Substation Operation Research Articles

IEC61850 기반 디지털 변전소의 보호 적정성 평가를 위한 디지털 트윈 개발

Digitalization of substations is universally expanding through digital transformation in existing and new substations. Accordingly, to improve the reliability of operation in digital substations, the requirement is not only expanded for the protection adequacy evaluation on each protection IED but also the constant evaluation of the protection adequacy of the entire digital substation. In general, there is a problem that the state change of the power system is not reflected in protection systems of substations because the protection systems operate without evaluating the protection adequacy of the entire substation after determining the correct value of the protection IEDs. The proposed method in this paper enables the constant evaluation of protection adequacy without additional facilities by applying digital twin technology. In addition, the interoperability of the digital twin model is secured by developing the information exchange between the devices of the digital twin model based on IEC61850.

An Immersive Virtual Reality Training Game for Power Substations Evaluated in Terms of Usability and Engagement

Safety-focused training is essential for the operation and maintenance concentrated on the reliability of critical infrastructures, such as power grids. This paper introduces and evaluates a system for power substation operational training by exploring and interacting with realistic models in virtual worlds using serious games. The virtual reality (VR) simulator used building information modelling (BIM) from a 115 kV substation to develop a scenario with high technical detail suitable for professional training. This system created interactive models that could be explored using a first-person-perspective serious game in a cave automatic virtual environment (CAVE). Different operational missions could be carried out in the serious game, allowing several skills to be coached. The suitability for vocational training carried out by utility companies was evaluated in terms of usability and engagement. The evaluation used a System Usability Scale (SUS) and a Game Engagement Questionnaire (GEQ) filled by 16 power substation operators demonstrating marginally acceptable usability, with improvement opportunities and high acceptance (by utility technicians) of this system for operation training focused on safety in such hazardous tasks.

An Intuitive VR-based Environment for Monitoring and Control of Electrical Power Substations

A Virtual Reality System provides an intuitive tridimensional user interface, with distinct interaction when compared to a traditional 2D layout, allowing the user to manipulate data similar to the real world. Such systems give the users physical and cognitive immersion, by granting a mental model compatible with field operation. In this work, we present the development aspects and some results of a Virtual Reality based solution to provide a more natural and intuitive environment for controlling electrical operation centers. The solution intends to minimize the issues caused by the operation of electric power substations due to the lack of spatial and functional information on the traditional operation interfaces. The research is being carried out with the collaboration between the energy electric company of Minas Gerais–Brazil (CEMIG) and the Federal University of Uberlândia. Besides operating generation and transmission actives, the environment presents great potential for the training of operators and other professionals of support and maintenance.

Seismic Finite Element Analysis of Lightning Arrester Combination by Casing and Pillar Insulator

The seismic performance of electrical equipment in substations has a great impact on the normal operation of the whole substation. The results of the modal analysis show that the fundamental frequency of the three devices is in the range of 0.9Hz∼1.1Hz. The maximum stress of the casing for the three devices is respectively 55.43MPa, 45.39MPa, 35.26MPa, when the peak acceleration 0.4g seismic action is verified. The maximum stress of insulator is respectively 47.01MPa, 62.72MPa and 30.85MPa, and the maximum relative displacement of the top for the equipment is 617.2mm.

Using ANSI/ISA-S88 in Reconfigurable Immersive Learning: A Pathway from Substation Operation Simulator to Reconfigurable Product and Production Demo Line for Learning Factory

Using ANSI/ISA-S88 in Reconfigurable Immersive Learning: A Pathway from Substation Operation Simulator to Reconfigurable Product and Production Demo Line for Learning Factory

Development of a Generalized Scaled-Down Realistic Substation Laboratory Model for Smart Grid Research and Education

This paper introduces a physical scaled-down realistic substation laboratory model development for translational research and education in smart grids. The development of a substation panel with four 3-<inline-formula> <tex-math notation="LaTeX">$\phi $ </tex-math></inline-formula> feeders of 415 V, 65 A rating is described in detail. The developed substation model can be configured to realize seven widely used substation bus bar arrangements. A programmable logic controller (PLC) is used to create interlock mechanisms for mimicking the actual substation operation practices. Provision is made to realize the gang and independent pole operation of circuit breakers, the manual and remote modes of operation, and different types of current transformer arrangements. The substation panel can host up to 10 commercial IEDs, and multiple substation panels can be cascaded to form a bigger station using the master-slave configuration of PLCs. All the potential transformer and current transformer measurements, circuit breaker, isolator, and earth switch status signals are made available for connecting field devices. The developed substation model can be used for advanced research on substation automation using IEC61850, validation of new protection strategies, implementation and testing of new algorithms (such as topology processing, state estimation) for energy management systems (EMS) like how they get implemented in the field.

Lidar SLAM Based on Particle Filter and Graph Optimization for Substation Inspection

Simultaneous Localization and Mapping (SLAM) is the core technology of intelligent substation inspection robot. Because of lightweight computation, Rao-Blackwellized Particle Filter (RBPF) is widely used in two-dimensional SLAM. However, it suffers from poor positioning accuracy, low robustness and rapid cumulative errors despite recent improvement. This paper presents a lidar SLAM system based on RBPF and graph optimization that can adapt to unstructured operating environment of substation. Firstly, the diversity of particles is increased by rebuilding the resample algorithm to improve the robustness of the system, and high-quality poses are estimated in submaps. Secondly, the multi-submap system is established to construct odometry constraints (one pose corresponds to two submaps). Furthermore, loop detector is an important part of optimization algorithm, and the branch-bound method is used to reduce computation burden and accelerate the loop detection. Finally, global poses of robot are optimized by the whole odometry and loop constraints in real time. Experiment results show that the proposed method is more accurate than other methods, and can maintain and produce high-precision positioning and mapping in complex substation operation and maintenance environment. It provides a new idea for intelligent substation inspection and positioning method.

Three-Dimensional Object Detection in Substation Operation Scene Based on Attention Mechanism

Three-Dimensional Object Detection in Substation Operation Scene Based on Attention Mechanism

Estimation of the potential of energy efficiency increase in SMARTGRID systems with prosum-ers based on electric vehicles

The modes of operation of power transformer substations 6 (20)/0.4 kV are analyzed. Scientific and technical solutions for the use of electric vehicles as prosumers of electric energy are substantiated. The potential influence of electric cars on electricity losses in "smart" electric networks is determined. Feasibility study of expediency of using electric mobiles as prosumers from the standpoint of loss reduction and efficiency of network equipment use is given. Quantitative indicators of the potential of equalization of the daily schedule of electric loads of the typical area of consumers of city electric networks are determined. The main indicator is the reduction of electricity losses in transformers by 7-10% compared with the existing ones when regulating the mode from the side of 0.4 kV with help of electric vehicles. Additionally, the possibility of increasing the capacity of electrical networks up to 45% identified.

Research and Implementation of SCD Precision Decoupling in Intelligent Substation for Single Equipment Replacement

In the process of reconstruction and expansion of intelligent substation, it is difficult to accurately define the influence scope of SCD file upgrade. In the wake of each modification of SCD file, all configuration information contained in SCD needs to be re-verified, which greatly increases the workload of debugging, operation and maintenance of intelligent substation. Via decoupling SCD files, the problems of modification and re-verification of SCD files in the reconstruction and expansion stage can be tackled. In this paper, SCD precision decoupling method for smart substation with single equipment replacement is proposed, which makes SCD decoupling work more detailed, adaptable to various expansion and technical transformation of substation. The decoupling of SCD is refined from logical structure to physical link level, and the decoupling range of SCD is precisely determined, so as to minimize the modification and reverification range of SCD files and reduce the change risk caused by SCD modification.

Research on Intelligent Monitoring and Maintenance Technology of Substation Based on Digital Twin

The design, research and development, test, operation and maintenance of power grid substation equipment are relatively independent. Related problems in each link cannot be comprehensively managed from the perspective of the full life cycle of equipment. Operation and maintenance personnel need to face data monitoring, network monitoring, equipment monitoring, business system monitoring, fault diagnosis and repair and other business scenarios. There are many types of information, complex association relationship, abstract and inefficient operation and maintenance information, “man-machine-object” can not be two-way cooperation and interaction, fault diagnosis and troubleshooting difficulties. Digital substation intelligent monitoring operational digital twin applications, digital intelligent substation operations provide operational monitoring service ability, realize the grid digital substation twin modeling and environment reconstruction, false or true merged superposition, two-way coordinated interaction, twin intelligence operations and panoramic visual monitoring, field devices for power grid operation maintenance, resource scheduling, and construction planning to provide guidance, Fully guarantee the safe and reliable operation of power grid equipment, realize the full life cycle management of power grid equipment, and improve the level of intelligence, visualization and digitalization of power grid.

Design of thermal imaging-based health condition monitoring and early fault detection technique for porcelain insulators using Machine learning

The inspection of insulator faults is an important task to prevent catastrophic failures in the operation of an electric substation. Manual inspection of overhead power line insulators can be very dangerous owning to the presence of high voltage in power sub-stations. Hence, in this paper, we present an infrared thermal (IRT) camera based non-invasive computer vision system for automatic monitoring and visual inspection of overhead on line power insulators. In the proposed work, initially, an optimal threshold method is applied to segment the region of interest (ROI) in IRT images. Subsequently, various geometrical, morphological, intensity and statistical features are computed from the segmented ROI, which are eventually utilized as an input to Gaussian kernel support vector machine to classify the different type of faults in insulator images. Computer vision based automatic inspection of insulators can play an important role from environment as well as human safety point of view. Timely inspection of insulators can ensure the environmental safety through prevention of fire that may be caused due to the insulator failures leading to the sudden breakdown of high-power lines. The proposed system achieved the true positive rate (TPR), and false negative rate (FNR) of 97.3%, and 2.66%, respectively. Whereas, the system obtained the Positive Predictive Value (PPV) and False Discovery Rates (FDR) of about 97% and 3%, respectively with the accuracy of 0.97 on the receiver operating characteristics (ROC) curve. The performance of the proposed method is compared with other existing state of the art methods and found that our method outperformed over them. Hence, we recommend proposed system to detect the severity of faults in IRT images long before any catastrophic failures take place at power sub-stations.

Research on 500kV Transformer on-load Tap Changer Fault Treatment and Physical Properties Testing

This article introduces the intermittent increase of acetylene content in the oil during the operation of a 500kV start-up substation of a power generation company. It is preliminarily judged that there is spark discharge in the oil chromatographic analysis and on-site partial discharge test. After returning to the factory for maintenance and internal inspection, it was found that the movable contact and the fixed contact of the selected part of the on-load tap-changer were not connected in place, which caused intermittent spark discharge and continued to increase acetylene. The problem is solved by adjusting the number of turns of the gear when the tap switch is switched forward and backward, and the transformer resumes normal operation.

Discussion on Overcurrent Protection in Complex Voltage Direction during Substation Operation

Discussion on Overcurrent Protection in Complex Voltage Direction during Substation Operation

Causes and Countermeasures of Heating of Electrical Joints in Substation Operation

Causes and Countermeasures of Heating of Electrical Joints in Substation Operation

Research on the Dangerous Points and Pre-control Measures in Substation Operation and Maintenance Management

Research on the Dangerous Points and Pre-control Measures in Substation Operation and Maintenance Management

Investigation of occupational hazard of 750 kV extra high voltage substations

Objective: To understand the current status of major occupational hazards in 750 kV extra high voltage (EHV) substations. Methods: In July 2019, through investigating and detecting the sulfur hexafluoride, power frequency electric field and noise occupational hazards of 750 kV EHV substations in substation 1, substation 2, substation 3, substation 4, substation 5, substation 6 and substation 7, the exposure intensity of the sulfur hexafluoride, power frequency electric field and noise intensity that the operators are exposed to during the inspection process were analyzed. Results: The qualified rate of 358 sulfur hexafluoride test results was 100.0% of the seven 750 kV EHV substations. The qualified rate of 8 h time-weighted average of the power frequency electric field of those 750 kV EHV substations contacted by operators was 100.0%. Among the 847 power frequency electric field detection points, the exceeding standard rate of power frequency electric field was 64.3%, and the differences in the power frequency electric field detection exceeding standard rates of different substations and inspection areas were statistically significant (χ2=87.52, 50.86, P<0.01) . The highest exceeding standard rate of power frequency electric field was the circuit breaker inspection area (94.4%, 34/36) . The noise intensity test results of the seven EHV substations were 41.1-79.7 dB (A) , and the qualified rate was 100.0%. Conclusion: The sulfur hexafluoride, power frequency electric field and noise that the operators contacted in 750 kV EHV substations meet the requirements of occupational exposure limits. The inspection areas of main transformers, capacitors, reactors, bus bars and switches have high power frequency electric field radiation, should be select equipment iand give priority to robot inspection, and reasonably adjust the inspection time to reduce the intensity level of substation operators' exposure to power frequency electric field.

Joint Inspection of HD Video and Robot in Substation Based on OCR Technology

The research on the joint inspection technology of HD video and robot in substation is of great significance in the operation and maintenance management of substation. The related research on multidimensional collaborative inspection technology of substation has attracted great attention. The substation monitoring system is designed to realize multidimensional collaborative inspection of HD video and inspection robot. OCR technology is used to improve the abnormal recognition system of inspection robot equipment. According to the collection of video information, DSP comprehensive information processing is carried out, and the detection information is analyzed by frequency domain filtering method through human-computer interaction interface. Meanwhile, the main component features of substation detection components are extracted by pattern recognition method, and the resolution model of similar features of video monitoring images is constructed. It plays an important role in the daily operation and maintenance of substation to construct the reliability visual tracking and identification model and optimize the multidimensional cooperative inspection system model.

Improvement and Application of Intelligent Inspection Robot in Substation Operation and Maintenance

Improvement and Application of Intelligent Inspection Robot in Substation Operation and Maintenance

Analysis and Coping Technology of Hidden Danger in Substation Operation and Maintenance

Analysis and Coping Technology of Hidden Danger in Substation Operation and Maintenance