Substation live working differentiated protection method and system based on activity envelope surface

Abstract

The substation live working differential protection method and system based on the activity envelope surface establish a three-dimensional geometric model of the substation working scene, determine the target working position and potential state of the worker; take the human joint activity limit as the constraint, uniformly sample in the three-dimensional posture space and construct a three-dimensional working activity envelope surface by using the convex hull algorithm; establish a three-dimensional simulation model of the substation containing the worker, solve the spatial electric field distribution by using the finite element method, and interpolate and map the field strength data to the envelope surface grid nodes; set the upper limit threshold and the lower limit threshold of the safety field strength based on the envelope surface field strength distribution, divide the envelope surface into a danger zone, a warning zone and a safety zone, and output a differential protection scheme. The application expands the traditional discrete point evaluation to continuous surface full field strength analysis, realizes the fine configuration of "key area key protection, general area general protection" of the shielding suit, and is suitable for all working conditions of ground potential, equipotential and in and out of equipotential.

Description

Technical Field

[0001] This invention relates to the fields of high voltage and insulation technology and power safety protection technology, specifically to a differentiated protection method and system for live-line work in substations based on an active envelope surface. Background Technology

[0002] In the operation, maintenance, and repair of substations, live-line work is a core means to ensure uninterrupted power grid operation and reduce the risk of power outages. Live-line work in substations can be categorized by potential state into ground potential work, equipotential work, and intermediate potential work during the transition from equipotential to equipotential. Under different potential states, the electric field environment in which workers operate differs significantly. During ground potential work, workers are located on the ground or grounding structure, and the electric field strength on their body surface is relatively low, but strong field concentration may occur in localized areas near live conductors. During equipotential work, workers are in direct contact with live conductors, and their entire body is in a strong electric field environment, with extremely high field strength at protruding parts such as the fingertips and elbows. During the transition from equipotential to equipotential, workers experience a dynamic change in electric field strength from low to high.

[0003] Currently, safety protection for live-line working in substations mainly relies on the overall protection of shielded suits and standardized working distance control. The selection and configuration of shielded suits are typically determined uniformly based on voltage levels, without differentiated design for the actual electric field distribution on the worker's body surface at different working positions and on different body parts. This approach may result in insufficient protection in areas with extremely high electric field strength, while creating unnecessary redundancy in areas with lower electric field strength, increasing the weight of the shielded suit and the burden on the worker.

[0004] In terms of safety assessment for live-line work, existing methods mainly rely on static discrete points for field strength verification or safety distance calculation. They fail to construct a three-dimensional continuous spatial envelope for the accessible activity range of workers during live-line work, thus failing to systematically assess the electric field exposure level throughout the entire process. Although some researchers have proposed a conceptual framework for an electrogeometric safety envelope in recent years, existing studies primarily use it for real-time early warning of personnel approaching live conductors, relying on online sensor monitoring. This envelope has not yet been applied to protection scheme design or combined with pre-calculated electric field simulations for protection zone optimization.

[0005] Furthermore, the selection and configuration of existing shielding suits are mainly determined uniformly based on voltage levels, lacking a zoned differentiated protection method based on quantitative distribution data of surface electric field strength. Actual measurement and simulation data show that the surface electric field strength difference between different working positions and different body parts within the same working position can reach several to tens of times under the same voltage level. Existing technologies struggle to achieve precise configurations of "key areas receiving key protection, and general areas receiving routine protection."

[0006] In summary, there is an urgent need to establish a differentiated protection method and system for live-line work in substations based on an active envelope surface. By constructing a three-dimensional active envelope surface and calculating its surface field strength distribution, an upgrade from discrete point assessment to continuous envelope surface assessment can be achieved. Furthermore, differentiated protection strategies can be implemented based on the field strength distribution, thereby optimizing the allocation of protection resources while ensuring safety. Summary of the Invention

[0007] To address the issues of insufficient precision in electric field protection for live-line work in existing substations and the lack of differentiated protection methods based on three-dimensional active space assessment, this invention provides a differentiated protection method and system for live-line work in substations based on the active envelope surface.

[0008] The present invention adopts the following technical solution.

[0009] This invention proposes a differentiated protection method for live-line working in substations based on the active envelope surface, including: Establish a three-dimensional geometric model of the substation operation scenario to determine the target operation location and potential status of the operators; Based on the target work position and potential state, and constrained by the limit angles of the human body's joints, a set of human reachable space points is obtained by uniformly sampling in the three-dimensional posture space. Using the human body center as the reference point, the farthest reachable points in each direction of the sampling point set are used to construct a three-dimensional closed surface using the convex hull algorithm, thereby generating a three-dimensional work activity envelope surface. Based on the three-dimensional geometric model and the three-dimensional operation activity envelope, a three-dimensional simulation model of the substation including the operators is established, the potential boundary conditions of each device are set, and the spatial electric field distribution is solved by the finite element method to obtain the full space potential and electric field intensity distribution. The full-space electric field intensity data is interpolated and mapped onto the mesh nodes of the three-dimensional active envelope surface to obtain the surface electric field intensity value of each node on the envelope surface. Based on the surface electric field strength values ​​of each node of the envelope, a safety field strength upper limit threshold and a conventional protection field strength lower limit threshold are set, dividing the envelope into three different protection level regions: danger zone, warning zone, and safe zone.

[0010] More preferably, determining the electrical potential status of the operator includes: When a worker is on the ground or a grounded structure and all parts of their body are at a safe distance from a live conductor, it is considered to be at ground potential; when a worker is in direct contact with a live conductor and their body potential is the same as the potential of the live conductor, it is considered to be at equipotential; when a worker is in a dynamic process of transitioning from ground potential to equipotential or vice versa, it is considered to be a process of entering or exiting equipotential.

[0011] More preferably, when constructing the three-dimensional activity envelope, if the operator is holding a tool, the reachable position of the handhold is used as a reference, and the tool end reachable point set is obtained by combining the length of the tool and its orientation sampling range, and then incorporated into the human reachable space point set to construct the three-dimensional activity envelope.

[0012] More preferably, when obtaining the set of reachable points at the end of the tool, the working tool is simplified into a rigid rod of length L. Taking the reachable position of the human handhold as a reference, the orientation angle is uniformly sampled within the operable orientation range of the working tool. The method for calculating the position point of the tool end is as follows: multiply the tool length by the orientation unit direction vector, and add the product result to the handhold position to obtain the tool end position.

[0013] More preferably, when setting the upper limit threshold of the safe field strength and the lower limit threshold of the conventional protective field strength, different upper limit thresholds of the safe field strength are set for different body parts.

[0014] More preferably, when determining differentiated protection zones based on the surface electric field intensity values ​​of each node of the envelope: If the electric field strength on the body surface is greater than the upper limit threshold of the safe field strength, it is determined to be a danger zone; if the electric field strength on the body surface is greater than the lower limit threshold of the conventional protection field strength but less than or equal to the upper limit threshold of the safe field strength, it is determined to be a warning zone; if the electric field strength on the body surface is less than or equal to the lower limit threshold of the conventional protection field strength, it is determined to be a safe zone.

[0015] More preferably, when outputting differentiated protection schemes based on the division results of the danger zone, warning zone, and safe zone, the enhancement measures are determined according to the multiples of the external field strength of the danger zone relative to the upper limit threshold of the safe field strength: When the external field strength of the body surface is greater than the upper limit threshold of the safe field strength but less than or equal to twice the upper limit threshold of the safe field strength, increase the number of conductive cloth layers; when the external field strength of the body surface is greater than twice the upper limit threshold of the safe field strength but less than or equal to five times the upper limit threshold of the safe field strength, increase the density of conductive fiber weaving; when the external field strength of the body surface is greater than five times the upper limit threshold of the safe field strength, add a metal mesh shielding layer.

[0016] More preferably, when outputting differentiated protection schemes, the reinforcement range is determined according to the area and distribution of the hazardous area: When the area of ​​the danger zone does not exceed 5% of the surface area of ​​the envelope and is distributed in a point-like manner, only the danger zone is locally reinforced and the reinforcement area is expanded by one grid node spacing. When the area of ​​the danger zone exceeds 5% or is distributed in a continuous area, the entire area is reinforced according to the corresponding level and expanded by one grid node spacing. One or two adjacent grid nodes at the boundary between the warning zone and the danger zone are gradually reinforced according to the level of the adjacent danger zone.

[0017] More preferably, when outputting differentiated protection schemes based on the division results of the danger zone, warning zone, and safety zone, the minimum distance between the three-dimensional active envelope surface and the nearest energized or grounded body is calculated. This minimum distance is the minimum distance from each grid node on the envelope surface to each discrete point on the surface of the energized or grounded body. This minimum distance is compared with the allowable distance of the safety regulations corresponding to the current working voltage level. If it does not meet the requirements, a working position adjustment suggestion is given.

[0018] More preferably, when providing suggestions for adjusting the work location: Locate the human body parts and working postures corresponding to the envelope nodes, calculate the required adjustment amount, and guide the workers to reduce the range of motion in that direction; after adjusting the working posture, reconstruct the active envelope and calculate the minimum spacing until the distance allowed by the safety regulations is met; if the requirements cannot be met by adjusting the posture due to the limitations of the work task, provide suggestions for supplementary insulation and shielding measures.

[0019] This invention also proposes a differentiated protection system for live-line work in substations based on an active envelope surface, including a modeling module, an envelope surface construction module, an electric field solution module, an electric field strength mapping module, and a zone determination module. The modeling module is used to create a three-dimensional geometric model of the substation operation scenario and determine the target operation position and potential status of the operators. The envelope construction module is used to uniformly sample and obtain a set of human reachable spatial points in the three-dimensional posture space based on the target operation position and potential state, with the activity limit angles of each joint of the human body as constraints, and use the convex hull algorithm to construct a three-dimensional closed surface using the farthest reachable point in each direction of the sampled points, based on the human body center as the reference point, to generate a three-dimensional operation activity envelope surface. The electric field solution module is used to establish a three-dimensional simulation model of the substation including the operators based on the three-dimensional geometric model and the three-dimensional operation activity envelope surface, set the potential boundary conditions of each device, and use the finite element method to solve the spatial electric field distribution to obtain the full space potential and electric field intensity distribution. The field strength mapping module is used to interpolate and map the full-space electric field strength data to the grid nodes of the three-dimensional active envelope surface to obtain the surface electric field strength value of each node on the envelope surface. The partitioning determination module is used to divide the envelope into three different protection level regions: a danger zone, a warning zone, and a safe zone, based on the surface electric field strength values ​​of each node of the envelope and setting an upper limit threshold for safe field strength and a lower limit threshold for conventional protection field strength.

[0020] More preferably, the envelope surface construction module is further configured to: When the operator holds the work tool, the reachable point of the handhold is used as a reference. The reachable point set of the tool end is obtained by combining the length of the work tool and the sampling range of its orientation. This set is then incorporated into the reachable point set of the human body and used to construct the three-dimensional activity envelope.

[0021] The present invention also proposes a terminal, including a processor and a storage medium: The storage medium is used to store instructions; The processor is used to perform the steps of the above method according to the instructions.

[0022] The present invention also proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Existing technologies for assessing the electric field safety of personnel working on energized surfaces in substations primarily rely on field strength verification at discrete points or uniform safety distance control, lacking the ability to continuously assess the three-dimensional activity space throughout the entire work process. This invention overcomes this limitation by innovatively introducing the concept of a three-dimensional activity envelope, mapping the human's accessible range of movement as a continuous closed surface. This method extends the assessment object from discrete points to continuous space, comprehensively covering all accessible spatial locations of personnel during the work process, effectively eliminating assessment blind spots, and achieving a systematic assessment of the electric field exposure level throughout the entire work process.

[0024] 2. Regarding protection strategies, traditional shielding suits are selected and configured primarily based on voltage levels, neglecting the differences in field strength between different body parts under the same working conditions, resulting in either excessive or insufficient protection. This invention is the first to achieve differentiated protection scheme generation based on the quantitative distribution of field strength on the body surface. By combining the field strength distribution of the envelope surface with zoning threshold determination, targeted local enhancement is applied to areas with concentrated field strength (such as fingertips, shoulders, and outer arms), while maintaining conventional protection in low-field-strength areas such as the torso and legs. This strategy of focusing protection on key areas reduces the overall weight of the shielding suit and the physiological burden on workers while ensuring safety.

[0025] 3. This invention establishes a unified evaluation framework applicable to all working conditions, including ground potential, equipotentiality, and the process of entering and exiting equipotentiality. The problems of localized field strength concentration during ground potential operations, whole-body exposure to strong electric fields during equipotential operations, and dynamic changes in field strength during the process of entering and exiting equipotentiality can all be uniformly incorporated into the active envelope surface analysis framework, achieving consistency in evaluation methods and systematic protection schemes. Attached Figure Description

[0026] Figure 1 A flowchart illustrating the differentiated protection method for live-line work in substations based on active envelope surfaces provided by this invention. Figure 2 This is a flowchart illustrating a differentiated protection method for live-line work in substations based on an active envelope surface, as provided in Embodiment 1 of the present invention. Figure 3 This is a schematic diagram of the construction of the envelope surface and field strength mapping for live-line working activities in substations provided by the present invention; Figure 4 This is a schematic diagram of differentiated protection zones under different operating conditions provided by the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0028] like Figure 1 As shown, this invention proposes a differentiated protection method for live-line work in substations based on the active envelope surface, specifically including the following steps: Establish a three-dimensional geometric model of the substation operation scenario to determine the target operation location and potential status of the operators; Determining the electrical potential status of the workers includes: When a worker is on the ground or a grounded structure and all parts of their body are at a safe distance from a live conductor, it is considered to be at ground potential; when a worker is in direct contact with a live conductor and their body potential is the same as the potential of the live conductor, it is considered to be at equipotential; when a worker is in a dynamic process of transitioning from ground potential to equipotential or vice versa, it is considered to be a process of entering or exiting equipotential.

[0029] Based on the target work position and potential state, and constrained by the limit angles of the human body's joints, a set of human reachable space points is obtained by uniformly sampling in the three-dimensional posture space. Using the human body center as the reference point, the farthest reachable points in each direction of the sampling point set are used to construct a three-dimensional closed surface using the convex hull algorithm, thereby generating a three-dimensional work activity envelope surface. When constructing the three-dimensional activity envelope, if the operator is holding a tool, the reachable position of the handhold is used as a reference. The tool's length and orientation sampling range are combined to obtain the tool end reachable point set, which is then incorporated into the human reachable space point set to construct the three-dimensional activity envelope.

[0030] When obtaining the set of reachable points at the end of the tool, the tool is simplified into a rigid rod of length L. Taking the reachable position of the human handhold as the reference, the orientation angle is uniformly sampled within the operable orientation range of the tool. The method for calculating the position point of the tool end is: multiply the tool length by the orientation unit vector, and add the product result to the handhold position to obtain the tool end position.

[0031] Based on the three-dimensional geometric model and the three-dimensional operation activity envelope, a three-dimensional simulation model of the substation including the operators is established, the potential boundary conditions of each device are set, and the spatial electric field distribution is solved by the finite element method to obtain the full space potential and electric field intensity distribution. The full-space electric field intensity data is interpolated and mapped onto the mesh nodes of the three-dimensional active envelope surface to obtain the surface electric field intensity value of each node on the envelope surface. Based on the surface electric field strength values ​​of each node of the envelope, a safety field strength upper limit threshold and a conventional protection field strength lower limit threshold are set, dividing the envelope into three different protection level regions: danger zone, warning zone, and safe zone.

[0032] When setting the upper limit threshold for safe field strength and the lower limit threshold for conventional protective field strength, different upper limit thresholds for safe field strength are set for different body parts.

[0033] When determining differentiated protection zones based on the surface electric field intensity values ​​of each node of the envelope: If the electric field strength on the body surface is greater than the upper limit threshold of the safe field strength, it is determined to be a danger zone; if the electric field strength on the body surface is greater than the lower limit threshold of the conventional protection field strength but less than or equal to the upper limit threshold of the safe field strength, it is determined to be a warning zone; if the electric field strength on the body surface is less than or equal to the lower limit threshold of the conventional protection field strength, it is determined to be a safe zone.

[0034] When outputting differentiated protection schemes based on the division of danger zones, warning zones, and safe zones, enhancement measures are determined according to the multiples of the external field strength of the danger zone relative to the upper limit threshold of the safe field strength: When the external field strength of the body surface is greater than the upper limit threshold of the safe field strength but less than or equal to twice the upper limit threshold of the safe field strength, increase the number of conductive cloth layers; when the external field strength of the body surface is greater than twice the upper limit threshold of the safe field strength but less than or equal to five times the upper limit threshold of the safe field strength, increase the density of conductive fiber weaving; when the external field strength of the body surface is greater than five times the upper limit threshold of the safe field strength, add a metal mesh shielding layer.

[0035] When outputting differentiated protection schemes, the reinforcement range is determined based on the area and distribution of the hazardous zone: When the area of ​​the danger zone does not exceed 5% of the surface area of ​​the envelope and is distributed in a point-like manner, only the danger zone is locally reinforced and the reinforcement area is expanded by one grid node spacing. When the area of ​​the danger zone exceeds 5% or is distributed in a continuous area, the entire area is reinforced according to the corresponding level and expanded by one grid node spacing. One or two adjacent grid nodes at the boundary between the warning zone and the danger zone are gradually reinforced according to the level of the adjacent danger zone.

[0036] When outputting differentiated protection schemes based on the division results of the danger zone, warning zone, and safety zone, the minimum distance between the three-dimensional active envelope surface and the nearest live or grounded body is calculated. This minimum distance is the minimum distance from each grid node on the envelope surface to each discrete point on the surface of the live or grounded body. This minimum distance is compared with the allowable distance of the safety regulations corresponding to the current working voltage level. If it does not meet the requirements, a working position adjustment suggestion is given.

[0037] When giving suggestions for adjusting the work location: Locate the human body parts and working postures corresponding to the envelope nodes, calculate the required adjustment amount, and guide the workers to reduce the range of motion in that direction; after adjusting the working posture, reconstruct the active envelope and calculate the minimum spacing until the distance allowed by the safety regulations is met; if the requirements cannot be met by adjusting the posture due to the limitations of the work task, provide suggestions for supplementary insulation and shielding measures.

[0038] This invention also proposes a differentiated protection system for live-line work in substations based on an active envelope surface, including a modeling module, an envelope surface construction module, an electric field solution module, an electric field strength mapping module, and a zone determination module. The modeling module is used to create a three-dimensional geometric model of the substation operation scenario and determine the target operation position and potential status of the operators. The envelope construction module is used to uniformly sample and obtain a set of human reachable spatial points in the three-dimensional posture space based on the target operation position and potential state, with the activity limit angles of each joint of the human body as constraints, and use the convex hull algorithm to construct a three-dimensional closed surface using the farthest reachable point in each direction of the sampled points, based on the human body center as the reference point, to generate a three-dimensional operation activity envelope surface. The electric field solution module is used to establish a three-dimensional simulation model of the substation including the operators based on the three-dimensional geometric model and the three-dimensional operation activity envelope surface, set the potential boundary conditions of each device, and use the finite element method to solve the spatial electric field distribution to obtain the full space potential and electric field intensity distribution. The field strength mapping module is used to interpolate and map the full-space electric field strength data to the grid nodes of the three-dimensional active envelope surface to obtain the surface electric field strength value of each node on the envelope surface. The partitioning determination module is used to divide the envelope into three different protection level regions: a danger zone, a warning zone, and a safe zone, based on the surface electric field strength values ​​of each node of the envelope and setting an upper limit threshold for safe field strength and a lower limit threshold for conventional protection field strength.

[0039] More preferably, the envelope surface construction module is further configured to: When the operator holds the work tool, the reachable point of the handhold is used as a reference. The reachable point set of the tool end is obtained by combining the length of the work tool and the sampling range of its orientation. This set is then incorporated into the reachable point set of the human body and used to construct the three-dimensional activity envelope.

[0040] The present invention also proposes a terminal, including a processor and a storage medium: The storage medium is used to store instructions; The processor is used to perform the steps of the above method according to the instructions.

[0041] The present invention also proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0042] Example 1 This invention provides a differentiated protection method and system for live-line work in substations based on an active envelope surface. Considering the differences in the range of activity of workers and the characteristics of the electric field distribution on their body surface under different potential states, a method for generating differentiated electric field safety protection schemes applicable to all working conditions, including ground potential, equipotential, and equipotential transition, is proposed based on the construction of a three-dimensional active envelope surface and the finite element solution of the spatial electric field.

[0043] Before describing the embodiments, the relevant terms are defined as follows: The work activity envelope is a continuous closed surface formed by fitting a set of three-dimensional points in the accessible work space of the worker under specific working conditions, constrained by the limits of human joint mobility. When the worker needs to hold a tool during the operation, this three-dimensional point set also includes the accessible position points of the end of the tool (such as the tip of an insulated operating rod, the end of a wrench, etc.). This surface reflects the maximum range of motion of the worker and their handheld tool during the operation.

[0044] Differentiated protection: Based on the surface field strength level of each region of the active envelope, the envelope is divided into regions with different protection levels, and differentiated shielding suit local enhancement and insulation shielding strategies are formulated for different regions.

[0045] like Figure 2 As shown, this embodiment of the invention proposes a differentiated protection method for live-line work in substations based on an active envelope surface, combined with... Figure 1 Let's take a look. Figure 1This is a flowchart illustrating an embodiment of a method provided by the present invention. The method includes steps S101 to S105, wherein: In step S101, a three-dimensional geometric model of the substation is established to determine the target location and potential status of the workers; In step S102, a three-dimensional operational activity envelope is constructed based on human joint movement constraints; In step S103, the spatial electric field distribution is solved using the finite element method, and the field strength data is mapped to the active envelope surface; In step S104, differential protection zoning is determined based on the field strength distribution of the envelope surface; In step S105, a differentiated protection scheme is output, including recommendations for local reinforcement of the shielding suit and safety verification conclusions for the work location.

[0046] In a preferred embodiment, the specific steps in step S101 above for establishing the three-dimensional geometric model of the substation and determining the target location and potential status of the workers include: Step S101-1: Based on the engineering two-dimensional design drawings, equipment parameter ledger and on-site measured dimensions of the work interval, use three-dimensional modeling software to establish three-dimensional geometric models of each live equipment (busbars, disconnecting switches, circuit breakers, instrument transformers, post insulators, etc.) as well as grounding bodies and frames in the target interval of the substation, and assemble them according to the actual spatial position to obtain the three-dimensional geometric model of the target work scene. Step S101-2: Determine the work content of this live-line operation according to the work task book (such as circuit breaker maintenance, knife contact processing, etc.), and determine the target work position and work posture (standing posture, squatting posture and work surface height) of the operator based on the position of the target equipment in the scene, and place the human body model into the three-dimensional geometric model; Step S101-3: Determine the potential state based on the relative position of the worker to the live conductor and the grounded conductor: When the worker is on the ground or grounding frame and all parts of his / her body are at a safe distance from the live conductor, it is determined to be at ground potential; when the worker is in direct contact with the live conductor and the human body potential is the same as the potential of the live conductor, it is determined to be at equipotential; when the worker is in a dynamic process of transitioning from ground potential to equipotential (or vice versa), it is determined to be a process of entering and exiting equipotential.

[0047] As a preferred embodiment, combined with Figure 3 The specific steps for constructing the active envelope surface in step S102 above include: Establish a local coordinate system with the center of the human torso as the origin; Using the limit angles of the human body's joints (shoulder, elbow, wrist, hip, knee, etc.) as constraints, uniform sampling is performed in the three-dimensional posture space to obtain 100 to 500 reachable spatial position points of the human body. The farthest reachable points in each direction from the sampling point set are used to generate continuous closed three-dimensional envelope surfaces using convex hull algorithms or surface fitting algorithms. .

[0048] In a preferred embodiment, when the operator holds the work tool, the aforementioned work activity envelope also includes the reachable range of the handheld tool. Specifically, when the operator holds the work tool (such as an insulated operating rod, wrench, temperature gun, etc.) during operation, the work tool is simplified to a length of... L For a rigid member, taking the reachable position of the human handhold as a reference, its orientation angle is uniformly sampled within the operable orientation range of the working tool, and calculated according to the formula... The position point at the end of the calculation tool; where, The location of the handheld point. Let the vector be the direction the tool is pointing towards the unit. Let be the tool length. This yields the set of reachable points at the tool's end; these points are then merged into the set of reachable points in the human body's space, and convex hull operations are performed to ensure that the generated activity envelope covers the maximum range of motion of the tool's end.

[0049] In a preferred embodiment, the specific steps of solving the electric field and mapping the field strength of the envelope surface in step S103 above include: Appropriate voltage boundary conditions are applied to each piece of equipment in the substation operation scenario: operating phase voltage is applied to the energized busbar (e.g., 63.5 kV for 110 kV, 127 kV for 220 kV, and 289 kV for 500 kV), and zero potential is applied to the grounding electrode and structure. The Laplace equation for the electrostatic field is solved using the finite element method. Obtain the potential of the entire space With electric field intensity distribution .

[0050] The obtained spatial electric field intensity data is interpolated and mapped onto the three-dimensional active envelope surface. Grid nodes P i The surface electric field intensity values ​​of each node are obtained. .

[0051] As a preferred embodiment, such as Figure 4 As shown, the specific steps for determining the differentiated protection zone in step S104 above include: Set a safe field strength upper limit threshold and the lower limit threshold of conventional protective field strength Both are apertures of the surface electric field strength (external field strength) of the envelope surface, directly obtained by mapping the surface electric field strength from each node of the envelope surface. As the object for partition determination. and To allow for parameter setting, the upper limit threshold for safe electric field strength is determined based on the work scenario, voltage level, and shielding capability of the protective equipment configured for the worker. Different upper limits can be set for different body parts; the facial area is checked separately at 240 kV / m, while other parts are judged according to the general threshold: when the worker is wearing a full set of standard shielding clothing (shielding efficiency not less than 40 dB, allowing the human body surface to withstand an electric field strength not exceeding 15 kV / m), the upper limit of the external electric field strength that the standard shielding clothing can withstand on the body surface is approximately 1500 kV / m. A larger value can be taken; a separate shielding mask is configured for the facial area, and its upper limit for the external electric field strength is checked at 240 kV / m. For low field strength operation scenarios (such as ground potential operation), this embodiment... , The values ​​are 15 kV / m and 5~8 kV / m respectively; for high field strength operation scenarios (such as equipotential work), in this embodiment... , We take values ​​of 300 kV / m and 100 kV / m respectively. For each node P on the envelope surface... i The protection level shall be determined according to the following rules: like If the area is deemed a danger zone, local reinforcement of the corresponding part of the shielding suit is required. like The area has been designated as a restricted zone; maintain standard protective clothing. like The area has been determined to be a safe zone and can be protected using standard protective measures.

[0052] Summarize the judgment results of all nodes and generate a differentiated protection level distribution map on the activity envelope surface.

[0053] In a preferred embodiment, the specific steps for outputting the differentiated protection scheme in step S105 above include: Based on the protection level distribution map, determine the spatial coordinates and area of ​​the shielding suit regions requiring localized reinforcement. For the corresponding hazardous areas, propose specific reinforcement plans: (1) According to the relative external field strength of the danger zone The enhancement measures are determined by tiered multipliers: < ≤2 At that time, the number of conductive fabric layers is increased (from the conventional 2 layers to 3-4 layers); 2 < ≤5 At the same time, increase the braiding density of conductive fibers (from the conventional 30% to 50%~60%). >5 When necessary, a metal mesh shielding layer should be added (and a conductive cloth layer should be added if necessary); when a single reinforcement measure is insufficient to meet the protection requirements, a combination of the above measures should be used for reinforcement.

[0054] (2) Determine the reinforcement range according to the area and distribution of the danger zone: When the area of ​​the danger zone does not exceed 5% of the surface area of ​​the envelope and is distributed in a point-like manner, only the danger zone is locally reinforced, and the reinforcement area is expanded by one grid node spacing, which is determined by the finite element meshing parameters; when the area of ​​the danger zone exceeds 5% or is distributed in a continuous area, the entire area is reinforced according to the corresponding level and expanded by one grid spacing; at the boundary between the warning zone and the danger zone, 1 to 2 adjacent grid nodes are reinforced according to the adjacent danger zone level.

[0055] Recommendations for standard shielding suit configurations are provided for the corresponding areas within the warning zone.

[0056] Calculate the minimum distance between the active envelope and the nearest charged / grounded body. d min That is, each grid node P on the envelope surface i To discrete points Q on the surface of the charged body (grounded body) j Minimum distance: d min =min‖P i Q j This spacing corresponds to the geometrically closest point pair between the envelope surface and the charged body. d min The safety regulations allow for the distance corresponding to the current operating voltage level. D Comparison; D Determined according to current safety regulations. d min < D If so, the following process will be used to provide suggestions for adjusting the work location: (1) Locating the nearest point pair: Determining the envelope node P i The corresponding human body part and working posture, that is, the sampling posture that causes the envelope to be closest to the charged body in that direction, is usually the posture of the arm or hand holding the tool extended forward to the limit in that direction. (2) Calculate the amount of adjustment required: based on Δ d = D d min + delta Calculate the amount of retraction required in this direction, where delta To add a safety margin, a value of 0.1~0.2 m can be used; (3) Provide adjustment suggestions: guide the operator to reduce the range of motion in this direction, such as retracting the arm extension, shortening the tool extension length, or adjusting the stance so that the envelope surface retracts as a whole in this direction; (4) Iterative verification: After adjusting the working posture, reconstruct the adjusted active envelope and calculate dmin until d min ≥ D ; (5) Shielding as a backup: If the requirements cannot be met by adjusting the posture due to the limitations of the task (such as having to operate in a position close to the live body), then provide suggestions for supplementary insulation shielding measures, such as installing an insulating baffle, insulating cover or insulating shielding tube between the envelope and the live body, and explain that after shielding, the insulation performance of the shielding material should be rechecked.

[0057] This invention is the first to propose a differentiated protection method and system for live-line work in substations based on an active envelope surface, extending traditional discrete point assessment to full-field strength analysis of continuous curved surfaces. It also proposes a differentiated protection zoning determination method based on quantitative distribution data of surface field strength, dividing the envelope surface into danger zones, warning zones, and safe zones, enabling refined design of shielding suits with "key areas receiving key protection." Furthermore, this invention constructs a unified electric field safety assessment and differentiated protection framework applicable to all operating conditions including ground potential, equipotentiality, and equipotential transitions, filling the gap in differentiated protection methods for all operating conditions of live-line work in substations.

[0058] The present invention will be described in detail below with reference to specific application scenarios.

[0059] Example 2 Scenario: A circuit breaker at a 110 kV substation is under maintenance. The worker is on the ground (at ground potential) and using an insulated operating rod to operate the circuit breaker. The work position is approximately 1.2 m away from the live busbar of phase A.

[0060] Step 1: Establish a 3D model of the 110 kV bay. Set the worker's position to ground potential, 1.2m away from the live busbar of phase A. The human model adopts a standard standing posture, with a height of 1.75m.

[0061] Step 2: Construct the operational envelope for ground potential operation. Consider the range of motion of the arms extending forward and upward to operate the insulating rod, with the torso as the center. Collect 200 sampling points in posture space to construct a three-dimensional operational envelope. The bounding box dimensions of the envelope are approximately 1.8 m × 1.0 m × 1.2 m.

[0062] Step 3: Finite element solution and field strength mapping. After solving, the field strength is mapped to the envelope surface. The results show that the field strength is highest at the top of the envelope surface, reaching 18~22 kV / m, 8~12 kV / m in the middle, and 3~5 kV / m at the bottom.

[0063] Step 4: Differentiated protection zone determination (in this embodiment) =15 kV / m =5~8 kV / m). The head / shoulder area is designated as a danger zone and requires local reinforcement of the shielding suit; the torso area is designated as a warning zone and should maintain standard protection; the leg area is designated as a safe zone.

[0064] Step 5: Protection Solution Output. A double-layer conductive fabric reinforcement layer is added to the head of the shielding suit, and the conductive fiber weave density in the shoulder area is increased to 50%; a shielding face shield is added to the face.

[0065] Example 3 Scenario: Heat treatment of the switch contacts on the busbar of a 220 kV substation. Workers use an insulated lifting platform to reach the equipotential level and inspect the switch contacts at busbar height.

[0066] Step 1: Establish a 3D model of the 220 kV bay. The workers are positioned on the insulated lifting platform, in an equipotential state.

[0067] Step 2: Construct the equipotential working envelope. The bounding box dimensions of the envelope are approximately 2.0 m × 1.2 m × 1.5 m.

[0068] Step 3: Finite element solution and field strength mapping. Under equipotential conditions, the field strength is highest at the fingertips (approximately 380 kV / m), 220-280 kV / m on the back of the hand, 120-180 kV / m on the forearm, and 60-90 kV / m on the torso.

[0069] Step 4: Differentiated protection zone determination (in this embodiment) 300 kV / m =100 kV / m). The fingertips are designated as the danger zone, the back of the hand / forearm as the warning zone, and the torso / legs as the safe zone.

[0070] Step 5: Protective Solution Output. Equip with a fully shielded face mask and helmet, shielded gloves to ensure reliable electrical connections, and add conductive fabric layers from the cuffs to the elbows.

[0071] Example 4: Scenario: For the entire process of workers gradually approaching the energized busbar from ground potential to equipotential in Example 3, a dynamic active envelope sequence is constructed for analysis.

[0072] Step 1: Discretize the equipotential path into 10 location points, starting from 1.5m away from the busbar and ending at the contact busbar.

[0073] Step 2: Construct an instantaneous activity envelope at each location point to form an envelope sequence.

[0074] Step 3: Calculate the field strength distribution at each instantaneous envelope surface and trace the spatiotemporal evolution trajectory of the field strength extrema. Analysis revealed that at a distance of approximately 0.4 m from the generatrix, the field strength at the head jumps from 120 kV / m to approximately 200 kV / m, and the field strength at the hand jumps from 250 kV / m to approximately 400 kV / m, an increase of over 60%.

[0075] Step 4: Differentiated protection recommendations for the output-to-output equipotential process: Near the potential transfer critical point, the operator should appropriately reduce the forward extension range of the arm to reduce the active envelope area, thereby reducing the peak field strength.

[0076] Example 5 This invention also proposes a differentiated protection system for live-line work in substations based on an active envelope surface, including a modeling module, an envelope surface construction module, an electric field solution module, an electric field strength mapping module, and a zone determination module. The modeling module is used to create a three-dimensional geometric model of the substation operation scenario and determine the target operation position and potential status of the operators. The envelope construction module is used to uniformly sample and obtain a set of human reachable spatial points in the three-dimensional posture space based on the target operation position and potential state, with the activity limit angles of each joint of the human body as constraints, and use the convex hull algorithm to construct a three-dimensional closed surface using the farthest reachable point in each direction of the sampled points, based on the human body center as the reference point, to generate a three-dimensional operation activity envelope surface. The electric field solution module is used to establish a three-dimensional simulation model of the substation including the operators based on the three-dimensional geometric model and the three-dimensional operation activity envelope surface, set the potential boundary conditions of each device, and use the finite element method to solve the spatial electric field distribution to obtain the full space potential and electric field intensity distribution. The field strength mapping module is used to interpolate and map the full-space electric field strength data to the grid nodes of the three-dimensional active envelope surface to obtain the surface electric field strength value of each node on the envelope surface. The partitioning determination module is used to divide the envelope into three different protection level regions: a danger zone, a warning zone, and a safe zone, based on the surface electric field strength values ​​of each node of the envelope and setting an upper limit threshold for safe field strength and a lower limit threshold for conventional protection field strength.

[0077] More preferably, the envelope surface construction module is further configured to: When the operator holds the work tool, the reachable point of the handhold is used as a reference. The reachable point set of the tool end is obtained by combining the length of the work tool and the sampling range of its orientation. This set is then incorporated into the reachable point set of the human body and used to construct the three-dimensional activity envelope.

[0078] Example 6 The present invention also proposes a terminal, including a processor and a storage medium: The storage medium is used to store instructions; The processor is used to perform the steps of the above method according to the instructions.

[0079] Example 7 The present invention also proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0080] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0081] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0082] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0083] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A differentiated protection method for live-line working in substations based on active envelope surfaces, characterized in that, include: Establish a three-dimensional geometric model of the substation operation scenario to determine the target operation location and potential status of the operators; Based on the target work position and potential state, and constrained by the limit angles of the human body's joints, a set of human reachable space points is obtained by uniformly sampling in the three-dimensional posture space. Using the human body center as the reference point, the farthest reachable points in each direction of the sampling point set are used to construct a three-dimensional closed surface using the convex hull algorithm, thereby generating a three-dimensional work activity envelope surface. Based on the three-dimensional geometric model and the three-dimensional operation activity envelope, a three-dimensional simulation model of the substation including the operators is established, the potential boundary conditions of each device are set, and the spatial electric field distribution is solved by the finite element method to obtain the full space potential and electric field intensity distribution. The full-space electric field intensity data is interpolated and mapped onto the mesh nodes of the three-dimensional operation activity envelope to obtain the surface electric field intensity value of each node on the envelope. Based on the surface electric field strength values ​​of each node of the envelope, a safety field strength upper limit threshold and a conventional protection field strength lower limit threshold are set, dividing the envelope into three different protection level regions: danger zone, warning zone, and safe zone.

2. The differentiated protection method for live-line working in substations based on active envelope surface according to claim 1, characterized in that: Determining the electrical potential status of the workers includes: When a worker is on the ground or a grounded structure and all parts of their body are at a safe distance from a live conductor, it is considered to be at ground potential; when a worker is in direct contact with a live conductor and their body potential is the same as the potential of the live conductor, it is considered to be at equipotential; when a worker is in a dynamic process of transitioning from ground potential to equipotential or vice versa, it is considered to be a process of entering or exiting equipotential.

3. The differentiated protection method for live-line working in substations based on active envelope surface according to claim 1, characterized in that: When constructing the three-dimensional activity envelope, if the operator is holding a tool, the reachable position of the handhold is used as a reference. The tool's length and orientation sampling range are combined to obtain the tool end reachable point set, which is then incorporated into the human reachable space point set to construct the three-dimensional activity envelope.

4. The differentiated protection method for live-line working in substations based on active envelope surface according to claim 3, characterized in that: When obtaining the set of reachable points at the end of the tool, the tool is simplified into a rigid rod of length L. Taking the reachable position of the human handhold as the reference, the orientation angle is uniformly sampled within the operable orientation range of the tool. The method for calculating the position point of the tool end is: multiply the tool length by the orientation unit vector, and add the product result to the handhold position to obtain the tool end position.

5. The differentiated protection method for live-line working in substations based on active envelope surface according to claim 1, characterized in that: When setting the upper limit threshold for safe field strength and the lower limit threshold for conventional protective field strength, different upper limit thresholds for safe field strength are set for different body parts.

6. The differentiated protection method for live-line working in substations based on active envelope surface according to claim 1, characterized in that: When determining differentiated protection zones based on the surface electric field intensity values ​​of each node of the envelope: If the electric field strength on the body surface is greater than the upper limit threshold of the safe field strength, it is determined to be a danger zone; if the electric field strength on the body surface is greater than the lower limit threshold of the conventional protection field strength but less than or equal to the upper limit threshold of the safe field strength, it is determined to be a warning zone. If the electric field strength on the body surface is less than or equal to the lower limit threshold of the conventional protective field strength, it is determined to be a safe zone.

7. The differentiated protection method for live-line working in substations based on active envelope surface according to claim 1, characterized in that: When outputting differentiated protection schemes based on the division of danger zones, warning zones, and safe zones, enhancement measures are determined according to the multiples of the external field strength of the danger zone relative to the upper limit threshold of the safe field strength: When the external field strength on the body surface is greater than the upper limit threshold of the safe field strength but less than or equal to twice the upper limit threshold of the safe field strength, the number of conductive cloth layers is increased. When the external field strength on the body surface is greater than twice the upper limit of the safe field strength but less than or equal to five times the upper limit of the safe field strength, the density of conductive fiber weaving should be increased; when the external field strength on the body surface is greater than five times the upper limit of the safe field strength, a metal mesh shielding layer should be added.

8. The differentiated protection method for live-line working in substations based on active envelope surface according to claim 7, characterized in that: When outputting differentiated protection schemes, the reinforcement range is determined based on the area and distribution of the hazardous zone: When the area of ​​the danger zone does not exceed 5% of the surface area of ​​the envelope and is distributed in a point-like manner, only the danger zone is locally reinforced and the reinforcement area is expanded by one grid node spacing. When the area of ​​the danger zone exceeds 5% or is distributed in a continuous area, the entire area is reinforced according to the corresponding level and expanded by one grid node spacing. One or two adjacent grid nodes at the boundary between the warning zone and the danger zone are gradually reinforced according to the level of the adjacent danger zone.

9. The differentiated protection method for live-line working in substations based on active envelope surface according to claim 1, characterized in that: When outputting differentiated protection schemes based on the division results of the danger zone, warning zone, and safety zone, the minimum distance between the three-dimensional active envelope surface and the nearest live or grounded body is calculated. This minimum distance is the minimum distance from each grid node on the envelope surface to each discrete point on the surface of the live or grounded body. This minimum distance is compared with the allowable distance of the safety regulations corresponding to the current working voltage level. If it does not meet the requirements, a working position adjustment suggestion is given.

10. The differentiated protection method for live-line working in substations based on active envelope surface according to claim 9, characterized in that: When giving suggestions for adjusting the work location: Locate the human body parts and working postures corresponding to the envelope nodes, calculate the required adjustment amount, and guide the workers to reduce the range of motion in that direction; after adjusting the working posture, reconstruct the active envelope and calculate the minimum spacing until the distance allowed by the safety regulations is met; if the requirements cannot be met by adjusting the posture due to the limitations of the work task, provide suggestions for supplementary insulation and shielding measures.

11. A substation live-line work differentiated protection system based on an active envelope surface, used to execute the substation live-line work differentiated protection method based on an active envelope surface as described in any one of claims 1-10, comprising a modeling module, an envelope surface construction module, an electric field solving module, an electric field strength mapping module, and a partitioning determination module, characterized in that: The modeling module is used to create a three-dimensional geometric model of the substation operation scenario and determine the target operation position and potential status of the operators. The envelope construction module is used to uniformly sample and obtain a set of human reachable spatial points in the three-dimensional posture space based on the target operation position and potential state, with the activity limit angles of each joint of the human body as constraints, and use the convex hull algorithm to construct a three-dimensional closed surface using the farthest reachable point in each direction of the sampled points, based on the human body center as the reference point, to generate a three-dimensional operation activity envelope surface. The electric field solution module is used to establish a three-dimensional simulation model of the substation including the operators based on the three-dimensional geometric model and the three-dimensional operation activity envelope surface, set the potential boundary conditions of each device, and use the finite element method to solve the spatial electric field distribution to obtain the full space potential and electric field intensity distribution. The field strength mapping module is used to interpolate and map the full-space electric field strength data to the grid nodes of the three-dimensional active envelope surface to obtain the surface electric field strength value of each node on the envelope surface. The partitioning determination module is used to divide the envelope into three different protection level regions: a danger zone, a warning zone, and a safe zone, based on the surface electric field strength values ​​of each node of the envelope and setting an upper limit threshold for safe field strength and a lower limit threshold for conventional protection field strength.

12. The substation live-line working differentiated protection system based on active envelope surface according to claim 11, characterized in that: The envelope surface construction module is also used for: When the operator holds the work tool, the reachable point of the handhold is used as a reference. The reachable point set of the tool end is obtained by combining the length of the work tool and the sampling range of its orientation. This set is then incorporated into the reachable point set of the human body and used to construct the three-dimensional activity envelope.

13. A terminal, comprising a processor and a storage medium; characterized in that: The storage medium is used to store instructions; The processor is configured to operate according to the instructions to perform the steps of the method according to any one of claims 1 to 10.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method according to any one of claims 1 to 10.

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