Feeder terminal and fault detecting and positioning method
By adding a traveling wave module to the feeder terminal and electrically connecting it to the positioning and timing module, and combining the detection methods of power frequency signal and traveling wave signal, the problem of inaccurate location of power line faults in the existing technology is solved, and high-precision fault detection and location are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING HEXINRUITONG POWER TECH
- Filing Date
- 2025-09-29
- Publication Date
- 2026-05-12
AI Technical Summary
Existing feeder terminals cannot accurately locate power line faults, and fault detection based solely on power frequency signals has inherent errors.
A traveling wave module is added to the feeder terminal and electrically connected to the positioning and timing module. By acquiring the electrical signals on the power line and determining the power frequency signal and traveling wave signal, the fault cycle and time are determined in combination with the timing information.
It achieves high-precision fault detection, avoids missed detection and delayed detection, and can accurately locate the fault location.
Smart Images
Figure CN122017444A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power line monitoring technology, specifically to a feeder terminal and a fault detection and location method. Background Technology
[0002] Feeder terminals are intelligent terminal devices installed in distribution rooms or on feeders. They can communicate with remote distribution substations, sending operational data of the power distribution equipment to the substations, and also receiving control commands from the substations to control and regulate the power distribution equipment. Feeder terminals are small in size, numerous in number, and can be installed on outdoor feeders. They are equipped with transmitters, direct AC sampling, and are resistant to high temperatures and extreme cold, adapting to harsh outdoor environments. With continuous technological advancements, current feeder terminals also possess the capability for power line fault detection.
[0003] Current feeder terminals typically detect faults by sampling power frequency signals, but they cannot accurately pinpoint the location of the fault. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a feeder terminal and a fault detection and location method.
[0005] In one embodiment, the present invention provides a feeder terminal, which includes a feeder module, a traveling wave module, and a positioning and timing module.
[0006] The feeder module is electrically connected to the positioning and timing module and the traveling wave module respectively. It is used to acquire electrical signals on the target power line and determine the power frequency signal in the electrical signals. Based on the timing information output by the positioning and timing module and the power frequency signal, it determines the target period when the target power line has a fault and sends it to the traveling wave module.
[0007] The traveling wave module is electrically connected to the positioning and timing module. It is used to acquire electrical signals on the target power line and identify the traveling wave signal in the electrical signals. Based on the timing information output by the positioning and timing module and according to the traveling wave signal and the target period, it determines the target time when a fault occurs on the target power line.
[0008] In one embodiment, the feeder module includes a first signal sensor, a first signal conditioning unit, and a first processing unit;
[0009] The first signal sensor is electrically connected to the signal input terminal of the first processing unit through the first signal conditioning unit, the timing input terminal of the first processing unit is electrically connected to the positioning timing module, and the communication terminal of the first processing unit is electrically connected to the traveling wave module.
[0010] The first signal sensor is used to acquire electrical signals on the target power line and output power frequency signals to the first processing unit through the first signal conditioning unit;
[0011] The first processing unit is used to determine the target period when the target power line fails, based on the timing information and the power frequency signal, and send it to the traveling wave module.
[0012] In one embodiment, the traveling wave module includes a second signal conditioning unit and a second processing unit;
[0013] The first signal sensor is also electrically connected to the signal input terminal of the second processing unit through the second signal conditioning unit. The timing input terminal of the second processing unit is electrically connected to the positioning timing module, and the communication terminal of the second processing unit is electrically connected to the communication terminal of the first processing unit.
[0014] The first signal sensor is used to acquire electrical signals on the target power line and output traveling wave signals to the second processing unit through the second signal conditioning unit;
[0015] The second processing unit is used to determine the target time when a fault occurs on the target power line based on the timing information and according to the traveling wave signal and the target period.
[0016] In one embodiment, the traveling wave module includes a second signal sensor, a second signal conditioning unit, and a second processing unit;
[0017] The second signal sensor is electrically connected to the signal input terminal of the second processing unit through the second signal conditioning unit. The timing input terminal of the second processing unit is electrically connected to the positioning timing module. The communication terminal of the second processing unit is electrically connected to the communication terminal of the first processing unit.
[0018] The second signal sensor is used to acquire electrical signals on the target power line and output traveling wave signals to the second processing unit through the second signal conditioning unit;
[0019] The second processing unit is used to determine the target time when a fault occurs on the target power line based on the timing information and according to the traveling wave signal and the target period.
[0020] In one embodiment, the second signal sensor includes a Rogowski coil and an integrating circuit;
[0021] The Rogowski coil is electrically connected to the input terminal of the integrating circuit, and the output terminal of the integrating circuit is electrically connected to the signal input terminal of the second processing unit through the second signal conditioning unit.
[0022] Rogowski coils are used to acquire electrical signals on the target power line and output differential signals to the integrator circuit;
[0023] The integrating circuit is used to restore the differential signal and output a traveling wave signal to the second processing unit through the second signal conditioning unit.
[0024] In one embodiment, the second signal conditioning unit includes a bandpass filter circuit and an ADC sampling circuit;
[0025] The bandpass filter circuit is electrically connected to the signal input terminal of the second processing unit through the ADC sampling circuit;
[0026] The bandpass filter circuit is used to perform bandpass filtering on the incoming signal to obtain a traveling wave signal, which is then output to the second processing unit through the ADC sampling circuit.
[0027] In one embodiment, the bandpass filter circuit has a filtering range of 100Hz to 2MHz; and / or, the sampling rate of the ADC sampling circuit is not less than 4MHz.
[0028] Secondly, the present invention provides a fault detection and location method, applied to the feeder terminal in any of the above embodiments; the fault detection and location method includes:
[0029] The feeder module acquires the electrical signals on the target power line and determines the power frequency signal in the electrical signals. Based on the timing information output by the positioning and timing module and according to the power frequency signal, it determines the target period when the target power line fails and sends it to the traveling wave module.
[0030] The traveling wave module acquires the electrical signals on the target power line and identifies the traveling wave signal within the electrical signals. Based on the timing information output by the positioning and timing module and according to the traveling wave signal and the target period, it determines the target time when a fault occurs on the target power line.
[0031] In one embodiment, determining the target period when a fault occurs in the target power line based on the timing information output by the positioning and timing module and according to the power frequency signal includes:
[0032] Based on timing information and difference algorithm, the target difference between the power frequency signal in the current cycle and the previous cycle is determined;
[0033] If the target difference is greater than the preset difference, the current period will be determined as the target period.
[0034] In one embodiment, determining the target time when a fault occurs on the target power line based on the timing information output by the positioning and timing module and according to the traveling wave signal and the target period includes:
[0035] Based on timing information, determine the traveling wave component in the traveling wave signal that corresponds to the target period;
[0036] Determine the maximum value in the traveling wave component, and then determine the time corresponding to the maximum value in the traveling wave component as the target time.
[0037] In one embodiment, after determining the target time when a fault occurs on the target power line, the fault detection and location method further includes:
[0038] The traveling wave module acquires the first recorded wave signal located before the target time from the traveling wave signal according to the first time interval, and acquires the second recorded wave signal located after the target time from the traveling wave signal according to the second time interval. It generates and saves a recorded wave file based on the first recorded wave signal, the target time, and the second recorded wave signal.
[0039] In one embodiment, after determining the target time when a fault occurs on the target power line, the fault detection and location method further includes:
[0040] The traveling wave module sends the target time to the feeder module;
[0041] The feeder module sends the target time and the positioning information output by the positioning and timing module to the processing backend, so that the processing backend can perform a two-end algorithm based on the positioning information, the target time and the propagation speed of the power line to obtain the fault location when the target power line has a fault.
[0042] In one embodiment, after determining the target time when a fault occurs on the target power line, the fault detection and location method further includes:
[0043] The traveling wave module sends the target time to the feeder module;
[0044] The feeder module uses a dual-end algorithm based on the positioning information output by the positioning and timing module, the target time, and the propagation speed of the power line to obtain the fault location when the target power line has a fault.
[0045] By employing the aforementioned feeder terminal and fault detection and location method, a traveling wave module is added to the existing feeder module and positioning and timing module, electrically connected to both. This allows the feeder module to acquire electrical signals on the target power line and identify the power frequency signal within them. Based on the timing information output by the positioning and timing module and the power frequency signal, the target period when a fault occurs on the target power line is determined and sent to the traveling wave module. The added traveling wave module further acquires electrical signals on the target power line and identifies the traveling wave signal within them. Based on the timing information output by the positioning and timing module and the traveling wave signal and the target period, the target time when a fault occurs on the target power line is determined. This invention achieves preliminary period detection based on the feeder module and power frequency signal, and further time detection based on the traveling wave module and traveling wave signal. The two modules work together, requiring minimal modification to the traditional feeder module, and achieving high-precision fault detection, effectively avoiding problems such as missed detection and delayed detection. Attached Figure Description
[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0047] Figure 1 This is a schematic diagram of the structure of a feeder terminal in one embodiment of the present invention;
[0048] Figure 2 This is a schematic diagram of a feeder module including a first signal sensor, a first signal conditioning unit, and a first processing unit in one embodiment of the present invention;
[0049] Figure 3 This is a schematic diagram of a traveling wave module including a second signal conditioning unit and a second processing unit in one embodiment of the present invention;
[0050] Figure 4 This is a schematic diagram of a traveling wave module including a second signal sensor, a second signal conditioning unit, and a second processing unit in one embodiment of the present invention;
[0051] Figure 5 This is a schematic diagram of the specific structures included in a feeder terminal according to one embodiment of the present invention;
[0052] Figure 6 This is a flowchart illustrating a fault detection and localization method in one embodiment of the present invention. Detailed Implementation
[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0054] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified. In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to implement and use the invention. In the following description, details are set forth for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.
[0055] Firstly, such as Figure 1 As shown, in one embodiment, the present invention provides a feeder terminal, which includes a feeder module, a traveling wave module, and a positioning and timing module.
[0056] The positioning and timing module can output timing information and positioning information. The timing information is used to synchronize the feeder terminals in time, and the positioning information is used to enable the feeder terminals to determine their current location.
[0057] The feeder module is electrically connected to the positioning and timing module and the traveling wave module respectively. It is used to acquire electrical signals on the target power line and determine the power frequency signal in the electrical signals. Based on the timing information output by the positioning and timing module and the power frequency signal, it determines the target period when the target power line has a fault and sends it to the traveling wave module.
[0058] Among them, power transmission line systems are usually used to transmit multiphase alternating current and cover long distances. Therefore, the target power line refers to the power line of a certain phase at a certain geographical location in the power transmission line system, such as the power line of phase A at location x.
[0059] The signals transmitted on power lines are usually obtained by superimposing multiple signals. Therefore, the electrical signal on the target power line refers to the mixed signal after superimposing multiple signals on the target power line, with the power frequency signal being the main one.
[0060] Specifically, power frequency signal refers to the alternating current frequency signal used in power systems, typically 50Hz in my country, and 60Hz in some countries (such as the United States). Power frequency signal includes power frequency voltage signal and power frequency current signal, and is widely used in power generation, transmission, and distribution. In this embodiment, the feeder module can acquire and process electrical signals on the target power line through relevant acquisition strategies to obtain the power frequency signal contained within the electrical signals, thereby facilitating functions such as monitoring of the feeder terminal.
[0061] In addition to performing traditional feeder terminal monitoring functions based on the obtained power frequency signal, the feeder module in this embodiment further performs preliminary fault analysis on the power frequency signal based on the timing information output by the positioning mode under the premise that the target power line is faulty, thereby determining the target period when the target power line is faulty and sending it to the traveling wave module.
[0062] It is important to note that when a fault exists on the target power line, the fault point will generate a traveling wave signal that propagates towards both ends of the line. Because the traveling wave signal has a high frequency, the feeder module used for power frequency signal acquisition cannot obtain a complete and accurate traveling wave characteristic. This results in fault detection based on power frequency signals failing to accurately detect the traveling wave characteristics. Therefore, this embodiment only uses the feeder module to perform preliminary fault detection based on power frequency signals, and the result obtained is not the final fault detection result.
[0063] The traveling wave module is electrically connected to the positioning and timing module. It is used to acquire electrical signals on the target power line and identify the traveling wave signal in the electrical signals. Based on the timing information output by the positioning and timing module and according to the traveling wave signal and the target period, it determines the target time when a fault occurs on the target power line.
[0064] The added traveling wave module also uses the timing information output by the positioning and timing module to perform signal processing. This allows the traveling wave module and the feeder module to be synchronized in time, enabling reliable signal interaction and ultimately improving fault detection accuracy.
[0065] Specifically, as mentioned above, the feeder module can determine the target period when the target power line experiences a fault based on the power frequency signal. In other words, while the feeder module cannot pinpoint the exact moment of the fault, that moment falls within the target period. The traveling wave module, on the other hand, can acquire and process the electrical signals on the target power line using relevant acquisition strategies, thereby obtaining a traveling wave signal contained within the electrical signals. Since the traveling wave signal obtained by the traveling wave module contains relatively complete traveling wave characteristics, it can accurately determine the exact moment of the fault on the target power line. Combined with the target period already determined by the feeder module, the traveling wave module only needs to consider the traveling wave signal within the target period, and through correlation analysis, obtain the target moment of the fault on the target power line.
[0066] By using the aforementioned feeder terminal, a traveling wave module is added to the existing feeder module and positioning / timing module, electrically connected to both. This allows the feeder module to acquire electrical signals on the target power line and identify the power frequency signal within them. Based on the timing information output by the positioning / timing module and the power frequency signal, the target period when a fault occurs on the target power line is determined and sent to the traveling wave module. The added traveling wave module further acquires electrical signals on the target power line and identifies the traveling wave signal within them. Based on the timing information output by the positioning / timing module and the traveling wave signal and the target period, the target time when a fault occurs on the target power line is determined. This invention achieves preliminary period detection based on the feeder module and power frequency signal, and further time detection based on the traveling wave module and traveling wave signal. The two modules work together, requiring minimal modification to the traditional feeder module, and achieving high-precision fault detection, effectively avoiding problems such as missed detections and delayed detections.
[0067] like Figure 2 As shown, in one embodiment, the feeder module includes a first signal sensor, a first signal conditioning unit, and a first processing unit.
[0068] The first signal sensor is electrically connected to the signal input terminal of the first processing unit through the first signal conditioning unit. The timing input terminal of the first processing unit is electrically connected to the positioning timing module. The communication terminal of the first processing unit is electrically connected to the traveling wave module.
[0069] The first signal conditioning unit is mainly used to condition the signal output by the first signal sensor so that it meets the relevant requirements of the first processing unit.
[0070] The first signal sensor is used to acquire electrical signals on the target power line and output power frequency signals to the first processing unit through the first signal conditioning unit.
[0071] Specifically, the first signal sensor is used to extract the signal component with the main frequency of power frequency in the electrical signal, and the first signal conditioning unit can adjust the amplitude and / or convert the signal component into an analog-to-digital signal, and finally output the power frequency signal to the first processing unit.
[0072] The first processing unit is used to determine the target period when the target power line fails, based on the timing information and the power frequency signal, and send it to the traveling wave module.
[0073] The first processing unit, as the core of the feeder module, is responsible for signal calculation and processing. Therefore, after receiving the power frequency signal, it can use the specific method mentioned in the above embodiment to obtain the target cycle when the target power line fails.
[0074] like Figure 3 As shown, in one embodiment, the traveling wave module includes a second signal conditioning unit and a second processing unit.
[0075] The first signal sensor is also electrically connected to the signal input terminal of the second processing unit through the second signal conditioning unit. The timing input terminal of the second processing unit is electrically connected to the positioning timing module, and the communication terminal of the second processing unit is electrically connected to the communication terminal of the first processing unit.
[0076] The second signal conditioning unit is mainly used to condition the signal output by the first signal sensor so that it meets the relevant requirements of the second processing unit.
[0077] The first signal sensor is used to acquire electrical signals on the target power line and output traveling wave signals to the second processing unit through the second signal conditioning unit.
[0078] As mentioned in the above embodiments, the first signal sensor is specifically used to extract the signal component in the electrical signal whose frequency is mainly power frequency. Although the signal component is mainly power frequency, it is still superimposed with some traveling wave. Therefore, the second signal conditioning unit can specifically extract, adjust the amplitude and / or convert the signal component into analog and digital signals, and finally output the traveling wave signal to the second processing unit.
[0079] The second processing unit is used to determine the target time when a fault occurs on the target power line based on the timing information and according to the traveling wave signal and the target period.
[0080] The second processing unit, as the core of the traveling wave module, is responsible for signal calculation and processing. Therefore, after receiving the traveling wave signal, it can use the specific method mentioned in the above embodiment to obtain the target time when the target power line fails.
[0081] It is understood that in this embodiment, the traveling wave module indirectly accesses the electrical signal through the first signal sensor in the feeder module, thereby obtaining the signal component mainly based on the power frequency based on the first signal sensor. Although this part is basically the same as the feeder module, the traveling wave module adopts a second signal conditioning module that is different from the first signal conditioning module in the feeder module. Through different conditioning strategies, the traveling wave signal input to the second processing unit contains more obvious and cleaner traveling wave characteristics, and the second processing unit can ultimately achieve more accurate fault detection.
[0082] like Figure 4 As shown, in one embodiment, the traveling wave module includes a second signal sensor, a second signal conditioning unit, and a second processing unit.
[0083] The second signal sensor is electrically connected to the signal input terminal of the second processing unit through the second signal conditioning unit. The timing input terminal of the second processing unit is electrically connected to the positioning timing module. The communication terminal of the second processing unit is electrically connected to the communication terminal of the first processing unit.
[0084] The second signal sensor is used to acquire electrical signals on the target power line and outputs traveling wave signals to the second processing unit through the second signal conditioning unit.
[0085] As mentioned in the above embodiments, the traveling wave module can indirectly access the electrical signal through the first signal sensor in the feeder module, thereby obtaining a signal component mainly based on the power frequency. However, the traveling wave characteristics contained in this signal component are not complete. Specifically, due to the characteristics of the first signal sensor, the first signal sensor attenuates the traveling wave characteristics to a certain extent, resulting in a partial loss of the traveling wave characteristics in this signal component compared to the traveling wave characteristics in the electrical signal.
[0086] Therefore, in this embodiment, a second signal sensor is added to extract the signal component in the electrical signal whose frequency is mainly a traveling wave, so that the signal component contains more complete traveling wave characteristics. After extraction, amplitude adjustment and / or analog-to-digital conversion by the second signal conditioning unit, a better traveling wave signal can be output to the second processing unit.
[0087] The second processing unit is used to determine the target time when a fault occurs on the target power line based on the timing information and according to the traveling wave signal and the target period.
[0088] The second processing unit, after receiving the traveling wave signal, can use the specific method mentioned in the above embodiment to obtain the target time when the target power line fails. Since the traveling wave signal used is better, the target time is also more accurate.
[0089] As a supplement, when a second signal sensor is added, the second signal conditioning unit still obtains the electrical signal on the target power line through the first signal sensor. In practice, the feeder terminal can be equipped with a corresponding switching unit to realize the access selection of the first signal sensor and the second signal sensor, so as to make the access of the traveling wave signal more flexible.
[0090] like Figure 5 As shown, in one embodiment, the second signal sensor includes a Rogowski coil and an integrating circuit.
[0091] The Rogowski coil is an alternating current sensor, a hollow ring-shaped coil available in both flexible and rigid forms. It can be directly fitted onto the conductor being measured to measure alternating current. Rogowski coils are suitable for measuring alternating current over a wide frequency range, have no special requirements for conductor or size, and possess fast instantaneous response capabilities. They are widely used in situations where traditional current measuring devices, such as current transformers, cannot be used, for current measurement, especially high-frequency, high-current measurements.
[0092] exist Figure 5 In the circuit, the Rogowski coil is electrically connected to the input terminal of the integrator circuit, and the output terminal of the integrator circuit is electrically connected to the signal input terminal of the second processing unit through the second signal conditioning unit.
[0093] Rogowski coils are used to acquire electrical signals on the target power line and output differential signals to the integrator circuit.
[0094] By leveraging the advantages of Rogowski coils—high bandwidth, high precision, and large current measurement—it is possible to better extract traveling wave characteristics from electrical signals. Based on the inherent characteristics of Rogowski coils, their output is a differential signal.
[0095] The integrating circuit is used to restore the differential signal and output a traveling wave signal to the second processing unit through the second signal conditioning unit.
[0096] Since the differential signal cannot be processed by the subsequent second signal conditioning unit (mainly because it cannot be sampled), an integrating circuit should be set after the Rogowski coil when using it. The characteristics of the integrating circuit are used to restore the differential signal output by the Rogowski coil, so that the traveling wave signal can be output to the second processing unit through the second signal conditioning unit.
[0097] like Figure 5 As shown, in one embodiment, the second signal conditioning unit includes a bandpass filter circuit and an ADC sampling circuit.
[0098] The bandpass filter circuit is electrically connected to the signal input terminal of the second processing unit through the ADC sampling circuit.
[0099] The bandpass filter circuit is used to perform bandpass filtering on the incoming signal to obtain a traveling wave signal, which is then output to the second processing unit through the ADC (analogue-to-digital conversion) sampling circuit.
[0100] The bandpass filter circuit is mainly used to bandpass filter the signal output by the first signal sensor or the second signal sensor, respectively filtering out the components with frequencies lower than the traveling wave and the components with frequencies higher than the traveling wave, thereby obtaining a traveling wave signal with more obvious traveling wave characteristics.
[0101] The ADC sampling circuit uses analog-to-digital conversion to sample signals, ensuring that the signals meet the requirements of subsequent processing units.
[0102] When the first signal sensor includes a Rogowski coil and an integrating circuit, and the first signal conditioning unit includes a bandpass filter circuit and an ADC sampling circuit, the integrating circuit needs to be located after the Rogowski coil and before the ADC sampling module. Therefore, the integrating circuit can be specifically set inside the Rogowski coil, or it can be set between the bandpass filter circuit and the ADC sampling circuit.
[0103] In one embodiment, the bandpass filter circuit has a filtering range of 100Hz to 2MHz.
[0104] In the transmission line system scenario, based on the frequency distribution of traveling wave characteristics corresponding to most faults, a bandpass filter circuit with a filtering range of 100Hz to 2MHz can effectively extract the traveling wave characteristics. Of course, in other embodiments, filtering ranges other than 100Hz to 2MHz can also be selected.
[0105] In one embodiment, the sampling rate of the ADC sampling circuit is not less than 4MHz.
[0106] According to the Nyquist theorem, an ADC sampling circuit with a sampling rate of at least 4MHz can basically guarantee the accuracy of traveling wave characteristic sampling. To further improve the accuracy of traveling wave characteristic sampling, in other embodiments, the sampling rate of the ADC sampling circuit can also be at least 10MHz.
[0107] like Figure 5 As shown, in one embodiment, the first signal sensor includes a power frequency transformer; in other embodiments, other types of sensor devices may be used as the first signal sensor.
[0108] like Figure 5 As shown, in one embodiment, the first signal conditioning unit includes a power frequency acquisition circuit. In other embodiments, other types of conditioning devices may be used as the first signal conditioning unit.
[0109] The power frequency acquisition circuit is similar in composition to the second signal conditioning unit mentioned above, and it can also perform functions such as filtering and analog-to-digital conversion.
[0110] like Figure 5 As shown, in one embodiment, the first processing unit includes a feeder CPU (Central Processing Unit). In other embodiments, other types of processing cores may be used as the first processing unit.
[0111] like Figure 5 As shown, in one embodiment, the second processing unit includes a traveling wave CPU; in other embodiments, other types of processing cores may also be used as the second processing unit.
[0112] When using a CPU, the traveling wave CPU and the ADC sampling circuit can exchange data via high-speed buses such as QSPI (Quad SPI) and LVDS (Low-Voltage Differential Signaling) to ensure the real-time transmission of traveling wave data.
[0113] In addition, when using a CPU, the traveling wave CPU and the feeder CPU can communicate and interact via Ethernet.
[0114] like Figure 5 As shown, in one embodiment, the positioning and timing module includes BeiDou / GPS (Global Positioning System). In other embodiments, other types of positioning devices may also be used as the positioning and timing module.
[0115] Specifically, the BeiDou / GPS system can output a second-pulse time synchronization signal (100ns level) as time information, enabling the feeder CPU and traveling wave CPU to add corresponding timestamps to the acquired power frequency signal and traveling wave signal. The timestamps include information above and below the second. For the traveling wave CPU, the traveling wave module also includes a storage unit electrically connected to the traveling wave CPU. The storage unit can perform timed storage and overwriting of the traveling wave signal, with a storage duration of not less than 200ms.
[0116] like Figure 5 As shown, in one embodiment, the feeder terminal further includes an Ethernet communication module and a wireless communication module that are electrically connected to the feeder module, thereby enabling the feeder module to transmit relevant fault data to the processing backend via wired means or via wireless means.
[0117] Secondly, the present invention provides a fault detection and location method, applied to the feeder terminal in any of the above embodiments; the fault detection and location method includes:
[0118] The feeder module acquires the electrical signals on the target power line and determines the power frequency signal in the electrical signals. Based on the timing information output by the positioning and timing module and according to the power frequency signal, it determines the target period when the target power line fails and sends it to the traveling wave module.
[0119] The traveling wave module acquires the electrical signals on the target power line and identifies the traveling wave signal within the electrical signals. Based on the timing information output by the positioning and timing module and according to the traveling wave signal and the target period, it determines the target time when a fault occurs on the target power line.
[0120] The feeder terminal used in the above-described fault detection and location method adds a traveling wave module electrically connected to both the original feeder module and the positioning and timing module. This allows the feeder module to acquire electrical signals on the target power line and identify the power frequency signal within them. Based on the timing information output by the positioning and timing module and the power frequency signal, it determines the target period when a fault occurs on the target power line and sends this information to the traveling wave module. The added traveling wave module further acquires electrical signals on the target power line and identifies the traveling wave signal within them. Based on the timing information output by the positioning and timing module and the traveling wave signal and the target period, it determines the target time when a fault occurs on the target power line. This invention achieves preliminary period detection based on the feeder module and power frequency signal, and further time detection based on the traveling wave module and traveling wave signal. The two modules work together, requiring minimal modification to the traditional feeder module, and achieving high-precision fault detection, effectively avoiding problems such as missed detections and delayed detections.
[0121] In one embodiment, determining the target period when a fault occurs in the target power line based on the timing information output by the positioning and timing module and according to the power frequency signal includes:
[0122] Based on timing information and difference algorithm, the target difference between the power frequency signal in the current cycle and the previous cycle is determined.
[0123] If the number of sampling points corresponding to one cycle of the power frequency signal is k, then the characteristic quantity up to the current cycle can be expressed as (I0-I -k And the characteristic quantity of the previous period can be expressed as (I) -k -I -2k If the target difference ΔI = (I0 - I) -k )-(I -k -I -2k ).
[0124] If the target difference is greater than the preset difference, the current period will be determined as the target period.
[0125] The preset difference can be set as I', which is used to characterize whether the difference between the two periods reaches the difference caused by the fault. If the target difference ΔI > the preset difference I', it is considered that the difference between the two periods reaches the difference caused by the fault. Since the difference algorithm is performed for each sampling point, the time when the fault occurs is within the current period, so the current period can be determined as the target period.
[0126] It should be noted that the characteristic quantity of the current period is represented as (I0-I... -k The term t0 represents the characteristic quantity within the previous period starting from the current time t0. Therefore, the feeder module can use the current time t0 to represent the target period and send it to the traveling wave module, so that after receiving the current time t0, the traveling wave can determine the corresponding target period based on the unit period.
[0127] Specifically, the feeder module can generate a fault recording command based on the current time t0, and then send the fault recording command to the traveling wave module.
[0128] In one embodiment, determining the target time when a fault occurs on the target power line based on the timing information output by the positioning and timing module and according to the traveling wave signal and the target period includes:
[0129] Based on the timing information, the traveling wave component in the traveling wave signal corresponding to the target period is determined.
[0130] As mentioned in the above embodiments, the feeder module can send a fault recording command containing the current time t0 to the traveling wave module. The traveling wave module can obtain the unit period of the power frequency signal of the feeder module in advance, and thus determine the target period based on the unit period and the current time t0. If the unit period is 20ms, then the target period is (t0-20)ms to t0.
[0131] Since the traveling wave module and the feeder module are based on the same timing information, the traveling wave module can accurately determine the traveling wave component in the traveling wave signal that corresponds to the target period.
[0132] Determine the maximum value in the traveling wave component, and then determine the time corresponding to the maximum value in the traveling wave component as the target time.
[0133] Among them, since the traveling wave generated when a power line fault occurs weakens as it propagates, the time corresponding to the maximum value of the traveling wave component is the target time when the fault occurs.
[0134] In one embodiment, after determining the target time when a fault occurs on the target power line, the fault detection and location method further includes:
[0135] The traveling wave module acquires the first recorded wave signal located before the target time from the traveling wave signal according to the first time interval, and acquires the second recorded wave signal located after the target time from the traveling wave signal according to the second time interval. It generates and saves a recorded wave file based on the first recorded wave signal, the target time, and the second recorded wave signal.
[0136] Wherein, if the first time interval is Δt1, then the time period represented by the first waveform signal is (t1-Δt1)~t1; if the second time interval is Δt2, then the time period represented by the second waveform signal is t1~(t1+Δt2); then the time period represented by the finally generated waveform data is (t1-Δt1)~(t1+Δt2), and the waveform data is stored in the storage unit.
[0137] The first time interval Δt1 and the second time interval Δt2 can be configured according to actual needs and the capacity of the storage unit.
[0138] In one embodiment, after determining the target time when a fault occurs on the target power line, the fault detection and location method further includes:
[0139] The traveling wave module sends the target time to the feeder module;
[0140] The feeder module sends the target time and the positioning information output by the positioning and timing module to the processing backend, so that the processing backend can perform a two-end algorithm based on the positioning information, the target time and the propagation speed of the power line to obtain the fault location when the target power line has a fault.
[0141] In this embodiment, when a fault occurs in the target power line, the resulting traveling wave signal is sent not only to the feeder terminal at this end but also to the feeder terminal at the other end, enabling both the feeder terminal at this end and the feeder terminal at the other end to acquire the corresponding fault data. The dual-end algorithm locates the fault point based on the respective positions of the two feeder terminals and the fault data.
[0142] Specifically, in this embodiment, after the feeder module obtains the target time sent by the traveling wave module (the traveling wave module can send the target time directly, or it can be included in the waveform data mentioned in the above embodiment for transmission) and the positioning information output by the positioning and timing module, it uploads them to the processing backend via wired or wireless means. The processing backend can also obtain the target time and positioning information uploaded by another feeder terminal, thereby determining the line length of the target power line between the two feeder terminals based on the two positioning information, and finally determining the fault location D = 1 / 2(V(t1-t1')+L).
[0143] Where t1 and t1' are two target times, V is the propagation speed of the electric field line, and L is the line length.
[0144] In one embodiment, after determining the target time when a fault occurs on the target power line, the fault detection and location method further includes:
[0145] The traveling wave module sends the target time to the feeder module;
[0146] The feeder module uses a dual-end algorithm based on the positioning information output by the positioning and timing module, the target time, and the propagation speed of the power line to obtain the fault location when the target power line has a fault.
[0147] Since the feeder module itself has computing capabilities, in addition to the background calculation method mentioned in the above embodiments, this embodiment can also enable the feeder module to perform local calculation of the fault point. It should be noted that when using local calculation, the feeder module in this embodiment needs to obtain the target time and location information of another feeder terminal. This information can be obtained through background forwarding or directly based on the communication link with the other feeder terminal. The specific calculation principle can be referred to in the above embodiments, and will not be repeated here.
[0148] To make the embodiments of the above fault detection and location method clearer, the above embodiments will now be described in combination, such as... Figure 6 As shown, in one embodiment, the fault detection and localization method includes:
[0149] Step 1: The feeder module determines the target difference ΔI = (I0 - I) based on the power frequency signal and the difference algorithm. -k )-(I -k -I -2k )>I' and perform fault diagnosis.
[0150] Step 2: If ΔI > I', then a fault is considered to exist, and the time t0 corresponding to the target period is further obtained; if ΔI ≤ I', then no fault is considered to exist, and the target difference ΔI = (I0 - I') is redefined. -k )-(I -k -I -2k ).
[0151] Step 3: After obtaining time t0, generate the corresponding waveform recording command based on time t0 and send it to the traveling wave module.
[0152] Step 4: If the traveling wave module receives the recording command, it retrieves the corresponding traveling wave component in the traveling wave signal according to the target period (t0-20ms) to t0 corresponding to time t0; if the traveling wave module does not receive the recording command, it performs data rolling over the traveling wave signal to ensure that the data volume of the traveling wave signal is >200ms.
[0153] Step 5: After retrieving the traveling wave components in the traveling wave signal that correspond to the target period (t0-20ms) to t0, obtain the time t1 when the fault occurs based on the maximum value algorithm.
[0154] Step 6: Based on application requirements, and according to time t1, the first time interval Δt1 and the second time interval Δt2, generate waveform data with a time period of (t1-Δt1) to (t1+Δt2).
[0155] Step 7: Transmit the waveform data, firstly to the internal storage unit for storage, and secondly to the feeder module for fault location.
[0156] Step 8: If background location calculation is used, the relevant data is sent to the processing backend so that the processing backend can locate the fault point using the dual-end algorithm; if background location calculation is not used, the feeder module directly performs local calculation to locate the fault point using the dual-end algorithm. Both background and local calculations require relevant fault data from the feeder terminal at the other end of the line.
[0157] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.
[0158] The above provides a detailed description of a feeder terminal and a fault detection and location method provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.
[0159] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.
Claims
1. A feeder terminal, characterized in that, The feeder terminal includes a feeder module, a traveling wave module, and a positioning and timing module; The feeder module is electrically connected to the positioning and timing module and the traveling wave module respectively, and is used to acquire electrical signals on the target power line and determine the power frequency signal in the electrical signals. Based on the timing information output by the positioning and timing module and according to the power frequency signal, the target period when the target power line fails is determined and sent to the traveling wave module. The traveling wave module is electrically connected to the positioning and timing module and is used to acquire the electrical signal on the target power line and determine the traveling wave signal in the electrical signal. Based on the timing information output by the positioning and timing module and according to the traveling wave signal and the target period, the target time when a fault occurs on the target power line is determined.
2. The feeder terminal according to claim 1, characterized in that, The feeder module includes a first signal sensor, a first signal conditioning unit, and a first processing unit; The first signal sensor is electrically connected to the signal input terminal of the first processing unit through the first signal conditioning unit, the timing input terminal of the first processing unit is electrically connected to the positioning timing module, and the communication terminal of the first processing unit is electrically connected to the traveling wave module. The first signal sensor is used to acquire the electrical signal on the target power line and output the power frequency signal to the first processing unit through the first signal conditioning unit; The first processing unit is used to determine the target period when the target power line fails, based on the timing information and the power frequency signal, and send it to the traveling wave module.
3. The feeder terminal according to claim 2, characterized in that, The traveling wave module includes a second signal conditioning unit and a second processing unit; The first signal sensor is also electrically connected to the signal input terminal of the second processing unit through the second signal conditioning unit, the timing input terminal of the second processing unit is electrically connected to the positioning timing module, and the communication terminal of the second processing unit is electrically connected to the communication terminal of the first processing unit. The first signal sensor is used to acquire the electrical signal on the target power line and output the traveling wave signal to the second processing unit through the second signal conditioning unit; The second processing unit is used to determine the target time when a fault occurs on the target power line based on the timing information and according to the traveling wave signal and the target period.
4. The feeder terminal according to claim 2, characterized in that, The traveling wave module includes a second signal sensor, a second signal conditioning unit, and a second processing unit. The second signal sensor is electrically connected to the signal input terminal of the second processing unit through the second signal conditioning unit, the timing input terminal of the second processing unit is electrically connected to the positioning timing module, and the communication terminal of the second processing unit is electrically connected to the communication terminal of the first processing unit. The second signal sensor is used to acquire the electrical signal on the target power line and output the traveling wave signal to the second processing unit through the second signal conditioning unit; The second processing unit is used to determine the target time when a fault occurs on the target power line based on the timing information and according to the traveling wave signal and the target period.
5. The feeder terminal according to claim 4, characterized in that, The second signal sensor includes a Rogowski coil and an integrating circuit; The Rogowski coil is electrically connected to the input terminal of the integrator circuit, and the output terminal of the integrator circuit is electrically connected to the signal input terminal of the second processing unit through the second signal conditioning unit. The Rogowski coil is used to acquire the electrical signal on the target power line and output a differential signal to the integrator circuit; The integrator circuit is used to restore the differential signal and output the traveling wave signal to the second processing unit through the second signal conditioning unit.
6. The feeder terminal according to any one of claims 3 to 5, characterized in that, The second signal conditioning unit includes a bandpass filter circuit and an ADC sampling circuit; The bandpass filter circuit is electrically connected to the signal input terminal of the second processing unit through the ADC sampling circuit; The bandpass filter circuit is used to perform bandpass filtering on the incoming signal to obtain the traveling wave signal, which is then output to the second processing unit through the ADC sampling circuit.
7. The feeder terminal according to claim 6, characterized in that, The bandpass filter circuit has a filtering range of 100Hz to 2MHz; and / or the sampling rate of the ADC sampling circuit is not less than 4MHz.
8. A fault detection and location method, characterized in that, Applied to the feeder terminal as described in any one of claims 1 to 7; The fault detection and location method includes: The feeder module acquires the electrical signal on the target power line and determines the power frequency signal in the electrical signal. Based on the timing information output by the positioning and timing module and according to the power frequency signal, it determines the target period when the target power line fails and sends it to the traveling wave module. The traveling wave module acquires the electrical signal on the target power line and determines the traveling wave signal in the electrical signal. Based on the timing information output by the positioning and timing module and according to the traveling wave signal and the target period, it determines the target time when a fault occurs on the target power line.
9. The fault detection and location method according to claim 8, characterized in that, The step of determining the target period when the target power line experiences a fault, based on the timing information output by the positioning and timing module and according to the power frequency signal, includes: Based on the timing information and the difference algorithm, the target difference between the power frequency signal in the current cycle and the previous cycle is determined; If the target difference is greater than the preset difference, then the current period is determined as the target period.
10. The fault detection and location method according to claim 8, characterized in that, The step of determining the target time when a fault occurs on the target power line based on the timing information output by the positioning and timing module and according to the traveling wave signal and the target period includes: Based on the timing information, determine the traveling wave component in the traveling wave signal that corresponds to the target period; Determine the maximum value in the traveling wave component, and determine the time corresponding to the maximum value in the traveling wave component as the target time.
11. The fault detection and location method according to claim 8, characterized in that, Following the step of determining the target time when a fault occurs on the target power line, the method further includes: The traveling wave module acquires a first recorded wave signal located before the target time from the traveling wave signal according to a first time interval, and acquires a second recorded wave signal located after the target time from the traveling wave signal according to a second time interval. It then generates and saves a recorded wave file based on the first recorded wave signal, the target time, and the second recorded wave signal.
12. The fault detection and location method according to claim 8, characterized in that, Following the step of determining the target time when a fault occurs on the target power line, the method further includes: The traveling wave module sends the target time to the feeder module; The feeder module sends the target time and the positioning information output by the positioning and timing module to the processing backend, so that the processing backend can perform a two-end algorithm based on the positioning information, the target time and the propagation speed of the power line to obtain the fault location when the target power line has a fault.
13. The fault detection and location method according to claim 8, characterized in that, Following the step of determining the target time when a fault occurs on the target power line, the method further includes: The traveling wave module sends the target time to the feeder module; The feeder module performs a two-end algorithm based on the positioning information output by the positioning and timing module, the target time, and the propagation speed of the power line to obtain the fault location when the target power line fails.