Pantograph-catenary Arc Research Articles

Simulation on Operating Overvoltage of Dropping Pantograph Based on Pantograph–Catenary Arc and Variable Capacitance Model

When the electric locomotive pantograph is dropping, the interruption of pantograph catenary contact causes electromagnetic oscillation and arcing. The frequent arc burning that occurs due to charge accumulation results in the amplitude of overvoltage increasing gradually, posing a threat to locomotive high-voltage equipment. However, the physical mechanisms and characteristics of overvoltage are still unclear. This paper proposes a simulation model of operating overvoltage due to a dropping pantograph based on the pantograph–catenary arc and variable capacitance. Distributed RLC electromagnetic oscillation is considered, which allows the real-time calculation of arc resistance and capacitance. Under the same working conditions, the error between the simulation and test results is less than 4.0%, which proves the credibility of the model. The variation law of overvoltage under different dropping speeds or catenary phases was investigated, which shows the max amplitude is 298.20 kV and steepness is 2096.80 kV/μs at 0.30 m/s speed. The waveform shows the characteristics of high amplitude and high steepness, similar to very fast transient overvoltage (VFTO). There is a sinusoidal relationship between the catenary phase and overvoltage amplitude. The closer the catenary phase to 90°, the higher the overvoltage amplitude. The research has important guiding significance for the overvoltage formation mechanism of a traction power supply system and the insulation coordination design of high-voltage equipment.

Study on the Influencing Factors of Electrical Characteristics of Articulated Split-Zone Insulator Arc

The frequent occurrence of the pantograph–catenary (PC) arc seriously threatens the safe and stable operation of electric multiple units (EMUs). In order to investigate the primary factors affecting the electrical characteristics of the PC arc, this paper first reveals the mechanism of arc generation when EMUs leave the split-zone insulator according to the actual mechanical structure of the PC articulated split-zone insulator. Then, based on the Habedank black box arc model, considering the dynamic changes in arc length during the actual operation of EMUs, a numerical simulation model suitable for describing the PC articulated split-zone insulator arc is established. Furthermore, by comparing with existing research results, the effectiveness of the proposed model is verified. Next, a series of simulation experiments were conducted to analyze the influence of different operating parameters of the EMUs on the electrical characteristics of the PC arc. More importantly, the paper proposes using the entropy weight method to calculate the impact strength of different operating parameters of the EMUs on the arc duration time of the contact wire split-zone region. The research results of this paper can provide some technical references for reducing the erosion of the PC contact wire and slide caused by arcs when the EMUs pass through the split-zone insulator.

Computational analysis of electromagnetic field exposure in passengers near high- current contact wire environments.

The electromagnetic environment of a railway station is composed of electrical, magnetic, and electromagnetic fields, which are generated by various sources such as traction current, voltage, pantograph-catenary arc, locomotive braking, wheel-rail rolling arc, and communication systems. However, there is public growing concern among the public about the potential negative human health effects of this electromagnetic environment. To analyze the distribution of electromagnetic fields in human tissues, electromagnetic simulation software is used to create a model that includes six track contact wires and four waiting passengers on three platforms. This model is used to analyze the magnetic field environment created by high currents in the contact wires of a multi-track high-speed railway station. By varying the loads on different contact wires, the distribution of electric field and magnetic flux density within human tissues of waiting passengers on different platforms is studied using this model. When the track is unoccupied, the calculation results show that the maximum values of the electric field and magnetic flux density of the passenger's human body tissue at the blind way on the platform and 1m of the blind way are 17.6mVm-1 and 52.7 μT, respectively. These values increase by 9.28mVm-1 and 16.4 μT compared to when the track is occupied. When more contact wires are loaded with currents, the electric field mode and magnetic flux density mode of human tissues increase at the same position on the platform. Specifically, when the contact wires of six tracks are loaded with current at the same time, the maximum values of the electric field mode and magnetic flux density mode of the waiting passengers' human tissues at the blind way on different platforms are 29.6mVm-1 and 88.1 μT, respectively. These maximum values are lower than the public electromagnetic exposure limits that are designated by the International Commission on Non-Ionizing Radiation Protection guidelines. The research results demonstrate that the magnetic field environment generated by the current in the contact wires of a railway station with six tracks does not pose a health risk to human tissues of passengers waiting at the blind way and 1m of the blind way on the platform. These findings can provide valuable data reference for the formulation of relevant standards for the design of electrified rail transit, as well as the suppression of electromagnetic interference and protection of human bioelectromagnetism.

Extended Pantograph–Catenary Arc Modeling and an Analysis of the Vehicular-Grounding Electromagnetic Transients of Electric Multiple Units

As the operating speed of electric multiple units (EMUs) in high-speed railways increases, pantograph–catenary (PC) detachment arcing occurs frequently. The resulting vehicular-grounding electromagnetic transients are related to the dynamic characteristics of the arc length. During large detachment, the processes of arc extinction and arc reignition may occur, resulting in more severe train body (TB) over-voltages and adverse effects on some vehicular electronic devices. As an extension of the previous works, this paper aims to establish a suitable PC arc model to examine the TB transient voltages. To begin with, the arc length dynamic characteristics are reasonably analyzed to deduce the relationship between the detachment distance and the arc length via the chain arc model. Then, the dynamic characteristics of the arc length are introduced, and an arc modeling scheme is proposed to elaborate the vehicle-grid electric power model for EMUs encountering various arcing scenarios. Based on this, the transient over-voltages are analyzed, accounting for both the arc extinction and arc reignition, as well as the mutual influences of multiple detachments in a short time. The influential factors, including arc length characteristics, phase angle, excitation inductance, and grounding parameters, are also involved in the performed analyses.

Research on the Influence of Pantograph Catenary Contact Loss Arcs and Zero-Crossing Stage on Electromagnetic Disturbance in High-Speed Railway

During train travel, various factors, such as body vibration, uneven contact lines, and hard spots on carbon sliding plates and over electric neutral zones, often lead to brief separation between the pantograph and the contact line, i.e., the pantograph catenary contact loss phenomenon. With the continuous increase in train speed and traction power, the probability of pantograph catenary contact loss occurrences rises with a gradual increase in the energy of electromagnetic radiation, making the pantograph catenary arc a primary source of interference affecting the electromagnetic safety of high-speed railways. Understanding the mechanism, characteristics, and influencing factors of electromagnetic interference caused by pantograph catenary contact loss discharges is of utmost importance for analyzing and resolving on-site equipment interference faults. Our analysis of the physical process of pantograph catenary contact loss reveals that when the distance between the pantograph and catenary is significant and the duration is lengthy, high-voltage breakdown occurs within the pantograph catenary gap as it comes close again after the complete extinguishing of the arc. To investigate the electromagnetic radiation characteristics resulting from high-voltage breakdown discharge arcs in the pantograph catenary contact loss process, we established a laboratory test platform for assessing the electromagnetic disturbance characteristics of high-voltage pantograph discharge. We designed a test procedure utilizing fixed-gap breakdown discharge to evaluate the impact of the arc zero-crossing stage on electromagnetic radiation disturbances. Our research indicates that when the pantograph catenary spacing remains constant, an increase in voltage level leads to an elevation in the current within the discharge circuit, resulting in an increased intensity of impulse radiation generated during pantograph catenary contact loss events. During the moment of gap breakdown, the antenna records the highest amplitude of electromagnetic radiation. Also, during the steady-state arc ignition phase of the pantograph catenary gap, the zero-crossing stage generates pulsed discharge currents within the circuit, accompanied by substantial electromagnetic radiation. As the arc current increases, the zero-crossing time shortens, and the pulse current during the zero-crossing process decreases, accompanied by a reduction in the excited electromagnetic radiation. These observations reveal novel characteristics of electromagnetic radiation disturbances during steady-state arc ignition. The outcomes of our study provide valuable insights that can contribute to our understanding of the characteristics and influencing factors of electromagnetic radiation in pantograph catenary contact loss discharges and offer theoretical guidance for the resolution of pantograph catenary contact loss interference faults.

Research on driving force and dynamic characteristics of pantograph–catenary arc

Pantograph–catenary (PC) system is the key current collection equipment for electrified rail vehicles. The PC arc ages the contact line and pantograph abnormally, which is a limiting factor for rail transit to increase the speed of operation. To reduce the harm caused by the PC arc, in this article, a new PC arc chain model was established, which considered the arc current element mass and the acceleration process, updating the control equations. Meanwhile, a PC arc experimental platform was built in order to verify this model. It is demonstrated that the simulation results obtained by this work fit the arc and are suitable to describe the arc in the field. Experiments have found that the evolution of PC arc can be divided into three distinct processes: arc initial process, rapid stretching process and violent oscillation process. Combined with the model, the driving force and dynamic characteristics of the PC arc root and column in each process have been studied. The electromagnetic force dominates the arc evolution in the first two processes, and then the wind load dominates the last process. Besides, thermal buoyancy dominates the arc root jumping behavior. The driving mechanism for the movement of arc has been revealed. The arc root first suppresses the arc column, and then the arc column pulls the arc root. It is helpful for controlling PC arcs in the field.

Research on the Model and Transient Characteristics of the Pantograph-Catenary Arc in Different Sections of Power Supply Lines

Research on the Model and Transient Characteristics of the Pantograph-Catenary Arc in Different Sections of Power Supply Lines

Structure Improvement and Control Algorithm Optimization-Based Ground Automatic Neutral-Section Passing Method for Train

Passing the neutral section can causes transient impact and speed loss of the train. Therefore, whether the potential danger of the pantograph-catenary system can be eliminated under the condition of full load operation becomes one of the essential factors for the safe and efficient operation of electric locomotives. This paper proposes an advanced method to optimize the structure and control algorithm, according to the drawbacks of existing methods, such as miniature circuit capacity, poor output driving ability, low control accuracy, and slow system response speed. In this method, the pantograph-catenary arc is restrained by controlling the dynamic alternating transfer of instantaneous power. Besides, the voltage pre-modulation algorithm is used to realize flexible voltage switching between different adjacent power supply arms. Compared with the existing methods, this method can provide better system response output capability. And this can effectively suppress transient impact and ensure full load train operation safety. Finally, in terms of transient suppression effect and resistance to external environmental interference, a series of functional verification and horizontal comparison experiments have proved the feasibility, superiority and robustness of this method.

An Overview of the Comprehensive Models for Studying the Electromagnetic Interference of High-Speed Trains

When a high-speed train passes through some sections of the power supply line, its pantograph will inevitably be separated from the power supply line. Although the separation time is extremely short, the pantograph catenary arc (PCA) will be generated during this period. The PCA produces electromagnetic interference (EMI), which cause the potential safety hazard to the operation of high-speed trains. This paper provides an overview of the comprehensive models for high-speed trains. The models can be used to comprehensively research the transient characteristics of the EMI of high-speed trains. It provides a basis for finding the corresponding interference suppression methods, so as to improve the safety of train operation and protect the electromagnetic environment around the train. The proposed model can also be applied to other types of trains by changing some relevant parameters.

Simulation and Verification of Effect of Arc Duration on Arc Temperature Based on COMSOL

The pantograph–catenary arc of urban rail has the characteristic of high temperature, which directly acts on the surface of the pantograph–catenary system, will seriously ablate pantograph and contact line, and affect the flow of the pantograph–catenary system. In this paper, based on MHD, a mathematical model of the arcing of urban rail pantograph–catenary system is established. COMSOL finite element software was used to simulate the arc temperature field of the pantograph–catenary arc. Through the temperature distribution cloud diagram and related images, the relationship between the arc central temperature, the duration, and the gap of the pantograph arc were studied. It is found that the arc temperature increases with the increase in arc duration when the arc gap is fixed. When the arc duration is fixed, the arc center temperature changes inversely with the increase in the arc gap. The feasibility of the simulation model is verified by the pantograph–catenary arc experiment platform. The research conclusion of this paper can provide a certain basis for the research of arc erosion on the surface of the pantograph–catenary system.

Simulation Study on Surface Temperature Distribution of Collector Strip Material Under Pantograph-Catenary Arc of Urban Rail

Simulation Study on Surface Temperature Distribution of Collector Strip Material Under Pantograph-Catenary Arc of Urban Rail

Dynamic physical characteristics of DC arc on arcing horn for HVDC grounding electrode line

The dynamic physical characteristics of a DC arc on an arcing horn for a high voltage direct current (HVDC) grounding electrode line are significantly different from those of the switching device arc, secondary arc, AC fault arc and pantograph-catenary arc. In this work, an experimental platform for the DC arc on the arcing horn was built, and mechanisms of the arc column short circuit and arc root movement were studied. This work further analyzes the characteristics and mechanisms of the arc motion when wind speed and direction, magnetic field and the expansion angle of the electrode are varied. Arc root movement is more likely to occur at the upper electrode. There is a competitive relationship between arc expansion and the transferring effect. The effect of wind on the arc column is greater than the effect on the arc root. The magnetic field has a significant driving effect on both the arc column and the arc root. The research results provide a comprehensive experimental basis for further probing the method of DC arc suppression, and the improvement of the arcing horn.

Drift characteristics and the multi-field coupling stress mechanism of the pantograph-catenary arc under low air pressure

The fault caused by a pantograph-catenary arc is the main factor that threatens the stability of high-speed railway energy transmission. Pantograph-catenary arc vertical drift is more severe than the case under normal pressure, as it is easy to develop the rigid busbar, which may lead to the flashover occurring around the support insulators. We establish a pantograph-catenary arc experiment and diagnosis platform to simulate low pressure and strong airflow environment. Meanwhile, the variation law of arc drift height with time under different air pressures and airflow velocities is analyzed. Moreover, arc drift characteristics and influencing factors are explored. The physical process of the arc column drifting to the rigid busbar with the jumping mechanism of the arc root on the rigid busbar is summarized. In order to further explore the mechanism of the above physical process, a multi-field stress coupling model is built, as the multi-stress variation law of arc is quantitatively evaluated. The dynamic action mechanism of multi-field stress on arc drifting characteristics is explored, as the physical mechanism of arc drifting under low pressure is theoretically explained. The research results provide theoretical support for arc suppression in high-altitude areas.

The evolution law of the pantograph–catenary arc with the multi-stress coupled force analysis under the sub-atmospheric pressure strong-airflow condition

As the unique power entrance, the pantograph–catenary plays a vital role in providing traction power for high-speed railways. Along with the operational velocity of trains constantly increasing, the poor contact between the contact wire and the pantograph strip happens frequently due to the “rigid point” existing on the contact wire, forming the “off-line” phenomenon. The off-line phenomenon is normally accompanied by the pantograph–catenary arc occurring, which seriously threatens the safety of the power supply for the high-speed train. Nowadays, as some railways have been built in remote places at high altitude, the motion characteristics of the pantograph–catenary arc under the sub-atmospheric pressure with strong airflow are extremely different from the case under normal pressure. Herein, a pantograph–catenary arc experimental platform is built for observing the evolutionary process of the arc under the sub-atmospheric pressure strong-airflow condition. The impact brought from different air pressures and airflows on the arc is analyzed, as the experimental results show that the pantograph–catenary arc has different motion characteristics when the arcing process is at different stages. To further explore the reason resulting in the varying motion characteristics of the arc, a multi-stress coupled force analysis model is established, with the consideration of the influence of air pressure, wind load, thermal buoyancy, air resistance, arc self-magnetism, etc. From the perspective of force acting on the arc, the arc formation mechanism at the development evolutionary stages is investigated under sub-atmospheric pressure strong-airflow conditions, which lays a theoretical foundation for effectively restraining the pantograph–catenary arc.

Study on the Modeling and Suppression of Arcing Generated by Articulated Split-Zone Insulator in Electrified Railways

In electrified railways, pantograph–catenary (PC) arc frequently occurs in the process of train passing through split-zone insulator, which threatens the current collection of PC and operation of electric multiple units (EMUs). So far, there have been a few studies on the analysis and modeling of the PC arc on split-zone insulator. It is noting that this research is different from that of split-phase region. This article first analyzes the dynamic variation process of PC distance as EMUs pass the insulator and deduces the formula, which can reflect the PC arc length variation according to the specific mechanical structure of insulator. Then, a black-box arc model of split-zone insulator is proposed. Next, a vehicle-to-grid model of the EMUs that contains the arc model of split-zone insulator is established to simulate and analyze the characteristics of the PC arc on split-zone insulator. Furthermore, the proposed arc model in this article is verified by comparing the simulated arc characteristic waveforms with the measured results. Finally, a sensitivity analysis of the arc model under different lifting angles of the contact wire is carried out in order to analyze the suppression of PC arc on split-zone insulator.

The Thermal Dissipation Characteristics Analysis of the Rotatable Circular Pantograph–Catenary System

As the unique power entrance of high-speed trains, the pantograph–catenary system (PCS) plays the critical role of power transmission for high-speed trains. The pantograph achieves the electrical power based on the sliding electrical contact between the pantograph strip and the high-voltage contact line. However, when the environmental temperature is relatively low especially during the winter, the contact line is covered by ice or snow easily. The ice or snow adhering on the surface of contact line may lead to poor electrical contact between the pantograph strip and the contact line, which may trigger the pantograph–catenary arc appearing. Accompanying with mechanic shock and friction heat, the off-line arc may deteriorate the quality of power transmission and meanwhile erode the contacting surface of the pantograph strip and the contact line to some extent. In order to solve this technique bottleneck, a novel rotatable circular-shape pantograph strip is proposed to improve the overall performance of the traditional pantograph strip. Compared with the traditional strip, the circular pantograph strip owns many advantages, such as less friction, better thermal dissipation, and better shock resistance. The thermal dissipation performance of both the traditional and circular pantograph strip is evaluated in this article, with the consideration of suffering off-line arc under the icing conditions.

Characteristics of pantograph‐catenary arc under low air pressure and strong airflow

Pantograph-catenary arc fault is the primary factor threatening the stability of the power transmission for high-speed railway. The motion characteristics of the pantograph-catenary arc under low air pressure and strong airflow is significantly different from the case under atmospheric pressure. In this paper, an experimental platform of pantograph-catenary arc was built to investigate arc root position-time and arc column longitudinal drift height-time characteristic curves under different air pressures and airflow velocites. Via analysing the corresponding results, it can be found that there are different arc root–arc column traction mechanisms at different stages of arc development. The arcing time and arc root stagnation time under low air pressure are significantly longer than the case under atmospheric pressure, resulting in more serious electrode ablation. The arc column longitudinal drift velocity and height are greater with the increase of airflow velocity. Two typical irregular arc motion phenomena—arc root jumping and arc reignition are observed. To clarify the internal mechanism of the above phenomenon, a magnetohydrodynamics (MHD) model of the pantograph-catenary arc was lauched, the influence mechanism of the pantograph-catenary arc temperature and voltage are studied, and the physical process of arc temperature oscillation is analysed. The research results provide theoretical support for arc protection in high-altitude areas.

For Safer High-Speed Trains: A Comprehensive Research Method of Electromagnetic Interference on Speed Sensors

When the pantograph of a high-speed train is separated from the power supply line, a panto-graph-catenary arc (PCA) occurs. This generates electromagnetic interference (EMI) and additional undesired effects on the electrical equipment (such as speed sensors) on the train. It creates a safety hazard for high-speed train operation. This article presents a new method for dealing with EMI caused by the PCA on speed sensors of high-speed trains. The proposed method consists of carrying out an in-depth analysis of the different coupling modes of EMI to identify the corresponding interference suppression measures. Thus, the safety of train operation can be ensured. By changing some relevant parameters, the proposed method can also be applied to other types of trains and electrical equipment.

Research on the Influence of Train Speed Change on the EMI of Pantograph-Catenary Arc to Main Navigation Stations

The electromagnetic interference (EMI) of the pantograph-catenary arc (PCA) to the main navigation stations will be affected when the speed of the high-speed train is changed. In order to study the influence of the speed change, we measured and analyzed the electric field intensity of the PCA generated at common and neutral section of power supply line at different train speeds. The frequency range in this study is the frequency of the main navigation stations (108 ~ 336 MHz). Both theoretical and experimental results show that PCA radiation increases with the increase of train speed. Besides, we calculated the maximum train speed without interfering the navigation signal. This work is useful for estimating EMI of the PCA at different train speeds and mitigating the interference to the navigation station near the highspeed railway by proposing corresponding speed limits.

Analysis of EMI from Pantograph-catenary Arc on Speed Sensor Based on the High-speed Train Model

There will be the pantograph-catenary arc (PCA) when the pantograph of a high-speed train is separated from the power supply line, and the electromagnetic interference (EMI) caused by the PCA can affect speed sensors of the train. To study the influence of the PCA, firstly, the traction control unit (TCU) speed sensor of the high-speed train is researched. The result shows both overvoltage and electromagnetic radiation (EMR) generated by the PCA can influence the signal of speed sensor. Secondly, the composite model of the train is established. Then, the interference of the PCA on the TCU speed sensor is verified. The results of practical measurements show the PCA causes a maximum overvoltage of 680 V on train body (TB) and increases the magnetic field around TB to a maximum of 58 dBµA/m. This is the reason of sensor malfunction, which is consistent with the theoretical and simulation results. Finally, the methods to reduce the EMI of the PCA are proposed.