Electromagnetic time reversal (EMTR) has emerged as a promising technique to locate disturbances in power grids, thanks its location accuracy and robustness against parameters uncertainties. Furthermore, reflective medium, like the one of network, it been shown that method requires no more than single observation point. In this paper, we present an experimental validation EMTR real networks. The is performed on full-scale unenergized 677-m-long, double-circuit 10-kV overhead distribution...

This paper investigates the use of norm criteria in electromagnetic time reversal (EMTR) technique to locate faults transmission lines. The energy root criterion and amplitude peak criterion, derived from 2-norm ∞-norm, are considered discussed contrastively. It is shown that both can effectively be used an EMTR method faults. ∞-norm originates temporal spatial variation quantity voltage/current wave propagation process. proven makes refocusing property waves propagating along In extremely...

In complex electromagnetic environments, such as substations, converter stations in power systems, and the compartments of aircraft, trains, automobiles, immunity testing is crucial. It requires that electric field sensor has features a large dynamic measurement range (amplitude from hundreds V/m to tens kV/m), fast response speed (response time order nanoseconds or sub-nanoseconds), wide test bandwidth (DC 1 GHz even above), miniaturization, robustness strong interference. This paper...

Recently published papers have proved the effectiveness of electromagnetic time reversal (EMTR) in locating position faults such as phase-to-ground shunt connections power grids. EMTR directly transposes idea focusing energy back to its source introduced original time-reversal (TR) methods. The current interpretation EMTR, based on metrics measuring or peak-amplitude focusing, is shown suffer from ambiguities that increase risk inaccurate fault location. After pointing out under what...

This article investigates how the accuracy of fault location estimated from a transmission line's natural frequencies is affected by imperfect modeling HVDC power-converter stations. These systems include large number devices each with specific frequency-dependent characteristics, as filters, reactors and surge protection systems. While it well-known that errors may ensue inaccurate termination models, not clear to what extent when neglecting one or more these devices. Results show...

This paper studies how propagation and termination losses affect full transient-based fault location techniques. Their accuracy is discussed in terms of both uncertainty, caused by a limited spatial resolution, systematic errors, bias the fault-location metrics. last case proven to be far likelier when are higher than dissipation line loads. Two different metrics studied, namely correlation normalized projection, as found literature, with unbiased, since it benefits from two mechanisms,...

This paper develops a one-dimensional norm detector for nanosecond-level transient electric field (E-field) measurement based on the digital technology. It has two main advantages over traditional method. First, measured signals can be stored and no transmission line is needed. Hence, it detect E-field coupled in hermetically sealed cavities, such as cockpit of an aircraft or vehicle under electromagnetic compatibility test. Second, commonly used norms waveform acquired by signal processing...

This paper proves that the accuracy of single-ended fault location techniques based on correlation transients in power lines can be significantly improved by inverse-filtering first. The reason for this is found reduction duration surge signal, thus increasing sensitivity fault-location metrics to position. Reported results show using proposed filtering strategy, faster sampling rates systematically and improve accuracy, as opposed case when no filter applied, which virtually improvement...

This article discusses the mechanisms enabling spatial resolution in fault location methods based on full transient signals, as opposed to those only using their early-time portion. idea is found recent travelling-wave (TWM) and electromagnetic time reversal (EMTR). Their discussed terms of sensitivity a system resonances change position coherence bandwidth. It proven that entire signal it possible bypass Fourier transform uncertainty principle, which limits time-domain reflectometry...

This article introduces the measurement and analysis of transient electric field (E-field) derived from switching operation modular multilevel converter (MMC) high voltage direct current (HVdc) circuit breaker (CB) in a 200 kV station constructed Zhoushan Islands, China. It is revealed that E-field quasi-static field. Although pulse kind electromagnetic interference to secondary electronic station, it can be used accurately monitor action moment MMC CB. The CB measured with an error less...

In this letter, a nanosecond-level transient electric field (E-field) sensor based on monopole electrically small rod antenna is proposed. The working principle and design process of the are analyzed in detail while finite-element simulation carried out to verify response characteristics both time frequency domains, whose upper cut-off can reach 680 MHz. For purpose assessing actual detection capability HVDC converter stations, designed letter was used detect radiation E-field valve hall...

Traditional location methods such as time of arrival and direction have been widely used to locate transient radiation sources. However, these approaches neglect the directional pattern Locating sources is a complicated task because waveform amplitude radiated signals in domain vary for different directions. In this article, ability electromagnetic reversal (EMTR) technique investigated. As typical source, impulse antenna (IRA) validate method. A model first established, procedure carried...

This paper investigates how the accuracy of fault location is affected by terminal reflection uncertainty and proposes a full-transient method based on particle swarm optimization (PSO) algorithm to solve bias. The LCC-HVDC system taken as research object, maximum relative error reach 9.3% 17.96% for hundreds kilometers line due coefficient converter station. PSO proposed optimize phase shift power transmission boundary coefficient, make simulation natural frequency being closest real which...

The electromagnetic time reversal (EMTR) method has recently shown a novel advantage in locating faults along transmission lines. Under the ideal condition for EMTR, key parameters line between direct and reversed phases are assumed to be identical. Thus, fault position can pinpointed via cross-correlation matching theory. However, due natural geographical causes, vary line; therefore, accurately obtaining is difficult. In this article, we first investigate impact of uncertain on performance...

Commutation failures in high-voltage direct current (HVDC) transmission systems often occur within inverter stations, posing challenges to the safe and consistent operation of HVDC projects. This paper examines data gathered from a wide-spectrum transient electromagnetic voltage monitoring apparatus. The findings uncover notable correlation between AC bus disturbances, stemming faults, occurrence commutation systems. Leveraging this correlation, we propose failure mitigation strategy for...

This paper proposes a miniaturization, wideband and nanosecond-level risetime transient electric field (E-field) sensor based on monopole electrically small rod antenna. The upper cut-off frequency of the can reach 680 MHz. For purpose assessing actual detection capability in HVDC converter stations, designed this was used to measure valve hall artificial short-circuit tests. measurement results E-field indicates that is able respond instantaneously generated by action key power electronic...

The conventional current or voltage signal-based condition monitoring systems for DC high-voltage equipment have the disadvantages of huge volume, inconvenient operation, and low measurement bandwidth sampling rate. To overcome these drawbacks, a simplified calculational model radiative near-field electric field in circuit breaker valve hall is proposed. This based on analytical finite-length current-carrying linear ideal conductor reveals physical mechanism non-invasive situational...

The paper discusses the implementation of a controllable line-commutated converter (CLCC) in Nanqiao station to prevent commutation failure multi-infeed high voltage direct current (HVDC) transmission systems. CLCC utilizes an auxiliary branch enhance and incorporates IGBT (Insulated Gate Bipolar Transistor) series with thyristor, offering improved switching capacity. topology, process, working principle are introduced, along discussion on control strategy for CLCC-HVDC system. system is...

Abstract-This paper introduces a novel fault location method utilizing polynomial-chaos expansion (PCE) designed specifically for non-uniform transmission lines affected by uncertain parameters.It considers the parameters arising from height and ground conductivity in lines, examining their impact on conventional methods, such as natural frequency full-transient analysis approach.These uncertainties lead to considerable errors, particularly magnified with increasing distances.To address...

In the case of short-circuit fault, DC converter station VSC-HVDC would produce transient electromagnetic field, which interfere and impact on secondary equipment in station. This paper analyzes field short circuit tests system a The time frequency characteristics electric signals valve hall have been discussed. For measurement probe near hybrid breaker, highest amplitude measured between two breakers is 5.1 kV/m while most components are below 1 MHz. These signal has potential application...

In this paper, the electromagnetic radiated disturbance of converter valve in a ±800kV UHVDC station has been measured and analyzed. The radiation level, characteristic time frequency domain during steady state stepwise power reduction operation process have obtained. waveforms electric field were composed multiple bipolar oscillation pulses which show repetition period about 6.6ms. spectrum consists several components, dominant are 1.35kHz 1.5kHz whole process. Under steady-state, amplitude...

Methods based on electromagnetic time reversal (EMTR) have recently demonstrated promising results. In particular, EMTR, as a correlation estimator metric, has offered quantitative definition for fault location candidates. As the already obtains system transfer functions by simulating occurrences, these are subsequently correlated with fault-generated function. Therefore, it is necessary to explore analysis related pre-fault processing of this metric. Firstly, impact impedance mismatch...