Figure - available from: Earth and Space Science
This content is subject to copyright. Terms and conditions apply.
EFM data recorded by different stations during a storm period on 5 December 2018, between 18:00 and 00:00 UTC (left) and lightning map for the storm system, provided by ENTLN (right). The plots are color‐coded based on time of day. Both Córdoba and Pilar mills reach their saturation levels.
Source publication
The atmospheric electric field is an important research parameter in understanding storm electrification and energy exchange between lightning and the atmosphere across the globe. The near-surface electric field can range from a few V/m (order of 10-100 V/m), mainly produced by the currents in the global electric circuit and local charge perturbati...
Citations
... Numerous variants have been developed, differing mainly in the number of measuring electrodes and aperture openings [36,52,[54][55][56][57][58]. ...
Due to the necessary transition to renewable energy, the transport of electricity over long distances will become increasingly important, since the sites of sustainable electricity generation, such as wind or solar power parks, and the place of consumption can be very far apart. Currently, electricity is mainly transported via overhead AC lines. However, studies have shown that for long distances, transport via DC offers decisive advantages. To make optimal use of the existing route infrastructure, simultaneous AC and DC, or hybrid transmission, should be employed. The resulting electric field strengths must not exceed legally prescribed thresholds to avoid potentially harmful effects on humans and the environment. However, accurate quantification of the resulting electric fields is a major challenge in this context, as they can be easily distorted (e.g., by the measurement equipment itself). Nonetheless knowledge of the undisturbed field strengths from DC up to several multiples of the fundamental frequency of the power-grid (up to 1\,kHz) is required to ensure compliance with the thresholds.
Both AC and DC electric fields can result in the generation of corona ions in the vicinity of the line. In the case of pure AC fields, the corona ions generated typically recombine in the immediate vicinity of the line and, therefore, have no influence on the field measurement further away. Unfortunately, this assumption does not hold for DC fields and hybrid fields, where corona ions can be transported far away from the line (e.g., by wind), and potentially interact with the measurement equipment yielding incorrect measurement results. This review will provide a comprehensive overview of the current state-of-the-art technologies and methods which have been developed to address the problems of measuring the electric field near hybrid power lines.
... In industrial manufacturing processes, they can be used to prevent electrostatic discharges (ESDs) to protect electronic equipment [4]. In atmospheric science, they are used to study the mechanisms of thunderstorms [5] and predict lightning [6]. They are also useful in the study of climate and geophysics [7]. ...
... We can see that the sensing electrodes are minimally affected by the driving voltage. For example, when 200 V at 246. 5 Hz is applied to the driving electrode (the shutter has a resonant frequency of 493 Hz), the induced charge on the sensing electrodes is 2.5 fC. The generated current is: ...
Micromachined electric field mills have received much interest for the measurement of DC fields; however, conventional designs with lateral moving shutters could have shutter lifting in the presence of strong fields, which affects their performance. This paper presents a MEMS electric field mill utilizing a vertical movement shutter to address this issue. The sensor is designed and fabricated based on a flexible PCB substrate and is released using a laser-cutting process. The movement of the shutter is driven by an electrostatic actuator. When the driving signal is a sine wave, the shutter moves in the same direction during both the positive and negative half-periods. This facilitates the application of a lock-in amplifier to synchronize with the signal at twice the frequency of the driving signal. In experimental testing, when the vertical shutter is driven at a resonance of 840 Hz, the highest sensitivity of the sensor is achieved and is measured to be 5.1 V/kVm−1. The sensor also demonstrates a good linearity of 1.1% for measuring DC electric fields in the range of 1.25 kV/m to 25 kV/m.
... Various designs for an EFM instrument have been proposed in preceding studies (Ogawa, 1973;Chubb, 1990;Bateman et al., 2007;Xu W et al., 2018;Antunes De Sá et al., 2020;Harrison and Marlton, 2020;Agorastou et al., 2022). An essential part of an EFM instrument is the rotary mechanism, which records the strength and direction of the electrostatic field. ...
... Overview of the EFM. et al.: A new EFM array controlled precisely by a GPS module 2007;Xu W et al., 2018;Antunes De Sá et al., 2020;Harrison and Marlton, 2020). ...
... -in meteorology to study the occurrence of thunderstorms [4][5][6]; ...
... For the vast majority of known EFM functional circuits, which include a differential transimpedance amplifier (TIA) [4,11,[13][14][15][16], a typical solution is the use of two TIA circuits that are connected in parallel, each of which is intended for a separate group of plates, outputs which are fed to the differential amplifier. Despite the simplicity of such an implementation, it contains a number of inherent disadvantages of TIA and is not optimal. ...
... In [4], the results of research on high-speed, autonomous EFMs for the study of thunderstorms are given. This paper proposes a ground-based EFM design in which the currents induced on both sets of electrodes are amplified by means of independent TIAs. ...
An electrostatic field mill (EFM) is widely used to measure the strength of electrostatic fields, the main drawback of which is the occurrence of large measurement errors (up to 15 % in the range from 0 to 1 kV/m). This paper examines the aspects of using transimpedance amplifiers (TIAs) for the tasks of converting the current received from the EFM sensor into voltage, which will make it possible to reduce the instrumental error and ensure the linearity of the atmospheric electrostatic field strength measurement. In the general case, for the functional circuits of the electrostatic field mill, which include a differential transimpedance amplifier, there is the use of two TIA circuits, which are connected in parallel. Despite the simplicity of implementation, such a configuration contains a number of disadvantages and is not optimal. In the paper, a comparative analysis of a typical circuit of a differential TIA and a circuit of an ungrounded differential transimpedance amplifier with zero voltage drop proposed by the authors is carried out. As a result of the analysis, it was established that the designed authentic circuit of the ungrounded differential transimpedance amplifier with zero voltage drop has better parameters of linearity and interference resistance, in contrast to the generally accepted one. The value of the signal-to-noise ratio for the proposed scheme improved by 42 % on average compared to the typical one. The main difference of the proposed scheme is that the stability of the amplification factor is ensured, the influence of the bias parameters of the operational amplifier is leveled, and the overall noise level is reduced. The use of the designed scheme of an ungrounded differential transimpedance amplifier with zero voltage drop could make it possible to increase the accuracy of the measurement of the electrostatic field strength
... Sensitive plates are a circle divided into an even number of sectors, which are electrically connected in two groups A and B through one element. Above them is a shielding plate, which is fixed on a grounded rotor rotating with an angular frequency ω [21]. The movement of the rotor alternately exposes the sensitive plates to the external electric field and shields them, thereby creating a time-varying electric current. ...
The object of research is the process of measuring the strength of the electrostatic field for a low dynamic range (from 0 to 1 kV/m). This study is aimed at increasing the sensitivity of the sensor of the electrostatic fluxmeter (EF) by determining its optimal geometric configuration, which will reduce the error of measuring the electrostatic field strength. To establish the actual value of the induced current, a computer model was built and simulation modeling of the EF sensor was carried out. On the basis of the constructed computer model, studies of the EF sensor were carried out to determine the numerical value of the induced current. As a result, it was established that the occurrence of edge effects leads to the appearance of methodological error, which occurs due to the fact that the average induced current is smaller compared to the calculated value. As a result of computer modeling of the EF sensor to determine the value of the optimal number of sectors, it was established that for the proposed design of the EF sensor, the optimal number of sectors is six. It was established that the optimal value of the distance between the sensitive plates and the shielded rotor should be in the range of 2.5–3 mm to ensure the maximum sensitivity of the EF sensor and its safe use. The determined optimal parameters of the EF geometric configuration will allow to form the necessary requirements for the construction of improved electrostatic field strength meters in a low dynamic range (from 0 to 1 kV/m). A promising direction of application of such devices in production will be the development of an additional system for monitoring the strength of the electrostatic field, which will allow to prevent the occurrence of a dangerous situation.
... The study [25] describes a new ground-based EFM design that focuses on reducing the manufacturing and operational costs of researching while maintaining the scientific capabilities offered by previous designs and commercially available devices. The theory of operation, data processing, and calibration of the device are also described. ...
The object of research is the process of measuring the strength of the atmospheric electrostatic field. This paper is devoted to an analytical review and comparative analysis of modern methods and instruments for measuring atmospheric electrostatic field strength. The results of scientific research and modern practical technologies, which are used to develop technical means and increase the accuracy of measuring the strength of electrostatic fields, are considered. In the work, the general functional requirements for the hardware of systems for measuring the atmospheric electrostatic field strength are formed and the main directions of research and practical tasks for its creation are defined. The design features and characteristics of existing measuring instruments are considered in detail. The advantages and disadvantages of electrometers, electrostatic field mills, microelectromechanical electrostatic field mills, and electric field imaging systems are determined given their portability, sensitivity, measuring frequency, accuracy, measurement range, linearity, and cost. The analysis of the state of modern methods and measuring instruments for the strength of the electrostatic field showed that one of the best solutions for measuring the electrostatic field strength of the atmosphere today is the use of an improved electrostatic field mill. It was determined that one of the important problems for ensuring the development of methods and means of atmospheric electrostatic field strength measuring is the need to generalize the structure of the measuring instruments and calculate its metrological characteristics. It has been established that solving the problem of increasing the accuracy of atmospheric electrostatic field strength measurement requires a comprehensive approach based on improving the design of the sensor structure of the meter, increasing the accuracy of navigation and positioning, increasing the autonomy of work, improving communication and data transmission systems, as well as ensuring high stability and reliability of work under the influence of external factors. Improving the structure and improving the characteristics of electrostatic field mills in the future will ensure the necessary accuracy, compactness, and availability for measurement and its inclusion in the automated system of atmospheric electrostatic field monitoring and forecasting.
... The corona charges released into the air during a thunderstorm affect the electric field near the ground, and the enhancement or shielding of the ground electric field is closely related to the protection of buildings and the instrumental detection of the atmospheric electric field [37][38][39][40]. As well as the effect of the building itself on the distortion of the electric field, the building's CD should also be considered. ...
... related to the protection of buildings and the instrumental detection of the atmospheric electric field [37][38][39][40]. As well as the effect of the building itself on the distortion of the electric field, the building's CD should also be considered. ...
... In conclusion, the effect of CD on the ground electric field cannot be neglected, which provides a basis for future lightning warnings and the evaluation of detectors of the atmospheric electric field [38]. However, the present model only simulates two buildings, and there has been little research to date on the interaction between multiple points, so in future work, we will discuss further the effects of the geometrical characteristics of multiple tips on CD and the correlation among them. ...
The effect of corona discharge from buildings or structures on the surrounding atmospheric electric field is very important in the measurement of urban atmospheric electric fields and the early warning of lightning. However, most previous studies were focused on independent buildings, with little research on three-dimensional building groups. Therefore, based on three-dimensional numerical simulation technology, this paper uses a double-needle system to simulate the characteristics of thunderstorm corona discharge from two equal-height buildings separated by a variable distance. The shielding effect of the double-needle system on the ground electric field is evaluated both with and without corona discharge, and the main conclusions are as follows: (1) The larger the distance between the two needles, the closer the peak corona current from each tip of the double-needle system is to that from an independent lightning rod at the same height. When the peak corona current from each tip of the double-needle system equals the peak corona current from an independent lightning rod at the same height to some level of approximation, the distance between the two needle systems is determined by the needle height at this time. (2) If the distance between the two needles is 0.1 m, the corona charge released by the double-needle system is almost equal to that released by an independent lightning rod. The corona charge released by the double-needle system is approximately twice as much as that released by an independent lightning rod when the distance between the two needles is increased to a certain value that increases with the needle height and the time of corona discharge. (3) The greater the value of the time of corona discharge, the stronger the shielding effect of the corona discharge on the ground electric field and the larger the shielding range, but the greater the value of the needle height, the smaller the shielding range. (4) Compared with the shielding effect with no corona discharge, that with corona discharge is greater, but the greater the value of the needle height, the less the enhancement. For example, for corona discharge with a time of 10 s, the needle height is 20 m, and the shielding range is ca. 70 m, which is 8.8 times that without corona discharge; however, for the needle height of 100 m, the shielding range is ca. 150 m, which is only 1.5 times that without corona discharge.
... Electric field measurements are an important aspect in the assessment of the electric environment under the HVDC transmission lines [1,2] in aircraft measurements where the profiling of the fair-weather electric field provides a valuable understanding of the surrounding environment during flights [3], as well as in the study of meteorological and atmospheric phenomena and especially weather forecasting [4]. In weather forecasting, the ability to measure both fair and foul weather electric fields can be utilized to predict an imminent thunderstorm or other extreme weather phenomena [5][6][7]. ...
... More specifically, the interface has a sensitivity of 45.75 mV/kV/m, which is combined with a measurable electric field range of ±20 kV/m. Additionally, it has a total power consumption of around 480 mW, which is significantly lower than the consumption in [4] and [26] and comparable to the consumption in [5]. In [5], lower power consumption is achieved mainly due to the low power motor used, which in this work was the main power contributor. ...
The design process of an integrated bandpass filter targeted for the noise filtering stage of the synchronous demodulation unit of an electric field mill sensor interface is presented. The purpose of this study of filter integration techniques is to avoid the challenging and, in some cases, impossible passive element integration process and to incorporate the final filter design in an entirely integrated field mill sensing system with superior performance and an optimized silicon-to-cost ratio. Four different CMOS filter implementations in the 0.18 μm process of XFAB, using OTA (Operational Transconductance Amplifier)-based configurations for passive element replacement in cascaded filter topologies and leapfrog techniques, are compared in terms of noise performance, total harmonic distortion, dynamic range, and power consumption, as well as in terms of integrability, silicon area, and performance degradation at process corners/mismatches. The optimum filter design performance-wise and process-wise is included in the final design of the integrated analog readout of a field mill sensor, and post-layout simulation results of the total circuit are presented.
... In atmospheric electricity, most measured surface quantity is the vertical electric field, also known as the potential gradient [8]. The local electric field has been measured to provide a better understanding of thundercloud electrification and the energy exchange between lightning and the atmosphere across the globe [9]; to forecast lightning incidents; and to define an electric field threshold for lightning strikes on aircraft [10]. In [11], an investigation of electrical activity in thunderstorms was conducted, whereby the electrostatic field was measured during flights inside electrified clouds, in which lightning strikes occur, to provide insight beyond that of surface measurements. ...
... Early measurements of the near-surface, fair weather atmospheric electric field in the absence of electrified clouds is around 100 V/m, maintained by the global electric circuit (GEC) [15]; the direction of the electric field in fair weather conditions at the surface is negative. When electrified clouds are present, the field can increase from a few kV/m to tens of kV/m as it is significantly influenced by the cloud's charge regions and lightning neutralization of the charges [9]. ...
... The edge effect increases with the number of vanes and causes a decrease in the electric field intensity. Field mills consisting of two to eight vanes are more frequently employed [3,9,18,20,[28][29][30][31]. ...
An overview of the electric field mill sensor specifications in applications related to the measurement of the atmospheric electric field was conducted. The different design approaches of the field mill sensor interface are presented and analyzed, while the sensitivity-related parameters of a field mill are discussed. The design of a non-complex analog sensor interface that can be employed for the measurement of the electric field in both fair and foul weather conditions, such as thunderstorms, is implemented using discrete components for experimental validation and is optimized in an integrated version in terms of noise and power consumption. Advanced noise simulations are conducted in a 180 nm CMOS process (XH018 XFAB). The energy-autonomous operation of the sensor for extended periods of time is made feasible due to the low power consumption of the front-end circuitry (165 μW at 3 V) as well as the proposed intermittent style of operation of the motor. The total sensing system is low power, and its realization is simple and cost-effective, while also offering adequate sensitivity (45 mV/kV/m), making it comparable to the existing works.
... The resistance between the rotating blade and the grounded base plate was measured as less than 100 Ohms. An identical method was adopted in the previous study [17]. A sensing module consists of sensing plates, a rotating blade, and a signal amplified circuit. ...
... The resistance between the rotating blade and the grounded base plate was measured as less than 100 Ohms. An identical method was adopted in the previous study [17]. ...
The gross charge distribution in an electrified cloud has already been estimated by polarity distribution of the electrostatic field on the ground surface. While either a dipole or a tripole charge structure is commonly accepted, the increase–decrease and motion of each point charge in those models are both still unclear. This paper presents a new network of electric field mills for multipoint electrostatic measurement to evaluate the temporal variations of a simple cloud charge model with second-scale resolution. Details of our newly developed equipment are described, with an emphasis on its advantages. This network was deployed in the north Kanto area of Japan and operated during the summer season in 2020. In order to simplify the relationship between cloud charge positions and the horizontal distribution of the measured electrostatic field, an isolated thundercloud is focused on. As an initial analysis, a negative point charge model is applied to an isolated cloud observed on 27 August 2020. The quantity and height of the point charge were estimated as being approximately −20 C and 7 km, respectively. The calculated charge location is generally coincident with the C-band radar echo regions. Significant correspondence is demonstrated between the intensity distribution of the electrostatic fields measured at seven sites and that calculated with estimated point charge. This result indicates the possibility to determine the amounts and positions of cloud charges inside the dipole charge structure based on multipoint measurement of the electrostatic field.
