has a dramatic impact on prognosis of patients with heart failure (HF). Hypothesis: wearable devices, including smartwatch (SW), might provide real-time informations in patients at risk of VAs. Aims: we therefore evaluated if SW detection of QRS interval width and voltage could reproducibly detect VAs and/or premature ventricular contractions (PVCs) in HF patients. Methods: HF patients (N=100) underwent continuous electrocardiographic (ECG) recordings through telemetry and SW during hospital admission. Left ventricular ejection fraction (EF) and laboratory pro-BNP levels assessments were obtained as well. Correlation of the ECG results was addressed using Pearson’s analysis for normally distributed data and Spearman’s analysis for non-parametric data. Bland-Altman was used for reliability between telemetry and SW ECG measurements. Results: mean EF was 45.92±12.12%; mean pro-BNP was 2826±5823 pg/mL. Using the SW and the ECG data, QRS width and voltage correlation coefficients were 0.990 (p<0.001) and 0.974 (p<0.001), respectively. Concordance was found between the two assessments for QRS width (bias, 0.20; SD 3.0; lower limit, –5.68; upper limit, 6.08), and voltage (bias, -0.029; SD, 0.611; lower limit, –1.227; upper limit, 1.169). Moreover, we found correlation coefficients of 0.964 (p<0.001) and 0.970 (p<0.001), respectively, for PVCs width and PVCs voltage using SW and telemetry or other ECG report. Similarly, both techniques showed positive concordance for PVCs width (bias, 0.368; SD, 2.65; lower limit, -4.83; upper limit, 5.56) and PVCs voltage (bias, 0.54; SD, 1.25; lower limit, -1.91; and upper limit, 2.996). Remarkably, VAs identification by the SW was reproducible and standardized. Conclusions: continuous monitoring through SW might be considered in HF patients upon discharge.

Application of the method combining transient earth voltage and ultrasonic detection technology in insulation detection of the high voltage switchgear

Application of the method combining transient earth voltage and ultrasonic detection technology in insulation detection of the high voltage switchgear

An LDO without a Capacitor Required in Applications

Linear voltage regulator with low voltage dropout is widely used in DC/DC circuits because of the advantages of simple structure, low noise, high efficiency, and small package size. In this paper, high stability LDO linear voltage regulator with low static current is designed. By using a voltage detection module, the pass transistor in the regulator can be quickly regulated or switched on and off under load transient conditions. In addition, the stability of the LDO is improved by using an NMOS pass transistor and diode clamp architecture. The test results show that the typical values of linear adjustment and load adjustment of the voltage regulator are 20 mV and 200 mV, respectively. The maximum output current is 60 mA, the load current is 20 mA, and the output pressure difference under 4.8 V output voltage is 210 mV. Compared with traditional LDO, although the output current is not the maximum, the difference and stability of output pressure are greatly improved.

A high-efficiency burst mode boost converter with a sharing main power NMOS for start-up

This paper presents a high-efficiency boost converter with a wide input range and a start-up strategy of sharing main power NMOS which can start-up at an input voltage of 700 mV. A burst mode with boundary conduction mode (BMBCM) control is utilized in the proposed boost converter to achieve high efficiency across the wide input power range. A method is also suggested to determine the optimal peak inductor current for a given input range. Compared to other start-up strategies, the proposed start-up circuit reduces chip area by sharing the main power NMOS with the normal operation mode, eliminating the need for an additional start-up power transistor. A new ultra-low-power voltage detection circuit is used to control the start-up process. The proposed boost converter is designed and fabricated in a 180 nm BCD process with an active chip area of only 0.33 mm2. The circuit achieves a peak efficiency of 94.8% at an input voltage of 3 V and an output voltage of 3.6 V, while maintaining an efficiency of at least 65.9% across the input power range of 7 μW to 300 mW.

Machine Learning Based Method for Impedance Estimation and Unbalance Supply Voltage Detection in Induction Motors.

Induction motors (IMs) are widely used in industrial applications due to their advantages over other motor types. However, the efficiency and lifespan of IMs can be significantly impacted by operating conditions, especially Unbalanced Supply Voltages (USV), which are common in industrial plants. Detecting and accurately assessing the severity of USV in real-time is crucial to prevent major breakdowns and enhance reliability and safety in industrial facilities. This paper presented a reliable method for precise online detection of USV by monitoring a relevant indicator, denominated by negative voltage factor (NVF), which, in turn, is obtained using the voltage symmetrical components. On the other hand, impedance estimation proves to be fundamental to understand the behavior of motors and identify possible problems. IM impedance affects its performance, namely torque, power factor and efficiency. Furthermore, as the presence of faults or abnormalities is manifested by the modification of the IM impedance, its estimation is particularly useful in this context. This paper proposed two machine learning (ML) models, the first one estimated the IM stator phase impedance, and the second one detected USV conditions. Therefore, the first ML model was capable of estimating the IM phases impedances using just the phase currents with no need for extra sensors, as the currents were used to control the IM. The second ML model required both phase currents and voltages to estimate NVF. The proposed approach used a combination of a Regressor Decision Tree (DTR) model with the Short Time Least Squares Prony (STLSP) technique. The STLSP algorithm was used to create the datasets that will be used in the training and testing phase of the DTR model, being crucial in the creation of both features and targets. After the training phase, the STLSP technique was again used on completely new data to obtain the DTR model inputs, from which the ML models can estimate desired physical quantities (phases impedance or NVF).

Highly sensitive refractive index, chemical potential, and applied electrical voltage detection in terahertz region with photonic spin Hall effect in a plasmonic sensor based on graphene and germanium layers

"In this work, a transverse spin-dependent shift (SDS) of the horizontal photonic spin Hall effect (PSHE) at a fixed frequency (5 THz) is simulated for detection of refractive index, chemical potential, and applied electrical voltage to a plasmonic sensor with four layers (germanium, organic layer, graphene, and gas medium). The variation of the refractive index of graphene with chemical potential and applied voltage is given from the simulated values. A refractive index resolution (1.73 × 10–12 RIU) is obtained when the refractive index n4 of the analyte layer is changed from 1 RIU to 1.1 RIU when the chemical potential μc is 0.003 eV and the amplified angle ∆ is 0.1°. A chemical potential resolution (6.32 × 10–14 eV) and corresponding voltage resolution (6.83 × 10–13 V) are obtained when the chemical potential is changed from 0.003 eV to 0.03 eV, the refractive index of gas medium n4 is 1.1 RIU and the amplified angle is ∆ = 0.1°. These values are very good in comparison with the situation when the spin Hall effect is not applied (7.47 × 10–6 RIU, 0.001166 eV, and 0.01259 V) for the same values of μc, n4, and ∆."

Resonance Characteristics of the LLC Resonant Half-Bridge Converter for the Rapid Charging of Personal Mobility Device Smart Batteries

This study discusses the resonance characteristics of the LLC resonant half-bridge converter and smart battery charging for the fast charging of personal mobility devices (e.g., electric kickboards, segways, hoverboards, electric bicycles, and electric motorcycles), whose use is rapidly increasing. Through the analysis of resonance characteristics, this study aims to validate that fS > f0 is the most appropriate correlation in the relationship between resonant frequency (f0) and switching frequency (fS) that is suitable for the rapid charging of batteries of personal mobility devices. Additionally, the proposed half-bridge converter does not charge the battery from discharge or misconnection based on the detection of the battery voltage for the batteries of personal mobility devices. Therefore, the proposed converter suggests a charging system based on battery state detection that stably performs rapid charging of the batteries of personal mobility devices by equalizing the battery voltage and the charger voltage through a pre-charge operation.

Bias-Voltage-SSHI Interface Circuit for Strong Coupling Piezoelectric Energy Systems

Compared with the standard extraction interface circuit (SEH), the harvested energy and harvested power of synchronized switching harvesting interface circuits (SSHI) and synchronous charge extraction interface circuit (SECE) cannot improve more effectively. This paper proposes a Bias-Voltage-SSHI Interface Circuit (BV-SSHI), consisting of a single peak voltage detection switch and a rectifier, to solve this problem. The proposed BV-SSHI improves the output voltage by biasing the voltage of the piezoelectric energy harvester and obtains similar harvested power as SSHI. Simulation results show that the BV-SSHI can obtain more harvested energy and harvested power than SEH under weak, medium, and strong coupling systems. Results show that the higher harvester's voltage and the larger phase difference cause the electrical restoring force (χV) to significantly weaken the vibration displacement, especially under strong coupling systems. Thus, the gain effect of the SSHI and SECE is weakened. The experimental results of the medium coupling systems show that the BV-SSHI can obtain 247.2% harvested energy and 121.2% maximum harvested power compared with SEH. The BV-SSHI can achieve at least 142.4% harvested energy and 100.3% maximum harvested power compared with what SSHI and SECE can achieve.

A SOC Correction Method Based on Unsynchronized Full Charge and Discharge Control Strategy in Multi-Branch Battery System

LiFePO4 batteries exhibit voltage plateau and voltage hysteresis characteristics during charging and discharging processes; however, the estimation of state-of-charge relies on voltage detection. Thus, the estimation accuracy of SOC is low in a traditional method. In this paper, a full charge and discharge SOC correction method is proposed; i.e., the SOC is corrected to 100% when the battery is fully charged and to 0% when fully discharged, and the actual usable capacity is corrected using the fully discharged capacity after being fully charged. Thereby, the cumulative error of the ampere-hour integration method is dynamically corrected. In engineering applications, however, the battery systems do not always undergo full charge and discharge cycling due to the operating conditions. By making full use of the distributed control characteristics of the multi-branch topology battery system, the present work proposes an optimized system control strategy to realize the unsynchronized full charge and discharge cluster by cluster, which extends the application of the full charge and discharge SOC correction method. The experimental results verify the accuracy of the proposed SOC correction method and the feasibility of the control strategy. A more reliable and efficient battery management scheme is provided for LFP battery system, which has high practical value in engineering.

A Period Energy Method for Demagnetization Detection in Surface Permanent Magnet Motors with Search Coils

Irreversible demagnetization of permanent magnets (PMs) in PM synchronous motors (PMSMs) degrades the performance and efficiency of a machine and its drive system. There are numerous fault diagnosis methods for detecting demagnetization under steady-state conditions. However, only a few works could be found on fault diagnosis under dynamic conditions, whereas the dynamic operation of a motor is a very common scenario, e.g., electric vehicles. The voltage and current signal-based traditional fault detection method is not only affected by the structure of the motor, but it also becomes complicated to extract signals involving fault characteristics. Hence, this paper proposes a search coil-based online method for detecting demagnetization faults in PMSMs under dynamic conditions, which are not affected by the motor structure. To gather the flux of the stator tooth, flexible Printed circuit board (FPCB) search coils are positioned at the stator slot. The search coil is made up of two branches that are one pole apart and arranged in reverse sequence. In this installation option, the output signal in the fault state cannot be eliminated, and the output signal in the health state is zero. This paper defines only that characteristic value related to the position angle of the rotor. Further, the aim was to simultaneously eliminate the influence of elements like the search coil installation error and the inherent dispersion of the permanent magnet on the detection results. To characterize the fault degree, the measurement differential between the health state and the fault state is further integrated according to a predetermined angle range. Last but not least, speed-independent detection of individual permanent magnet demagnetization faults is possible using rotor position and stator tooth flux. A six-phase PMSM was used in experiments to show the efficiency of the suggested approach. The findings of the experiment demonstrate that the suggested strategy may precisely ascertain when a defect will occur.

Simulation and Experimentation of a Grounding Network Detection Scheme Based on a Low-Frequency Electromagnetic Method.

The grounding network is a significant component of substations, and the corrosion of its ground resistance is predominantly detected using the electromagnetic method. However, the application of electromagnetic methods for detecting corrosion within earthing networks has received relatively limited attention in research. Currently, the prevailing method utilizes electromagnetic techniques to identify the breakage points within the given earthing network. In this study, we propose a corrosion detection method for grounding networks based on the low-frequency electromagnetic method, which measures the resistance value between individual nodes of the network. Specifically, an excitation source signal of a predetermined frequency was transmitted to the measurement segment of the grounding network, which facilitated the direct measurement of the strength of the induced magnetic field above the center of the measuring conductor. The recorded electromagnetic data were subsequently uploaded to the host computer for data processing, and the computer interface was constructed based on a LABVIEW design. By leveraging the relationship between the induced electric potential, current strength, excitation source strength, and additional voltage detection devices, the resistance of the conductor under examination could be determined. Furthermore, the proposed method was tested under suitable conditions, and it demonstrated favorable results. Thus, the proposed method can serve as a foundation for developing electromagnetic testing instruments tailored to the investigated grounding network.