10kV series-parallel compensation method and device

Abstract

The invention discloses a 10kV series-parallel compensation method. The method comprises the following steps: acquiring capacitor topological data of a series-parallel compensator; acquiring a power grid operation state, determining a field current threshold and a field voltage threshold in combination with the compensation target value, and determining a field power grid operation state judgment result according to the field current threshold and the field voltage threshold; acquiring a field voltage and current state, performing fault judgment based on the field voltage and current state to obtain a fault judgment result, and performing credibility judgment on the fault judgment result according to a power grid operation state judgment result; and when the fault judgment result is credible, performing series-parallel connection compensation control based on the topological data of the capacitor. According to the invention, mutual verification of a fault judgment result and a power grid operation state is realized, the accuracy of the fault judgment result is ensured, the adaptability of the series-parallel compensation device to different line terminals is improved, and the series-parallel compensation device at different line terminals can adaptively adjust series-parallel compensation.

Description

Technical Field

[0001] The present invention relates to the technical field of distribution network compensation, and in particular to a 10kV series-parallel compensation method and device. Background Art

[0002] The voltage quality of the distribution network is an important indicator to measure whether the power supply quality meets the standards. The quality of the distribution network is directly related to the safe and economic operation of power-consuming equipment and the normal operation of production. With the development of society, the distribution network covers a wider range and the voltage quality of the distribution network is getting higher and higher. However, the construction of some distribution networks in my country lags seriously behind the transmission network. Its grid is weak, the lines are long, the wire diameter is small, the facilities are aging (especially the mountain village lines), the number of distribution transformers is large, and even many lines have rapidly changing industrial loads or multiple large-capacity motors, resulting in low voltage at the end of the line and serious voltage drop. The existing series compensation technology has no obvious effect on the series capacitor compensation of lines with high power factors. The mixed compensation of series and parallel capacitors can overcome the shortcomings of simple series capacitor compensation, and it also has obvious effects on lines with high power factors, small wire diameters, and long distances. However, the use of series capacitor compensation devices and parallel capacitor compensation devices to manage the distribution network will increase economic costs, space and floor space.

[0003] For example, a "low-voltage series compensation device and control method" disclosed in a Chinese patent document, with the publication number: CN114759565A, discloses a primary circuit and an Internet of Things controller; the primary circuit is connected in series in the transmission line, including a compensation transformer for series compensation, primary side switching switches K1, K2, K3, and a secondary side switching switch K4; the primary side switching switches K1, K2, K3 are switches for changing the compensation polarity, short-circuiting the primary side, and changing the primary side series-parallel combination mode respectively; the secondary side switching switch K4 switches the secondary side of the compensation transformer on and off on the one hand, and interlocks with the primary side on and off state on the other hand, but this scheme also has the problem that the compensation effect of the series capacitor of the line with a high power factor is not obvious. Summary of the invention

[0004] In order to solve the problem that the compensation effect of series capacitors in the prior art is not obvious, the present invention provides a 10kV series-parallel compensation method and device, which improves the adaptability of the series-parallel compensation device to different line terminals, improves the compensation accuracy and thus enhances the compensation effect.

[0005] In order to achieve the above object, the present invention provides the following technical solutions: A 10 kV series-parallel compensation method comprises: obtaining capacitor topology data of a series-parallel compensator; Obtain the grid operation status, determine the on-site current threshold and the on-site voltage threshold in combination with the compensation target value, and determine the on-site grid operation status judgment result based on the on-site current threshold and the on-site voltage threshold; Obtaining the on-site voltage and current status, performing fault judgment based on the on-site voltage and current status to obtain a fault judgment result, and performing credibility judgment on the fault judgment result according to the grid operation status judgment result; When the fault judgment result is credible, series-parallel compensation control is performed based on the capacitor topology data. The field data threshold is obtained by monitoring the power grid operation status, and the field status is judged according to the field data threshold. The credibility is judged according to the similarity between the field data threshold and the fault judgment result, so as to realize the mutual verification of the fault judgment result and the power grid operation status, ensure the accuracy of the fault judgment result, improve the adaptability of the series-parallel compensation device to different line terminals, so that the series-parallel compensation device can adaptively adjust the series-parallel compensation at different line terminals. And there is no need to network the monitoring data.

[0006] Preferably, after obtaining the grid operation status, the field current threshold and the field voltage threshold are determined according to the difference between the compensation target value and the grid operation status; the compensation target value is determined by the grid output target. A dynamic threshold based on the actual operation status can be obtained.

[0007] Preferably, when obtaining the grid operation status judgment result, the discrete on-site current threshold or on-site voltage threshold is removed; the on-site current threshold and the on-site voltage threshold are paired to determine the ratio of completed pairing, thereby removing the discrete data of the grid operation status and improving the judgment accuracy.

[0008] Preferably, when only one party in the pair reaches the compensation target value, a corresponding threshold with a mark is generated; The ratio of the marked thresholds is determined, and the credibility of the corresponding thresholds is determined according to the ratio, so as to realize the accuracy screening of the data based on the operation status of the power grid.

[0009] Preferably, the obtaining of the on-site voltage and current status includes on-site current data and on-site voltage data, and fault judgment is performed in combination with the on-site current threshold and the on-site voltage threshold; When one of the on-site current data and the on-site voltage data exceeds the corresponding threshold, the corresponding fault judgment result is marked, thereby realizing the screening of fault judgment results under different states.

[0010] Preferably, the method includes determining the field data confidence level based on the historical field current data and field voltage data, and judging whether the real-time field current data and field voltage data are credible based on the field data confidence level, so as to realize the credible screening of the field data.

[0011] Preferably, when judging the credibility of the fault judgment result, the similarity between the fault judgment result and the grid operation status judgment result is determined; when the similarity reaches the similarity requirement, series-parallel compensation control is performed according to the fault judgment result to realize feedback control of the fault judgment.

[0012] Preferably, in the series-parallel compensation control, a closing signal and an opening signal are respectively sent according to different fault judgment results, and when the opening signal is working, the series-parallel compensator is in a bypass state, so as to realize control of different states.

[0013] A 10kV series-parallel compensation device is applicable to a 10kV series-parallel compensation method as described in any one of the above, comprising an isolating switch, the isolating switch is connected to a bypass contactor through a busbar, the bypass contactor is connected to a series capacitor, the series capacitor includes a plurality of capacitors connected in parallel; the busbar is connected to a parallel capacitor. The utilization rate of the internal space is improved, and the floor space is reduced.

[0014] Preferably, the parallel capacitors and the series capacitors are arranged in layers, and the parallel capacitors and the series capacitors are installed horizontally, so as to improve the compactness and reduce the space occupation.

[0015] The present invention has the following advantages: The field data threshold is obtained by monitoring the operation status of the power grid, and the fault judgment is made on the field status according to the field data threshold. The credibility is judged according to the similarity between the field data threshold and the fault judgment result, thereby realizing mutual verification of the fault judgment result and the operation status of the power grid, ensuring the accuracy of the fault judgment result, improving the adaptability of the series-parallel compensation device to different line terminals, so that the series-parallel compensation device can spontaneously adjust the series-parallel compensation at different line terminals; and there is no need to connect the monitoring data to the Internet. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described below are merely exemplary. A person skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0017] Figure 1 Schematic diagram of the method steps in the embodiment.

[0018] Figure 2 It is a schematic diagram of the overall structure in the embodiment.

[0019] Figure 3 It is a schematic diagram of the overall side view structure in the embodiment.

[0020] Figure 4 It is a schematic diagram of the overall rear view structure in the embodiment.

[0021] In the figure: 1-isolating switch; 2-series capacitor; 3-bypass contactor; 4-thyristor valve; 5-damping reactor; 6-parallel contactor; 7-parallel capacitor; 8-current transformer; 9-voltage transformer; 11-Internet of Things controller. DETAILED DESCRIPTION

[0022] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0023] like Figure 1 As shown, in a preferred embodiment, the present solution discloses a 10kV series-parallel compensation method, comprising the following steps: firstly obtaining capacitor topology data of the series-parallel compensator; obtaining respective capacitor arrangement conditions for different series-parallel compensators; and controlling the isolating switch connected to the capacitor.

[0024] Then, the real-time grid operation status is obtained. According to the real-time grid operation status and the compensation target value, the on-site current threshold and the on-site voltage threshold are determined. At the same time, the grid operation status is judged, and the actual situation of the on-site voltage threshold and the on-site current threshold is used as the result of the grid operation status judgment.

[0025] Then, the real-time on-site voltage and current status is obtained. A fault judgment is performed based on the on-site voltage and current status to obtain a fault judgment result, wherein the fault judgment result is the existence of a fault or the elimination of a fault. The credibility of the fault judgment result is judged based on the grid operation status judgment result; the fault judgment result and the grid operation status are mutually verified. If either side is unreliable, the whole process is unreliable.

[0026] When the fault judgment result is credible, the isolating switch connected to the capacitor is controlled to perform series-parallel compensation control.

[0027] In other embodiments, the method includes obtaining capacitor topology data, wherein the capacitor topology data includes capacitor state data and capacitor position data, wherein the capacitor state data includes capacitor on / off state symbols and capacitor current data. Data is collected from capacitors in different positions and arrangements to obtain capacitor state data. The position of each capacitor is detected to obtain the relative position of each capacitor, and the relative position of the capacitor is used as the capacitor position data. The capacitor status data includes a status data group, which includes capacitor voltage and current data, access status data, and access mode data. In other embodiments, it includes obtaining the on-site voltage and current status, determining whether there is a fault based on the on-site voltage and current status, and generating a capacitor input signal when there is no fault; when there is a fault, generating a capacitor bypass signal, and when the capacitor bypass signal is generated, the capacitor is in a bypass state.

[0028] In other embodiments, it includes setting capacitor input conditions, and judging whether the capacitor is switched on according to the capacitor input conditions. The capacitor input conditions include series capacitor input conditions and parallel capacitor input conditions.

[0029] In other embodiments, the capacitor is judged to be put into operation according to the on-site voltage and current state and the capacitor input condition respectively. First, the on-site voltage and current state is determined, including collecting voltage and current through a voltage collector and a current collector. The on-site voltage and current state includes on-site current data and on-site voltage data.

[0030] The field data confidence is determined according to the field voltage data and the field current data, and the field voltage data and the field current data are screened according to the field data confidence, and the field voltage data and the field current data within a certain range are obtained after screening. The remaining field voltage data and field current data are judged respectively, and the field voltage threshold and the field current threshold are set; the field current data and the field voltage data are divided into groups according to time.

[0031] When the field voltage data exceeds the field voltage threshold and the field current data does not exceed the field current threshold, the confidence of the field data in the group is offset by one unit toward the field current data. If the field current data does not meet the field data confidence requirement at this time, the group of data is discarded. Otherwise, it is continued to be judged based on the group of data that the fault still exists.

[0032] When the field voltage data does not exceed the field voltage threshold and the field current data does not exceed the field current threshold, it is determined that the working state represented by the set of field voltage data and field current data is a working state in which the fault is eliminated.

[0033] When the field voltage data exceeds the field voltage threshold and the field current data exceeds the field current threshold, it is determined that the working state represented by the set of field voltage data and field current data is a working state in which a fault exists.

[0034] When the field voltage data does not exceed the field voltage threshold and the field current data exceeds the field current threshold, the confidence of the field data in the group is offset by one unit toward the field voltage data. If the field voltage data does not meet the field data confidence requirement at this time, the group of data is discarded. Otherwise, it is continued to be judged based on the group of data whether the fault still exists.

[0035] In other embodiments, the field data confidence includes two in a group, and the two field data confidences in the group are determined according to the field voltage data and the field current data, respectively. The historical data of the field voltage data and the field current data are obtained respectively, and the historical data are used as a training library for training to obtain the historical prediction model of the field voltage data and the field current data. When obtaining the field data confidence, the field current confidence value is obtained through the historical prediction model and the field voltage data, and the field voltage confidence value is obtained through the historical prediction model and the field current data. The field voltage confidence value and the field current confidence value are the predicted values, and an offset range is set for the field voltage confidence value and the field current confidence value. When the field voltage data and the field current data are within the offset range of the field voltage confidence value and the field current confidence value, the corresponding field voltage data and the field current data are judged to be credible data.

[0036] In other embodiments, after the field voltage data and the field current data are screened and paired, multiple groups of field data are obtained; each group of field data is judged according to the field voltage threshold and the field current threshold, so that each group of field voltage data and field current data obtains its own fault judgment result. All fault judgment results are summarized to obtain a fault judgment result set. The fault judgment set includes two results: fault existence and fault elimination.

[0037] Among them, when one of the field voltage data and field current data of the same group exceeds the corresponding threshold, the corresponding fault existence result of the group is marked. Determine the proportion of the marked fault existence to all fault judgment results, and determine the credibility of the fault judgment result according to the proportion. Determine the fault judgment results of a fixed range, count the marks of the fault judgment results within the fixed range, and when the proportion of the marks within the fixed range to all fault judgment results reaches the set threshold, the fault judgment result with the largest number among the fault judgment results in the fixed range is used as the fault judgment result of the fixed range.

[0038] The set threshold is 0-5%.

[0039] In other embodiments, the determination of the field voltage threshold and the field current threshold includes obtaining the grid operation state, obtaining the voltage data and the current data in the grid operation state, determining the compensation target value, judging the voltage data and the current data in the grid operation state according to the compensation target value, and stopping obtaining the field voltage threshold and the field current threshold when the voltage data and the current data in the grid operation state reach the compensation target value. When the voltage data and the current data in the grid operation state do not reach the compensation target value, determining the difference between the voltage data and the current data in the grid operation state and the compensation target value, and determining the field voltage threshold and the field current threshold according to the difference.

[0040] In other embodiments, the compensation target value includes a voltage compensation target value and a current compensation target value. The compensation target value is determined by the power grid output target. The judging of the voltage data and current data in the power grid operation state according to the compensation target value includes judging the voltage data in the power grid operation state according to the voltage compensation target value, and judging the current data in the power grid operation state according to the current compensation target value.

[0041] When the voltage data does not reach the voltage compensation target value and the current data reaches the current compensation target value, a marked field voltage threshold is generated according to the voltage data, and no field current threshold is generated at this time.

[0042] When the voltage data reaches the voltage compensation target value and the current data reaches the current compensation target value, the field voltage threshold and the field current threshold are not generated.

[0043] When the voltage data does not reach the voltage compensation target value and the current data does not reach the current compensation target value, a field current threshold is generated according to the current data, and a field voltage threshold is generated according to the voltage data.

[0044] When the voltage data reaches the voltage compensation target value and the current data does not reach the current compensation target value, a marked field current threshold is generated according to the current data, and no field voltage threshold is generated at this time.

[0045] After the data judgment of the power grid operation status is completed, the field current threshold and the field voltage threshold are formed into a pairing group of two. The pairing group is paired at the same time node. Then, the proportion of the field current threshold and the field voltage threshold with the mark to the total field current threshold and the field voltage threshold is determined, and the credibility of the field current threshold and the field voltage threshold is determined according to the proportion.

[0046] When judging the credibility, a fixed range of grid operation status judgment results is determined, and the marks of the grid operation status results within the fixed range are counted. When the proportion of the marks within the fixed range to all grid operation status judgment results reaches a set threshold, the grid operation status judgment results within the fixed range are judged to be credible. The set threshold is between 0 and 5%.

[0047] When it is determined that the field current threshold and the field voltage threshold are credible, all the field current thresholds and field voltage thresholds obtained within a fixed range are taken to generate a scatter plot, the scatter plot is fitted and discrete points are determined, and when the field current threshold or field voltage threshold corresponding to the discrete point is marked, the discrete point is removed. At this time, the removed discrete point represents that the grid operation state corresponding to the marked field current threshold or field voltage threshold is unreliable data.

[0048] The scatter plot is fitted to generate a field current threshold curve and a field voltage threshold curve, and the average values ​​in the curves are used as the field current threshold and the field voltage threshold within a fixed range.

[0049] In other embodiments, it includes determining the marking ratio of the fault judgment results and determining the marking distribution of the fault judgment results; determining the marking ratio of the power grid operation status judgment results and determining the marking distribution of the power grid operation status judgment results.

[0050] Determine the similarity between the mark distribution of the fault judgment result and the mark distribution of the power grid operation status judgment result. When the similarity meets the requirement, it means that the fault judgment result and the power grid operation status judgment result are similar, so as to realize the mutual verification of the fault judgment result and the power grid operation status, and ensure the accuracy of the fault judgment result. Further judge the mark ratio of the fault judgment result and the mark ratio of the power grid operation status judgment result. When the mark ratio of the fault judgment result is greater than the mark ratio of the power grid operation status judgment result, the credibility of the corresponding power grid operation status judgment result is reduced by one level, and then the credibility of the corresponding fault judgment result is reduced by one level.

[0051] In other embodiments, when the similarity between the mark distribution of the fault judgment result and the mark distribution of the power grid operation status judgment result does not meet the requirements, the credibility of the corresponding fault judgment result is reduced by one level, and the credibility of the corresponding power grid operation status judgment result is reduced by one level.

[0052] The similarity requirement includes taking the difference between the marking ratio of the fault judgment result and the marking ratio of the power grid operation status judgment result, determining the similarity matrix of the marking ratio of the fault judgment result and the marking ratio of the power grid operation status judgment result, and determining the eigenvalue of the similarity matrix. When the eigenvalue of the similarity matrix is ​​the same as the difference result, it is judged that the similarity meets the requirement; when the eigenvalue of the similarity matrix is ​​different from the difference result, it is judged that the similarity does not meet the requirement.

[0053] In other embodiments, when it is determined that the similarity meets the requirements, the series-parallel compensation control is performed according to the result of the fault judgment. When the result of the fault judgment is that the fault is eliminated, a closing signal is issued to put the main switch of the isolating switch in the closed state, and the bypass circuit breaker and the bypass contactor are opened. When the result of the fault judgment is that the fault exists, an opening signal is issued to put the main switch of the isolating switch in the open state, and the bypass circuit breaker and the bypass contactor are closed at the same time, so that the series-parallel compensation device is in the bypass state.

[0054] The closing signal and the opening signal have opposite signal contents, and the isolating switch and the bypass circuit breaker form an OR gate circuit connection.

[0055] When in use, the voltage and current status of the series-parallel compensation device is monitored in real time, and the current and voltage status of the distribution network line to which the series-parallel compensation device is connected is monitored, and all monitoring data are summarized in the series-parallel compensation device provided with an Internet of Things controller, and the voltage and current status of the site is judged inside the series-parallel compensation device, and the series-parallel compensation is adaptively performed according to the grid operation status judgment result and the fault judgment result, thereby improving the adaptability of the series-parallel compensation device to different line terminals, so that the series-parallel compensation device can spontaneously adjust the series-parallel compensation at different line terminals. And there is no need to network the monitoring data.

[0056] The isolating switch includes a main switch and a ground switch. The ground switch is independently controlled and is not controlled by the IoT controller. When the ground switch is closed, the main switch automatically opens and temporarily interrupts the closing command of the IoT controller, and enters the maintenance mode. This allows the operation and maintenance personnel to inspect the inside of the series-parallel compensation device in a safe manner.

[0057] like Figure 2-4 As shown, in a preferred embodiment, the present invention discloses a 10kV series-parallel compensation device, including an isolating switch, wherein the isolating switch includes an incoming isolating switch and an outgoing isolating switch arranged in sequence, and the incoming isolating switch and the outgoing isolating switch both include a grounding switch and a main switch.

[0058] The utility model comprises a frame, wherein the incoming line isolating switch and the outgoing line isolating switch are respectively arranged on the front of the frame. The frame is connected with a bypass circuit breaker.

[0059] The isolating switch is connected to a bypass contactor, which is arranged on a busbar. The bypass contactor is connected to a series capacitor, which includes a plurality of capacitors arranged in parallel on the busbar.

[0060] The busbar is also provided with a thyristor valve, the thyristor valve is connected in series with a damping reactor, and the thyristor valve is connected in parallel with a bypass contactor.

[0061] The busbar is also connected to a parallel capacitor, and the parallel capacitor and the series capacitor are arranged in layers, and both the parallel capacitor and the series capacitor are installed horizontally, which can not only improve the utilization rate of the internal space of the device, reduce the floor space, but also facilitate installation and later maintenance.

[0062] It includes a transformer for measuring line current. The transformer includes a circular low-voltage open-type transformer. When installing, two semicircles are wrapped around the phase-splitting cable and clamped with a clamp. It has a small size and light weight, which further reduces the size of the device and optimizes the internal wiring.

[0063] In other embodiments, the device mainly includes a bypass circuit breaker, an isolating switch 1, a series capacitor 2, a bypass contactor 3, a thyristor valve 4, a damping reactor 5, a parallel contactor 6, a parallel capacitor 7, a current transformer 8, a voltage transformer 9 and an Internet of Things controller 11. The circuit breaker is installed outside the series-parallel compensation device, and the remaining components are installed inside the compact 10kV series-parallel compensation device. The isolating switch 1 is connected to the series capacitor 2 through the busbar and the bypass contactor 3, and the series capacitor 2 is connected to the busbar after being connected in parallel through copper stranded wire. The thyristor valve 4 and the damping reactor 5 are connected in series and then connected in parallel with the bypass contactor 3 and the series capacitor 2. The device includes a stainless steel shell, salt spray and corrosion-resistant air inlet dustproof cotton, so as to be applied to the marine environment.

[0064] Enter from the bottom and connect to the moving contact side of the main switch 1 on the left. The static contact side of the main switch 1 on the left is connected to one end of the series capacitor 2 through the busbar and copper strands, which is called the power side. The other end of the series capacitor 2 is also connected to the static contact side of the main switch 1 on the right through the busbar and copper strands. The moving contact side of the main switch 1 on the right extends from the bottom of the device through a cable and is connected to the power side of the line, which is called the load side. The two ends of the bypass contactor 3 are connected to the power side and the load side respectively. One end of the parallel contactor 6 is connected to the power side, and the other end is connected to the parallel capacitor 7. One end of the three-phase capacitor is short-circuited. The damping reactor 5 and the thyristor 4 are connected in series and connected to the power side and the load side respectively.

[0065] The device is in maintenance status. Close the bypass circuit breaker manually or through the IoT controller, open the main switch of the two sets of disconnectors 1 and close the ground switch of disconnector 1 with the operating handle, and the device can be put into maintenance status. In the maintenance status, maintenance personnel can open the side door to check or repair the internal components of the device.

[0066] The device is in bypass state. When a fault occurs in the device or line, the main switches of the two sets of disconnectors 1 are in the closed state, the ground switch of disconnector 1 is in the open state, the bypass circuit breaker is open, and the bypass contactor 3 is closed, which can temporarily put the device in bypass state. The device will monitor the status of the voltage and current on site in real time. When the fault is eliminated and the input conditions are met, the device enters the operation state; if the fault is not eliminated, the device will remain in the bypass state.

[0067] The device is in operation. When the input conditions are met, the main switches of the two sets of disconnectors 1 are in the closed state, the ground switch of disconnector 1 is in the open state, the bypass circuit breaker is open, and the bypass contactor 3 is open, the device can be put into operation. At this time, the series compensation capacitor has been connected in series to the line. When the series compensation capacitor is put into operation, if the parallel capacitor input conditions are met, the parallel contactor is closed.

[0068] These modifications or improvements made on the basis of the present invention without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A 10kV series-parallel compensation method, characterized in that: include: Get capacitor topology data of series-shunt compensator; Obtain the grid operation status, determine the on-site current threshold and the on-site voltage threshold in combination with the compensation target value, and determine the on-site grid operation status judgment result based on the on-site current threshold and the on-site voltage threshold; Obtaining the on-site voltage and current status, performing fault judgment based on the on-site voltage and current status to obtain a fault judgment result, and performing credibility judgment on the fault judgment result according to the grid operation status judgment result; When the fault judgment result is credible, series-parallel compensation control is performed based on the capacitor topology data.

2. A 10kV series-parallel compensation method according to claim 1, characterized in that: After the grid operation status is obtained, the on-site current threshold and the on-site voltage threshold are determined respectively according to the difference between the compensation target value and the grid operation status; the compensation target value is determined by the grid output target.

3. A 10kV series-parallel compensation method according to claim 1 or 2, characterized in that: When obtaining the grid operation status judgment result, the discrete on-site current threshold or on-site voltage threshold is removed; the on-site current threshold and the on-site voltage threshold are paired, and the ratio of the paired values ​​is determined.

4. A 10kV series-parallel compensation method according to claim 3, characterized in that: When only one party in a pair reaches the compensation target value, a corresponding threshold with a mark is generated; A ratio of the marked thresholds is determined, and the confidence level of the corresponding threshold is determined based on the ratio.

5. A 10kV series-parallel compensation method according to claim 1 or 2, characterized in that: The obtaining of the on-site voltage and current status includes on-site current data and on-site voltage data, and fault judgment is performed in combination with the on-site current threshold and the on-site voltage threshold; When one of the field current data and the field voltage data exceeds the corresponding threshold, the corresponding fault judgment result is marked.

6. A 10kV series-parallel compensation method according to claim 5, characterized in that: The method includes determining the field data confidence level according to the historical field current data and field voltage data, and judging whether the real-time field current data and field voltage data are credible according to the field data confidence level.

7. A 10kV series-parallel compensation method according to claim 1, characterized in that: When judging the credibility of the fault judgment result, the similarity between the fault judgment result and the grid operation status judgment result is determined; when the similarity reaches the similarity requirement, series-parallel compensation control is performed according to the fault judgment result.

8. A 10kV series-parallel compensation method according to claim 7, characterized in that: In the series-parallel compensation control, a closing signal and an opening signal are sent respectively according to different fault judgment results. When the opening signal is working, the series-parallel compensator is in a bypass state.

9. A 10kV series-parallel compensation device, applicable to a 10kV series-parallel compensation method as claimed in any one of claims 1 to 8, characterized in that: It includes an isolating switch, wherein the isolating switch is connected to a bypass contactor via a busbar, the bypass contactor is connected to a series capacitor, and the series capacitor includes a plurality of capacitors connected in parallel; and the busbar is connected to a parallel capacitor.

10. A 10kV series-parallel compensation device according to claim 9, characterized in that: The parallel capacitors and the series capacitors are arranged in layers, and the parallel capacitors and the series capacitors are installed horizontally.

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