Method for monitoring insulation of a high-voltage power supply system and high-voltage power supply device

Abstract

This application provides an insulation monitoring method and equipment for a high-voltage power supply system, relating to the field of power system insulation monitoring technology. The high-voltage power supply system is equipped with a two-level isolation architecture, including a primary isolation architecture between the high-voltage circuit and a floating ground reference point, and a secondary isolation architecture between the floating ground reference point and the protective ground. The method includes: performing insulation monitoring between the high-voltage circuit and the floating ground reference point to obtain a first-level monitoring result; performing insulation monitoring between the floating ground reference point and the protective ground to obtain a second-level monitoring result; and generating corresponding insulation anomaly alarm information based on the first-level and second-level monitoring results. This application achieves automatic dynamic insulation monitoring of the high-voltage power supply system while miniaturizing and reducing the cost of the insulation monitoring equipment. It can not only detect insulation anomalies in a timely manner, but also more accurately determine the location of insulation anomalies through tiered monitoring, thereby improving fault handling efficiency and ensuring the safe and stable operation of the system.

Description

Technical Field

[0001] This application relates to the field of power system insulation monitoring technology, and in particular to an insulation monitoring method and high-voltage power supply equipment for a high-voltage power supply system. Background Technology

[0002] The subway traction power supply system is a high-voltage power supply system, and insulation performance is the safety guarantee of such a system. In a high-voltage power supply system, the electrical isolation (i.e., insulation performance) between different circuits and between a circuit and the grounding terminal (protective earthing, PE) must meet two key requirements: power frequency withstand voltage and impulse withstand voltage. This is to prevent high-voltage circuits from experiencing insulation failure due to prolonged exposure to operating voltage or instantaneous high-voltage surges, which could lead to leakage, short circuits, and other safety problems. To ensure the safe operation of the power supply system, insulation monitoring equipment is needed to monitor the system's insulation performance, allowing for timely implementation of appropriate measures in the event of insulation failure.

[0003] Currently, the grounding terminal of the primary circuit (i.e., the high-voltage circuit) of existing high-voltage power supply systems is directly connected to the protective earth (PE). To ensure that the high-voltage circuit meets the highest safety regulations for grounding, it needs to be designed with the highest insulation standards, using high-voltage compatible insulation materials and large-sized withstand voltage components. This leads to an increase in the size and weight of the power supply system equipment and a rise in cost. Furthermore, because the grounding terminal of the primary circuit (i.e., the high-voltage circuit) of the power supply system is directly connected to the protective earth (PE), and the safety regulations for grounding need to meet the highest safety standards, insulation monitoring equipment needs to directly monitor the voltage, current, and other related parameters between the high-voltage circuit and the protective earth (PE). Therefore, the withstand voltage requirements of the corresponding insulation monitoring equipment also need to meet the highest safety standards. This necessitates the use of high-voltage compatible large-sized withstand voltage components and insulation materials for the insulation monitoring equipment, significantly increasing its size and design cost. It also increases the difficulty of monitoring insulation anomalies in high-voltage power supply systems, and reduces accuracy and fault handling efficiency. Summary of the Invention

[0004] This application provides an insulation monitoring method and a high-voltage power supply device for a high-voltage power supply system, in order to solve the problems of large size, high design cost, increased difficulty, reduced accuracy and fault handling efficiency of insulation monitoring devices in the prior art.

[0005] In a first aspect, embodiments of this application provide an insulation monitoring method for a high-voltage power supply system. The high-voltage power supply system is equipped with a two-level isolation architecture, comprising a primary isolation architecture formed between the high-voltage circuit and a floating ground reference point, and a secondary isolation architecture formed between the floating ground reference point and the protective ground. The method includes: Insulation monitoring is performed between the high-voltage circuit and the floating ground reference point to obtain the first-level monitoring results; Insulation monitoring is performed between the floating ground reference point and the protective ground to obtain the second-level monitoring results; Based on the results of the first-level monitoring and the second-level monitoring, corresponding insulation abnormality alarm information is generated.

[0006] In one possible implementation, the withstand voltage standard value between the high-voltage circuit and the floating ground reference point is greater than or equal to the withstand voltage standard value between the floating ground reference point and the protective ground.

[0007] In one possible implementation, the insulation monitoring between the high-voltage circuit and the floating ground reference point to obtain a first-level monitoring result includes: The first DC voltage and / or the first AC voltage between the high-voltage circuit and the floating ground reference point are collected, and the first DC voltage and / or the first AC voltage are used as the first-level monitoring result.

[0008] In one possible implementation, the insulation monitoring between the floating ground reference point and the protective ground to obtain the second-level monitoring results includes: The second DC voltage or the second AC voltage between the floating ground reference point and the protected ground is collected, and the second DC voltage or the second AC voltage is used as the second-level monitoring result.

[0009] In one possible implementation, the step of performing insulation monitoring between the floating ground reference point and the protective ground to obtain a second-level monitoring result further includes: The leakage current between the floating ground reference point and the protective ground is collected, and the DC and AC quantities of the leakage current are used as the second-level monitoring results.

[0010] In one possible implementation, the first-level monitoring results include a first DC voltage and / or a first AC voltage between the high-voltage circuit and the floating ground reference point; the second-level monitoring results include a second DC voltage or a second AC voltage between the floating ground reference point and the protective ground, as well as the DC and AC quantities of leakage current. The step of generating corresponding insulation abnormality alarm information based on the first-level monitoring results and the second-level monitoring results includes: When the first DC voltage is greater than a preset first voltage value and / or the first AC voltage is greater than a preset second voltage value, a first alarm message is generated; the first alarm message is used to indicate an abnormality in the floating ground insulation. When the second DC voltage is greater than a preset third voltage value or the second AC voltage is greater than a preset fourth voltage value, a second alarm message is generated; the second alarm message is used to indicate an abnormality in the protective ground insulation. When the DC leakage current is greater than a preset first current value or the AC leakage current is greater than a preset second current value, a third alarm message is generated; the third alarm message is used to indicate an abnormal leakage current to the protective ground.

[0011] In one possible implementation, the method further includes: When at least one of the second alarm message and the third alarm message is generated simultaneously with the first alarm message, the high-voltage power supply system is controlled to enter standby mode.

[0012] Secondly, embodiments of this application provide a high-voltage power supply device, including: a high-voltage circuit, multiple power control modules, a system control module, and a monitoring module; The high-voltage circuit is connected to the plurality of power control modules and the system control module; The plurality of power control modules and the system control module are connected in communication. The grounding terminals of the plurality of power control modules and the system control module are all connected to a floating ground reference point; The monitoring module is communicatively connected to the power control module and the system control module, and the metal casing of the monitoring module is connected to the protective ground. The monitoring module is used to implement the insulation monitoring method for the high-voltage power supply system described in any of the first aspects above.

[0013] In one possible implementation, the grounding terminals of the plurality of power control modules and the system control module are all connected to the same floating ground reference point.

[0014] In one possible implementation, the floating ground reference point and the protective ground are mutually insulated, and the safety distance is greater than or equal to a preset threshold.

[0015] In this embodiment, by setting up a two-level isolation architecture of high-voltage circuit-floating ground reference point and floating ground reference point-protected earth (PE) in the high-voltage power supply system, the original high withstand voltage standard (such as the highest safety standard requiring an impulse withstand voltage of 18kV) link of the high-voltage circuit to the protective earth is split into two links with lower withstand voltage standards (such as each segment with a maximum impulse withstand voltage of 12kV). This not only ensures that the actual total withstand voltage standard of the high-voltage circuit to ground still meets the requirements of the highest safety standard, but also that the high-voltage circuit-floating ground reference point and floating ground reference point-protected earth segments only need to be adapted to the lower withstand voltage standard. Furthermore, the insulation monitoring equipment only needs to be adapted to the lower withstand voltage standard and does not need to be adapted to the highest safety standard. Therefore, it can significantly reduce the amount of insulation material used in high-voltage power supply equipment and monitoring equipment, reduce the specifications of withstand voltage components, and realize the miniaturization and low cost of power supply equipment and monitoring equipment. Furthermore, by utilizing a two-level isolation architecture to perform graded insulation status monitoring on the high-voltage circuit-floating ground reference point and the floating ground reference point-protected earth (PE) architectures respectively, and generating corresponding insulation anomaly alarm information based on the first-level and second-level monitoring results, automatic dynamic insulation monitoring of the high-voltage power supply system is realized. This eliminates the need for regular inspections by technicians, not only enabling timely detection of insulation anomalies, but also allowing for more accurate determination of the location of insulation anomalies through graded monitoring, thereby improving fault handling efficiency and ensuring the safe and stable operation of the system.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this specification. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a two-level isolation architecture of a high-voltage power supply system provided in an embodiment of this application; Figure 2 This is a schematic flowchart of an insulation monitoring method for a high-voltage power supply system provided in an embodiment of this application; Figure 3 This is a flowchart illustrating an insulation monitoring method for a high-voltage power supply system provided in another embodiment of this application; Figure 4 This is a schematic diagram of the structure of a high-voltage power supply device provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a high-voltage power supply device provided in another embodiment of this application; Figure 6 This is a schematic diagram of the structure of a monitoring device provided in one embodiment of this application. Detailed Implementation

[0019] The present application will be described more clearly below with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the function of the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application. These all fall within the protection scope of the present application.

[0020] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0021] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0022] In the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0024] Furthermore, the term "multiple" mentioned in the embodiments of this application should be interpreted as two or more.

[0025] The subway traction power supply system is a high-voltage power supply system, and insulation performance is the safety guarantee of such a system. In a high-voltage power supply system, the electrical isolation capability (i.e., insulation performance) between different circuits and between a circuit and the grounding terminal (protective earth, PE) must meet two key requirements: power frequency withstand voltage and impulse withstand voltage. This is to prevent high-voltage circuits from experiencing insulation failure due to long-term exposure to operating voltage or instantaneous high-voltage impulses, which could lead to leakage, short circuits, and other safety problems. Power frequency withstand voltage indicates the circuit's insulation capability under long-term AC operating voltage, while impulse withstand voltage indicates the circuit's insulation capability against instantaneous high voltages such as lightning strikes and switching overvoltages. To ensure the safe operation of the power supply system, insulation monitoring equipment is needed to monitor the system's insulation performance, allowing for timely measures to be taken in the event of insulation failure.

[0026] Currently, the grounding terminal of the primary circuit (i.e., the high-voltage circuit) of existing high-voltage power supply systems is directly connected to the protective earth (PE). To ensure that the high-voltage circuit meets the highest safety standards for grounding, it needs to be designed with the highest insulation standards, using high-voltage compatible insulation materials and large-sized withstand voltage components. This leads to an increase in the size and weight of the power supply system equipment and a rise in cost. Furthermore, because the primary circuit (i.e., the high-voltage circuit) of the power supply system is directly connected to the protective earth (PE), and the safety requirements for grounding need to meet the highest safety standards, insulation monitoring equipment needs to directly monitor the voltage, current, and other related parameters between the high-voltage circuit and the protective earth (PE). Therefore, the withstand voltage requirements of the corresponding insulation monitoring equipment also need to meet the highest safety standards. This necessitates the use of high-voltage compatible large-sized withstand voltage components and insulation materials for the insulation monitoring equipment, significantly increasing its size and design cost. It also increases the difficulty of monitoring insulation anomalies in the high-voltage power supply system, and reduces accuracy and fault handling efficiency.

[0027] To address the aforementioned technical issues, this application proposes a two-stage isolation architecture for high-voltage power supply systems, allowing insulation monitoring equipment to withstand only the lower withstand voltage requirements after grading, and enabling two-stage monitoring of the insulation status of the high-voltage power supply system. In other words, a floating ground reference point (an intermediate reference point that is not directly grounded) is introduced between the high-voltage circuit and the protective earth (PE), forming a two-stage isolation architecture: high-voltage circuit → primary isolation → floating ground → secondary isolation → PE. The primary isolation is responsible for the insulation between the high-voltage circuit and the floating ground, while the secondary isolation is responsible for the insulation between the floating ground and the protective earth (PE). This breaks down the highest withstand voltage standard of the high-voltage circuit to ground (e.g., 5.6kV power frequency withstand voltage and 18kV impulse withstand voltage), so that the withstand voltage standard required for each isolation stage is lower than the highest withstand voltage standard. For example, each isolation stage meets the standard of 5.6kV power frequency withstand voltage and 12kV impulse withstand voltage, but the total withstand voltage of the high-voltage circuit to ground still meets the highest withstand voltage standard. Thus, the insulation monitoring equipment does not need to directly withstand the full withstand voltage of the high-voltage circuit to the protective earth, but only needs to meet the lower withstand voltage requirements after the classification, thereby reducing the size and design cost of the entire high-voltage power supply system and insulation monitoring equipment. Furthermore, based on this two-level isolation architecture, the insulation voltage between the high-voltage circuit and the floating ground, and the insulation voltage / leakage current between the floating ground and the protective ground are monitored respectively. Alarm information corresponding to each level is generated according to the hierarchical monitoring results, realizing dynamic hierarchical monitoring of insulation status. This not only enables timely detection of insulation anomalies, but also allows for more accurate determination of the location of insulation anomalies, thereby improving fault handling efficiency and ensuring the safe and stable operation of the system.

[0028] The insulation monitoring method for the high-voltage power supply system provided in this application is described below with reference to the accompanying drawings.

[0029] Figure 1 This is a schematic diagram of a two-level isolation architecture for a high-voltage power supply system provided in an embodiment of this application.

[0030] It should be noted that in traditional high-voltage power supply systems, the high-voltage circuit is typically connected to the protective earth (PE). Figure 1 As shown by the red dashed line in the diagram), high-voltage circuits (high voltage, such as DC voltage 1500VDC, AC voltage 900VAC) typically require the protective earth (PE) to meet the highest safety standards (such as 5.6kV / 18kV).

[0031] The high-voltage power supply system provided in this embodiment introduces a floating ground reference point between the high-voltage circuit and the protective ground. This floating ground reference point is an intermediate reference point that is not directly grounded; for example... Figure 1 As shown, the grounding terminal of the high-voltage circuit is connected to the floating ground reference point, which is connected to the protective earth (PE). A primary isolation is formed between the high-voltage circuit and the floating ground reference point, and a secondary isolation is formed between the floating ground reference point and the protective earth (PE). Figure 1(As shown by the blue dashed line in the diagram), the first-level isolation handles the insulation between the high-voltage circuit and the floating ground reference point, and the second-level isolation handles the insulation between the floating ground reference point and the protective earth (PE). This means that each level of isolation architecture only needs to handle a portion of the withstand voltage and does not need to meet the highest safety standards. For example, the withstand voltage between the high-voltage circuit and the floating ground reference point, as well as between the floating ground reference point and the protective earth (PE), only needs to meet the 5.6kV / 12kV withstand voltage standard.

[0032] It should be noted that this embodiment only schematically illustrates the two-level isolation architecture between the high-voltage circuit and the floating ground reference point, and between the floating ground reference point and the protective ground of the high-voltage power supply system. In actual scenarios, the high-voltage power supply system also includes circuit modules such as system control circuit, low-voltage circuit, and communication circuit. Their specific connection methods and working principles will not be described in detail.

[0033] Figure 2 This is a flowchart illustrating an insulation monitoring method for a high-voltage power supply system according to an embodiment of this application. The implementation of the insulation monitoring method provided in this embodiment depends on... Figure 1 The high-voltage power supply system shown has a two-level isolation architecture.

[0034] like Figure 2 As shown, the insulation monitoring method in this application embodiment may include the following steps: Step S201: Insulation monitoring is performed between the high-voltage circuit and the floating ground reference point to obtain the first-level monitoring results.

[0035] Step S202: Insulation monitoring is performed between the floating ground reference point and the protective ground to obtain the second-level monitoring results.

[0036] In steps S201 and S202, a floating ground reference point is introduced between the high-voltage circuit and the protective ground PE, thereby forming a situation as follows: Figure 1 As shown, the high-voltage circuit → primary isolation → floating ground → secondary isolation → PE is a two-level isolation architecture. Therefore, when monitoring the insulation status of the entire high-voltage power supply system, the primary isolation architecture of "high-voltage circuit → primary isolation → floating ground" and the secondary isolation architecture of "floating ground → secondary isolation → PE" can be monitored separately (i.e., graded insulation status monitoring) to obtain the monitoring results corresponding to each level of the architecture.

[0037] Step S203: Based on the results of the first-level monitoring and the second-level monitoring, generate corresponding insulation abnormality alarm information.

[0038] In this step, corresponding insulation alarm information is generated for each level of isolation architecture based on the monitoring results. For example, for the first level monitoring results of the first level isolation architecture of "high voltage circuit → primary isolation → floating ground", corresponding primary alarm information is generated to indicate the insulation abnormality between the high voltage circuit and the floating ground; for the second level monitoring results of the second level isolation architecture of "floating ground → secondary isolation → PE", corresponding secondary alarm information is generated to indicate the insulation abnormality between the floating ground and the protective ground PE.

[0039] In this embodiment, by setting up a two-level isolation architecture of high-voltage circuit-floating ground reference point and floating ground reference point-protected earth (PE) in the high-voltage power supply system, the original high withstand voltage standard (such as the highest safety standard requiring an impulse withstand voltage of 18kV) link of the high-voltage circuit to the protective earth is split into two links with lower withstand voltage standards (such as each segment with a maximum impulse withstand voltage of 12kV). This not only ensures that the actual total withstand voltage standard of the high-voltage circuit to ground still meets the requirements of the highest safety standard, but also that the high-voltage circuit-floating ground reference point and floating ground reference point-protected earth segments only need to be adapted to the lower withstand voltage standard. Furthermore, the insulation monitoring equipment only needs to be adapted to the lower withstand voltage standard and does not need to be adapted to the highest safety standard. Therefore, it can significantly reduce the amount of insulation material used in high-voltage power supply equipment and monitoring equipment, reduce the specifications of withstand voltage components, and realize the miniaturization and low cost of power supply equipment and monitoring equipment. Furthermore, by utilizing a two-level isolation architecture to perform graded insulation status monitoring of the high-voltage circuit-floating reference point and the floating reference point-protected ground (PE), and generating corresponding insulation anomaly alarm information based on the graded monitoring results, automatic dynamic insulation monitoring of the high-voltage power supply system is realized. This eliminates the need for regular inspections by technicians, enabling timely detection of insulation anomalies. Graded monitoring also allows for more accurate determination of the location of insulation anomalies, thereby improving fault handling efficiency and ensuring the safe and stable operation of the system.

[0040] In one possible implementation, the withstand voltage standard value between the high-voltage circuit and the floating ground reference point is greater than or equal to the withstand voltage standard value between the floating ground reference point and the protective ground.

[0041] In this embodiment, the two-level isolation architecture is to segment and split the high withstand voltage of the entire link from the high-voltage circuit to the protective ground. The withstand voltage standards of the two-level architecture can be the same. For example, the original highest withstand voltage standard of the high-voltage circuit to the protective ground is an impulse withstand voltage of 18kV. By adding a floating ground reference point, the withstand voltage standard of the first-level isolation architecture of "high-voltage circuit-floating ground reference point" and the impulse withstand voltage standard of the second-level isolation architecture of "floating ground reference point-protected ground" are both reduced to 12kV, or both are reduced to 9kV, etc., as long as the total withstand voltage of the two-level isolation architecture is greater than or equal to the highest withstand voltage standard (impulse withstand voltage of 18kV).

[0042] In this embodiment, the withstand voltage standard of the primary isolation architecture (between the high-voltage circuit and the floating ground) can also be higher than that of the secondary isolation architecture (between the floating ground and the protective ground). This results in a gradually decreasing gradient characteristic in the distribution of withstand voltage standards along the "high-voltage circuit - floating ground reference point - protective ground" link. However, it is necessary to ensure that the total withstand voltage standard of the primary and secondary architectures is greater than or equal to the maximum withstand voltage requirement of the high-voltage circuit to the protective ground. For example, if the maximum withstand voltage standard of the high-voltage circuit to the protective ground is an impulse withstand voltage of 18kV, the withstand voltage standard of the primary isolation architecture is set to an impulse withstand voltage of 12kV, and the impulse withstand voltage standard of the secondary isolation architecture is 10kV, etc.

[0043] It should be noted that the specific value of the withstand voltage standard of the two-level isolation architecture needs to be determined according to the actual needs of the scenario. The withstand voltage value in this embodiment is only an example and does not constitute a limitation on this application.

[0044] In this embodiment, since the primary isolation architecture directly connects to the high-voltage circuit, it is the core architecture with the highest high-voltage stress and withstands power frequency / impulse voltage in the entire link. The secondary isolation architecture only connects to the floating ground and has no direct high-voltage input, so its voltage stress is lower than that of the primary isolation architecture. Therefore, the withstand voltage standard of the primary isolation architecture is set to be greater than or equal to that of the secondary isolation architecture. This ensures that the system's withstand voltage capability is precisely matched with the actual voltage stress, which not only ensures the withstand voltage capability of the primary isolation architecture and reduces the breakdown probability of the core high-voltage section, but also reduces the design redundancy of the secondary architecture. This allows the secondary isolation architecture to be designed with a lower withstand voltage standard for lightweighting, such as appropriately reducing the electrical clearance between the floating ground reference point and the protective ground, and using a thinner insulation layer between the floating ground reference point and the protective ground, thereby reducing equipment size and insulation material costs. Furthermore, this design improves the flexibility and adaptability of the high-voltage power supply system architecture. If the actual scenario requires an increase in the overall withstand voltage standard, only the withstand voltage standard of the primary isolation architecture needs to be increased. The secondary isolation architecture can maintain its original withstand voltage standard or be slightly increased, without the need for a complete redesign, thus improving versatility and scalability.

[0045] Figure 3 This is a flowchart illustrating an insulation monitoring method for a high-voltage power supply system provided in another embodiment of this application.

[0046] In one possible embodiment, such as Figure 3 As shown, the step of performing graded insulation status monitoring on the two-level isolation architecture to obtain graded monitoring results includes the following steps: Step S301: Insulation monitoring is performed between the high-voltage circuit and the floating ground reference point to obtain the first-level monitoring results.

[0047] It should be noted that the high-voltage power supply system in this embodiment may be, but is not limited to, a subway traction power supply system. This embodiment uses a subway traction power supply system as an example for illustration. Typically, a subway traction power supply system includes circuits with multiple voltage levels and multiple power supplies. For example, a subway traction power supply system includes: a traction circuit: used to provide high-voltage power to the subway; a high-voltage circuit (i.e., the primary circuit, including high-voltage DC circuits and high-voltage AC circuits): connecting the traction circuit and the low-voltage auxiliary circuit, used for high-voltage conversion, control power supply, etc.; and low-voltage auxiliary circuits (AC power supply, DC power supply, system control circuits, etc.): used to provide low-voltage power to system equipment and control power supply logic, etc.

[0048] In this step, the high-voltage circuit (primary side circuit) includes both high-voltage DC circuit and high-voltage AC circuit. Both the high-voltage DC circuit and the high-voltage AC circuit need to be monitored for insulation at the floating ground reference point to ensure the overall insulation safety of the system.

[0049] In one possible embodiment, the insulation monitoring between the high-voltage circuit and the floating ground reference point to obtain the first-level monitoring result includes: collecting a first DC voltage and / or a first AC voltage between the high-voltage circuit and the floating ground reference point, and using the first DC voltage and / or the first AC voltage as the first-level monitoring result.

[0050] In this embodiment, the first DC voltage is the DC voltage difference between the high-voltage DC circuit and the floating ground reference point in the high-voltage circuit, and the first AC voltage is the AC voltage difference between the high-voltage AC circuit and the floating ground reference point in the high-voltage circuit. Since the high-voltage circuit (both the high-voltage DC circuit and the high-voltage AC circuit) and the floating ground reference point need to meet insulation requirements, the voltage difference between the high-voltage circuit and the floating ground reference point should be very small (ideally close to 0V). Therefore, the first DC voltage and / or first AC voltage collected between the high-voltage circuit and the floating ground reference point are used as the first-level monitoring result. Based on this first-level monitoring result, it is possible to quickly and accurately determine whether there is a risk of insulation failure between the high-voltage circuit and the floating ground reference point (for example, if the first DC voltage and / or first AC voltage are too high, it indicates a risk of insulation failure).

[0051] In this embodiment, the floating ground is an intermediate reference point that is not directly grounded. By monitoring the insulation status of "high voltage circuit (primary side) → floating ground", the insulation monitoring equipment does not need to withstand the full withstand voltage (e.g., 5.6kV / 18kV) of "high voltage circuit (primary side) → PE", but only needs to be adapted to the graded withstand voltage (e.g., 5.6kV / 12kV) of "high voltage circuit (primary side) → floating ground", thus realizing the miniaturization and low cost of the insulation monitoring equipment.

[0052] In some possible embodiments, both the first DC voltage and the first AC voltage can be acquired by corresponding voltage sampling circuits. The specific acquisition process will not be described in detail in this embodiment.

[0053] Step S302: Insulation monitoring is performed between the floating ground reference point and the protective ground to obtain the second-level monitoring results.

[0054] In one possible implementation, the insulation monitoring between the floating ground reference point and the protective ground to obtain the second-level monitoring result includes: collecting a second DC voltage or a second AC voltage between the floating ground reference point and the protective ground, and using the second DC voltage or the second AC voltage as the second-level monitoring result.

[0055] In this embodiment, during the operation of the high-voltage power supply system, an induced voltage may be generated on the floating ground reference point. The induced voltage between the floating ground and the protective earth (PE) may be direct current or alternating current. Therefore, in order to determine whether the insulation between the floating ground and the protective earth (PE) is safe, the second direct current voltage or the second alternating current voltage between the floating ground reference point and the protective earth (PE) can be used as the second-level monitoring result. Regardless of whether the voltage induced between the floating ground and the protective earth (PE) is direct current or alternating current, as long as it exceeds a certain safety threshold, the insulation between the floating ground and the protective earth (PE) can be determined to be faulty.

[0056] In one possible implementation, the insulation monitoring between the floating ground reference point and the protective ground to obtain the second-level monitoring result further includes: collecting the leakage current between the floating ground reference point and the protective ground, and using the DC and AC quantities of the leakage current as the second-level monitoring result.

[0057] It should be noted that when there is leakage current between the floating ground and the protective earth (PE), it indicates that there may be a risk of leakage at the equipment grounding terminal. Therefore, when monitoring the insulation of the system equipment, it is necessary to monitor the leakage current (DC and AC) between the floating ground and the protective earth (PE). The DC and AC values ​​of the leakage current should also be used as the second-level monitoring results. When the DC or AC value of the leakage current is too high, it also indicates that the insulation of the system equipment has failed.

[0058] In this embodiment, by monitoring the insulation voltage and leakage current between the secondary isolation architecture (floating ground → PE), insulation anomalies can be quickly detected and the location of insulation anomalies can be accurately located (such as insulation failure between intermediate nodes and grounding terminals, and leakage risk at the grounding terminal). Furthermore, the insulation monitoring equipment only needs to be adapted to the low withstand voltage requirements between "floating ground → PE", which further enables the insulation monitoring equipment to be miniaturized and easy to deploy.

[0059] In one possible implementation, such as Figure 3As shown, the first-level monitoring results include the first DC voltage and / or the first AC voltage between the high-voltage circuit and the floating ground reference point; the second-level monitoring results include the second DC voltage or the second AC voltage between the floating ground reference point and the protective ground, as well as the DC and AC leakage current; the step of generating corresponding insulation abnormality alarm information based on the graded monitoring results includes the following steps: Step S303: When the first DC voltage is greater than a preset first voltage value and / or the first AC voltage is greater than a preset second voltage value, a first alarm message is generated; the first alarm message is used to indicate an abnormality in the floating ground insulation.

[0060] In this step, the values ​​of the preset first voltage value and the preset second voltage value are determined according to the actual situation. For example, the preset first voltage value can be 1Vdc and the preset second voltage value can be 10Vac. That is, when the first DC voltage is greater than 1Vdc and / or the first AC voltage is greater than 10Vac, it indicates that the floating ground insulation is abnormal, that is, the insulation between the high voltage circuit and the floating ground reference point has failed.

[0061] Step S304: When the second DC voltage is greater than the preset third voltage value or the second AC voltage is greater than the preset fourth voltage value, a second alarm message is generated; the second alarm message is used to indicate an abnormality in the protective ground insulation.

[0062] Step S305: When the DC leakage current is greater than the preset first current value or the AC leakage current is greater than the preset second current value, a third alarm message is generated; the third alarm message is used to indicate that the leakage current to the protective ground is abnormal.

[0063] It should be noted that the preset first current value and the preset second current value are determined according to the actual situation. For example, the preset first current value can be 3mA and the preset second current value can be 10mA.

[0064] It should be noted that the preset third voltage value can be equal to the preset first voltage value (for example, both are 1Vdc) or unequal to it (for example, the preset first voltage value can be 1Vdc and the preset third voltage value can be 0.8Vdc). Similarly, the preset fourth voltage value can be equal to the preset second voltage value (for example, both are 10Vac) or unequal to it (for example, the preset second voltage value is 10Vac and the preset fourth voltage value is 8Vac). The specific value is determined according to the actual needs, and this embodiment does not limit it.

[0065] Steps S304 and S305 primarily monitor the insulation status between the floating ground and the protective earth (PE), comprising two parts: The first part is monitoring the insulation voltage: In step S304, when the second DC voltage exceeds a preset third voltage value (e.g., 1Vdc) or the second AC voltage exceeds a preset fourth voltage value (e.g., 10Vac), a PE insulation abnormality alarm is triggered, indicating that the insulation between the intermediate node and the grounding terminal of the system equipment has failed. The second part is monitoring the leakage current: In step S305, the leakage current includes DC current and AC current. When the DC current exceeds a preset first current value (e.g., 3mA) or the AC current exceeds a preset second current value (e.g., 10mA), a PE leakage current abnormality alarm is triggered, indicating that there is a risk of leakage in the PE.

[0066] In this embodiment, by comparing the first-level monitoring results and the second-level monitoring results with the corresponding voltage / current thresholds, the insulation abnormality location in the two-level isolation architecture can be quickly detected, realizing dynamic real-time monitoring of system equipment and improving the efficiency and accuracy of insulation monitoring.

[0067] In one possible implementation, such as Figure 3 As shown, the insulation monitoring method for a high-voltage power supply system provided in this embodiment further includes step S306: when at least one of the second alarm information and the third alarm information is generated simultaneously with the first alarm information, the high-voltage power supply system is controlled to enter a standby state.

[0068] In this step, a tiered response strategy is set based on the alarm information from the two-level monitoring. When the first alarm information is generated based on the first-level monitoring result, a level one alarm is triggered; when the second and / or third alarm information is generated based on the second-level monitoring result, a level two alarm is triggered. If only a level one alarm (floating ground insulation abnormality) or only a level two alarm (PE insulation abnormality / leakage current abnormality) is triggered, it indicates that the entire system equipment has a minor local insulation defect. Relevant personnel are reminded to conduct an inspection, and the system continues to operate normally to avoid system shutdown affecting subway operations. If both level one and level two alarms are triggered simultaneously, it indicates that the system has a serious risk of insulation failure. It is necessary to immediately shut down the high-voltage power supply system (such as the subway traction power supply system), stop supplying power to it, and put it into standby mode to avoid safety accidents.

[0069] In this embodiment, the floating ground reference point serves as the core node for two-level isolation. It decomposes the high withstand voltage requirement of the original high-voltage circuit → PE into two segments ("high-voltage circuit (primary side) → floating ground" and "floating ground → PE"). Each segment only needs to withstand the lower withstand voltage after the classification, thus requiring the insulation monitoring equipment to meet only the lower withstand voltage requirements after classification. This reduces the specifications of the equipment's withstand voltage components, achieving miniaturization and low cost of the insulation monitoring equipment, facilitating deployment and installation. Furthermore, based on the two-level isolation architecture, graded insulation status monitoring is performed, and corresponding alarm information is generated according to the monitoring results. This enables real-time dynamic monitoring of the high-voltage power supply system. Compared to manual periodic monitoring, this graded monitoring method can capture insulation anomalies in real time, not only promptly detecting insulation faults but also more accurately determining the location of insulation anomalies, facilitating rapid maintenance by relevant personnel, improving monitoring accuracy and fault handling efficiency, and enhancing the overall reliability and safety of the system.

[0070] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0071] Figure 4 This is a schematic diagram of the structure of a high-voltage power supply device provided in an embodiment of this application.

[0072] like Figure 4 As shown, the high-voltage power supply equipment provided in this embodiment includes: a high-voltage circuit, multiple power control modules, a system control module, and a monitoring module; the high-voltage circuit is connected to the multiple power control modules and the system control module; the multiple power control modules and the system control module are communicatively connected; the grounding terminals of the multiple power control modules and the system control module are all connected to a floating ground reference point; the monitoring module is communicatively connected to the power control modules and the system control module, and the metal casing of the monitoring module is connected to a protective ground; the monitoring module is used to execute an insulation monitoring method for the high-voltage power supply system.

[0073] It should be noted that the high-voltage power supply system in this embodiment may be, but is not limited to, a subway traction power supply system. This embodiment uses a subway traction power supply system as an example for illustration. Typically, a subway traction power supply system includes circuits with multiple voltage levels and multiple power supplies. For example, a subway traction power supply system includes: a traction circuit: used to provide high-voltage power to the subway; a high-voltage circuit (i.e., the primary circuit, including high-voltage DC circuits and high-voltage AC circuits): connecting the traction circuit and the low-voltage auxiliary circuit, used for high-voltage conversion, control power supply, etc.; and low-voltage auxiliary circuits (AC power supply, DC power supply, system control circuits, etc.): used to provide low-voltage power to system equipment and control power supply logic, etc.

[0074] It is understood that this embodiment mainly uses the high-voltage circuit, power control module, system control module and monitoring module as examples to illustrate the two-level isolation architecture of the system, and the connection methods and working principles of other circuits / modules will not be described in detail.

[0075] In this embodiment, the high-voltage circuit (high-voltage power) is connected to the power control module and the system control module. The power control module is mainly used for high-voltage side power conversion, converting the high voltage output from the high-voltage circuit into a voltage / current suitable for the system requirements. It also adjusts the output power in real time according to the system's operating status to ensure stable system operation. The power control module and the system control module are connected via a Controller Area Network (CAN) bus. The system control module is mainly used for signal processing, logic judgment, and command issuance, and transmits information with the power control module via the CAN bus. The monitoring module communicates with the power control module and the system control module via the CAN bus to monitor the system status in real time.

[0076] It should be noted that since the monitoring module is a part that can be touched by people, it needs to be insulated from the high-voltage circuit inside the equipment. That is, the high-voltage circuit needs to meet the highest safety requirements for the protective ground PE to ensure insulation safety.

[0077] In this embodiment, as Figure 4 As shown, a floating ground reference point (such as...) is added between the grounding terminal of each control module and the metal casing of the monitoring module. Figure 4 (The blue dashed box in the image) Since both the power control module and the system control module are connected to the high-voltage circuit, their grounding terminals (GND) are connected to the floating ground reference point, forming a primary isolation architecture. The metal casing of the monitoring module is connected to the protective ground, forming a secondary isolation architecture. This creates a two-stage isolation architecture: "high-voltage circuit → primary isolation → floating ground → secondary isolation → PE". The primary isolation provides insulation between the high-voltage circuit and the floating ground, while the secondary isolation provides insulation between the floating ground and the protective ground (PE). This breaks down the highest withstand voltage standard of the high-voltage circuit to ground (e.g., 5.6kV for power frequency and 18kV for impulse), so that the withstand voltage standard required for each isolation stage is lower than the highest withstand voltage standard. For example, each isolation stage meets the standard of 5.6kV for power frequency and 12kV for impulse, but the total withstand voltage of the high-voltage circuit to PE still meets the highest withstand voltage standard requirement.

[0078] In one possible implementation, the grounding terminals of the plurality of power control modules and the system control module are all connected to the same floating ground reference point.

[0079] It should be noted that if each control module is connected to its own floating ground reference point, the insulation safety requirements are met for each control module. However, since there is information exchange between multiple control modules, different floating ground reference points will lead to differences in communication reference potential, resulting in poor communication signal. Therefore, it is necessary to connect the grounding terminals of multiple control modules to the same floating ground reference point to ensure that the reference potential is consistent.

[0080] In one possible implementation, the floating ground reference point and the protective ground are mutually insulated, and the safety distance is greater than or equal to a preset threshold. For example... Figure 4 The yellow dashed line in the diagram indicates that the floating ground and PE are insulated from each other.

[0081] It should be noted that the value of the preset threshold can be determined according to the actual situation.

[0082] In this embodiment, the floating ground reference point is an intermediate node that is not directly grounded. The metal casing of the monitoring module is connected to the PE. The floating ground reference point and the PE can be insulated from each other by maintaining a certain physical distance, or by filling the space between the floating ground reference point and the metal casing of the monitoring module with insulating material.

[0083] For example, such as Figure 5 The high-voltage power supply equipment shown can have its floating ground reference point, in a real-world scenario, as a sheet metal component (such as...). Figure 5 The blue dashed line (as shown in the image) is located inside the high-voltage power supply equipment and is spaced a certain distance (safety distance) from the metal casing of the high-voltage power supply equipment or filled with insulating material (such as the gray part between the blue dashed line and the equipment casing) to ensure mutual insulation between the protective ground (PE) connecting the sheet metal parts and the metal casing of the equipment. The entire high-voltage power supply equipment includes multiple cabinets, with each power control module constituting one cabinet. For example, the power control module for the high-voltage DC circuit is one cabinet (such as the first cabinet), and the power control module for the high-voltage AC circuit is one cabinet (such as the second cabinet). It also includes multiple cabinets such as rectifier cabinets. The grounding terminals of multiple cabinets are all connected to the same sheet metal part (floating ground) to ensure that the reference potential of multiple cabinets is the same.

[0084] In one possible implementation, based on Figure 4 or Figure 5 The two-stage isolation architecture in the high-voltage power supply equipment shown allows for tiered monitoring during insulation monitoring. For example, as... Figure 4 As shown, primary insulation monitoring is performed on the primary isolation architecture of "high voltage circuit → primary isolation → floating ground", and secondary insulation monitoring is performed on the secondary isolation architecture of "floating ground → secondary isolation → PE". The results of the two-level insulation monitoring are used to determine whether there is a risk of insulation failure in the equipment.

[0085] It should be noted that detailed power supply information for each module of the aforementioned high-voltage power supply equipment can be found in relevant technologies and will not be elaborated upon here; furthermore, based on Figure 4 or Figure 5 The detailed implementation process of graded insulation monitoring of the high-voltage power supply equipment shown can be found in the relevant method implementation section, and will not be repeated here.

[0086] Figure 6 This is a schematic diagram of the structure of a monitoring device provided in one embodiment of this application. Figure 6 As shown, the device 600 of this embodiment includes a processor 610 and a memory 620, wherein the memory 620 stores a computer program 621 that can run on the processor 610. When the processor 610 executes the computer program 621, it implements the steps in any of the above method embodiments. Alternatively, when the processor 610 executes the computer program 621, it implements the functions of each module / unit in the above device embodiments.

[0087] For example, computer program 621 may be divided into one or more modules / units, one or more of which are stored in memory 620 and executed by processor 610 to complete this application. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of computer program 621 in device 600.

[0088] Those skilled in the art will understand that Figure 6 This is merely an example of a device and does not constitute a limitation on the device. It may include more or fewer components than shown, or combinations of certain components, or different components, such as input / output devices, network access devices, buses, etc.

[0089] The processor 610 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0090] The memory 620 can be an internal storage unit of the device, such as a hard disk or RAM, or an external storage device, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. The memory 620 can also include both internal and external storage units. The memory 620 is used to store computer programs and other programs and data required by the device. The memory 620 can also be used to temporarily store data that has been output or will be output.

[0091] For the sake of simplicity and clarity, only the above-described functional modules / units are used as examples. In practical applications, the functions described above can be assigned to different functional modules / units as needed. These modules / units can be implemented in hardware, software, or a combination of both.

[0092] An embodiment of this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the insulation monitoring method in the above-described method embodiments.

[0093] This invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the insulation monitoring methods described in the above-described method embodiments.

[0094] Computer programs include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. Computer-readable media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0095] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0096] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An insulation monitoring method for a high-voltage power supply system, characterized in that, The high-voltage power supply system is equipped with a two-level isolation architecture, which includes a primary isolation architecture formed between the high-voltage circuit and the floating ground reference point, and a secondary isolation architecture formed between the floating ground reference point and the protective ground. The method includes: Insulation monitoring is performed between the high-voltage circuit and the floating ground reference point to obtain the first-level monitoring results; Insulation monitoring is performed between the floating ground reference point and the protective ground to obtain the second-level monitoring results; Based on the results of the first-level monitoring and the second-level monitoring, corresponding insulation abnormality alarm information is generated.

2. The insulation monitoring method for a high-voltage power supply system according to claim 1, characterized in that, The withstand voltage standard value between the high voltage circuit and the floating ground reference point is greater than or equal to the withstand voltage standard value between the floating ground reference point and the protective ground.

3. The insulation monitoring method for a high-voltage power supply system according to claim 1, characterized in that, The insulation monitoring between the high-voltage circuit and the floating ground reference point, to obtain the first-level monitoring results, includes: The first DC voltage and / or the first AC voltage between the high-voltage circuit and the floating ground reference point are collected, and the first DC voltage and / or the first AC voltage are used as the first-level monitoring result.

4. The insulation monitoring method for a high-voltage power supply system according to claim 1, characterized in that, The insulation monitoring between the floating ground reference point and the protective ground, to obtain the second-level monitoring results, includes: The second DC voltage or the second AC voltage between the floating ground reference point and the protected ground is collected, and the second DC voltage or the second AC voltage is used as the second-level monitoring result.

5. The insulation monitoring method for a high-voltage power supply system according to claim 1, characterized in that, The method of performing insulation monitoring between the floating ground reference point and the protective ground to obtain the second-level monitoring results also includes: The leakage current between the floating ground reference point and the protective ground is collected, and the DC and AC quantities of the leakage current are used as the second-level monitoring results.

6. The insulation monitoring method for a high-voltage power supply system according to claim 1, characterized in that, The first-level monitoring results include the first DC voltage and / or the first AC voltage between the high-voltage circuit and the floating ground reference point; the second-level monitoring results include the second DC voltage or the second AC voltage between the floating ground reference point and the protective ground, as well as the DC and AC leakage current. The step of generating corresponding insulation abnormality alarm information based on the first-level monitoring results and the second-level monitoring results includes: When the first DC voltage is greater than a preset first voltage value and / or the first AC voltage is greater than a preset second voltage value, a first alarm message is generated; the first alarm message is used to indicate an abnormality in the floating ground insulation. When the second DC voltage is greater than a preset third voltage value or the second AC voltage is greater than a preset fourth voltage value, a second alarm message is generated; the second alarm message is used to indicate an abnormality in the protective ground insulation. When the DC leakage current is greater than a preset first current value or the AC leakage current is greater than a preset second current value, a third alarm message is generated; the third alarm message is used to indicate an abnormal leakage current to the protective ground.

7. The insulation monitoring method for a high-voltage power supply system according to claim 6, characterized in that, Also includes: When at least one of the second alarm message and the third alarm message is generated simultaneously with the first alarm message, the high-voltage power supply system is controlled to enter standby mode.

8. A high-voltage power supply device, characterized in that, include: High-voltage circuit, multiple power control modules, system control module, and monitoring module; The high-voltage circuit is connected to the plurality of power control modules and the system control module; The plurality of power control modules and the system control module are connected in communication. The grounding terminals of the plurality of power control modules and the system control module are all connected to a floating ground reference point; The monitoring module is communicatively connected to the power control module and the system control module, and the metal casing of the monitoring module is connected to the protective ground. The monitoring module is used to perform the insulation monitoring method for a high-voltage power supply system as described in any one of claims 1 to 7.

9. The high-voltage power supply equipment according to claim 8, characterized in that, The grounding terminals of the multiple power control modules and the system control module are all connected to the same floating ground reference point.

10. The high-voltage power supply equipment according to claim 8, characterized in that, The floating ground reference point and the protective ground are mutually insulated, and the safety distance is greater than or equal to a preset threshold.

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