Development of One-Dimensional Norm Detector for Nanosecond-Level Transient Electric Field Measurement

The measurement of the transient pulsed electromagnetic (EM) field is essential for analyzing electromagnetic compatibility. Due to their good performance, D-dot sensors, combined with numerical integration computation for signal recovery, are commonly used to measure electromagnetic pulses (EMPs). However, the integration approach is occasionally flawed due to a non-ideal frequency response or noise, causing distortions in the reconstructed signal. In order to better understand the dynamic performance of the sensor, a nonlinear Hammerstein model is employed in the system identification for the sensor with the calibration data collected in the laboratory environment. When identifying the linear component based on the ultra-wideband characteristics of the measured transient pulse, a two-step identification approach with two different pulse excitation modes, low frequency and high frequency, is utilized to conduct the modeling across the entire frequency range. Based on the reliable identification and modeling of the D-dot sensor, a compensation system that corresponds to the nonlinear Hammerstein model has been developed for the practical signal recovery of the incident E-field. After compensation, the dynamic characteristics of the sensor are significantly improved, and the system compensation approach outperforms the integration method in signal recovery for the incident E-field.

Section: Two-step Identification Methods For Broadband Measurement Sy...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Identification and Compensation for D-Dot Measurement System in Transient Electromagnetic Pulse Measurement

Jin

Liu

2022

“…The basic unit used to implement the FIR filter algorithm includes a storage unit, multiplication unit, an adder, and delay unit. For different compensation filtering effects in different frequency bands to be achieved, a design method of frequency sampling needs to be adopted to design the filter [ 18 , 19 ]. The filter order was 1024, and the coefficients of the filter can be easily designed using FDATOOL (Natick, MA, USA) in MATLAB.…”

Section: Circuit Designmentioning

confidence: 99%

Development of a Transient Magnetic Field Sensor Based on Digital Integration and Frequency Equalization

Ouyang

Yao

Chen

2021

Transient magnetic field sensors are used in various electromagnetic environment measurement scenarios. In this paper, a novel magnetic field sensor based on a digital integrator was developed. The antenna was a small B-DOT loop. It was designed optimally for the simulation. The magnetic field signal was digitally integrated with the improved Al-Alaoui algorithm, resulting in less integration error. To compensate for the bandwidth loss of the optical fiber system, we specially designed an FIR (finite impulse response) filter for frequency compensation. The circuit was described, and the transimpedance amplifier was specially designed to ensure the low noise characteristic of the receiver. The sensitivity of the sensor was calibrated at 68.2 A·m−1/mV, the dynamic range was 50 dB (1–300 kA/m), the linear correlation coefficient was 0.96, and the bandwidth was greater than 100 MHz. It was tested and verified under the action of an A-type lightning current. The sensor exhibited high-precision performance and flat amplitude-frequency characteristics. Therefore, it is suitable for lightning positioning, partial discharge testing, electromagnetic compatibility management, and other applications.

“…It cannot measure weak electromagnetic pulses and its designed bandwidth is less than 150 MHz [ 9 ]. Kong presented a norm detector without an external connecting line for transient electrical signal measurement based on high-speed digital acquisition and storage technology that can measure the coupled electrical signals in hermetically-sealed cavities and calculate the commonly used norms of the measured signal using a specially designed signal processing software [ 10 ]. Azpúrua presented a digital measurement system intended to be used to assess the radiated electromagnetic interference (EMI) in both time and frequency domains in his paper [ 11 ].…”

Section: Introductionmentioning

confidence: 99%

Design of Wideband GHz Electric Field Sensor Integrated with Optical Fiber Transmission Link for Electromagnetic Pulse Signal Measurement

Zhang

et al. 2018

The detection of high frequency overvoltage and partial discharge is of great significance in evaluating the insulation condition of high-voltage power equipment. A wideband GHz electric field (E-field) sensor for electromagnetic pulse (EMP) signal measurement was proposed in this paper. An optical fiber transmission link was adopted in the design in order to implement high-voltage isolation and reduce electromagnetic interference during transmission. The designed sensor was mainly made up of a differential electric field (D-dot) antenna, transmitter, and receiver. The D-dot antenna was designed to detect high frequency E-field strength and generate a corresponding voltage signal, which was converted into an optical signal by the transmitter. The optical signal could be transmitted a large distance through an optical fiber without electromagnetic interference and changed back to a voltage signal again by a receiver. The design process of the sensor was introduced in detail, and experiments were performed using a gigahertz transverse electromagnetic (GTEM) cell and an EMP simulator to verify it. The results indicated that the designed sensor had a good performance besides an expectable delay due to the optional amplifier.