An online monitoring method and device for reactive power equipment

Abstract

The present invention provides an on-line monitoring method and device for reactive power equipment. The method includes: obtaining the secondary voltage signal of a bus voltage transformer in real time; wherein, the bus voltage transformer is connected to a plurality of reactive power equipment to be measured; determining at least one trigger waveform corresponding to each switching-on / off moment according to the respective switching-on / off moments of each reactive power equipment to be measured; recording the oscillation frequency of the at least one trigger waveform, and determining the operating state of each reactive power equipment to be measured based on the oscillation frequency. Compared with the prior art, the present invention does not need to install a voltage divider on the reactive power equipment for testing, can monitor the reactive power equipment in real time and continuously without cutting off the power supply, can continuously obtain a large number of monitoring samples compared with manual operation, accurately and timely reflects the changes in the operating state and characteristics of the equipment, and eliminates potential safety hazards.

Description

Technical Field

[0001] The present invention relates to the field of reactive power switching, and particularly to an on-line monitoring method and device for reactive power equipment. Background Art

[0002] When a vacuum circuit breaker switches reactive power equipment, reignition overvoltage may occur, causing insulation damage or even tripping of the equipment, resulting in harm to the safe and stable operation of the power grid. Currently, the prior art mainly tests by installing a voltage divider on the equipment. This method requires cutting off the power supply of the equipment, installing contact monitoring equipment and then performing switching operations. This method has a large workload and there are safety hazards when personnel conduct on-site tests; moreover, this method mainly relies on manual operation, so the obtained samples are extremely limited, and it is difficult to reflect the characteristic changes and operating status in the actual operation of the equipment in a timely and accurate manner, and it is very difficult to conduct long-term monitoring. Summary of the Invention

[0003] The present invention provides an on-line monitoring method and device for reactive power equipment to solve the technical problem of difficult long-term monitoring by manual operation.

[0004] To solve the above technical problem, an embodiment of the present invention provides an on-line monitoring method for reactive power equipment, including:

[0005] Obtaining a secondary voltage signal of a bus voltage transformer in real time; wherein, the bus voltage transformer is connected to a plurality of reactive power equipment to be measured;

[0006] Determining at least one trigger waveform corresponding to each switching moment according to the switching moments of each reactive power equipment to be measured;

[0007] Recording the oscillation frequency of the at least one trigger waveform, and determining the operating state of each reactive power equipment to be measured based on the oscillation frequency. Implementing the embodiments of the present application, compared with the prior art, there is no need to install a voltage divider on the reactive power equipment for testing, and the reactive power equipment can be monitored in real time and continuously without cutting off the power supply. Compared with manual operation, a large number of monitoring samples can be continuously obtained, accurately and timely reflecting the equipment operating state and characteristic changes and eliminating safety hazards.

[0008] As a preferred solution, the determining at least one trigger waveform corresponding to each switching moment according to the switching moments of each reactive power equipment to be measured is specifically:

[0009] The switching moments include a tripping moment and a closing moment;

[0010] Determining at least one first trigger waveform corresponding to each tripping moment according to the tripping moments of each reactive power equipment to be measured;

[0011] Determine at least one second trigger waveform corresponding to each of the closing moments according to the respective closing moments of each reactive power device to be measured.

[0012] As a preferred solution, determining the operating state of each reactive power device to be measured based on the oscillation frequency specifically includes:

[0013] Obtain the first oscillation frequency corresponding to the first trigger waveform. When the first oscillation frequency is within the first preset range, it is determined that there is a reignition in the reactive power device to be measured. When the first oscillation frequency is within the second preset range, it is determined that there is no reignition in the reactive power device to be measured. Wherein, the minimum value of the second preset range is greater than the maximum value of the first preset range.

[0014] Obtain the second oscillation frequency corresponding to the second trigger waveform. When the second oscillation frequency is within the third preset range, it is determined that there is a reignition in the reactive power device to be measured. When the second oscillation frequency is within the fourth preset range, it is determined that there is no reignition in the reactive power device to be measured. Wherein, the minimum value of the fourth preset range is greater than the maximum value of the third preset range. Implementing the embodiments of the present application, for the oscillation frequencies respectively obtained for the first trigger waveform corresponding to the opening moment and the second trigger waveform corresponding to the closing moment, different or the same preset ranges can be set according to the application scenario and the model and parameters of the reactive power device to be measured, so that the determination of the reignition phenomenon of the reactive power device to be measured is more targeted, and the identification and monitoring of the operating state of the reactive power device to be measured are more accurate.

[0015] As a preferred solution, before determining at least one trigger waveform corresponding to each switching moment in the secondary voltage signal according to the respective switching moments of each reactive power device to be measured, it further includes: storing the transient voltage signal of the bus voltage transformer within a preset time range before and after the switching moment.

[0016] As a preferred solution, after determining the operating state of each reactive power device to be measured, it further includes:

[0017] Calculate the reignition rate according to the operating state of each reactive power device to be measured; record the circuits of the reactive power devices with a reignition rate greater than the preset value; send an alarm message to the cloud platform.

[0018] Correspondingly, an on-line monitoring device for reactive power devices provided by an embodiment of the present invention includes an acquisition module, an identification module, and an evaluation module; wherein,

[0019] The acquisition module is used to obtain the secondary voltage signal of the bus voltage transformer in real time; wherein, the bus voltage transformer is connected to a plurality of reactive power devices to be measured;

[0020] The identification module is used to determine at least one trigger waveform corresponding to each switching time according to the switching times of each reactive power device to be measured.

[0021] The evaluation module is used to record the oscillation frequencies of the at least one trigger waveform and determine the operating state of each reactive power device to be measured based on the oscillation frequencies.

[0022] As a preferred solution, the identification module determines at least one trigger waveform corresponding to each switching time according to the switching times of each reactive power device to be measured, specifically:

[0023] The switching times include the opening time and the closing time;

[0024] The identification module determines a first trigger waveform corresponding to each opening time according to the opening times of each reactive power device to be measured;

[0025] According to the closing times of each reactive power device to be measured, a second trigger waveform corresponding to each closing time is determined.

[0026] As a preferred solution, the evaluation module determines the operating state of each reactive power device to be measured based on the oscillation frequencies, specifically:

[0027] The evaluation module obtains a first oscillation frequency corresponding to the first trigger waveform. When the first oscillation frequency is within a first preset range, it is determined that there is a reignition in the reactive power device to be measured; when the first oscillation frequency is within a second preset range, it is determined that there is no reignition in the reactive power device to be measured; wherein, the minimum value of the second preset range is greater than the maximum value of the first preset range;

[0028] The evaluation module obtains a second oscillation frequency corresponding to the second trigger waveform. When the second oscillation frequency is within a third preset range, it is determined that there is a reignition in the reactive power device to be measured; when the second oscillation frequency is within a fourth preset range, it is determined that there is no reignition in the reactive power device to be measured; wherein, the minimum value of the fourth preset range is greater than the maximum value of the third preset range.

[0029] As a preferred solution, the on-line monitoring device further includes a storage module, and the storage module is used to store the transient voltage signals of the bus voltage transformer within a preset time range before and after the switching time before determining at least one trigger waveform corresponding to each switching time in the secondary voltage signal according to the switching times of each reactive power device to be measured.

[0030] As a preferred solution, the on-line monitoring device further includes an alarm module. The alarm module is used to calculate the restrike rate according to the operating status of each reactive power device to be measured after the evaluation module determines the operating status of each reactive power device to be measured; record the circuits of the reactive power devices with a restrike rate greater than a preset value; and send an alarm message to the cloud platform. Description of the Drawings

[0031] Figure 1 : A schematic flowchart of an embodiment of an on-line monitoring method for reactive power devices provided by the present invention.

[0032] Figure 2 : A schematic structural diagram of an embodiment of an on-line monitoring device for reactive power devices provided by the present invention. Detailed Embodiments

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] Embodiment 1:

[0035] Please refer to Figure 1 , Figure 1 An on-line monitoring method for reactive power devices provided by an embodiment of the present invention includes steps S1 to S3, where

[0036] Step S1: Real-time obtain the secondary voltage signal of the bus voltage transformer; where the bus voltage transformer is connected to a plurality of reactive power devices to be measured.

[0037] In this embodiment, the bus voltage transformer is connected to a plurality of reactive power devices or devices to be measured, and the secondary voltage signal of the bus voltage transformer is obtained in real time. The secondary voltage signal can be mutually verified with the action signals of each switching reactive power device in the substation automation system, and to a certain extent reflects the operation actions of the reactive power devices and provides the operation information of the reactive power devices.

[0038] Before step S2, this embodiment further includes: storing the transient voltage signals of the bus voltage transformer within a preset time range before and after each switching moment of the reactive power device to be measured. Preferably, the preset time range is 0.1 s.

[0039] Step S2: Determine at least one trigger waveform corresponding to each switching moment according to the respective switching moments of each reactive power device to be measured.

[0040] In this embodiment, the switching times of each reactive power device to be measured include the opening time and the closing time. For any reactive power device to be measured, according to the time of each opening, the transient waveform monitoring method or device is used to capture the trigger waveform in the secondary signal at this time as the first trigger waveform. The first trigger waveforms at the opening times of the same reactive power device to be measured are grouped together and considered to be generated by the reactive power device to be measured in this loop.

[0041] Correspondingly, for any reactive power device to be measured, according to the time of each closing, the transient waveform monitoring method or device can also be used to identify the trigger waveform when the secondary signal is closed as the second trigger waveform. Similarly, the second trigger waveforms at the closing times of the same reactive power device to be measured are grouped together and considered to be generated by the reactive power device to be measured in this loop.

[0042] Step S3, record the oscillation frequencies of the at least one trigger waveform, and based on the oscillation frequencies, determine the operating state of each reactive power device to be measured.

[0043] Specifically, in this embodiment, according to the at least one first trigger waveform and the at least one second trigger waveform obtained in step S2, the first oscillation frequency corresponding to each first trigger waveform and the second oscillation frequency corresponding to each second trigger waveform are obtained. When the first oscillation frequency is within the first preset range, for example, 10 to 15 kHz, it is confirmed that there is a reignition in the reactive power device to be measured. When the first oscillation frequency is within the second preset range, for example, 20 to 30 kHz, it is determined that there is no reignition in the reactive power device to be measured. Generally, the minimum value of the second preset range is greater than the maximum value of the first preset range.

[0044] Correspondingly, in this embodiment, when the second oscillation frequency is within the third preset range, such as 1 to 5 kHz, it is determined that there is a reignition in the reactive power device to be measured; when the second oscillation frequency is within the fourth preset range, such as 10 to 30 kHz, it is determined that there is no reignition in the reactive power device to be measured; wherein, the minimum value of the fourth preset range is greater than the maximum value of the third preset range. Therefore, for the oscillation frequencies obtained separately for the first trigger waveform corresponding to the opening time and the second trigger waveform corresponding to the closing time, different or the same preset ranges can be set according to the application scenario and the model and parameters of the reactive power device to be measured, so as to make the determination of the reignition phenomenon of the reactive power device to be measured more targeted and the identification and monitoring of the operating state of the reactive power device to be measured more accurate.

[0045] After obtaining the operating states of the reactive power devices to be measured at each moment, calculate the restrike rate according to the operating states of each reactive power device to be measured. As an example of this embodiment, the restrike rate is the ratio of the number of restrikes to the total number of opening operations, or the ratio of the number of restrikes to the total number of closing operations, or the ratio of the number of restrikes to the total number of opening and closing operations, etc. When the value of the restrike rate reaches the preset value, it is considered that the restrike rate exceeds the standard, and overvoltage or partial discharge may occur in the reactive power devices of the corresponding circuit. Record, store and analyze the circuits of the reactive power devices with a restrike rate greater than the preset value, and send the corresponding alarm information to the cloud platform to notify the technical personnel to conduct power outage inspection or testing in a timely manner. Since the embodiment does not involve primary equipment, the monitoring cost is extremely low, which can effectively replace the traditional off-line manual switching test, with high safety, and it is easy to obtain a large amount of data as samples, and can be tested in real time and for a long time. At the same time, a single bus voltage transformer can be tested once to obtain the operating conditions of the reactive power outgoing lines of multiple circuits, with simple operation and convenient testing.

[0046] Correspondingly, an on-line monitoring device for reactive power devices according to an embodiment of the present invention further includes an acquisition module 101, an identification module 102 and an evaluation module 103; wherein,

[0047] The acquisition module 101 is used to acquire the secondary voltage signal of the bus voltage transformer in real time; wherein, the bus voltage transformer is connected to a plurality of reactive power devices to be measured;

[0048] The identification module 102 is used to determine at least one trigger waveform corresponding to each switching moment according to the switching moments of each reactive power device to be measured;

[0049] The evaluation module 103 is used to record the oscillation frequency of the at least one trigger waveform, and determine the operating state of each reactive power device to be measured based on the oscillation frequency.

[0050] In this embodiment, the identification module 102 determines at least one trigger waveform corresponding to each switching moment according to the switching moments of each reactive power device to be measured, specifically:

[0051] The switching moments include opening moments and closing moments;

[0052] The identification module 102 determines a first trigger waveform corresponding to each opening moment according to the opening moments of each reactive power device to be measured;

[0053] According to the closing moments of each reactive power device to be measured, determine a second trigger waveform corresponding to each closing moment.

[0054] In this embodiment, the evaluation module 103 determines the operating state of each reactive power device to be measured based on the oscillation frequency, specifically:

[0055] The evaluation module 103 obtains a first oscillation frequency corresponding to the first trigger waveform. When the first oscillation frequency is within a first preset range, it is determined that there is a reignition in the reactive power device to be measured; when the first oscillation frequency is within a second preset range, it is determined that there is no reignition in the reactive power device to be measured; wherein, the minimum value of the second preset range is greater than the maximum value of the first preset range.

[0056] The evaluation module 103 obtains a second oscillation frequency corresponding to the second trigger waveform. When the second oscillation frequency is within a third preset range, it is determined that there is a reignition in the reactive power device to be measured; when the second oscillation frequency is within a fourth preset range, it is determined that there is no reignition in the reactive power device to be measured; wherein, the minimum value of the fourth preset range is greater than the maximum value of the third preset range.

[0057] In this embodiment, the on-line monitoring device further includes a storage module, and the storage module is configured to store the transient voltage signal of the bus voltage transformer within a preset time range before and after the switching time before determining at least one trigger waveform corresponding to each switching time in the secondary voltage signal according to the switching time of each reactive power device to be measured.

[0058] In this embodiment, the on-line monitoring device further includes an alarm module, and the alarm module is configured to calculate a reignition rate according to the operating state of each reactive power device to be measured after the evaluation module determines the operating state of each reactive power device to be measured; record the circuit of the reactive power device with a reignition rate greater than a preset value; and send an alarm message to the cloud platform.

[0059] Compared with the prior art, the embodiment of the present invention has the following beneficial effects:

[0060] The present invention provides an on-line monitoring method and device for reactive power devices. The method includes: obtaining a secondary voltage signal of a bus voltage transformer in real time; wherein, the bus voltage transformer is connected to a plurality of reactive power devices to be measured; determining at least one trigger waveform corresponding to each switching time according to the switching time of each reactive power device to be measured; recording the oscillation frequency of the at least one trigger waveform, and determining the operating state of each reactive power device to be measured based on the oscillation frequency. Compared with the prior art, the present invention does not need to install a voltage divider on the reactive power device for testing, can monitor the reactive power device in real time and continuously without cutting off the power supply, can continuously obtain a large number of monitoring samples compared with manual operation, accurately and timely reflects the changes in the operating state and characteristics of the device, and eliminates potential safety hazards.

[0061] The specific embodiments described above further elaborate on the object, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. In particular, for those skilled in the art, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An on-line monitoring method for reactive power equipment, characterized in that Including: Obtaining the secondary voltage signal of the bus voltage transformer in real time; wherein, the bus voltage transformer is connected to a plurality of reactive power devices to be measured; Determining at least one trigger waveform corresponding to each switching moment in the secondary voltage signal according to the switching moments of each reactive power device to be measured; Recording the oscillation frequency of the at least one trigger waveform, and determining the operating state of each reactive power device to be measured based on the oscillation frequency; The determining of at least one trigger waveform corresponding to each switching moment according to the switching moments of each reactive power device to be measured is specifically: The switching moments include the opening moment and the closing moment; Determining a first trigger waveform corresponding to each opening moment according to the opening moments of each reactive power device to be measured; Determining a second trigger waveform corresponding to each closing moment according to the closing moments of each reactive power device to be measured; The determining of the operating state of each reactive power device to be measured based on the oscillation frequency is specifically: Obtaining a first oscillation frequency corresponding to the first trigger waveform, and when the first oscillation frequency is within a first preset range, determining that there is a reignition in the reactive power device to be measured; when the first oscillation frequency is within a second preset range, determining that there is no reignition in the reactive power device to be measured; wherein, the minimum value of the second preset range is greater than the maximum value of the first preset range; Obtaining a second oscillation frequency corresponding to the second trigger waveform, and when the second oscillation frequency is within a third preset range, determining that there is a reignition in the reactive power device to be measured; when the second oscillation frequency is within a fourth preset range, determining that there is no reignition in the reactive power device to be measured; wherein, the minimum value of the fourth preset range is greater than the maximum value of the third preset range.

2. The on-line monitoring method of a reactive power device according to claim 1, characterized in that, Before determining at least one trigger waveform corresponding to each switching moment in the secondary voltage signal according to the switching moments of each reactive power device to be measured, it further includes: storing the transient voltage signal of the bus voltage transformer within a preset time range before and after the switching moment.

3. An on-line monitoring method for a reactive power device according to any one of claims 1 to 2, characterized in that, After determining the operating state of each reactive power device to be measured, it further includes: Calculating the reignition rate according to the operating state of each reactive power device to be measured; recording the circuits of the reactive power devices with a reignition rate greater than a preset value; sending an alarm message to the cloud platform.

4. An on-line monitoring device for reactive power equipment, characterized in that, Including an acquisition module, an identification module and an evaluation module; wherein, The acquisition module is used to obtain the secondary voltage signal of the bus voltage transformer in real time; wherein, the bus voltage transformer is connected to a plurality of reactive power devices to be measured; The identification module is used to determine at least one trigger waveform corresponding to each switching moment according to the switching moments of each reactive power device to be measured; The evaluation module is used to record the oscillation frequency of the at least one trigger waveform, and determine the operating state of each reactive power device to be measured based on the oscillation frequency; The identification module determines at least one trigger waveform corresponding to each switching moment according to the switching moments of each reactive power device to be measured, specifically: The switching moments include the opening moment and the closing moment; The identification module determines a first trigger waveform corresponding to each opening moment according to the opening moments of each reactive power device to be measured; Determine a second trigger waveform corresponding to each of the closing moments according to the closing moments of each reactive power device to be measured; The evaluation module determines the operating state of each reactive power device to be measured based on the oscillation frequency, specifically: The evaluation module obtains a first oscillation frequency corresponding to the first trigger waveform. When the first oscillation frequency is within a first preset range, it is determined that there is a reignition in the reactive power device to be measured; when the first oscillation frequency is within a second preset range, it is determined that there is no reignition in the reactive power device to be measured; wherein, the minimum value of the second preset range is greater than the maximum value of the first preset range; The evaluation module obtains a second oscillation frequency corresponding to the second trigger waveform. When the second oscillation frequency is within a third preset range, it is determined that there is a reignition in the reactive power device to be measured; when the second oscillation frequency is within a fourth preset range, it is determined that there is no reignition in the reactive power device to be measured; wherein, the minimum value of the fourth preset range is greater than the maximum value of the third preset range.

5. The on-line monitoring device for a reactive power device according to claim 4, characterized in that, The on-line monitoring device further includes a storage module, which is used to store the transient voltage signal of the bus voltage transformer within a preset time range before and after the switching moment before determining at least one trigger waveform corresponding to each switching moment in the secondary voltage signal according to the switching moments of each reactive power device to be measured.

6. An on-line monitoring device for a reactive power device according to any one of claims 4 to 5, characterized in that, The on-line monitoring device further includes an alarm module, which is used to calculate the reignition rate according to the operating state of each reactive power device to be measured after the evaluation module determines the operating state of each reactive power device to be measured; record the circuits of the reactive power devices with a reignition rate greater than a preset value; and send an alarm message to the cloud platform.

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