Stray Voltage Research Articles

Finite Element Analysis of Electrostatic Coupling in LISA Pathfinder Inertial Sensors

In the LISA Pathfinder (LPF) mission, electrostatic noise can reach the femto-Newtonian level despite the fact that the LPF’s sensors are equipped with potential shielding. Most of the existing simulation studies focus on the electrostatic edge effect and related fields, while the simulation study of the patch effect is neglected. For that reason, this paper analyzes the basic principle of electrostatic noise and constructs a simulation model for studying the coupling effects of a TM’s residual charge and stray bias voltage. The patch effect and other perturbation factors are simulated by the simulation model with finite element operation, focusing on the suppression effect of the protective ring on the edge effect, the realization of the patch effect in the simulation model, and the possible influence. The results show that electrode area and the spacing between the electrode and the TM together limit the suppression effect of the protective ring on the edge effect. The spatial and temporal variations of the patch effect significantly affect the distributed electric field between the electrodes and the TM, as well as the charge distribution density of the TM. In the worst-case scenario of LPF electrostatic input parameters, the electrostatic noise is about 1.03 × 10−15 m/s2/√Hz at 1 mHz, which is about 6% different from the expected performance estimate. Finally, considering the limitations of multiple environmental factors on the inertial sensors, the present model will be useful to explore the interactive effects of multi-field coupling and to further investigate the impact of low-energy electron charging on the performance of the inertial sensors.

Exposure to natural stray currents of low voltage affects the behaviour and some stress biomarkers of weaned piglets

With the modernisation of pig breeding facilities, pigs may be exposed to both on-farm and off-farm sources of stray voltages. Data from ruminant species suggest that exposition to stray voltages may be a source of stress and impair animal welfare, but data are scarce for pigs. The aim of this study was to evaluate the impact of stray currents of voltages under 0.5 Volts in pig housing on piglet behaviours and some biomarkers after weaning. Two replicates of 820 piglets were reared in a farm naturally exposed to stray voltage for seven weeks. The difference in electrical potential between the floor and each drinker and feeder was measured every two weeks. Piglets exposed to high-voltage drinkers (HVD > 125 mV) spent more time orally manipulating pen mates (P = 0.0031). They also spent more time lying inactive with open eyes (P = 0.0027) and less time nosing pen mates (P = 0.043), but these effects were influenced by the voltage in feeders (P = 0.0021 and P = 0.024, respectively). Piglets exposed to high-voltage feeders (HVF > 50 mV) spent less time lying with their eyes closed (P = 0.024) and more time aggressing pen mates (P = 0.0081). Fifty days after entering the farm, blood hydroperoxide concentration was higher in piglets exposed to HVD (P = 0.039). The increase in socio-negative behaviours and oxidative stress in pigs exposed to stray voltages in pig housing suggested that stray voltages might have moderate detrimental consequences for piglets in post-weaning facilities.

Effect of Stray and High Voltage Exposure on Livestock: An Overview

Electricity is essential to dairy farming and electrically powered machines are used for milking, automatic feed dispensers and heated water bowls. Leakage of current from these equipments, high voltage lines or faulty connections between the electrical circuit and the earth can lead to an undesirable electrical phenomenon called stray voltage. Stray voltage is a small voltage (<10V) that can be measured between two possible contact points. Cows can sense voltages at approximately one-tenth of a human being. Humans have inherently higher body resistance than cows and generally have shoes or boots while working in barns, which further increases resistance. Consequently, humans do not feel what animals feel. Stray voltages less than 0.5 volts are considered normal. Stray voltages vary, depending on the circuits used and the amount of moisture in the soil around the grounding rod. Impact of stray currents on livestock at current 1 - 3 mA: At current 4 - 6 mA: common behavioral response such as flinching or delaying drinking water. At current > 6 mA (up to 10): Feed intake is reduced, resulting in lower meat and milk production. Common symptoms of stray voltage in cows include hesitation to enter the parlor, they may stampede or rush out of the parlor when released, cows dance or step around constantly while in the milking parlor, Normal milk letdown is interrupted, Increased milking time, Udder irritation caused by residual milk and increased somatic cell count which increases the incidence of mastitis.

Degradation of RC Columns under Combined Exposure to Axial Loading, Stray Currents, and Chloride Ingress.

Coastal regions, home to a significant portion of the world's population, confront a formidable challenge: the corrosive impact of chloride-rich environments on vital infrastructure. These areas often host essential transportation systems, such as trains and metros, reliant on pre-existing electrical infrastructure. Unfortunately, complete isolation of this infrastructure is rarely feasible, resulting in the emergence of stray currents and electrical potentials that expedite corrosion processes. When coupled with conducive mediums facilitating chemical electrocell formation, the corrosion of reinforced concrete elements accelerates significantly. To combat this issue, international standards have been established, primarily focusing on augmenting the thickness of reinforcement bar covers and restricting stray voltage between rails and the ground. Nevertheless, these measures only provide partial solutions. When subjected to service loads, these elements develop cracks, especially when exposed to stray currents and chlorides, dramatically increasing corrosion rates. Corrosion products, which expand in volume compared to steel, exert internal forces that widen cracks, hastening the deterioration of structural elements. The study deals with the degradation of reinforced concrete columns under the combined action of loads, chloride-rich environments, and electrical voltage-simulating stray currents. In these conditions, degradation and reduction of load-bearing capacity accelerate compared to unloaded conditions, significantly amplifying the corrosion rate. Astonishingly, even in the absence of mechanical loads, stray currents alone induce tensile stresses in elements due to corrosion product formation, leading to longitudinal cracks parallel to the reinforcement bars.

Electric shock control of farmed animals: Welfare review and ethical critique

AbstractThe available methods of electric shock control or containment of farmed animals are increasing and potentially include: (i) fixed and movable electric fencing; (ii) cattle trainers; (iii) prods or goads; (iv) wires in poultry barns; (v) dairy collecting yard backing gates; (vi) automated milking systems (milking robots); and (vii) collars linked to virtual fencing and containment systems. Since any electric shock is likely to cause a farmed animal pain, any such control or containment must, to be ethically justifiable, bring clear welfare benefits that cannot be practicably delivered in other ways. Associated areas of welfare concern with ethical implications include the displacement of stockpersons by technology, poor facility design, stray voltage, coercive behavioural change and indirect impacts on human society and values.

Stray voltage? [Essay

Stray voltage may sound funny and inconsequential - but it may be extremely dangerous to you, electrical equipment, and home and farm animals. The introduction of ground fault receptacles may assist in the detection of stray currents in outdoor use. These receptacles can detect low ground wire currents and interrupt the circuit if a particular current level is exceeded. There is no defined “maximum” allowable level for stray voltage. As noted earlier, this is based upon a multitude of reasons—only checking and correcting can prevent the problem from becoming more than a simple nuisance. Be safe and check your electrical system.

Possible causes of aberrations in adverse grouping behavior of dairy cows: A field study

In the Dutch national surveillance system, an increasing number of reports were received in the summer of 2017 from farmers about unusual behavior of their cows. The cows were grouping during the day in summer in one part of the barn and did not move for several hours, which, according to the farmers, led to reduced food and water intake and lying time and resulted in decreased milk production and increased risk of lameness. Many farmers perceived magnetic fields from, for instance, high-voltage lines, automated milking systems, or solar panels as possible causes for the behavior of their cows. Our aim for the study was to study potential factors such as magnetic fields and other factors such as barn climate and insect burden for adverse grouping behavior of dairy cows in the barn. For each case herd, 2 control herds were selected in the same postal area code. A case was a herd in which cattle grouped at least on 7 occasions in a month for several hours. In a control herd, the cows were in the barn during the same time period as in the matching case herd but did not show adverse grouping behavior. A questionnaire was administered by telephone in 31 case herds and 62 control herds. The questionnaire gathered information on behavior of the cows and potential risk factors. In addition, data on the distance of the herd to high-voltage lines was obtained. From a total of 74 variables, all variables with a P-value ≤0.10 were included in full multivariable logistic regression model. Backward selection was carried out at P ≤ 0.10. The grouping behavior of the cows started in most herds in June, was seen only during the day, and lasted mostly 6 to 8 h, with cows often grouped in the northern part of the barn. Identified risk factors appeared to be recently constructed barns, measured stray voltage in barns, and presence of fans in barns. Given the cross-sectional design of the case-control study, causality for these risk factors leading to adverse behavior of the cows could not be proven. Dissemination of the results to farmers hopefully results in measures that can prevent the unusual grouping behavior of cows.

Impact of Stray Voltage on Renewable Energy-based Farm in Pacific Island Country

Recent advancements in solar technology offer an enormous opportunity for the people of Pacific Islands to use electricity from the off-grid solar system for both their energy needs and farming activities. However, a farm’s productivity and animal health might be seriously threatened if it experiences stray voltages caused by the improper grounding of its installed electrical systems. As a shift in the neutral point of an electrical system creates a current flow to the ground through conducting elements, the impacts of stray voltages need to be addressed from both technical and economic viewpoints. In this research, the effects of stray voltages passing through animals are explored using circuit designs for solar sources considering variable grounding resistances due to the different body resistances of various types of animals, and environmental and grounding design issues. A comparison of the stray voltages of two different sources (off-grid solar and traditional grid) with various configurations are conducted to determine their effects on a farm. Finally, their economic impacts together with possible techniques for mitigating them are explained.

Impact of Stray Voltage on Renewable Energy-based Farm in Pacific Island Country

Impact of Stray Voltage on Renewable Energy-based Farm in Pacific Island Country

Stray Voltages In Dairies

A stray electrical current passing through a cow's body may cause reduced milk production and health problems. The electrical current can be caused by poor or faulty wiring, faulty equipment, improper grounding, or originate off the farm and be introduced through the grounded neutral wiring network. Stray voltages are usually low alternating current voltages on the grounded neutral wires of the farm wiring system. Power suppliers may use the terms neutral-to-ground voltage and neutral-to-earth voltage to refer to the problem. Lost milk production and the costs for treatment of the cow's health problems can lead to substantial economic losses. This 3-page fact sheet is a minor revision written by J. A. Watson, R. A. Bucklin, and D. R. Bray, and published by the Department of Agricultural and Biological Engineering, November 2019. AE55/AE019: Stray Voltages in Dairies (ufl.edu)

An Integrated Semi-Double Stage-Based Multilevel Inverter With Voltage Boosting Scheme for Photovoltaic Systems

This article proposes a single-phase, seven-level, transformerless inverter, employing a semi-double stage-based conversion technique, which is particularly suitable for photovoltaic (PV) applications. The proposed configuration achieves voltage boosting using a non-isolated interleaved buck-boost converter, which is fused with the inverter configuration through two switched capacitors (SCs). The interleaved front-end boost stage is capable of achieving a voltage gain of three while resulting in reduced peak current stress on the switching devices. In this topology, a part of the load power is transferred directly from the PV source, while the other part is transferred through the SCs. The proposed topology and the associated pulsewidth modulation (PWM) technique are capable of reducing the leakage current by isolating the terminals of the PV source in the freewheeling state. This article also presents a thorough analysis of the stray capacitor voltage and the common-mode voltage (CMV). These analyses reveal that the high-switching frequency transitions are eliminated in both of these waveforms. Furthermore, the proposed topology results in the reduction of low-frequency transitions in the stray capacitor voltage and the CMV, which in turn result in further reduction of the leakage current. The simulation and experimental results are in agreement with the mathematical analysis of the proposed inverter.

Corrosion behavior of X80 steel under disbond coating interfered with AC

Purpose This paper aims to research the corrosion behavior of the metal under the disbonded coatings interfered with AC through electrochemical method. Design/methodology/approach The corrosion behavior of the metal under disbond coating interfered with alternate stray current (AC) was studied by electrochemical methods using the rectangular coating disbonded simulator. The obtained data from electrode potential test, electrochemical impedance spectroscopy (EIS) and polarization curves in simulated soil solution indicated that under the natural corrosion condition, the self-corrosion potential and the corrosion current density of the metal at different depths under disbond coating had obviously changed if there was AC interference. Findings The self-corrosion potential of the metal at the same depths under disbond coating shifted negatively with the rising of the AC voltage. Under the condition of cathode polarization, there was still obvious potential gradient with the extension of the deep peeling of the coating gap, and the corrosion current density of the test points was minimum, and the protection effect was best when the cathode protection potential was −1.0 V. When the metal was applied with over-protection, the corrosion rate of the metal increased as AC stray current flowing through it increased. Originality/value This paper used the rectangular aperture device to study the corrosion behavior of X80 steel under the disbonded coatings through electrochemical methods when the AC stray current interference voltage was 0V, 1V, 5V or 10V and the protection potential was 0V, −0.9V, −1.0V, −1.2V or −1.3V, respectively. There is great significance to the safe operation and long-term service of pipeline steel in soil environment.

Anomalously large spin-current voltages on the surface of SmB6

The spin-polarized surface states of topological insulators have attracted interest both from a fundamental and applied point of view. A recent proposal describes a method of probing these surface states with ferromagnetic contacts, which was subsequently applied to a variety of materials. In this study, we use this method on the potential topological insulator SmB$_6$ with a new design based on the Corbino geometry. Though the signal behaves as predicted for all orientations of current and magnetic field, its magnitude is much larger than expected. Possible parasitic effects such as stray field-induced Hall voltages are excluded, leaving the origin of the observations uncertain. This corroborates the need for careful analysis when interpreting results of similar experiments.

Technology Update: New Instrumented Docking Gun System Maximizes Perforating Performance

Technology Update Accidental detonation of a perforating gun at surface can have catastrophic consequences. To decrease risks, layers of procedural controls have been implemented to reduce the inadvertent application of power caused by human error, stray voltage, or the presence of radio frequency (RF) energy. Explosives handling procedures and controls, such as locking out the firing panel and acquisition system, are used to mitigate the human error risk. Mitigating RF risks requires establishing RF-free exclusion zones, with all RF transmissions shut down. Exclusion zones are effective, but adhering to them relies on strict procedural controls. With increased industry and personal reliance on RF transmitters, such as cellular phones, RF silence is becoming more difficult to achieve. Although RF-immune initiators were introduced more than 20 years ago to allow wellsite operations to continue without RF silence imposed, their complex initiation technologies require high power levels, which improve the safety margin to stray volt-age but significantly reduce overall system reliability. Perforating has always been a hands-on operation that relies on supervisor experience. Over the last decade, perforating reliability has continued to improve as service companies and operators have implemented detailed training programs, procedural checklists, and advanced hardware. However, these reliability improvements have begun to plateau, acting as an impetus to develop new perforating systems that would be more effective than procedural controls in addressing the main causes of perforating misruns: damaged or improper wiring, mechanical seal failures, and initiator malfunctions. Plug-In Design With Built-In Safety With a focus on resolving these issues, Schlumberger developed the Tempo instrumented docking perforating gun system—the industry’s first perforating system that fully integrates a plug-in gun with real-time advanced downhole measurements for monitoring and confirming operations to mitigate risk while increasing safety, reliability, and efficiency (Fig. 1). Created for all environments, the system uses modularized initiators combined with RF filtering mechanisms and an addressable switch to provide an enhanced level of safety to operations. Proprietary docking components are the key element of the gun system’s plug-in design. They streamline assembly and eliminate the major cause of perforating misfires: technique-sensitive crimping and wiring. The initiator can be plugged into a perforating gun by using simple mechanical and electrical connections without requiring complicated assembly. The new system eliminates all complex field wiring connections and crimping, which simplifies the arming process that has a direct impact on both wellsite efficiency and reliability.

Magnetic Susceptibility Study of Sub‐Pico‐emu Sample Using a Micromagnetometer: An Investigation through Bistable Spin‐Crossover Materials

A promising and original method to study the spin-transition in bistable spin-crossover (SCO) materials using a magnetoresistive multiring sensor and its self-generated magnetic field is reported. Qualitative and quantitative studies are carried out combining theoretical and experimental approaches. The results show that only a small part of matter dropped on the sensor surface is probed by the device. At a low bias-current range, the number of detected nanoparticles depends on the amplitude of the current. However, in agreement with the theoretical model, the stray voltage from the particles is proportional to the current squared. By changing both the bias current and the concentration of particle droplet, the thermal hysteresis of an ultrasmall volume, 1 × 10-4 mm3 , of SCO particles is measured. The local probe of the experimental setup allows a highest resolution of 4 × 10-14 emu to be reached, which is never achieved by experimental methods at room temperature.

Hardware-Based Cascaded Topology and Modulation Strategy With Leakage Current Reduction for Transformerless PV Systems

Leakage current reduction of the single-phase transformerless cascaded H-bridge PV inverter is investigated in this paper. The high-frequency common-mode loop model of a typical single-phase cascaded H-bridge PV system is established. Based on the model, the main factors that affect the leakage current are discussed. The reason why the typical single-phase cascaded H-bridge inverter fails to reduce the leakage current is explained. In order to solve the problem, a cascaded topology based on the H5 inverter is presented, along with a new modulation strategy, which can ensure that the stray capacitor voltage is free of high-frequency components. In this way, the leakage current can be effectively reduced. Finally, a prototype with TMS320F28335DSP + XC3S400FPGA digital control is built. The performance tests of cascaded H-bridge and the proposed topologies are carried out. The experimental results verify the effectiveness of the proposed solution.

An easy way to measure accurately the direct magnetoelectric voltage coefficient of thin film devices

TbxDy1−xFe2/Pt/Pb(Zrx, Ti1−x)O3 thin films were grown on Pt/TiO2/SiO2/Si substrate by multi-target sputtering. The magnetoelectric voltage coefficient αΗΜΕ was determined at room temperature using a lock-in amplifier. By adding, in series in the circuit, a capacitor of the same value as that of the device under test, we were able to demonstrate that the magnetoelectric device behaves as a voltage source. Furthermore, a simple way to subtract the stray voltage arising from the flow of eddy currents in the measurement set-up, is proposed. This allows the easy and accurate determination of the true magnetoelectric voltage coefficient. A large αΗΜΕ of 8.3V/cm. Oe was thus obtained for a Terfenol-D/Pt/PZT thin film device, without DC magnetic field nor mechanical resonance.

Monitoring and remediation of on-farm and off-farm ground current measured as step potential on a Wisconsin dairy farm: A case study

ABSTRACTGround current commonly referred to as “stray voltage” has been an issue on dairy farms since electricity was first brought to rural America. Equipment that generates high-frequency voltage transients on electrical wires combined with a multigrounded (electrical distribution) system and inadequate neutral returns all contribute to ground current. Despite decades of problems, we are no closer to resolving this issue, in part, due to three misconceptions that are addressed in this study. Misconception 1. The current standard of 1 V at cow contact is adequate to protect dairy cows; Misconception 2. Frequencies higher than 60 Hz do not need to be considered; and Misconception 3. All sources of ground current originate on the farm that has a ground current problem. This case study of a Wisconsin dairy farm documents, 1. how to establish permanent monitoring of ground current (step potential) on a dairy farm; 2. how to determine and remediate both on-farm and off-farm sources contributing to step potential; 3. which step-potential metrics relate to cow comfort and milk production; and 4. how these metrics relate to established standards. On-farm sources include lighting, variable speed frequency drives on motors, radio frequency identification system and off-farm sources are due to a poor primary neutral return on the utility side of the distribution system. A step-potential threshold of 1 V root mean square (RMS) at 60 Hz is inadequate to protect dairy cows as decreases of a few mV peak–peak at higher frequencies increases milk production, reduces milking time and improves cow comfort.

Technology Update: New Perforating Gun System Increases Safety and Efficiency

Technology Update Achieving greater efficiency in perforation systems can help lower operating costs, particularly when completing long horizontal wellbores in unconventional plays. The DynaStage perforating system, developed by DynaEnergetics, incorporates new technology in the addressable firing system and an improved mechanical design that eliminates potential human error. The system can operate more efficiently than traditional systems and, with its additional safety features, allow other wellsite operations to run in parallel with the perforation process. As a result, the system can achieve improvements in perforation quality and performance reliability, with fewer misruns, while operating efficiently enough to lower total completion costs. The DynaStage system has successfully completed field trials in multiple basins and been commercialized. The system targets two areas to improve operational efficiency and reduce operating cost. Safety—the system has a simple, intrinsically safe design that eliminates the risk of inadvertent detonation from stray current or voltage. Surface explosive handling and arming can be conducted in less time and in parallel with other operations. The design eliminates the need to hold the gun system at shallow subsurface depth during simultaneous operations. Both factors reduce wait times at the wellsite. Reliability—the design of the electronic system and simplification of the mechanical field assembly process help to reduce the number of misruns, which increases efficiency and lowers the cost of completions. Surface Assembly Perforating operations with explosives place the explosive components and workers in close proximity, especially during the arming process. Traditional resistorized detonators can contribute to an increased risk of injury and destruction when connecting the detonator to the gun string and the wireline truck. Safety procedures have been developed to address the risks in this process, and the American Petroleum Institute (API) provides guidelines for safe handling of explosives through Recommended Practice 67 (API RP 67). One of the established best practices is to suspend all surface operations while working with the resistorized detonators. The arming and connection of a gun string at the surface can take up to an hour, meaning that no other wellsite operations can be completed during this time. The DynaStage system removes the risks of this process by providing an addressable and radio frequency (RF)- safe system with immunity to high voltage and current levels. The firing system is built on a low-voltage, digital communication platform that uses the DynaEnergetics detonator technology, proven to successfully communicate and initiate on command during more than 300,000 perforating operations, without a safety incident. This technology enables the verification of all components in the system, including the addressable switch, the RF-safe detonator, and the RF-safe ignitor, during all phases of the operation.

A Method to Determine Stray Voltage Sources—Part I: Concept and Theory

Stray voltages have always been a concern to utility companies and customers. But methods to troubleshoot and monitor nonroutine stray voltage problems are very limited. This paper presents a passive, measurement-based method to identify the contributors to the common cause of stray voltages, the neutral-to-earth voltage (NEV) rise at the service entrance point. The paper shows that the NEV can be decoupled into two components: those related to the customer under investigation and those outside the customer facility. A method to quantify the relative contributions of the two components is proposed. A new concept called current return ratio is introduced to facilitate the decoupling and to quantify the grounding conditions of the system. This paper presents the background, circuit model, concept, and theory of the proposed method.