Pantograph-catenary System Research Articles

Electric trucks pantograph-catenary interaction condition monitoring method based on semantic segmentation network and linear fitting

Abstract The pantograph-catenary system (PCS) in dual-source electric trucks is crucial for maintaining a stable connection to the power grid, which directly impacts power quality. Ensuring reliable contact between the pantograph and catenary requires accurate detection of the contact point (CPT). However, existing CPT detection methods designed for trains are not well-suited for electric trucks due to differences in structural design. To address this challenge, this paper proposes a novel CPT detection method that integrates semantic segmentation and linear fitting techniques. Firstly, we introduce a lightweight Pantograph and Contact Line Segmentation Network (PCSN), which accurately extracts the regions of the pantograph and contact line. Secondly, a position correction algorithm combined with a least-squares linear fitting technique is employed to detect the CPT of electric trucks. Experimental results demonstrate that the proposed method achieves a detection error within ±5 pixels. In terms of processing speed, it reaches 76.9 FPS on an RTX 3080 GPU, 47.13 FPS on an Intel I9-12900 CPU, and 11.63 FPS on an embedded Jetson TX2 device.

Modelling and simulation of double-pantograph catenary system of Taiwan railway

Abstract In view of the insufficient transportation capacity of Taiwan Railways in populated urban areas and intercity railways, increasing the maximum operating speed can be a solution for the problem. However, it is unknown whether the overhead contact line (OCL) system of the Taiwan Railways can tolerate such speed changes. For the unique railway system used in Taiwan, the literature does not present research on the dynamic interaction behaviour for the typical EMU trains with two pantographs, which are widely used in Taiwan railway system. Further, in response to the government policy to localize the supply chain of railway components, this research aims to establish a reliable simulation model so that domestic manufacturers may use this model for the design and development of the pantograph-catenary system. In this study, the catenary system model is established based on theoretic principles, specifications and parameters are adapted from data used by Taiwan Railway Co. The pantograph model was constructed as multi-body model, with parameters taken from the pantograph equipped on the TEMU2000 tilting train. This model is used to analyse catenary system to investigate the potential loss of contact between the double pantographs and the contact wire with increased train speed. The loss of contact and other phenomena will be analysed to explore possible solutions or optimization strategies for catenary system design.

Prediction model for icing growth characteristics of high-speed railway contact lines

The sliding electrical contact is the only means by which high-speed trains obtain energy. When icing occurs on the contact lines, the impact vibrations of the pantograph-catenary system are further exacerbated, electrical arcing becomes more frequent, and abnormal wear is caused, seriously threatening the safety of the energy supply for high-speed railways. To address the unclear mechanisms, unpredictable patterns, and challenging characterization of contact lines icing, this paper proposes a dynamic simulation method for the first time. Furthermore, a surrogate model for predicting contact line icing is developed using deep learning algorithms. First, based on grid updating, flow field analysis, and icing calculations, key icing parameters are obtained to establish a numerical model of contact lines icing under time-varying meteorological parameters. Then, the effects of factors such as wind speed, temperature, and liquid water content on the dynamic evolution characteristics of contact line icing are analyzed. Finally, using the CNN-GRU algorithm, a prediction model for contact line icing is constructed to predict the icing mass and contours. This research clarifies the evolution patterns of contact lines icing, addresses challenges in monitoring and predicting icing states, and lays a theoretical foundation for high-speed railways' safe and stable operation under icing conditions.

Pantograph-Catenary Coupling System Dynamics Analysis with Rigid-Flexible Pantograph for Straddle-Type Monorail

The flexible pantograph of straddle-type monorail has influence on the dynamics performance of pantograph-catenary system. This paper established a rigid-flexible pantograph-catenary-vehicle coupling dynamics model of monorail. By embedded the rigid-flexible pantograph into the vehicle dynamic analysis model, the rigid-flexible pantograph-catenary coupling dynamics model that could consider the random irregularity of track beam ultimately established. The validity of model has been approved by the pantograph dynamics test of Chongqing monorail line 3. The dynamic performance of the pantograph-catenary system, calculated by the dynamics models with rigid and rigid-flexible pantograph are compared in detail. The results show that the pantograph flexibility affects the vibration characteristics and the current collection quality of pantograph-catenary system.

A pantograph-catenary arcing detection model for high-speed railway based on semantic segmentation and generative adversarial network

ABSTRACT Pantograph-catenary arcing refers to an abnormal phenomenon occurring in pantograph-catenary system due to poor contact or other factors, which significantly impacts the normal operation of high-speed railway. Therefore, the detection of arcing occurrences holds significant importance for the intelligent maintenance of pantograph-catenary systems. However, the scarcity of arcing data in pantograph-catenary datasets limits the efficacy of supervised learning methods for arcing detection. To address this issue, we propose a novel pantograph-catenary arcing detection model that integrates semantic segmentation with generative adversarial networks. The model first modifies the loss function of the U 2 -Net network to tailor it specifically for pantograph-catenary semantic segmentation. To generate finer normal pantograph-catenary images, attention mechanism is incorporated into the SPADE-based pantograph-catenary scene generation model. Finally, an improved differencing method is employed to compute the arcing image by subtracting the generated normal pantograph-catenary image from the actual pantograph-catenary image. The experimental results validate the effectiveness of the method for pantograph-catenary arcing detection in the absence of prior arcing knowledge, with a recall rate of 75.3% and an F1-Score of 69.63%. Compared to other advanced pantograph-catenary arcing methods, this method exhibits superior performance.

Study on the Length of the Effective Vibration Area of the Catenary in a Pantograph–Catenary Interaction System

The effective vibration area includes most of the catenary vibration caused by pantograph–catenary interactions and is the basis of the real-time catenary model for hardware-in-the-loop simulation. However, while the length of the effective vibration area is one of the most important parameters of the real-time catenary model, it has not been fully studied at present. In this paper, the length of the effective vibration area is first investigated. A pantograph–catenary interaction model is developed based on the modal superposition method. After the validation of the model, the vibration energy distribution of the catenary is used to determine the length of the effective vibration area based on the converged total energy. The influence of vehicle velocity and contact wire tension on the vibration energy distribution and length of the effective vibration area is investigated. The obtained appropriate length of effective vibration area is validated by a real-time catenary model and online measurement data of the contact force. The investigation results show that the energy distribution of the catenary can accurately determine the length of effective vibration area, and it increases with increasing vehicle velocity but decreases with increasing contact wire tension. The appropriate length of effective vibration area should be at least 160 m (approximately three spans) in the pantograph–catenary system.

Analysis of the dynamic performance of pantograph-catenary system with posture of pan-head

Abstract This article focuses on the changes in the contact pressure between the pantograph and the catenary caused by variations in the pan-head posture. Starting from the kinematics and dynamics of the pantograph and based on the theories of multibody dynamics and finite element analysis, the pantograph head model is validated, and a pantograph rigid-flexible coupling model considering the flexibility of the pantograph head is established. A coupling model between the pantograph model and the rigid contact catenary is established to extract the pantograph posture and dynamic performance data during operation. By finely considering and modeling the structural characteristic parameters of the pantograph, the influence of different pantograph head characteristic parameters on the dynamic performance of the catenary system is studied. This provides a research basis for understanding the degree of influence of different characteristic parameters on the catenary dynamics.

Optimising Dual Pantograph-Catenary System Performance in Curved Sections for Enhanced High-Speed Railway Operations

Optimising Dual Pantograph-Catenary System Performance in Curved Sections for Enhanced High-Speed Railway Operations

Study on thermo-mechanical coupling model in pantograph-catenary system of rail vehicle

Study on thermo-mechanical coupling model in pantograph-catenary system of rail vehicle

Fatigue life enhancement of catenary droppers for high-speed railways based on arrangement optimization

While high-speed trains rely on the pantograph-catenary system (PCS) to collect electric energy, the catenary droppers constantly work as the key component of hanging contact wire, ensuring the stability of highspeed current-carrying slide. During train operation, dropper suffers from high-frequency bending and stretching due to the repeated interaction within PCS, which would inevitably accelerate the process of fatigue fracture and potentially threat the operation safety. Herein we propose a strategy of life prolong method for the catenary droppers, based on the fatigue analysis and machine learning technique. Firstly, a three-dimensional finite element (FE) model considering the spatial distribution of dropper has been constructed to simulate the interaction within the PCS. Then, the FE model was used to carry out parameterization numerical calculations combined with machine learning techniques, to seek the potential optimal scheme of the dropper arrangement. Subsequently, the performance of benchmark and optimum structure were detailly compared and analyzed in the static characteristics and dynamic response. Finally, the fatigue life was estimated according to the stress analysis results of the dropper. The results indicated that the method proposed in this paper can effectively extend the fatigue life of droppers.

Rapid Adaptation for Active Pantograph Control in High-Speed Railway via Deep Meta Reinforcement Learning.

Active pantograph control is the most promising technique for reducing contact force (CF) fluctuation and improving the train's current collection quality. Existing solutions, however, suffer from two significant limitations: 1) they are incapable of dealing with the various pantograph types, catenary line operating conditions, changing operating speeds, and contingencies well and 2) it is challenging to implement in practical systems due to the lack of rapid adaptability to a new pantograph-catenary system (PCS) operating conditions and environmental disturbances. In this work, we alleviate these problems by developing a revolutionary context-based deep meta-reinforcement learning (CB-DMRL) algorithm. The proposed CB-DMRL algorithm combines Bayesian optimization (BO) with deep reinforcement learning (DRL), allowing the general agent to adapt to new tasks quickly and efficiently. We evaluated the CB-DMRL algorithm's performance on a proven PCS model. The experimental results demonstrate that meta-training DRL policies with latent space swiftly adapt to new operating conditions and unknown perturbations. The meta-agent adapts quickly after two iterations with a high reward, which require only ten spans, approximately equal to 0.5 km of PCS interaction data. Compared with state-of-the-art DRL algorithms and traditional solutions, the proposed method can promptly traverse scenario changes and reduce CF fluctuations, resulting in an excellent performance.

A Reinforcement Learning-Based Pantograph Control Strategy for Improving Current Collection Quality in High-Speed Railways.

In high-speed railways, the pantograph-catenary system (PCS) is a critical subsystem of the train power supply system. In particular, when the double-PCS (DPCS) is in operation, the passing of the leading pantograph (LP) causes the contact force of the trailing pantograph (TP) to fluctuate violently, affecting the power collection quality of the electric multiple units (EMUs). The actively controlled pantograph is the most promising technique for reducing the pantograph-catenary contact force (PCCF) fluctuation and improving the current collection quality. Based on the Nash equilibrium framework, this study proposes a multiagent reinforcement learning (MARL) algorithm for active pantograph control called cooperative proximity policy optimization (Coo-PPO). In the algorithm implementation, the heterogeneous agents play a unique role in a cooperative environment guided by the global value function. Then, a novel reward propagation channel is proposed to reveal implicit associations between agents. Furthermore, a curriculum learning approach is adopted to strike a balance between reward maximization and rational movement patterns. An existing MARL algorithm and a traditional control strategy are compared in the same scenario to validate the proposed control strategy's performance. The experimental results show that the Coo-PPO algorithm obtains more rewards, significantly suppresses the fluctuation in PCCF (up to 41.55%), and dramatically decreases the TP's offline rate (up to 10.77%). This study adopts MARL technology for the first time to address the coordinated control of double pantographs in DPCS.

Comparative study of the current-carrying property of different copper-impregnated carbon skateboards/contact wires

The pantograph-catenary system plays a crucial role in the current acquisition of Electric Multiple Unit. To obtain better carbon skateboard/contact wire matching properties, this study discusses the current-carrying properties of four different copper-impregnated carbon skateboards with chromium-zirconium-copper alloy contact wires at different currents. The test results demonstrate that the CI-D carbon skateboards are able to withstand higher currents with relatively stable electrical contact resistance and have a lower wear rate. According to tribological analysis, adhesive wear was the main wear mechanism of copper-impregnated carbon skateboards under the test conditions, which micro-analysis revealed as oxidized layers over a wide range of small areas. Small amounts of oxide particles and third-body abrasive debris cause abrasive wear on the carbon skateboard surface.

Active Displacement Control of Pantograph-catenary System for a Half-body Railway Model

The pantograph is an essential component that provides electrical contact between the overhead wires and the electric train. The quality of the current collection in high-speed trains is directly influenced by the mechanical interaction between the pantograph collector head and the overhead contact line. To overcome these challenges and improve pantograph performance, researchers and engineers have explored innovative solutions, including the introduction of active control mechanisms. Excitation by the vehicle is one of the normal disturbances in the dynamic interaction of the pantograph and the overhead line. The vertical effects of vehicle-track vibrations on the interaction between the pantograph and the overhead contact line have not yet been adequately researched. To fill this research gap, this study establishes models for both the pantograph-catenary interaction and the vehicle-track system. In this study, the performance of the modified Skyhook-Proportional-Integral-Derivative (PID) controller was investigated for a half-body of a railway pantograph-catenary system. Track irregularities such as step, sine, and random were applied to perturb the suspension system. The performance of both passive and active systems was investigated by considering the track irregularities as a basis. The root mean square analysis (RMS) found that active displacement control of pantograph-catenary systems for a half-body railway model equipped with modified Skyhook-PID controllers performed better than the passive systems. In summary, the future experimental approach for active half-body railway model could incorporate this simple modification of the Skyhook-PID controller.

Pantograph–Catenary Interaction Prediction Model Based on SCSA-RBF Network

As a traditional numerical simulation method for pantograph–catenary interaction research, the pantograph–catenary finite element model cannot be applied to the real-time monitoring of pantograph–catenary contact force, and the computational cost required for the multi-parameter joint optimization of the pantograph–catenary system with the finite element model is very high. In this paper, based on the selective crow search algorithm–radial basis function (SCSA-RBF) network, the time-domain signal of the panhead acceleration, which can be obtained in real-time through non-contact test technology, is taken as the boundary condition to directly solve the pantograph dynamic equation and a data-physics coupling model that can quickly predict the pantograph–catenary interaction is proposed. The prediction model is trained and verified using the dataset generated through the finite element model. Furthermore, the prediction model is applied to the multi-parameter joint optimization of six pantograph dynamic parameters and nine pantograph dynamic parameters, considering nonlinear panhead stiffness, and optimization suggestions under various speeds and filtering frequencies are given.

Summary of abnormal wear status of pantograph-catenary system in metro

Summary of abnormal wear status of pantograph-catenary system in metro

Toward Reliable High-Speed Railway Pantograph-Catenary System State Detection: Multitask Deep Neural Networks With Runtime Reliability Monitoring

Toward Reliable High-Speed Railway Pantograph-Catenary System State Detection: Multitask Deep Neural Networks With Runtime Reliability Monitoring

An exploration of the super-critical speed dynamic behaviours of the pantograph-catenary system

The train operating speed is traditionally limited to lower than 0.7 times the critical speed of the catenary. The material’s strength limits the tensile forces of the tension wires, preventing the further improvement of the train speed. A novel super-critical speed operating strategy of the pantograph catenary system (PCS) is proposed, using the relatively low tensile values of the catenary to make the pantograph run at a speed ratio larger than 1. The analytical results of a string under a moving load show the theoretical possibility of the super-critical speed operating strategy in moving load problems. The finite element method (FEM) is adopted for the model of the catenary. The differences between the simple catenary and the stitched catenary running at the super-critical speed regime are compared. Then, the tensile forces designation of the stitched catenary with different speed ratio values beyond 400 km/h is studied. Finally, the dynamic behaviours of the PCS reaching the super-critical speed regime are discussed, consisting of the continuous acceleration process and the transition process from the high-tension section to the low-tension section. The proposed super-critical speed operating strategy may be promising for the next-generation high-speed PCS.

Assessment of railway pantograph-catenary interaction performance with realistic pantograph strip imperfection

In high-speed rail operations, the pantograph-catenary system is commonly utilised to transmit electricity to the high-speed train. This is achieved through a sliding contact between the pantograph strip and the contact wire of the catenary. The pantograph strip, typically made of softer carbon material, is designed to experience wear, ensuring that the replaceable and cost-effective strip is more likely to deteriorate than the contact wire. However, imperfections in the pantograph strip can adversely affect the interaction performance of the pantograph-catenary system. To quantify the effect of pantograph strip imperfections on the interaction performance, this paper aims to incorporate the measurement data of pantograph strip wear into the numerical simulation of pantograph-catenary interaction. The study collected 58 sets of measurement data on pantograph strip wear from Shanghai Hongqiao station. By employing a well-developed pantograph-catenary model, several numerical simulations were conducted to investigate the dispersion of dynamic behaviours caused by strip wear. The results demonstrate that the inclusion of strip imperfections introduces a certain level of dispersion in the interaction behaviours of the pantograph-catenary system. Specifically, at the operating speed of 300 km/h, strip imperfections can lead to a 16.62% increase in the standard deviation of the contact force and an overall decrease in the minimum contact force. Consequently, it is crucial to update the technical specifications to account for the impact of pantograph strip disturbances. Furthermore, each strip's wear induces a comparable level of dispersion in the contact force standard deviation. However, the contact force on the rear strip typically exhibits greater fluctuation, making it a significant contributor to the overall interaction performance.

Modeling and analysis of transition-point disappearance in high-speed railway pantograph-catenary system

During the operation of high-speed railway, the transition-point disappearance phenomenon, which is caused by the deformation of pantograph head, poses a safety threat to the pantograph-catenary system. In this study, the analytical model for transition-point disappearance analysis is presented. The instantaneous profile, as well as the deformation process of the pantograph head under different contact force values and positions or different pantograph-head parameters can be solved using the model. Curve equation, force analysis, coordinate axis rotation, and few other methods are adopted to achieve simplified modeling. The proposed modeling method and analysis conclusion provide theoretical support for the permissible contact force range calculation and pantograph-head parameters optimization to prevent transition-point disappearance. The effectiveness of the proposed model is verified using both finite element simulation and experimental measurements. Finally, a case analysis for the prevention of transition-point disappearance is conducted, using pantographs with the models CX-GI and DSA250 as examples.