Insulation monitoring analysis system deployment system and method thereof

Abstract

The invention provides a deployment system and method of an insulation monitoring analysis system, and the system comprises a neutral point ungrounded system which comprises a first insulation monitoring analysis screen, a first edge side sensor, a first insulation monitoring management system, a three-phase injection resistor, and a first blocking module; the neutral point arc suppression coil or small resistance grounding system comprises a decoupling cabinet, a second insulation monitoring analysis screen, a second edge side sensor, a second blocking module and a second insulation monitoring management system. The method is applied to deployment of the deployment system of the insulation monitoring analysis system. The system has the remarkable advantages of real-time monitoring and efficient analysis, system isolation and protection, flexibility and expandability, data accuracy and reliability and the like, and has wide application prospects and important practical value in an electric power system.

Description

Technical Field

[0001] The invention relates to the technical field of power equipment monitoring in a power supply and distribution system, and in particular to a deployment method of an insulation monitoring and analysis system. Background Art

[0002] The insulation monitoring and analysis system can monitor the system insulation resistance of the ungrounded neutral point system, arc suppression coil grounding system, and low resistance grounding system. However, the insulation monitoring and analysis system has a complex structure and must be uniformly planned and effectively coordinated with the site to achieve flexible application.

[0003] 1. The insulation monitoring and analysis system has many components and is not planned in an orderly manner, which can easily lead to configuration confusion and fail to effectively guide on-site applications.

[0004] 2. Relying solely on insulation monitoring devices can only monitor a single busbar, while there may be multiple busbars in the same distribution system, and there is a lack of management and monitoring of the insulation of the entire station.

[0005] 3. The traditional use of AC leakage current to monitor the insulation status of high-voltage feeder lines cannot effectively evaluate the insulation condition of the feeder lines directly. The AC leakage current contains resistive and capacitive components, and the power supply and distribution system usually has a larger capacitive component, while the resistive component is the effective component for measuring insulation, resulting in the inability to effectively measure the insulation condition of the feeder lines. Summary of the invention

[0006] In order to solve various problems existing in the prior art, the purpose of the present invention is to provide a deployment system and method of an insulation monitoring and analysis system. The system and method have significant advantages such as real-time monitoring and efficient analysis, system isolation and protection, flexibility and scalability, and data accuracy and reliability. They have broad application prospects and important practical value in power systems.

[0007] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0008] A deployment system for an insulation monitoring and analysis system, the system comprising:

[0009] A neutral point ungrounded system, comprising a first insulation monitoring and analysis screen, a first edge side sensor, a first insulation monitoring and management system, a three-phase injection resistor R1, and a first DC isolation module, wherein the first edge side sensor is used to monitor the insulation state of the system in real time, and its output signal is connected to the first insulation monitoring and analysis screen, the first insulation monitoring and analysis screen is connected to the first insulation monitoring and management system through a first gateway for displaying and analyzing insulation monitoring data, the first insulation monitoring and management system runs on a PC or other terminal device, and is used to receive transmission data from the first gateway, and to perform further analysis, processing and display, one end of the three-phase injection resistor R1 is connected to the first insulation monitoring and analysis screen, the other end of the three-phase injection resistor R1 is connected to a power supply, one end of the first DC isolation module is connected to a power supply, and the other end of the first DC isolation module is grounded;

[0010] A neutral point arc suppression coil or low resistance grounding system comprises a decoupling cabinet, a second insulation monitoring and analysis screen, a second edge side sensor, a second DC isolation module, and a second insulation monitoring and management system. One end of the decoupling cabinet is connected to the arc suppression coil or low resistor for separating the arc suppression coil or low resistor from other monitoring and management systems. The other end of the decoupling cabinet is connected to the second insulation monitoring and analysis screen. The second insulation monitoring and analysis screen is used to monitor the insulation status of each part in the system. The second insulation monitoring and analysis screen is connected to the second insulation monitoring and management system through a second gateway. The second insulation monitoring and management system runs on a PC or other terminal device for receiving transmission data from the second gateway for further analysis, processing and display. One end of the second DC isolation module is connected to a power supply, and the other end of the second DC isolation module is grounded.

[0011] A deployment method for an insulation monitoring and analysis system is applied to the above-mentioned deployment system for insulation monitoring and analysis system for deployment, and the method comprises:

[0012] The first and second insulation monitoring and analysis screens are respectively deployed in the duty room of the substation, the first and second edge side sensors are respectively deployed near the cable interlayer or the cable head line, and the three phases A, B and C are passed through the sensors, and the decoupling cabinet is deployed between the small resistor or arc suppression coil at the neutral point of the power supply and distribution transformer and the ground; the three-phase injection resistor R1 is deployed in the PT cabinet of the power supply and distribution system, and the first and second DC isolation modules are respectively deployed between the star midpoints of all high-voltage PTs with star midpoints and the ground; the first and second insulation monitoring and management systems are respectively deployed in the server in the duty room, and the insulation status of the power supply and distribution system is monitored and managed through the first and second insulation monitoring and management systems.

[0013] According to a deployment method of an insulation monitoring and analysis system provided by the present invention, when deploying a neutral point ungrounded system, the method includes:

[0014] Deploy the first edge sensor near the cable interlayer or cable head line and make the three phases A, B and C pass through the sensor;

[0015] A three-phase injection resistor R1 is deployed in one of the PT cabinets with a high-voltage star midpoint in the power supply and distribution system, and one end of the three-phase injection resistor R1 is connected to the three-phase busbars A, B, and C of the power supply and distribution system respectively, and the other end of the three-phase injection resistor R1 is connected in a star connection;

[0016] A first DC isolation module is connected in series between the star midpoint of all PTs with high-voltage star midpoints in the power supply and distribution system and the ground;

[0017] A first insulation monitoring device, a first gateway, a first display, and a first leakage current monitoring device are deployed and installed in the first insulation monitoring and analysis screen.

[0018] According to a deployment method of an insulation monitoring and analysis system provided by the present invention, one end of a DC output port of a first insulation monitoring device is connected to the star midpoint of a three-phase injection resistor in a PT cabinet, and the other end is grounded, so as to inject a DC voltage into a power supply and distribution system and complete the system insulation resistance calculation, and transmit information such as the output current and DC voltage of the first insulation monitoring device to a first gateway;

[0019] The first leakage current monitoring device is connected to the first edge-side sensor and is used to collect leakage current information of the high-voltage feeder line;

[0020] The communication port of the first gateway is connected to the first insulation monitoring device, the first leakage current monitoring device, and the first insulation monitoring management system respectively.

[0021] According to a deployment method of an insulation monitoring and analysis system provided by the present invention, when deploying a neutral point arc suppression coil or a low resistance grounding system, the method comprises:

[0022] Deploy the second edge sensor near the cable interlayer or cable head line and make the three phases A, B and C pass through the sensor;

[0023] A second DC isolation module is connected in series between the star midpoint of all PTs with high-voltage star midpoints in the power supply and distribution system and the ground;

[0024] A second insulation monitoring device, a second gateway, a second display, and a second leakage current monitoring device are deployed and installed in the second insulation monitoring and analysis screen.

[0025] According to a deployment method of an insulation monitoring and analysis system provided by the present invention, one end of the DC output port of the second insulation monitoring device is connected to one end of the single-phase injection resistor R2 of the decoupling cabinet, and the other end is grounded, so as to inject DC voltage into the power supply and distribution system and complete the system insulation resistance calculation, and transmit the output current, DC voltage and other information of the insulation monitoring device to the second gateway;

[0026] The second leakage current monitoring device is connected to the second edge-side sensor and is used to collect leakage current information of the high-voltage feeder line.

[0027] The communication port of the second gateway is connected to the second insulation monitoring device, the second leakage current monitoring device, and the second insulation monitoring management system respectively.

[0028] According to a deployment method of an insulation monitoring and analysis system provided by the present invention, a decoupling cabinet is connected between a small resistor or arc suppression coil at a neutral point and the earth, and a reactor L1, a high-voltage isolation capacitor C, two fast circuit breakers VSC, a decoupling integrated controller ZK, a single-phase injection resistor R2, and a sensor are arranged in the decoupling cabinet. The reactor L1 and the high-voltage isolation capacitor C are connected in series between the small resistor or arc suppression coil and the earth, and two fast circuit breakers VSC are connected in parallel at both ends of the reactor L1 and the high-voltage isolation capacitor C. The sensor is used to collect the ground current of the decoupling cabinet, and the decoupling integrated controller ZK is used to realize ground current detection and control of the fast circuit breaker VSC.

[0029] According to a deployment method of an insulation monitoring and analysis system provided by the present invention, when the insulation monitoring device injects a DC voltage into the high-voltage feeder branch, the DC leakage current information is sensed and collected in real time by the edge side sensor, that is, the sensing information amount of the edge side sensor is the DC leakage current information of the sensed high-voltage feeder branch under the premise that the insulation monitoring device injects a DC voltage.

[0030] According to a deployment method of an insulation monitoring and analysis system provided by the present invention, multiple decoupling cabinets and insulation monitoring and analysis screens are connected through the insulation monitoring and management system to monitor the insulation resistance status of the power supply and distribution system of the entire station. The low insulation resistance alarm of the system includes:

[0031] Warning:

[0032] Condition 1: System insulation resistance ≤ kV voltage resistance value 1 × system bus line voltage rating;

[0033] Condition 2: Duration t ≥ alarm delay;

[0034] Alarm conditions: Alarm occurs when conditions 1 and 2 are met simultaneously;

[0035] Warning:

[0036] Condition 1: System insulation resistance ≤ kV voltage resistance value 2 × system bus line voltage rating;

[0037] Condition 2: Duration t ≥ pre-alarm delay;

[0038] Pre-alarm conditions: Pre-alarm occurs when conditions 1 and 2 are met simultaneously;

[0039] And the kilovolt voltage resistance value 2 is greater than the kilovolt voltage resistance value 1.

[0040] According to a deployment method of an insulation monitoring and analysis system provided by the present invention, when the insulation monitoring and management system monitors the insulation resistance state of a branch of a power supply and distribution system, its branch insulation resistance calculation method includes:

[0041] Branch insulation resistance = (injected DC voltage - insulation monitoring device output current * injection resistance) / high voltage feeder branch DC leakage current;

[0042] When the insulation monitoring and management system locates the insulation resistance fault position of the power supply and distribution system, it includes:

[0043] When the system insulation resistance of the power supply and distribution system generates an alarm or a pre-alarm, the branch whose branch insulation resistance meets the alarm or pre-alarm condition is the faulty branch.

[0044] It can be seen that compared with the prior art, the method provided by the present invention has the following beneficial effects:

[0045] 1. The present invention specifically explains the neutral point situation of the power supply and distribution system, the neutral point small resistor or arc suppression coil system, the deployment method of the neutral point ungrounded system, and determines the deployment position, thereby realizing the effective positioning and on-site application of the insulation monitoring and analysis system.

[0046] 2. The present invention constructs an insulation monitoring management system based on the PC, which can access the data of multiple decoupling cabinets and insulation monitoring analysis screens, realize the status monitoring of insulation resistance when there are multiple busbars and multiple transformers in the whole station, and avoid the problem of needing to inspect one by one and not effectively realizing interactive alarm when multiple insulation monitoring devices are used.

[0047] 3. The edge-side sensor of the present invention can sense the DC leakage current of the high-voltage feeder line under the DC voltage after the insulation monitoring device injects the DC voltage. The insulation monitoring management system based on the PC can calculate the branch insulation resistance of the feeder branch through the DC leakage current, and the loop with low branch insulation resistance is the loop with insulation problems, thereby locating the insulation fault and avoiding the problem of being unable to locate the system insulation status in real time after monitoring the system insulation resistance alone.

[0048] 4. In the neutral point arc suppression coil or low-resistance grounding system of the present invention, the introduction of the decoupling cabinet effectively separates the arc suppression coil or low-resistance from other monitoring and management systems, which can reduce mutual interference between systems and improve the stability and reliability of the system.

[0049] 5. The system of the present invention can monitor the insulation status of the neutral point ungrounded system and the neutral point arc suppression coil or low-resistance grounded system in real time, and can promptly discover potential insulation problems to avoid the expansion of faults.

[0050] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a circuit principle diagram of a neutral point ungrounded system in an embodiment of a deployment system of an insulation monitoring and analysis system of the present invention.

[0052] Figure 2 It is a circuit principle diagram of a neutral point arc suppression coil or a low resistance grounding system in an embodiment of a deployment system of an insulation monitoring and analysis system of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0055] See also Figure 1 and Figure 2 This embodiment provides a deployment system for an insulation monitoring and analysis system, including:

[0056] A neutral point ungrounded system includes a first insulation monitoring and analysis screen 10, a first edge side sensor, a first insulation monitoring and management system 11, a three-phase injection resistor R1, and a first DC isolation module C1. The first edge side sensor is used to monitor the insulation state of the system in real time, and its output signal is connected to the first insulation monitoring and analysis screen 10. The first insulation monitoring and analysis screen 10 and the first insulation monitoring and management system 11 are connected through a first gateway 103 for displaying and analyzing insulation monitoring data. The first insulation monitoring and management system 11 runs on a PC or other terminal device and is used to receive transmission data from the first gateway 103 and perform further analysis, processing and display. One end of the three-phase injection resistor R1 is connected to the first insulation monitoring and analysis screen 10, and the other end of the three-phase injection resistor R1 is connected to a power supply. One end of the first DC isolation module C1 is connected to a power supply, and the other end of the first DC isolation module C1 is grounded.

[0057] A neutral point arc suppression coil or low resistance grounding system comprises a decoupling cabinet U1, a second insulation monitoring and analysis screen 20, a second edge side sensor, a second DC isolation module C2, and a second insulation monitoring and management system 21. One end of the decoupling cabinet U1 is connected to the arc suppression coil or low resistance for separating the arc suppression coil or low resistance from other monitoring and management systems. The other end of the decoupling cabinet U1 is connected to the second insulation monitoring and analysis screen 20. The second insulation monitoring and analysis screen 20 is used to monitor the insulation status of each part in the system. The second insulation monitoring and analysis screen 20 is connected to the second insulation monitoring and management system 21 via a second gateway 203. The second insulation monitoring and management system 21 runs on a PC or other terminal device for receiving transmission data from the second gateway 203 and performing further analysis, processing and display. One end of the second DC isolation module C2 is connected to a power supply, and the other end of the second DC isolation module C2 is grounded.

[0058] Furthermore, the three-phase injection resistor is used to inject a current signal of a specific frequency into the system in order to better monitor the insulation status. The monitoring effect can be optimized by changing the resistance value or adjusting the frequency of the injected current.

[0059] Furthermore, the DC isolation module is connected between the power supply and the ground, and its main function is to isolate the DC component to prevent it from interfering with the system, which helps to improve the accuracy of the monitoring data and the stability of the system.

[0060] Furthermore, the insulation monitoring management system runs on a PC or other terminal device, receives data from the insulation monitoring analysis screen through a gateway, and performs in-depth analysis, processing and display of the data, providing strong support for system maintenance and fault diagnosis.

[0061] Furthermore, in the neutral point arc suppression coil or low resistance grounding system, the decoupling cabinet U1 separates the arc suppression coil or low resistance from other monitoring and management systems, which can reduce mutual interference and ensure that the second insulation monitoring and analysis screen can accurately monitor the insulation status of the system.

[0062] A deployment method embodiment of an insulation monitoring and analysis system

[0063] This embodiment provides a deployment method for an insulation monitoring and analysis system, which is applied to the above-mentioned deployment system for insulation monitoring and analysis system for deployment. The method includes:

[0064] The first and second insulation monitoring and analysis screens are respectively deployed in the duty room of the substation, the first and second edge side sensors are respectively deployed near the cable interlayer or the cable head line, and the three phases A, B and C are passed through the sensors, and the decoupling cabinet U1 is deployed between the small resistor or arc suppression coil at the neutral point of the power supply and distribution transformer and the ground; the three-phase injection resistor R1 is deployed in the PT cabinet of the power supply and distribution system, and the first and second DC isolation modules are respectively deployed between the star midpoints of all high-voltage PTs with star midpoints and the ground; the first and second insulation monitoring and management systems are respectively deployed in the server in the duty room, and the insulation status of the power supply and distribution system is monitored and managed through the first and second insulation monitoring and management systems.

[0065] Specifically, when deploying a neutral point ungrounded system, it includes:

[0066] The first edge side sensor is deployed near the cable mezzanine or the cable head line and ensures that the three phases A, B, and C all pass through the sensor; wherein, the sensor is placed near the cable mezzanine or the cable head line, ensuring that the three phases A, B, and C all pass through the sensor, so as to monitor the current condition of the cable line in real time.

[0067] A three-phase injection resistor R1 is deployed in one of the PT cabinets with a high-voltage star midpoint in the power supply and distribution system, and one end of the three-phase injection resistor R1 is connected to the three-phase busbars A, B, and C of the power supply and distribution system, and the other end of the three-phase injection resistor R1 is connected in a star connection. The high-voltage star midpoint is selected in the PT cabinet, and the three-phase injection resistor R1 is connected. Its function is to inject a weak DC signal into the system so that the subsequent insulation monitoring device can evaluate the insulation status of the system by measuring the signal.

[0068] A first DC isolation module C1 is connected in series between the star midpoint of all PTs with high-voltage star midpoints in the power supply and distribution system and the ground to prevent DC signals from directly flowing into the ground grid, thereby protecting the safety of equipment and systems.

[0069] A first insulation monitoring device 101 , a first gateway 103 , a first display 102 , and a first leakage current monitoring device 104 are deployed and installed in the first insulation monitoring and analysis screen 10 .

[0070] In this embodiment, one end of the DC output port of the first insulation monitoring device 101 is connected to the star midpoint of the three-phase injection resistor in the PT cabinet, and the other end is grounded, so as to inject DC voltage into the power supply and distribution system and complete the system insulation resistance calculation, and transmit the output current, DC voltage and other information of the first insulation monitoring device 101 to the first gateway 103.

[0071] The first leakage current monitoring device 104 is connected to the first edge-side sensor and is used to collect leakage current information of the high-voltage feeder line.

[0072] The communication port of the first gateway 103 is connected to the first insulation monitoring device 101 , the first leakage current monitoring device 104 , and the first insulation monitoring management system 11 respectively.

[0073] In this embodiment, comprehensive monitoring of the system insulation status can be achieved through the combination of an insulation monitoring device, a gateway, a display and a leakage current monitoring device. The insulation monitoring device calculates the insulation resistance value by measuring the DC signal and leakage current generated by the injection resistor, and uploads it to the insulation monitoring management system through the gateway, and finally displays the monitoring results on the display.

[0074] Specifically, when deploying a neutral point arc suppression coil or a low resistance grounding system, it includes:

[0075] The second edge-side sensor is deployed near the cable interlayer or the cable head line and the three phases A, B, and C all pass through the sensor.

[0076] A second DC isolation module C2 is connected in series between the star midpoint of all PTs with a high-voltage star midpoint in the power supply and distribution system and the ground to prevent the DC signal from directly flowing into the ground grid.

[0077] A second insulation monitoring device 201 , a second gateway 203 , a second display 202 , and a second leakage current monitoring device 204 are deployed and installed in the second insulation monitoring and analysis screen 20 .

[0078] In this embodiment, one end of the DC output port of the second insulation monitoring device 201 is connected to one end of the single-phase injection resistor R2 of the decoupling cabinet U1, and the other end is grounded, so as to inject DC voltage into the power supply and distribution system and complete the system insulation resistance calculation, and transmit the output current, DC voltage and other information of the insulation monitoring device to the second gateway 203. Because in the neutral point arc suppression coil or low resistance grounding system, more accurate current injection and measurement are required to adapt to different grounding methods.

[0079] The second leakage current monitoring device 204 is connected to the second edge-side sensor and is used to collect leakage current information of the high-voltage feeder line.

[0080] The communication port of the second gateway 203 is connected to the second insulation monitoring device 201 , the second leakage current monitoring device 204 , and the second insulation monitoring management system 21 respectively.

[0081] In this embodiment, a decoupling cabinet U1 is connected between a small resistor or arc suppression coil at the neutral point and the earth. A reactor L1, a high-voltage isolation capacitor C, two fast circuit breakers VSC, a decoupling integrated controller ZK, a single-phase injection resistor R2, and a sensor are arranged in the decoupling cabinet U1. The reactor L1 and the high-voltage isolation capacitor C are connected in series between the small resistor or arc suppression coil and the earth. Two fast circuit breakers VSC are connected in parallel between the reactor L1 and the high-voltage isolation capacitor C. The sensor is used to collect the ground current of the decoupling cabinet U1, and the decoupling integrated controller ZK is used to realize ground current detection and control of the fast circuit breaker VSC.

[0082] Furthermore, the reactor L1 is connected in series with the high-voltage isolation capacitor C between a small resistor or arc suppression coil and the ground. Its main function is to limit the high-frequency component in the short-circuit current and provide a certain inductive impedance, which helps to stabilize the voltage and current waveforms of the system.

[0083] Furthermore, the high-voltage isolation capacitor C is connected in series with the reactor L1 to isolate the DC and pass the AC. In the system, the DC component can be prevented from causing adverse effects on the system, while the AC signal is allowed to pass to maintain the normal operation of the system.

[0084] Furthermore, two fast circuit breakers VSC are connected in parallel between the reactor L1 and the high-voltage isolation capacitor C, and can quickly operate after receiving the command from the decoupling integrated controller ZK to cut off or restore the circuit connection. This fast response capability is crucial to protecting the system from short circuits, overloads and other faults.

[0085] Furthermore, the decoupling integrated controller ZK is the core component of the entire decoupling cabinet U1. It is responsible for the detection, analysis and control of the ground current. By receiving the ground current information collected by the sensor, the decoupling integrated controller ZK can evaluate the operating status of the system in real time, and according to the preset algorithm and logic, send control instructions to the fast circuit breaker VSC to adjust the connection status of the circuit, thereby realizing effective control of the ground current.

[0086] Furthermore, in the decoupling cabinet U1, the single-phase injection resistor R2 is used to inject a weak DC signal into the system so that the insulation monitoring device can measure and evaluate the insulation state of the system.

[0087] Furthermore, the sensor is used to collect the ground current information of the decoupling cabinet U1 and transmit it to the decoupling integrated controller ZK. This embodiment uses sensors with high precision and high reliability to ensure that the collected data is accurate and provide a reliable decision-making basis for the decoupling integrated controller ZK.

[0088] It can be seen that the decoupling cabinet U1 realizes the effective control and management of the ground current in the neutral point small resistance or arc suppression coil grounding system through the coordinated work of its internal components, which can improve the safety and stability of the system, reduce the possibility of faults, and reduce maintenance costs.

[0089] In this embodiment, when the insulation monitoring device injects a DC voltage into the high-voltage feeder branch, the DC leakage current information is sensed and collected in real time by the edge side sensor, that is, the sensing information amount of the edge side sensor is the DC leakage current information of the sensed high-voltage feeder branch under the premise that the insulation monitoring device injects a DC voltage.

[0090] In this embodiment, multiple decoupling cabinets U1 and insulation monitoring and analysis screens are connected through the insulation monitoring management system to monitor the insulation resistance status of the power supply and distribution system of the entire station. The low insulation resistance alarm of the system includes:

[0091] Warning:

[0092] Condition 1: System insulation resistance ≤ kV voltage resistance value 1 × system bus line voltage rating;

[0093] Condition 2: Duration t ≥ alarm delay;

[0094] Alarm conditions: Alarm occurs when conditions 1 and 2 are met simultaneously;

[0095] Warning:

[0096] Condition 1: System insulation resistance ≤ kV voltage resistance value 2 × system bus line voltage rating;

[0097] Condition 2: Duration t ≥ pre-alarm delay;

[0098] Pre-alarm conditions: Pre-alarm occurs when conditions 1 and 2 are met simultaneously;

[0099] And the kilovolt voltage resistance value 2 is greater than the kilovolt voltage resistance value 1.

[0100] In this embodiment, when the insulation monitoring and management system monitors the insulation resistance state of the branch of the power supply and distribution system, the branch insulation resistance calculation method includes:

[0101] Branch insulation resistance = (injected DC voltage - insulation monitoring device output current * injection resistance) / high voltage feed branch DC leakage current.

[0102] When the insulation monitoring and management system locates the insulation resistance fault position of the power supply and distribution system, it includes:

[0103] When the system insulation resistance of the power supply and distribution system generates an alarm or a pre-alarm, the branch whose branch insulation resistance meets the alarm or pre-alarm condition is the faulty branch.

[0104] In summary, the present invention specifically explains the neutral point situation of the power supply and distribution system, the neutral point small resistor or arc suppression coil system, and the neutral point ungrounded system to clarify the deployment method, and determines the deployment position, thereby realizing the effective positioning and field application of the insulation monitoring and analysis system. The present invention constructs an insulation monitoring and management system based on the PC, which can access the data of multiple decoupling cabinets and insulation monitoring and analysis screens, realizes the state monitoring of insulation resistance when there are multiple busbars and multiple transformers in the whole station, and avoids the problem that when multiple insulation monitoring devices are used, they need to be inspected one by one and interactive alarms are not effectively realized.

[0105] The present invention can sense the DC leakage current of the high-voltage feeder line under the DC voltage after the DC voltage is injected by the insulation monitoring device through the edge side sensor. The insulation monitoring management system based on the PC can calculate the branch insulation resistance of the feeder branch through the DC leakage current, and the circuit with low branch insulation resistance is the circuit with insulation problems, thereby realizing the location of insulation faults and avoiding the problem of being unable to locate the system insulation status in real time after monitoring the system insulation status by relying solely on the system insulation resistance.

[0106] In the neutral point arc suppression coil or low resistance grounding system of the present invention, the introduction of the decoupling cabinet effectively separates the arc suppression coil or low resistance from other monitoring and management systems, which can reduce mutual interference between systems and improve the stability and reliability of the system. The system of the present invention can monitor the insulation status of the neutral point ungrounded system and the neutral point arc suppression coil or low resistance grounding system in real time, and can timely discover potential insulation problems to avoid fault expansion.

[0107] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A deployment system for an insulation monitoring and analysis system, characterized in that: The system includes: A neutral point ungrounded system, comprising a first insulation monitoring and analysis screen, a first edge side sensor, a first insulation monitoring and management system, a three-phase injection resistor R1, and a first DC isolation module, wherein the first edge side sensor is used to monitor the insulation state of the system in real time, and its output signal is connected to the first insulation monitoring and analysis screen, the first insulation monitoring and analysis screen is connected to the first insulation monitoring and management system through a first gateway for displaying and analyzing insulation monitoring data, the first insulation monitoring and management system runs on a PC or other terminal device, and is used to receive transmission data from the first gateway, and to perform further analysis, processing and display, one end of the three-phase injection resistor R1 is connected to the first insulation monitoring and analysis screen, the other end of the three-phase injection resistor R1 is connected to a power supply, one end of the first DC isolation module is connected to a power supply, and the other end of the first DC isolation module is grounded; A neutral point arc suppression coil or low resistance grounding system comprises a decoupling cabinet, a second insulation monitoring and analysis screen, a second edge side sensor, a second DC isolation module, and a second insulation monitoring and management system. One end of the decoupling cabinet is connected to the arc suppression coil or low resistor for separating the arc suppression coil or low resistor from other monitoring and management systems. The other end of the decoupling cabinet is connected to the second insulation monitoring and analysis screen. The second insulation monitoring and analysis screen is used to monitor the insulation status of each part in the system. The second insulation monitoring and analysis screen is connected to the second insulation monitoring and management system through a second gateway. The second insulation monitoring and management system runs on a PC or other terminal device for receiving transmission data from the second gateway for further analysis, processing and display. One end of the second DC isolation module is connected to a power supply, and the other end of the second DC isolation module is grounded.

2. A method for deploying an insulation monitoring and analysis system, characterized in that: The method is applied to a deployment system of an insulation monitoring and analysis system as claimed in claim 1 for deployment, and the method comprises: The first and second insulation monitoring and analysis screens are respectively deployed in the duty room of the substation, the first and second edge side sensors are respectively deployed near the cable interlayer or the cable head line, and the three phases A, B and C are passed through the sensors, and the decoupling cabinet is deployed between the small resistor or arc suppression coil at the neutral point of the power supply and distribution transformer and the ground; the three-phase injection resistor R1 is deployed in the PT cabinet of the power supply and distribution system, and the first and second DC isolation modules are respectively deployed between the star midpoints of all high-voltage PTs with star midpoints and the ground; the first and second insulation monitoring and management systems are respectively deployed in the server in the duty room, and the insulation status of the power supply and distribution system is monitored and managed through the first and second insulation monitoring and management systems.

3. The method according to claim 2, characterized in that: When deploying a system with an ungrounded neutral point, include: Deploy the first edge sensor near the cable interlayer or cable head line and make the three phases A, B and C pass through the sensor; A three-phase injection resistor R1 is deployed in one of the PT cabinets with a high-voltage star midpoint in the power supply and distribution system, and one end of the three-phase injection resistor R1 is connected to the three-phase busbars A, B, and C of the power supply and distribution system respectively, and the other end of the three-phase injection resistor R1 is connected in a star connection; A first DC isolation module is connected in series between the star midpoint of all PTs with high-voltage star midpoints in the power supply and distribution system and the ground; A first insulation monitoring device, a first gateway, a first display, and a first leakage current monitoring device are deployed and installed in the first insulation monitoring and analysis screen.

4. The method according to claim 3, characterized in that: One end of the DC output port of the first insulation monitoring device is connected to the star midpoint of the three-phase injection resistor in the PT cabinet, and the other end is grounded, so as to inject DC voltage into the power supply and distribution system and complete the system insulation resistance calculation, and transmit the output current, DC voltage and other information of the first insulation monitoring device to the first gateway; The first leakage current monitoring device is connected to the first edge-side sensor and is used to collect leakage current information of the high-voltage feeder line; The communication port of the first gateway is connected to the first insulation monitoring device, the first leakage current monitoring device, and the first insulation monitoring management system respectively.

5. The method according to claim 2, characterized in that: When deploying a neutral point arc suppression coil or a low resistance grounding system, include: Deploy the second edge sensor near the cable interlayer or cable head line and make the three phases A, B and C pass through the sensor; A second DC isolation module is connected in series between the star midpoint of all PTs with high-voltage star midpoints in the power supply and distribution system and the ground; A second insulation monitoring device, a second gateway, a second display, and a second leakage current monitoring device are deployed and installed in the second insulation monitoring and analysis screen.

6. The method according to claim 5, characterized in that: One end of the DC output port of the second insulation monitoring device is connected to one end of the single-phase injection resistor R2 of the decoupling cabinet, and the other end is grounded, so as to inject DC voltage into the power supply and distribution system and complete the system insulation resistance calculation, and transmit the output current, DC voltage and other information of the insulation monitoring device to the second gateway; The second leakage current monitoring device is connected to the second edge-side sensor and is used to collect leakage current information of the high-voltage feeder line. The communication port of the second gateway is connected to the second insulation monitoring device, the second leakage current monitoring device, and the second insulation monitoring management system respectively.

7. The method according to claim 6, characterized in that: A decoupling cabinet is connected between the small resistor or arc suppression coil at the neutral point and the ground. A reactor L1, a high-voltage isolation capacitor C, two fast circuit breakers VSC, a decoupling integrated controller ZK, a single-phase injection resistor R2, and a sensor are arranged in the decoupling cabinet. The reactor L1 and the high-voltage isolation capacitor C are connected in series between the small resistor or arc suppression coil and the ground. Two fast circuit breakers VSC are connected in parallel at both ends of the reactor L1 and the high-voltage isolation capacitor C. The sensor is used to collect the ground current of the decoupling cabinet. The decoupling integrated controller ZK is used to realize ground current detection and control of the fast circuit breaker VSC.

8. The method according to claim 2, characterized in that: When the insulation monitoring device injects a DC voltage into the high-voltage feeder branch, the edge-side sensor senses and collects the DC leakage current information in real time, that is, the sensing information of the edge-side sensor is the DC leakage current information of the induced high-voltage feeder branch under the premise that the insulation monitoring device injects a DC voltage.

9. The method according to claim 2, characterized in that: Through the insulation monitoring management system, multiple decoupling cabinets and insulation monitoring and analysis screens are connected to monitor the insulation resistance status of the power supply and distribution system of the entire station. The low insulation resistance alarms of the system include: Warning: Condition 1: System insulation resistance ≤ kV voltage resistance value 1 × system bus line voltage rating; Condition 2: Duration t ≥ alarm delay; Alarm conditions: Alarm occurs when conditions 1 and 2 are met simultaneously; Warning: Condition 1: System insulation resistance ≤ kV voltage resistance value 2 × system bus line voltage rating; Condition 2: Duration t ≥ pre-alarm delay; Pre-alarm conditions: Pre-alarm occurs when conditions 1 and 2 are met simultaneously; And the kilovolt voltage resistance value 2 is greater than the kilovolt voltage resistance value 1.

10. The method according to claim 2, characterized in that: When the insulation monitoring and management system monitors the insulation resistance status of the branch of the power supply and distribution system, the branch insulation resistance calculation method includes: Branch insulation resistance = (injected DC voltage - insulation monitoring device output current * injection resistance) / high voltage feeder branch DC leakage current; When the insulation monitoring and management system locates the insulation resistance fault position of the power supply and distribution system, it includes: When the system insulation resistance of the power supply and distribution system generates an alarm or a pre-alarm, the branch whose branch insulation resistance meets the alarm or pre-alarm condition is the faulty branch.

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