System and method for monitoring electrical distribution system

Abstract

Systems and methods for monitoring an electrical distribution system are disclosed. An electrical conductor monitoring system for a single-phase or multi-phase conductor is described. The monitoring system may be configured to monitor the health of the conduction system based on the current magnitude and angle vector of the multi-phase sequence and / or the multi-phase or single-phase current. In one example, a monitoring system includes an insulation health monitoring system having an input measurement device disposed at an input of a power distribution system and configured to measure a three-phase input current and an output measurement device disposed at an output of the power distribution system. An output measurement device disposed at an output of the power distribution system and configured to measure a three-phase output current; and a monitoring device communicatively coupled to the measuring device and configured to receive the three-phase input current and the three-phase output current from the measuring device and determine a state of the insulation system based on the three-phase input current and the three-phase output current. Other embodiments are described.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 685,565, filed August 21, 2024, entitled “Electrical Insulation Monitoring System and Method,” the disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to monitoring power distribution systems, such as electrical busbar systems, including: determining leakage current and / or detecting faults and their severity, and more specifically, to monitoring a power distribution system by online analysis of electrical parameters between a set of nodes along each section of the power distribution system. Background Technology

[0004] High-power and high-demand power distribution systems typically use conductors arranged in prefabricated conduits to distribute electrical energy from power sources to electrical equipment such as switchgear, switchboards, transformers, and computing devices. The conduits provide mechanical support and facilitate the organization required to extend conductor lengths and multiple connection sections. Conductors may include power cables or wires arranged in cable trays and / or busbars arranged in busbar trunking or busbar conduits to form electrical busbar trunking. Such power distribution systems are common in data centers but are also prevalent in other applications such as laboratories, warehouses, and manufacturing facilities.

[0005] While cable trays and busbars have become popular power distribution systems due to their ease of installation, configuration, and reconfiguration, such systems face substantial challenges, including contact failure and insulation failure.

[0006] All insulators have a reference level of leakage current. Insulation failure occurs when the leakage current exceeds this reference level. Such failures can occur due to insulation degradation or other damage leading to an increase in current leaking to ground and / or from one conductor to another. For example, over time, the leakage current in a faulty section of a conduit may increase (e.g., but not limited to, due to water or other environmental factors), eventually leading to system failure. Such system failures result in unexpected and costly downtime and / or equipment damage.

[0007] Therefore, the standard requires busbars and other conductors to undergo contactor and insulation resistance testing on each busbar duct for a predetermined period of time (e.g., but not limited to one minute). Existing methods for testing or measuring insulation resistance require the section of conductor under test to be de-energized (or disconnected from the main system) during the test or measurement. Such offline measurements result in production losses and are therefore rarely performed during planned maintenance periods (e.g., every six months or year). Consequently, the increase in leakage current in the faulty section between test events will go undetected, leading to an accelerated deterioration of the fault severity.

[0008] For the reasons mentioned above, faults in high-power distribution systems are often not detected until circuit breakers, switches, fuses, or other protective devices have tripped and sections of the distribution system have been taken offline and, in many cases, damaged. Therefore, distribution systems will benefit from technologies for detecting and analyzing fault conditions within connected and active sections. Summary of the Invention

[0009] This summary is provided to introduce, in a simplified form, some concepts further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0010] This disclosure describes various implementations of a fault detection system for a power distribution system.

[0011] In one example, a power distribution system may include: a conduction system formed by at least one segment of a multiphase conductor configured to carry current between a current source and a current load; a measurement system operatively coupled to the multiphase conductor to measure current information of the multiphase conductor, the measurement system including at least one upstream sensor and at least one downstream sensor disposed at opposite ends of the measurement segment of the multiphase conductor; and a conduction system monitoring device communicatively coupled to the sensor system, the conduction system monitoring device being operated to: determine a sequence component based on current information received from the sensor system; determine a sequence component difference based on a comparison of an upstream sequence component at an upstream node of the measurement segment and a downstream sequence component at a downstream node of the measurement segment, the sequence component difference being associated with a leakage current of at least one of the multiphase conductors; and determine the state of the conduction system based on the sequence component difference.

[0012] In some implementations of power distribution systems, multiphase conductors include three-phase conductors.

[0013] In various implementations of the power distribution system, the conduction system monitoring device is also operated to determine the sequence component difference as the zero-sequence component difference based on the difference between the upstream zero-sequence component and the downstream zero-sequence component. In some implementations of the power distribution system, the conduction system monitoring device is also operated to determine an inter-phase fault in response to the zero-sequence component difference being greater than a zero-sequence threshold.

[0014] In various implementations of the power distribution system, the conduction system monitoring device is also operated to determine the sequence component difference as the negative sequence component difference based on the difference between the upstream negative sequence component and the downstream negative sequence component. In some implementations of the power distribution system, the conduction system monitoring device is also operated to determine a phase-to-ground fault in response to the negative sequence component difference being greater than a negative sequence threshold.

[0015] In an example implementation of the power distribution system, the state includes the state of the insulation system, which is configured to provide insulation between multiphase conductors and between the multiphase conductors and ground.

[0016] In some implementations of the power distribution system, the conduction system monitoring device is configured to determine the progression of an increase in the sequence component difference. In various implementations of the power distribution system, the conduction system monitoring device is configured to determine whether a fault caused by a sequence component difference exceeding a threshold is due to deterioration of the insulation system.

[0017] In some implementations of power distribution systems, the conduction system monitoring device is also operated to: determine the fault state of each phase of a multiphase conductor, and determine the phase with the interphase fault based on the sequence component difference of each phase of the multiphase conductor.

[0018] In one example, an electrical insulation health monitoring system for a power distribution system having three-phase conductors and an insulation system may include: a measuring device including an input measuring device and an output measuring device, the input measuring device being disposed at an input of the power distribution system and configured to measure the three-phase input current at the input, and the output measuring device being disposed at an output of the power distribution system and configured to measure the three-phase output current at the output; and an insulation health monitoring device communicatively coupled to the input measuring device and the output measuring device and configured to receive the three-phase input current and the three-phase output current to determine the instantaneous state of the insulation system based on the measured three-phase input current and the three-phase output current.

[0019] In some implementations of an electrical insulation health monitoring system, the insulation health monitoring device is configured to determine the instantaneous state of the insulation system by: deriving sequence components from the measured three-phase input current and three-phase output current, obtaining the sequence component difference between the input current sequence component of the three-phase input current and the output current sequence component of the three-phase output current, and determining the instantaneous state of the insulation system based on the sequence component difference.

[0020] In various implementations of the electrical insulation health monitoring system, the insulation health monitoring device is also configured to: determine that the insulation system is in a healthy state based on the determination that the difference between the sequence components is less than the corresponding tolerance, or determine that the insulation system contains a fault based on the determination that one or more differences in the sequence components are greater than the corresponding tolerance.

[0021] In some implementations of the electrical insulation health monitoring system, the sequence components include a zero-sequence component and a negative-sequence component, and the difference includes a first difference between the zero-sequence component of the three-phase input current and the zero-sequence component of the three-phase output current, and a second difference between the negative-sequence component of the three-phase input current and the negative-sequence component of the three-phase output current. The insulation health monitoring device is also configured to determine the type and severity of the detected fault based on a threshold, which includes a phase-to-ground fault based on determining that the first difference is greater than a first threshold, and a phase-to-phase fault based on determining that the second difference is greater than a second threshold.

[0022] In an example implementation of the electrical insulation health monitoring system, the insulation health monitoring device is further configured to determine the degradation mode based on the instantaneous state of the insulation system, wherein the degradation mode includes natural degradation modes applicable to warranty service and non-natural degradation modes that need to be investigated.

[0023] In one example, a method for monitoring the insulation health of an insulation system in a power distribution system may include: setting up a measurement system operatively coupled to at least one conductor of a conduction system in the power distribution system to measure current information of current flowing from a source through the at least one conductor to a load; the measurement system including at least one source-side sensor and at least one load-side sensor arranged at opposite ends of a measurement section of the at least one conductor; and performing via the insulation health monitoring system: collecting current information of the source-side current from the at least one source-side sensor and current information of the load-side current from the at least one load-side sensor, determining a source-side current vector (IS) and a load-side current vector (IL) based on the current information, and determining a fault current (If) based on the difference between IS and IR. f ), and based on I f Estimate insulation resistance (R) i ).

[0024] In some embodiments of the method, the method further includes monitoring the insulation health based on R. i Determine the remaining useful life (RUL) of at least one component of the insulation system. In various embodiments of the method, the method further includes determining the RUL based on an insulation health monitoring system. i =V / I f Determine R i Where V is the power supply voltage. In some embodiments of the method, the source-side current vector (IS) includes the magnitude (I1) and angle of the source-side current. Furthermore, the load-side current vector (IS) includes the magnitude (I2) and angle of the load-side current.

[0025] In an example implementation of the method, the method further includes applying a filter via an insulation health monitoring system to use current information at the power supply frequency of interest.

[0026] The shortcomings and deficiencies of existing systems can be addressed by an electrical insulation health monitoring system for a power distribution system with three-phase conductors and an insulation system. This electrical insulation health monitoring system includes: a measuring device comprising an input measuring device and an output measuring device, the input measuring device being located at the input end of the power distribution system and configured to measure the three-phase input current, and the output measuring device being located at the output end of the power distribution system and configured to measure the three-phase output current; and an insulation health monitoring device communicatively connected to the measuring device and configured to receive the measured three-phase input current and three-phase output current from the measuring device and determine the instantaneous state of the insulation system based on the measured three-phase input current and three-phase output current.

[0027] Another example implementation includes a method for monitoring the insulation health of a power distribution system having three-phase conductors and an insulation system. The method includes: measuring a three-phase input current at an input terminal of the power distribution system and a three-phase output current at an output terminal of the power distribution system; receiving the measured three-phase input current and three-phase output current; and determining the instantaneous state of the insulation system based on the measured three-phase input current and three-phase output current. Attached Figure Description

[0028] Features of the disclosed embodiments are described by way of example with reference to the accompanying drawings, in which:

[0029] Figures 1A to 1C An illustrative example of a power distribution system according to this disclosure is depicted;

[0030] Figure 2A and Figure 2B An illustrative example of an electrical conductor monitoring system according to this disclosure is described;

[0031] Figure 3 An illustrative example of an electrical conductor monitoring system according to this disclosure is described;

[0032] Figure 4 A chart depicting monitoring information of the healthy conductor section according to this disclosure;

[0033] Figure 5 A chart depicting monitoring information of a faulty conductor segment according to this disclosure;

[0034] Figure 6 An illustrative example of the workflow of an electrical conductor monitoring system according to this disclosure is described;

[0035] Figure 7 A table depicting fault indication information of an electrical conductor monitoring system according to this disclosure is provided.

[0036] Figure 8 An illustrative example of an electrical conductor monitoring system according to this disclosure is described;

[0037] Figure 9 An illustrative example depicting the phase shift of the current in vector form;

[0038] Figure 10 A graph depicts amplitude (D) monitoring information according to this disclosure;

[0039] Figure 11 The phase difference value according to this disclosure is described Charts of monitoring information;

[0040] Figure 12 The insulation resistance (R) according to this disclosure is described i Charts showing monitoring information over time; and

[0041] Figure 13 A graph depicting monitoring information of a fault indicator according to this disclosure is provided. Detailed Implementation

[0042] In this disclosure, various features of an electrical conductor monitoring system are described with reference to the accompanying drawings, in which one or more features of the electrical conductor monitoring system are shown and described. The various features described in this disclosure and depicted in the drawings can be used independently of each other or in combination with each other. The electrical conductor monitoring system disclosed herein can be embodied in many different forms and should not be construed as limited to the examples set forth herein. Rather, these examples are provided to convey some features of the electrical conductor monitoring system to those skilled in the art.

[0043] An electrical conductor monitoring system according to some embodiments may include a pair of online sensors configured to measure power distribution parameters between two nodes along a section of a conductor in a power distribution system. In some embodiments, the sensors may detect parameters of current and / or voltage. The electrical conductor monitoring system may analyze the measured parameters and / or information determined based on the parameters measured at the two nodes to determine whether a fault condition exists within the monitored section of the conductor. In some embodiments, a fault condition may include component degradation, for example, indicated by a gradual increase in current leakage relative to a baseline current leakage. In various embodiments, a fault condition may include a failure indicated by a sudden increase in the amount of current leakage. In some embodiments, a fault condition may include the presence of leakage current, for example, exceeding a tolerance level, a threshold, and / or the baseline leakage current.

[0044] In various implementations, an electrical conductor monitoring system can be configured to monitor the state of one or more components of a power distribution system. For example, in some implementations, the electrical conductor monitoring system may be an electrical insulation monitoring system or may operate at least partially as an electrical insulation monitoring system configured to monitor the insulation state of sections of conductors based on determined leakage currents.

[0045] Directional phrases used herein (such as, for example, left, right, front, back, top, bottom, up, down, variations thereof, and derivatives thereof) refer to the orientation of the elements shown in the accompanying drawings and are not limiting of the claims unless expressly stated in the claims.

[0046] As used in this article, when ordinal numbers such as “first” and “second” are used to modify nouns, such use is intended only to distinguish one item from another and, unless otherwise stated, is not intended to require a sequential order.

[0047] As used herein, the statement that two or more parts or components are “connected” means that these parts are joined together or operate together, directly or indirectly, for example, indirectly joined together or operate together through one or more intermediate parts or components (wherever a link occurs). As used herein, “fixedly connected” or “fixed” means that two components are connected to move as a whole while maintaining a constant orientation relative to each other.

[0048] Figures 1A to 1C An illustrative example of a power distribution system according to this disclosure is depicted. For example... Figures 1A to 1CAs shown, the power distribution system (or electrical system) 100 may include a conduction system 120 configured to electrically connect one or more power sources 103 to one or more loads 105. The conduction system 120 may include a conduit 110 in which a conductor 112 is disposed to carry current from the source 103 to the load 105.

[0049] In various embodiments, the conductive system 120 may be formed from multiple segments or sections 121a to 121d. Segments 121a to 121d may be connected via connectors 122a to 122c, which are configured to connect a conductor 112 of one segment to a conductor 112 of another segment. In other embodiments, the conductive system 120 may be formed from a single continuous segment 121 (e.g., without connectors 122a to 122c).

[0050] The power distribution system 100 can be any suitable power distribution system, including but not limited to busbar systems, bus conduits, cable trays or conduits, junction boxes, etc. Furthermore, the power distribution system 100 can include any type of conductor, including but not limited to cables, busbars, wires, etc. In various embodiments, the power distribution system 100 can be a multiphase system, such as a three-phase system, a two-phase system, or a five-phase system. In some embodiments, the power distribution system 100 can be a single-phase system. In various embodiments, the power distribution system 100 can be a three-phase system. In some embodiments, the power distribution system 100 can be configured for AC current. In various embodiments, the power distribution system 100 can be configured for DC current.

[0051] In some implementations, the power distribution system 100 and / or its components may be configured to be the same as or substantially similar to the PowerWave or Pow-R-Way busbar systems offered by Eaton PLC in Dublin, Ireland.

[0052] Although three-phase circuits for busbar systems are used in some examples of power distribution system 100, the implementation is not limited to this, as power distribution system 100 may be or may include other phase systems and / or conductors.

[0053] refer to Figure 1A The power distribution system 100 is depicted as a busbar system 120. The busbar system 120 includes multiple sections of busbars (or busbar "tracks") 121a to 121d connected in series. The busbar system is connected to the power source 103 at the input (line side) end 123a and to the load 105 at the output (load side) end 123b.

[0054] refer to Figure 1B and Figure 1CEach busbar trough 121 includes a busbar 112 arranged longitudinally within the main body or conduit 110 of the track 121. Figure 1C In a non-limiting example, busbar 121 is configured as a three-phase “sandwich” type busbar track with a three-phase four-wire system having A conductor 112a, B conductor 112b, C conductor 112c, optional neutral conductor or N conductor 112n, and grounding element 117.

[0055] The conductors (including conductor 112) of the power distribution system 100 may include insulated and non-insulated ends for forming electrical connections. (Reference) Figure 1B and Figure 1C Conductor 112 is coated with insulating portion 114. For example, the busbar may be coated with epoxy resin (such as epoxy powder), vinyl, and / or other insulating materials. In some embodiments, other insulating elements 115 may be included to replace or supplement the coated insulating portion 114, such as insulating blocks or other structures arranged around conductor 112. Insulating elements 114 and / or insulating elements 115 are used to reduce, minimize, eliminate, or prevent current leakage between conductors 112 and / or between conductor 112 and ground. Insulating elements 114 and / or insulating elements 115 may constitute the insulation system of system 120.

[0056] Figure 2A and Figure 2B An illustrative example of an electrical conductor monitoring system according to this disclosure is depicted. More specifically, Figure 2A and Figure 2B A block diagram depicting the internal view of the conductive section 121 of the electrical conductor monitoring system 200. Figure 2A and Figure 2B In a non-limiting example, the conduction section 121 is a busbar track of a three-phase busbar system. For example, conductors 112a to 112n may be or may include R-phase conductor 112a, Y-phase conductor 112b, B-phase conductor 112c, and grounding conductor 112n.

[0057] like Figure 2A and Figure 2BAs shown, one or more sensors 150, 151 may be electrically connected to one or more of conductors 112a to 112d. Sensors 150, 151 may be configured to measure one or more parameters associated with the current flowing through conductors 112a to 112d. Non-limiting examples of parameters may include current, voltage, etc. In some embodiments, sensors 150, 151 may include a pair of sensors configured to measure parameter values ​​at two different nodes 231, 232 along a measurement segment 230 along conductors 112a to 112n. A first sensor, upstream sensor, M1 sensor, or input sensor 150 may be configured to measure electrical parameters at an input or upstream location of conductor 121, and a second sensor, downstream sensor, M2 sensor, or output sensor 151 may be configured to measure electrical parameters at an output or downstream location of conductor 121. For example, with regard to the flow of current from power source 103 to load 105, sensor M1 is located upstream of sensor M2.

[0058] Although sensors 150 and 151 are depicted as being arranged within a single busbar section 121, the implementation is not limited thereto, as sensors 150 and 151 can be arranged in different sections (see, for example, [link to relevant documentation]). Figure 3 For example, sensor 150 may be arranged in a first segment 121a, and sensor 151 may be arranged in a second segment 121n, wherein the first segment 121a is upstream of the second segment 121n relative to the flow of current from power source 103 to load 105. Although only one power source or upstream sensor 150 and one load or downstream sensor 151 are depicted, the implementation is not limited thereto. For example, the upstream sensor 150 may be or may include multiple sensors (e.g., one sensor for each conductor 112a to 112n), and the downstream sensor 151 may be or may include multiple sensors (e.g., one sensor for each conductor 112a to 112n).

[0059] As described in more detail in this disclosure, the parameter values ​​(and / or electrical characteristics determined based on the measured parameter values) measured by sensors 150, 151 can be analyzed (e.g., compared) to assess any leakage current occurring in one or more conductors 112a to 112n as current flows from power source 103 to load 105. In some embodiments, the electrical characteristics determined based on the measured parameter values ​​may be or may include sequence values ​​for multiphase systems, such as negative sequence values, zero sequence values, and / or positive sequence values. For example, an electrical conductor monitoring system 200 can be operated to determine, for example, the sequence values ​​of a multiphase system such as negative sequence values, zero sequence values, and / or positive sequence values. Figure 2A The ground current leakage 210 between phase 112c and ground 112n shown, and as Figure 2BInterphase current leakage 211 between the phases shown (e.g., Y phase 112b and B phase 112c).

[0060] Figure 3 An illustrative example of an electrical conductor monitoring system according to this disclosure is depicted. For example... Figure 3 As shown, the electrical conductor monitoring system 300 may include a measurement system 310 and a conduction system monitoring device 312. The measurement system 310 may include multiple sensors, such as sensors 150 and 151 configured to measure one or more electrical parameters. In some embodiments, sensors 150 and 151 may be current sensors (e.g., but not limited to current transformers), power meters, or any other suitable measuring device. Figure 3 In a non-limiting example, input sensor 150 is located at input terminal 123a of bus trunking system 120 and is configured to continuously measure the input current of each of the three phases, and transmit the measured three-phase input current to monitoring device 312 via a wired or wireless connection. Output sensor 151 is located at output terminal 123b of bus trunking system 120 and is configured to continuously measure the output current of each of the three phases, and transmit the measured three-phase output current to monitoring device 312 via a wired or wireless connection.

[0061] In some implementations, busbars 121a to 121n can be connected in series without any contacts, and therefore for a healthy system (e.g., a system without short circuits or leakage currents at or below tolerance, threshold, or baseline amounts), the current values ​​for each phase remain the same (or substantially the same or reduced from the expected or baseline leakage current) when measured by the input sensor 150 at input 123a and the output sensor 151 at output 123b.

[0062] exist Figure 3In the depicted embodiment, monitoring device 312 is configured to receive measured three-phase input current and three-phase output current from input sensor 150 and output sensor 151, and determine the instantaneous state of system 120 based on the measured three-phase input current and three-phase output current. Monitoring device 312 may be, for example, a processing unit included in (e.g., but not limited to) a server, personal computer, portable computing device, workstation, main circuit breaker in load panel 330, etc. The processing unit may include a processor and memory. The processor may be, for example, but not limited to, a microprocessor, microcontroller, or some other suitable processing device or circuit system. The memory may be any one or more of various types of internal and / or external storage media (such as, but not limited to, RAM, ROM, EPROM, EEPROM, flash memory, etc.) that provide storage registers (e.g., machine-readable media) for data storage (including, but not limited to, internal storage areas of a computer), and may be volatile or non-volatile memory. The memory may store software or firmware applications for monitoring the state of system 120 and / or its components (such as insulation indicated by the determined leakage current).

[0063] Upon receiving the measured input and output phase currents, the monitoring device 312 extracts or derives sequence components, including positive-sequence, negative-sequence, and / or zero-sequence components, from the measured three-phase input and three-phase output currents. In some embodiments, the monitoring device 312 can compare the input sequence components with the corresponding output sequence components. For example, the monitoring device 312 obtains the difference between the positive-sequence components of the output phase current and the positive-sequence components of the input phase current by subtracting the positive-sequence component of the output phase current from the positive-sequence component of the input phase current. In various embodiments, the monitoring device 312 can determine a first difference or zero-sequence difference between the zero-sequence components of the output phase current and the zero-sequence components of the input phase current by subtracting the zero-sequence component of the output phase current from the zero-sequence component of the input phase current. In some embodiments, the monitoring device 312 can determine a second difference or negative-sequence difference between the negative-sequence components of the output phase current and the negative-sequence components of the input phase current by subtracting the negative-sequence component of the output phase current from the negative-sequence component of the input phase current.

[0064] In various implementations, monitoring device 312 can be operated to determine the transient state of system 120 and / or its components (e.g., insulation systems) based on sequence component differences, predefined baseline values ​​(tolerances), and predefined thresholds. Sequence component differences may include a first difference or zero difference associated with a zero-sequence component and a second difference or negative difference associated with a negative-sequence component. Predefined tolerances may include a first tolerance or zero-sequence tolerance associated with a zero-sequence component and a second tolerance or negative-sequence tolerance associated with a negative-sequence component. Predefined thresholds may include a first threshold or zero-sequence threshold associated with a zero-sequence component and a second threshold or negative-sequence threshold associated with a negative-sequence component. Tolerance values ​​and thresholds can be set or determined based on one or more threshold factors, including but not limited to the type of sensors 150, 151, the length of busbar system 120, the length of measurement section 230, voltage ratings, current ratings, and / or other factors. For example, a first tolerance may be (e.g., but not limited to) 10% of the three-phase input current, and a predefined first threshold may be (e.g., but not limited to) 20% of the three-phase input current.

[0065] The monitoring device 312 can be operated to determine whether the system 120 (and / or its components) is in a healthy or faulty state based on whether the first difference and / or the second difference is less than or greater than the corresponding tolerance. Figure 4 A graph depicts monitoring information of healthy conductor segments according to this disclosure, and Figure 5 A chart depicts monitoring information of a faulty conductor segment according to this disclosure.

[0066] For example, refer to Figure 4 Figure 405 shows that the first difference between the measured zero-sequence three-phase input current and the three-phase output current has no peak (ΔZ is below the fault threshold), and Figure 410 shows that the second difference between the measured negative-sequence three-phase input current and the three-phase output current has no peak (ΔN is below the fault threshold). In another example, refer to Figure 5 Figure 505 illustrates a phase-to-ground fault in busbar system 120 based on a peak value (ΔZ above the fault threshold) detected in the first difference between the measured zero-sequence values ​​of the three-phase input current and the three-phase output current (e.g., as shown in Figure 505). Figure 2A The short circuit 210 between phase and ground shown in Figure 510, and Figure 510 showing the peak value (ΔN above the fault threshold) detected in the second difference between the measured negative sequence of the three-phase input current and the three-phase output current, indicates that the bus trunking system 120 contains phase-to-phase faults (e.g., as shown in Figure 510). Figure 2B The short circuit 211 between phase Y and phase B is shown.

[0067] The monitoring device 312 can also be configured to determine the severity of a detected fault. For example, the monitoring device 312 can determine that a phase-to-ground fault has a low severity based on the fact that a first difference is greater than a first tolerance but less than a first threshold. In such a low-severity phase-to-ground fault scenario, the busbar system 120 can continue to operate. The monitoring device 312 can determine that a phase-to-ground fault has a high severity based on the fact that a first difference is greater than the first threshold. In such a high-severity phase-to-ground fault scenario, it may be necessary to immediately shut down the busbar system 120. The monitoring device 312 can determine that a phase-to-phase fault has a low severity based on a second difference that is greater than a second tolerance but less than a second threshold. In such a low-severity phase-to-phase fault scenario, the busbar system 120 can continue to operate and remain operational. The monitoring device 312 can determine that a phase-to-phase fault has a high severity based on the fact that a second difference is greater than the second threshold, requiring the immediate shutdown of the busbar system 120.

[0068] In some implementations, upon detecting a fault and its type (e.g., low severity – above tolerance / below threshold, or high severity – above threshold), monitoring device 312 may also be configured to detect power losses in the insulation system and identify one or more faulty phases of the insulation system. That is, sensors 150, 151 may measure the input and output power of each phase (e.g., but not limited to phases A, B, C or R, Y, B) at the corresponding ends 123a, 123b (or over the span of measurement section 230), detect power losses, and identify the faulty phase based on the detected power losses.

[0069] For example, in some embodiments, the input sensor 150 can measure the input power of each phase A, B, and C at input terminal 123a (or upstream node 231 of measurement section 230), and the output sensor 151 can measure the output power of each phase A, B, and C at output terminal 123b (or downstream node 232 of measurement section 230). The monitoring device 312 then obtains the difference between the input power (or sequence component) and the output power (or sequence component) of each phase by subtracting the phase output power (or sequence component) from the corresponding phase input power (or sequence component).

[0070] If the difference between the output power (or sequence component) and the input power (or sequence component) is less than the baseline power loss (power loss tolerance), the monitoring device 312 determines that the corresponding phase is healthy. If the difference is greater than the power loss tolerance, the monitoring device 312 determines that the corresponding phase is faulty. The power loss tolerance may vary depending on, for example, but not limited to, the type of measuring device, the length of the insulation system 24, the length of the measuring section 230, the current rating, the ampere rating, etc.

[0071] Table 1 provides illustrative fault phase identification:

[0072]

[0073]

[0074] Table 1

[0075] In Table 1, the power loss of each phase (PLossA, PLossB, PLossC) is determined by assigning a value of "0" to a healthy state and a value of "1" to a fault state. By determining the power loss of each phase, the monitoring device 312 can detect a variety of fault scenarios (e.g., but not limited to all phase faults).

[0076] In addition, monitoring device 312 may also include an indicator. The indicator may be (e.g., but not limited to) a set of LEDs, a graphic display, and / or audio components, and is configured to indicate the transient status of the insulation system, including alerts to the user regarding detected faults and their severity. In some embodiments, monitoring device 312 may include a display to present warning messages, fault states, system status, etc. In various embodiments, monitoring device 312 may be configured to transmit messages indicating warning messages, fault states, system status, etc., via a network to an operator's computing device.

[0077] For example, if system 120 (or its components, such as the insulation system) is determined to be healthy, no alarm is generated, and the indicating device indicates the health status by illuminating or displaying (e.g., but not limited to, a green LED). If system 120 (or its components, such as the insulation system) is determined to contain a low-severity fault, the indicating device generates a moderate alarm indicating the low severity, the type of fault, and any recommended remedies. If system 120 (or its components, such as the insulation system) is determined to contain a high-severity fault, the indicating device may generate a severe alarm indicating the high severity, the type of fault, and remedies requiring immediate action. Furthermore, the indicating device may indicate the identification of one or more faulty phases by, for example, displaying or transmitting messages to a user. In some embodiments, in the event of a severe fault, the monitoring device may shut down, isolate, or otherwise prevent power flow through the affected conductor section.

[0078] Figure 6 An illustrative example of a monitoring method for an electrical conductor monitoring system according to this disclosure is described. More specifically, Figure 6 A monitoring method 600 for real-time monitoring of the status of electrical conduction systems in a power distribution system is shown. Method 600 can be performed by one of monitoring systems 200 or 300 and / or any of its components.

[0079] In step 610, the input measuring device (M1 or upstream sensor) measures the three-phase input current at the input terminal (or upstream node) of the bus trunking system (or the measurement section of the bus trunking system), and the output measuring device (M2 or downstream sensor) measures the three-phase output current at the output terminal (or downstream node) of the bus trunking system (or the measurement section of the bus trunking system). The measuring device then transmits the measured input and output three-phase current data to the monitoring device.

[0080] At step 620, the monitoring device derives sequence components from the measured three-phase input and three-phase output currents, which include, for example, zero-sequence, positive-sequence, and / or negative-sequence components. In some examples, the output measuring device (or downstream sensor) may determine the sequence components and transmit the three-phase current data including the sequence components to the monitoring device.

[0081] At step 630, the monitoring device compares the sequence components of the measured three-phase input current and the three-phase output current by obtaining the difference between the output component sequence and the corresponding input component sequence.

[0082] At step 640, the monitoring device determines the instantaneous state of the busbar system (or the measurement section of the busbar system) based on the difference and predefined tolerances and thresholds. If the difference is within the tolerance range, at step 642, the insulation device determines that the insulation system is healthy. If the difference between the measured negative-sequence components of the three-phase input current and the three-phase output current is greater than a second tolerance, at step 644, the monitoring device determines that the busbar system contains a phase-to-phase fault. If the difference between the measured zero-sequence components of the three-phase input current and the three-phase output current is greater than a first tolerance, at step 646, the monitoring device determines that the busbar system contains a phase-to-ground fault. The monitoring device then further determines the severity of the detected fault and sends an alarm to the operator based on the severity of the detected fault (e.g., exceeding the tolerance but below the threshold; exceeding the threshold; etc.).

[0083] Therefore, monitoring system 300 and method 600 allow for real-time monitoring of the instantaneous status of the busbar system (and / or its components, such as insulation systems) without requiring the shutdown of system 120 as required by existing insulation fault measurement systems, thus eliminating production and profit losses associated with using existing electrical insulation fault measurement systems. Furthermore, by providing alerts based on the severity of the detected faults, monitoring system 300 and method 600 enable operators to take appropriate remedial measures as needed.

[0084] Figure 7A graph depicts fault indication information of the electrical conductor monitoring system according to this disclosure. By providing a progression of the severity of the detected fault, the electrical insulation monitoring system 300 helps to accurately determine whether warranty service should apply due to the detected fault. For example, if the change in fault severity indicates a natural insulation degradation pattern as shown in graph 705, it can be determined that the fault is covered under warranty due to insulation degradation. However, if the change in fault severity indicates a non-natural insulation degradation pattern (i.e., a sudden surge) as shown in graph 710, further investigation can be performed to accurately determine whether warranty service applies. For example, if the investigation indicates that the detected fault was caused by an accident or operator negligence, the warranty is not applicable.

[0085] Furthermore, the electrical insulation monitoring system 300 is implemented by adding measuring devices 150, 151 at the input terminals 123a and 123b (or upstream node 231 and downstream node 232) of system 120, thus requiring minimal modifications to the equipment of system 120. Moreover, the monitoring system 300 and method 600 are applicable to any configuration of three-phase system, such as grounded or ungrounded three-phase three-wire systems or three-phase four-wire systems, including three-phase systems operating under balanced or unbalanced loads.

[0086] In some implementations, differential monitoring methods may include using differential input and output power or current measurements to identify the phase of a fault and / or estimate the severity of the fault. Such differential values ​​can also be used to estimate the fault current magnitude (e.g., in amperes (e.g., milliamperes or mA)) and insulation resistance (R0). i ).

[0087] Differential monitoring methods can be used in single-phase or multi-phase AC systems, communication systems, and / or DC power supply systems, as well as systems operating at low, medium, or high voltages. In some implementations, the input signal is an AC sinusoidal measurement signal. However, implementations are not limited to this, as various implementations can operate with other types of signals, such as DC signals, pulse signals, triangular waveform signals, etc., where voltage and current flow through the line. Therefore, differential methods can be used in power distribution systems and communication systems to locate faults or signal leaks (e.g., due to insulation degradation, damage, or leakage).

[0088] Figure 8 An illustrative example of an electrical conductor monitoring system according to this disclosure is depicted. For example... Figure 8As shown, the electrical conductor monitoring system 800 may include a conduction system 120 (e.g., busbar, cable (with or without trays or other conduits), transmission line, communication line, etc.), wherein the measurement section 230 is operatively coupled to sensors 150, 151 configured to measure the electrical parameters of the measurement section 230. In some embodiments, the conduction system 120 may be a single-phase conduction system. The monitoring device 312 may be communicatively coupled to the sensors 150, 151.

[0089] Sensors 150 and 151 can be configured to measure electrical parameters of the power flowing through measurement section 230, such as current, voltage, and / or other parameters. The information measured by sensors 150 and 151 can be, or can be used to, determine the current in vector form as IS (power supply side or upstream side) and IL (load side or downstream side). In some embodiments, IL may include... As the amplitude and phase of the power frequency current on the power supply side or upstream side, IS can include The amplitude and phase of the power frequency current on the load side or downstream side.

[0090] In some implementations, the amplitude (D) can be determined as follows: D = I1 - I2. The amplitude can be a peak value obtained from the current spectrum at a specified power supply frequency (e.g., 50Hz, 60Hz, etc.). In various implementations, the phase difference or angle ( or It can be determined in the following ways: In various implementations, the differential method performed by the monitoring system can be used to monitor the amplitude (D) and phase difference over time. Both. Figure 9 An illustrative example of phase shift or mismatch of current in vector form is depicted. Phase shift or mismatch can occur due to various factors, such as current sensor phase error, insulation capacitance, faults, etc.

[0091] In some implementations, a current mismatch method based on a differential method according to various embodiments can be used. This is used to detect and monitor faults, such as single-phase faults (e.g., line-to-neutral or line-to-ground). In some implementations, current mismatch methods based on differential methods according to various embodiments can be used. To detect and monitor faults, such as DC power supply insulation leakage current faults (e.g., line (+) to loop (-) or line (+) to ground (0V)).

[0092] In some implementations, the differential method can be performed by executing a software application on the monitoring device. In various implementations, the differential method may include collecting instantaneous samples of the current on the power supply side (upstream) and the load side (downstream), for example, by measurement via sensors 150, 151. A bandpass filter can be applied to focus on a desired frequency of interest, such as the power supply frequency (or multiple frequencies) or any other analog signal (DC / AC). A phase shift can be determined between the two filtered signals (IS and IL). If a phase shift exists, the shift can be measured and the angle can be recorded. or Phase shift can be removed and two signals can be made in phase (i.e., the phase difference is zero or approximately zero). The residual signal can be determined by subtracting two instantaneous signals (with zero phase shift), and the residual amplitude offset between the two signals can be calculated.

[0093] Figure 10 A graph depicts monitoring information on the amplitude (D) according to this disclosure. For example... Figure 10 As shown, Figure 1005 depicts a healthy system with an amplitude (D) below the reference baseline, while Figure 1010 depicts a faulty system with an amplitude (D) above the reference baseline. Figure 11 The phase difference value according to this disclosure is described Charts of monitoring information. For example... Figure 11 As shown, Figure 1105 depicts the phase difference values. A healthy system is below the reference baseline, and Figure 1110 depicts the phase difference. Systems with faults exceeding the reference baseline. For Figure 10 and Figure 11 The charts and fault indicator monitoring information depicted can be determined in the following ways:

[0094] Differential methods can be used for periodic AC signals, DC signals, communication signals, etc. For example, the spectrum of a residual signal can be determined, and the peak value of a desired frequency within the spectrum can be calculated. For DC signals, the average value or mean of the DC signal can be determined in the time domain, or the peak value at 0 Hz can be determined in the spectrum. For non-periodic signals, the greater the severity of the fault, the higher the D... or D and The greater the offset between the two in the time domain, the better. For periodic signals, the peak value, variance, standard deviation, and / or other statistical parameters in the time domain or spectrum of AC signals or other periodic types can be used.

[0095] In some implementations, for a given line current, the fault current I fThe fault current can be determined or estimated using the deviation of the current relative to the corresponding baseline value (i.e., fault current = baseline value - (IS – IL)). Once the leakage fault current (I) is determined... f (Unit: mA), then the insulation resistance (R) can be determined using the following formula. i The estimated value of R: i =V / I f Where V is the power supply voltage. In some implementations, the fault current (Ifault) is... f The value can be determined by monitoring system 300 according to the monitoring method and / or by monitoring system 800 according to the differential monitoring method.

[0096] In a healthy system, R i It is in the megaohm (MΩ) range. However, due to faults or insulation damage or deterioration, the insulation resistance may drop to the kΩ range, the Ω range, and even to about 0Ω.

[0097] Figure 12 The R described in this disclosure i A chart showing monitoring information over time. For example... Figure 12 As shown in Figure 1205, R i It can decrease over time, for example, to the level of failure and / or malfunction. Figure 13 A graph depicts monitoring information from a fault indicator according to this disclosure. For example... Figure 13 As shown in Figure 1305, the fault current or fault indicator corresponding to the baseline can be determined—used to determine whether the system is in a healthy state or a faulty state.

[0098] According to various implementation methods of monitoring systems, the fault current R (or Rfault current) is continuously monitored over a period of time. i The value of this value allows the monitoring system to determine the remaining service life (RUL) of the insulation system and / or a portion of the insulation. For example, each increase in insulation temperature reduces the insulation's life by a percentage point decrease in RUL. In a non-limiting example, a 10-degree Celsius increase in insulation temperature would result in an approximately 50% decrease in RUL. The temperature increase may be due to the amount of leakage current. Therefore, RUL can be determined based on leakage current (e.g., based on the increase in insulation temperature corresponding to an increase in leakage current).

[0099] In some implementations, multiple frequencies (e.g., those present in the power supply voltage spectrum), such as harmonics or load frequencies, can be considered in the residual current analysis. Power supply frequency voltages (e.g., 50Hz or 60Hz) will have higher amplitudes, such as 110V, 220V, 440V, etc. Therefore, most of the leakage current will have a 50 / 60Hz component. The harmonics of the power supply frequency will have very low amplitudes (in the mV or 1V range). Therefore, the amplitudes of these harmonic frequency components may be reduced in the residual time-domain current spectrum. If the current spectra of the power supply current and load current are subtracted, the resulting differences can only be observed in the line frequency (e.g., 50 / 60Hz) component, and the corresponding harmonic components may not show any difference. Without being limited to theory, the resulting variation is solely due to insulation leakage current, as it depends on the power supply voltage and insulation resistance value, and not due to interference from nearby conductors. For the same R... i Low / high voltage will result in low / high leakage current values. The magnitude of each frequency component in the power supply voltage spectrum (e.g., power supply frequency and power supply frequency harmonics and / or other components) divided by the magnitude of the same frequency component in the residual current spectrum can indicate (R0). i The value of ) is crucial for monitoring the RUL of conductor insulation.

[0100] Therefore, monitoring such modes according to some implementation methods can achieve effective and accurate monitoring of the conduction system and associated components (such as insulation systems).

[0101] While specific embodiments have been described in detail, those skilled in the art will understand that various modifications and substitutions can be made to these details in light of the general teachings of this disclosure. Therefore, the specific configurations disclosed are intended to be illustrative only and not to limit the scope of the disclosed concepts, which should be given the full breadth of the appended claims and any and all their equivalents.

Claims

1. A power distribution system, comprising: A conduction system, formed by at least one segment of a multiphase conductor, is configured to transmit current between a current source and a current load. A measurement system, operatively coupled to the multiphase conductor to measure current information of the multiphase conductor, the measurement system including at least one upstream sensor and at least one downstream sensor arranged at opposite ends of a measurement section of the multiphase conductor; as well as The conduction system monitoring device is communicatively connected to the sensor system, and the conduction system monitoring device operates as follows: The order component is determined based on the current information received from the sensor system. The sequence component difference is determined by comparing the upstream sequence component at the upstream node of the measurement section with the downstream sequence component at the downstream node of the measurement section. The sequence component difference is associated with the leakage current of at least one of the multiphase conductors. The state of the conduction system is determined based on the sequence component difference.

2. The power distribution system according to claim 1, wherein, The multiphase conductor includes a three-phase conductor.

3. The power distribution system according to claim 2, wherein the conduction system monitoring device is further operated to determine the sequence component difference as the zero-sequence component difference based on the difference between the upstream zero-sequence component and the downstream zero-sequence component.

4. The power distribution system according to claim 3, wherein the conduction system monitoring device further operates to determine an interphase fault in response to the zero-sequence component difference being greater than a zero-sequence threshold.

5. The power distribution system according to claim 2, wherein the conduction system monitoring device is further operated to determine the sequence component difference as a negative sequence component difference based on the difference between the upstream negative sequence component and the downstream negative sequence component.

6. The power distribution system according to claim 3, wherein the conduction system monitoring device further operates to determine a phase-to-ground fault in response to a negative sequence component difference greater than a negative sequence threshold.

7. The power distribution system according to claim 2, wherein, The state includes the state of the insulation system, which is configured to provide insulation between the multiphase conductors and between the multiphase conductors and ground.

8. The power distribution system of claim 7, wherein the conduction system monitoring device is configured to determine the progression of the increase in the sequence component difference.

9. The power distribution system of claim 8, wherein the conduction system monitoring device is configured to determine whether a fault caused by the sequence component difference exceeding a threshold is due to deterioration of the insulation system.

10. The power distribution system according to claim 2, wherein the conduction system monitoring device is further operable to: determine the fault state of each phase of the multiphase conductor, and The phase with the interphase fault is determined based on the sequence component difference of each phase of the multiphase conductor.

11. An electrical insulation health monitoring system for use in a power distribution system having three-phase conductors and an insulation system, comprising: A measuring device includes an input measuring device and an output measuring device, the input measuring device being disposed at the input end of the power distribution system and configured to measure the three-phase input current at the input end, and the output measuring device being disposed at the output end of the power distribution system and configured to measure the three-phase output current at the output end; as well as An insulation health monitoring device is communicatively connected to the input measuring device and the output measuring device, and the insulation health monitoring device is configured to receive the three-phase input current and the three-phase output current to determine the instantaneous state of the insulation system based on the measured three-phase input current and three-phase output current.

12. The electrical insulation health monitoring system according to claim 11, wherein, The insulation health monitoring device is configured to determine the instantaneous state of the insulation system in the following manner: The sequence components are derived from the measured three-phase input current and three-phase output current. Obtain the sequence component difference between the input current sequence component of the three-phase input current and the output current sequence component of the three-phase output current, and The instantaneous state of the insulation system is determined based on the difference in the sequence components.

13. The electrical insulation health monitoring system according to claim 12, wherein, The insulation health monitoring device is also configured to: The insulation system is determined to be in a healthy state based on the determination that the difference in the sequence components is less than the corresponding tolerance, or The insulation system is determined to contain a fault based on determining that one or more differences in the sequence components are greater than the corresponding tolerance.

14. The electrical insulation health monitoring system according to claim 13, wherein, The order components include zero-order components and negative-order components. The difference includes a first difference between the zero-sequence component of the three-phase input current and the zero-sequence component of the three-phase output current, and a second difference between the negative-sequence component of the three-phase input current and the negative-sequence component of the three-phase output current. The insulation health monitoring device is further configured to determine the type and severity of detected faults based on thresholds, the types including phase-to-ground faults based on determining that the first difference is greater than a first threshold and phase-to-phase faults based on determining that the second difference is greater than a second threshold.

15. The electrical insulation health monitoring system according to claim 11, wherein, The insulation health monitoring device is also configured to determine a degradation mode based on the instantaneous state of the insulation system, wherein the degradation mode includes a natural degradation mode applicable to warranty service and a non-natural degradation mode requiring investigation.

16. A method for monitoring the insulation health of an insulation system in a power distribution system, the method comprising: A measurement system is provided, the measurement system being operatively coupled to at least one conductor of the conduction system of the power distribution system to measure current information of current flowing from a power source through the at least one conductor to a load, the measurement system including at least one power-side sensor and at least one load-side sensor arranged at opposite ends of a measurement section of the at least one conductor. as well as The following is performed via the insulation health monitoring system: Collect current information of the power supply side current of the at least one power supply side sensor and current information of the load side current of the at least one load side sensor. Based on the current information, the power supply side current vector (IS) and the load side current vector (IL) are determined. The fault current (I) is determined based on the difference between IS and IR. f ),as well as Based on I f Estimate insulation resistance (R) i ).

17. The method of claim 16, further comprising, via the insulation health monitoring system, based on R i Determine the remaining useful life (RUL) of at least one component of the insulation system.

18. The method of claim 16, further comprising, via the insulation health monitoring system, based on R i =V / I f Determine R i ,in, V is the power supply voltage value.

19. The method of claim 16, wherein, The power supply side current vector (IS) includes the magnitude (I1) and angle of the power supply side current. Furthermore, the load-side current vector (IS) includes the magnitude (I2) and angle of the load-side current.

20. The method of claim 16, further comprising applying a filter via the insulation health monitoring system to use current information at a power frequency of interest.

Images