CN103326335B - System and method for false action resistance of distance section III based on domain double-type fault characteristic - Google Patents

Abstract

The invention relates to an anti-misoperation system and method for distance III section based on regional double-type fault characteristics, and belongs to the technical field of electric power system relay protection. The system includes a fault feature module of the protection system and a fault feature module of the power grid. The fault feature module of the protection system uses the fault feature of the protection system to realize the opening or blocking of the stage III protection of the upper level; Opening or blocking is an effective supplement to the fault signature module of the protection system. When the lower-level system fails, the upper-level protection device judges whether to delay action according to the action criterion of the distance section III. At the same time, the protection system fault feature module and the grid fault feature module use the protection system fault features and grid fault features collected in the area to determine whether to open Distance III section. The invention can realize good anti-maloperation effect, effectively improve the anti-maloperation and anti-chain tripping capabilities of the distance III section, improve the remote backup function, and ensure the safe and effective operation of the system in the transition period.

Description

Anti-misoperation system and method for distance section III based on regional double-type fault characteristics

technical field

The invention relates to an anti-misoperation system and method for distance III section based on regional double-type fault characteristics, and belongs to the technical field of electric power system relay protection.

Background technique

Relay protection is the first line of defense to ensure the safe operation of the power grid. In recent years, as the structure of the power grid has become increasingly complex, the defects of traditional backup protection are increasingly exposed because they only use local information to judge faults, which seriously threatens the security of the power grid while the protection function is not performing well. However, the particularity of relay protection determines that the improvement and innovation of protection should be carried out step by step. Therefore, before realizing the radical innovation of the backup protection principle, it is necessary to find a safe and effective backup protection mode suitable for the transition period. At present, there are two important problems in the anti-maloperation measures of the distance section III: the contradiction between anti-maloperation and sensitivity, and the need to retain the remote backup function. Therefore, it is necessary to improve the characteristics of the distance section III to find a good balance between sensitivity and reliability, or use other auxiliary methods to distinguish overload and fault so that the protection of section III will not malfunction.

At present, scholars at home and abroad have made a lot of beneficial achievements in improving the anti-misoperation measures of the distance section III, which are mainly divided into three categories:

1) The load limit feature is added to the protection action feature

Taking the directional impedance relay shown in Figure 1 as an example, the circular area 1 is the action area of the impedance relay, and area 2 is the area where the load impedance (including normal load and overload) is located. It can be seen from the figure that there is an overlapping area 3 between the original action area of the directional relay and the load impedance. If the load intrudes into the area 3 when the line is running, the directional relay will malfunction. To this, load limit lines 1 and 2 are added to form a new protection characteristic area together with area 1, which can effectively prevent protection from overload misoperation, and reserve as much action space as possible for high-resistance faults and remote backup functions.

2) Local auxiliary criterion to prevent misoperation

The impedance relay with the circular characteristic in Figure 1 itself cannot distinguish internal faults and overloads very well, and additional auxiliary criteria can be added to distinguish this, for example:

I ₂ +I ₀ >0.5I ₁ (1)

In the formula, I ₁ , I ₂ , and I ₀ are the positive, negative, and zero-sequence currents at the place where the protection is installed, U ₁ is the positive-sequence voltage, is the angle between positive sequence voltage and positive sequence current, is the line impedance angle. Take formulas (1) and (2) together or combine them with the directional impedance relay, then formula (1) can start when asymmetric fault occurs, formula (2) can start when symmetrical fault, and formula (1) can start when overload , (2) are not activated, so as to prevent the distance protection from misoperation.

3) Power flow transfer identification to prevent misoperation

Power flow transfer identification is one of the research directions of wide-area protection. Its principle is to use the real-time measured synchronous electrical quantity information in the power grid to calculate the power flow transfer of the power grid after the line is removed. If a nearby protection distance section III operates after the line is cut off, compare the measured power flow change of the activated protection with the calculated power flow transfer. If the two are consistent, it is considered that the action of the distance section III is caused by the power flow transfer caused by the line cut off at the previous moment, and then the distance III section is blocked to prevent misoperation; if the two are inconsistent, it is considered that the action of the section III is caused by an internal fault As a result, that is, the open distance section III will isolate the fault.

The advantage of the above ideas is that they improve the reliability of protection from different angles, but for the first method, due to the complexity of the actual power grid and the flexibility of the operation mode, the measurement impedance of faults and accident overloads in the area is often There are overlapping areas, and it is difficult to find a suitable balance point while ensuring the sensitivity of internal faults and the reliability of anti-misoperation when formulating the load limit characteristics; for the second method, it is necessary to use the information of the protection installation itself to set the auxiliary judgment According to the data, when the lower-level component fails, because the distance between the protection and the fault point is too far, and the impact on other branches of the terminal station cannot be estimated, how to ensure the sensitivity of the auxiliary criterion to the lower-level line fault needs further study; for the first Among the three methods, the power flow transfer identification needs to collect the synchronous electrical quantity information of each node of the power grid combined with the parameters of the power grid components for calculation, which requires high synchronization conditions, and requires a large amount of information interaction and calculation.

Contents of the invention

Aiming at the above problems and the defect that the traditional distance section III is overloaded and easy to malfunction, the present invention proposes a distance III section anti-maloperation system and method based on the characteristics of regional double-type faults. Starting from the reality of the power system, the invention focuses on perfecting the remote backup function. Using the fault characteristics of the protection system in the area and the fault characteristics of the power grid to open the distance section III, it can effectively improve the protection of the distance section III section before the power system realizes the complete innovation of the backup protection principle. Malfunction, anti-chain tripping capabilities, perfect remote backup function, to ensure the safe and effective operation of the system during the transition period.

The anti-misoperation system of distance Ⅲ section based on regional double-type fault features, the system includes two modules: protection system fault feature module and power grid fault feature module. Among them, the fault feature module of the protection system includes the part for judging whether the TV and TA in the lower station are disconnected, the part for judging whether the lower station loses synchronization with the adjacent station, the part for judging whether the communication between the lower station and the adjacent station is interrupted, and the part for judging whether the protection device of the lower station is In the failure part, judging whether part of the information of the lower-level station is missing or all the information is interrupted, this module uses the fault characteristics of the protection system to realize the opening or blocking of the protection of the third stage of the upper-level component; Whether a certain protection at the outlet of the lower-level station satisfies the action criterion, the part for judging whether the bus voltage of the lower-level station meets the revoltage condition, and the part for judging whether a certain outgoing line of the lower-level station (including the line where Section III is located) is in a non-full-phase operation state. Use the fault characteristics of the power grid to realize the opening or blocking of the stage III protection of the upper level component. In this system, the protection system fault feature module and the power grid fault feature module use the fault feature information collected by the regional master station to judge whether the protection system fault feature and the power grid fault feature are satisfied respectively. The fault feature module of the power grid is a supplement to the fault feature module of the protection system, so that the protection of the distance section III can also be opened when a fault occurs in the adjacent range; it further enables the protection system to prevent maloperation and anti-malfunction in the transition period of the innovation of the backup protection principle. The chain tripping ability has been improved, and the remote backup function has been improved.

The anti-misoperation method of the distance section III based on the regional double-type fault characteristics, the method includes the steps:

Step 1: When the lower-level system fails, the upper-level protection device judges whether to act according to the action criterion of the distance section III;

Step 2: The fault feature module of the protection system includes the part for judging whether TV and TA in the lower station are disconnected, the part for judging whether the lower station loses synchronization with the adjacent station, the part for judging whether the communication between the lower station and the adjacent station is interrupted, and the judgment for the protection of the lower station Whether the device fails or not, judging whether the lower-level station is missing part of the information or all the information is interrupted, respectively uses the fault characteristic information collected by the regional master station to judge whether the protection system is faulty;

At the same time, in the fault feature module of the power grid, the part of judging whether the protection installation of section III and a certain protection at the outlet of the lower-level station meets the action criterion part, the part of judging whether the bus voltage of the lower-level station satisfies the revoltage condition, and the part of judging a certain outgoing line of the lower-level station (including where section III is located) line) whether it is in non-full-phase operation state or not;

Step 3:: perform an OR operation on the output signals of the protection system fault module and the power grid fault characteristic module, and send a logic signal for blocking or opening the distance section III;

Step 4: Perform an AND operation on the action signal of distance III section protection in step 1 and the logic signal in step 3 to determine whether the distance III section is delayed.

The specific case analysis shows that the anti-maloperation system and method of the distance III section based on the characteristics of regional double-type faults can achieve a good anti-maloperation effect by using simple and practical principles, and effectively improves the anti-maloperation and anti-chain tripping capabilities of the distance III section , improve the remote backup function, and ensure the safe and effective operation of the system during the transition period. Its logic block diagram is shown in Figure 2.

1. Protection system fault feature module

As the remote backup of the lower-level components in the distance section III is not to provide a backup for the complete protection of the lower-level components in terms of sensitivity, but to provide a backup for the lower-level components when their own protection fails due to abnormal reasons. Therefore, the abnormal state of the protection system can be used as a trigger, and the regional backup protection platform can be used to collect the fault characteristics of the protection system of the lower station to open the distance section III of the upper-level components, so that the distance section III can be fully utilized only through simple and practical principles At the same time as the backup protection function, it can largely avoid the occurrence of overload misoperation. Among them, the fault feature module of the protection system includes the following:

1) Determine whether the TV and TA in the lower-level station are disconnected

When the TV and TA of a station in the system are disconnected, it is often necessary to block the related distance and current protection. For the unblocked protection, the protection may refuse to operate due to the large measurement error of the transformer disconnection. device disconnection information as a startup feature. There are special identification criteria for TV and TA disconnection. The original protection device in the substation includes this function. Therefore, the area protection host does not need to perform repeated identification, and the identification results of the faulty station can be uploaded for application.

2) Judging whether the lower-level station loses synchronization with the adjacent station

At present, high-voltage transmission lines are generally equipped with current differential protection as the main protection. The current differential protection is second to none in the line main protection of various principles because of its simple principle, sensitive and reliable operation, and little influence by various factors. When a lower-level station loses synchronization with an adjacent station, the current differential of the corresponding line will be blocked. In order to improve the reliability of fault removal, the distance section III of the station can be opened at this time.

If with the popularization and application of PMU, the future inter-station current differential synchronization signal is provided by the PMU device, or the PMU device is used to assist in judging whether the inter-station "ping-pong timing method" is accurately synchronized, in addition to the differential current exceeding the limit, the The fault information or auxiliary judgment result of the PMU device is used as a characteristic signal of out-of-synchronization.

3) Judging whether the communication between the subordinate station and the adjacent station is interrupted

The interruption of communication between two adjacent stations is a more serious situation than the loss of synchronization. At this time, all the longitudinal protections of the corresponding lines will be invalid. It is necessary to open the upper-level distance section III to provide remote backup functions.

4) Judging whether the protection device of the lower station is invalid

When a certain set of protection devices in the station fails, for dual protection devices, failure of one set will reduce the reliability of protection, and for only one set of protection devices, failure will mean that the protection refuses to operate. Therefore, when it is known that the protection device fails, the upper section III can be opened.

5) Judging whether the lower-level station is missing part of the information or all information is interrupted

This situation is different from feature 3), the communication failure in this situation mainly occurs within the range of the subordinate station itself. Part of the missing information may be caused by partial damage to the communication network in the station. At this time, the protection of the busbar, transformer and outgoing lines in the station will be affected, and the upper-level section III should be opened as a backup. Since each station is equipped with a station domain backup protection host, the station domain host uses the centralized information of the whole station to identify faults in the station, so the characteristics of some missing information can be detected and identified by the station domain host, and the identification results are uploaded to the regional host.

2. Grid fault feature module

The fault feature module of the protection system achieves a good anti-malfunction effect through simple and practical principles. However, if the relevant components of the protection device fail, and the protection of the component itself refuses to operate due to an undiscovered protection system failure, the fault cannot be removed because the third section is in a locked state and cannot provide it with a remote backup function; on the other hand , when a fault occurs on the line where the distance section III is located, even if the relevant protection system of the line is running soundly, it is still hoped that the distance section III can assist in the near backup function to increase the overall sensitivity of the protection.

Therefore, in order to further improve the rationality and practicability of the system, in addition to using the fault characteristics of the protection system to open the distance section III, it is necessary to supplement the start-up measures using the fault characteristics of the power grid, so that the protection of the distance section III can also be used when a fault occurs within the adjacent range. open. Further improve the anti-misoperation and anti-chain tripping capabilities of the protection system during the transitional period of the innovation of the backup protection principle, and improve the remote backup function. The power grid fault feature module includes:

1) Judging whether the protection installation place of section III and a certain protection at the exit of the lower station meet the action criterion part

Equations (1) and (2) are used as the start-up criteria for asymmetrical faults and symmetrical faults, which is one of the measures to prevent misoperation at distance Ⅲ section. However, when this criterion was applied in the past, due to platform limitations, the information was only collected from the installation of the distance section III protection.

However, on the regional backup protection platform, because the regional host has the ability to gather multiple information, it can obtain the fault characteristics reflected by the outgoing line protection of the lower-level stations. Then when a fault occurs at a certain point, since the protection located on the same line as the changed point satisfies the criteria (1) and (2), it can act sensitively and open the protection section III of the superior line to realize its remote backup function. The superior protection simultaneously judges the criteria (1) and (2), which helps to sensitively open the distance section III when the superior line fails, and assists in undertaking the near-backup function.

2) Judging whether the bus voltage of the lower station satisfies the complex pressure condition

The condition of bus bar recompression is:

The complex voltage condition is composed of phase low voltage, negative sequence voltage and zero sequence voltage criteria, in which the theoretical value of negative sequence and zero sequence voltage is zero when the line is overloaded, and will not malfunction. And it is generally believed that the minimum voltage of the busbar is not less than 80% of the rated voltage when overloaded, so it is reliable to set the low voltage components to 0.7U _N. The re-voltage criterion (3) can act sensitively when the components in the lower station fail, and open the section III of the upper level distance. When the protection of the components in the station refuses to operate, the section III can provide remote backup to remove the fault. At the same time, the complex pressure element also has a certain ability to respond to the failure of the outgoing line.

3) Judging whether a certain outgoing line of the lower station (including the line where Section III is located) is in the non-full-phase operation state

High-voltage lines are often equipped with single-phase reclosing. During single-phase reclosing, the zero-sequence direction protection of non-full-phase lines will be blocked, and the zero-sequence current differential sensitivity of adjacent lines will decrease. Different from the previous two features, there is no short-circuit fault at this time, but due to the performance degradation of the protection system, the upper stage III protection can also be opened to deal with faults that may occur at any time. In addition to single-phase coincidence, breaker jumping will also cause non-full-phase operation, which can be treated as the same state. Since non-full-phase operation is a disconnection fault, it can be used as a kind of fault characteristic of the power grid.

Beneficial effects of the present invention: Aiming at the problems existing in the current improvement measures for the prevention of misoperation of the distance section III and the defect of the traditional distance section III being overloaded and prone to misoperation, the present invention proposes an anti-misoperation of the distance section III based on the characteristics of two types of faults in the area system and method. Starting from the reality of the power system, the invention focuses on perfecting the remote backup function. Using the fault characteristics of the protection system in the area and the fault characteristics of the power grid to open the distance section III, it can effectively improve the protection of the distance section III section before the power system realizes the complete innovation of the backup protection principle. Malfunction, anti-chain tripping capabilities, perfect remote backup function, to ensure the safe and effective operation of the system during the transition period. First, when the lower-level system fails, the upper-level protection device judges whether to act according to the action criterion of the distance section III. At the same time, the protection system fault feature module and the grid fault feature module use the protection system fault features and grid fault features collected in the area to determine whether to open Distance III section. Then, according to the output information of the fault feature module of the protection system and the fault feature module of the power grid, it is judged whether the action of the distance section III is delayed. The specific case analysis shows that the anti-misoperation system of the distance III section based on the characteristics of regional double-type faults can achieve a good anti-maloperation effect by using simple and practical principles, effectively improving the anti-maloperation and anti-chain tripping capabilities of the distance III section, and perfecting the The remote backup function is provided to ensure the safe and effective operation of the system during the transition period.

Description of drawings

Figure 1 is a schematic diagram of the load limitation characteristics of the distance section III.

Fig. 2 is a schematic diagram of the anti-misoperation logic of distance III section provided by the present invention.

Figure 3 is a schematic diagram of the fault characteristics of the protection system.

Fig. 4 is a logical schematic diagram of an example of anti-misoperation at distance III provided by the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment further illustrate the present invention.

An anti-maloperation system for distance III section based on regional double-type fault characteristics, as shown in Figure 3, which is a schematic diagram of the fault characteristics of the protection system. Taking the protection of the distance III segment at point 1 as an example, and station _B2 is its subordinate station, the complete logic of protecting the distance III segment at point 1 against misoperation can be expressed as Figure 4.

1. Protection system fault feature module

The regional backup protection platform is used to collect the fault characteristics of the protection system of the lower-level station to open the distance section III of the upper-level components.

1) A certain TV or TA in the subordinate station is disconnected

When a certain TV or TA in station _B2 is disconnected (as shown in case a in Figure 3), it is often necessary to block the related distance and current protection. For the unblocked protection, the protection may also be rejected due to the large measurement error of the transformer disconnection. Therefore, the transformer disconnection information of the subordinate station can be used as a starting feature.

There are special identification criteria for TV and TA disconnection, and the original protection device in the substation includes this function. Therefore, the area protection host B ₀ does not need to perform repeated identification, and the identification results of station B ₂ can be uploaded for application.

2) The lower-level station loses synchronization with an adjacent station

When station B ₂ loses synchronization with station B ₃ (as shown in case b in Figure 3), the current differential of line L ₃ will be blocked. In order to improve the reliability of fault removal, the signal of differential current exceeding the limit can be used as the signal of loss of synchronization Signal, and upload this signal to the master station B ₀ to open the distance III section of protection 1. If the differential current limit is caused by TA disconnection, section III can still be opened.

3) The communication between the subordinate station and an adjacent station is interrupted

Interruption of communication between two adjacent stations (as shown in case c in Figure 3) is a more serious situation than loss of synchronization. At this time, all longitudinal protections of the corresponding lines will fail, and it is necessary to open the upper-level distance section III to provide remote backup functions. In view of this situation, station B ₂ can take no signal exchange with an adjacent station within a certain period of time as a characteristic of communication interruption, and upload this signal to the regional master station B ₀ .

4) A set of protective devices in the lower station fails

When a set of protection devices at station _B2 fails (as shown in case d in Figure 3), for dual protection devices, the failure of one of the protection devices will reduce the protection reliability, and for only one protection device, failure will mean that the protection refuses move. Therefore, when it is known that the protection device fails, the upper section III can be opened.

5) Part of the information of the subordinate station is missing or all the information is interrupted

This situation is different from feature 3), and the communication failure in this situation mainly occurs within the scope of the subordinate station itself (as shown in case e in Figure 3). Part of the missing information may be caused by partial damage to the communication network in the station. At this time, the protection of the busbar, transformer and outgoing lines in the station will be affected, and the upper-level section III should be opened as a backup. Since each station is equipped with a station domain backup protection host, the station domain host uses the centralized information of the whole station to identify faults in the station, so the characteristics of some missing information can be detected and identified by the station domain host, and the identification results are uploaded to the regional host.

2. Grid fault feature module

Use the regional backup protection platform to collect the fault characteristics of the power grid to open the distance section III of the upper-level components.

1) The protection installation place of section III and a certain protection at the exit of the lower station satisfy the formulas (1) and (2)

Taking protection 1 in Figure 3 as an example, when a fault occurs at point K ₁ of the lower line L ₂ , due to the long distance between protection 1 and the fault point and the influence of other branches of station B ₂ , it is likely that the protection 1 Criterion (1) and (2) refuse to move, and then make distance III section refuse to move.

However, on the regional backup protection platform, since the regional host has the ability to collect multiple information, it can obtain the fault characteristics reflected by the outgoing line protection of the lower-level stations, that is, the information of protection 2, 3, and 5. Then when the K ₁ point fails, since the protection 3 and the K ₁ point are located on the same line, the criteria (1) and (2) can act sensitively, and open the section III of the protection 1 to realize its remote backup function. While the protection 1 judges the criteria (1) and (2) at the same time, it is helpful to sensitively open the distance section III when the line L ₁ fails, and assists in undertaking the near-backup function.

2) The bus voltage of the lower-level station meets the condition of re-voltage

Taking protection 1 in Figure 3 as an example, the complex voltage condition is composed of phase low voltage, negative-sequence voltage and zero-sequence voltage criteria, in which the theoretical value of negative-sequence and zero-sequence voltage is zero when the line is overloaded, and will not malfunction. And it is generally believed that the minimum voltage of the busbar is not less than 80% of the rated voltage when overloaded, so it is reliable to set the low voltage components to 0.7U _N. The bus voltage of station B ₂ satisfies the negative voltage condition.

3) A certain outgoing line of the lower-level station (including the line where Section III is located) is in a non-full-phase operation state

Taking protection 1 in Figure 3 as an example, high-voltage lines are often equipped with single-phase reclosing. During single-phase reclosing, the zero-sequence direction protection of non-full-phase lines will be blocked, and the zero-sequence current differential sensitivity of adjacent lines will decrease. If one of the lines L ₂ and L ₃ out of station B ₂ is in a non-full-phase operation state at this time, one section of the protection section III will be opened.

Aiming at the problems existing in the current anti-maloperation improvement measures of the distance III section and the defect of the traditional distance III section being overloaded and prone to misoperation, the present invention proposes an anti-maloperation system and an anti-maloperation method for the distance III section based on regional double-type fault characteristics. Starting from the reality of the power system, the system focuses on perfecting the remote backup function. By using the fault characteristics of the protection system in the region and the fault characteristics of the power grid to open the distance section III, it can effectively improve the protection of the distance section III section before the power system realizes the complete innovation of the backup protection principle. Malfunction, anti-chain tripping capabilities, perfect remote backup function, to ensure the safe and effective operation of the system during the transition period. The invention can realize good anti-misoperation effect, effectively improves the anti-maloperation and anti-chain tripping capabilities of the distance section III, improves the remote backup function, and ensures the safe and effective operation of the system during the transition period.

Claims (3)

1. The anti-maloperation system of distance III section based on regional double-type fault characteristics, which is characterized in that the system includes a protection system fault feature module and a power grid fault feature module; The fault characteristic module of the protection system uses the fault characteristics of the protection system to realize the opening or blocking of the protection of the stage III section of the upper-level component, including judging whether the TV and TA in the lower-level station are disconnected, judging whether the lower-level station and the adjacent station are out of synchronization, judging Whether the communication between the subordinate station and the adjacent station is interrupted, the part for judging whether the protection device of the subordinate station is invalid, and the part for judging whether the information of the subordinate station is partially missing or all information is interrupted; The part of judging whether the TV and TA in the lower-level station are disconnected is that when the TV and TA of a certain station in the system are disconnected, it is often necessary to block the relevant distance and current protection. For the protection that is not blocked, it may also be due to the disconnection of the transformer Large measurement errors lead to protection refusal to operate, so the transformer disconnection information of the lower-level station is used as a start-up feature; The part of judging whether the lower-level station loses synchronization with the adjacent station is that current high-voltage transmission lines are generally equipped with current differential protection as the main protection. When a certain lower-level station loses synchronization with the adjacent station, the current differential protection of the corresponding line will be In addition, when the current differential synchronization signal between stations is provided by the PMU device, or the PMU device is used to assist in judging whether the "ping-pong time synchronization method" between stations is accurately synchronized, in addition to the differential current exceeding the limit, the fault information of the PMU device can also be Or the auxiliary discrimination result is used as a characteristic signal of loss of synchronization; The part of judging whether the communication between the lower-level station and the adjacent station is interrupted is a situation where the communication interruption between two adjacent stations is more serious than the loss of synchronization. At this time, all the longitudinal protections of the corresponding lines will fail, and it is necessary to open the upper-level Distance III section provides remote backup function; The part of judging whether the protection device of the lower station is invalid is that when a certain protection device in the station fails, for the dual protection device, the failure of one of the protection devices will reduce the protection reliability, and for the only one protection device, the failure will mean that The protection refuses to move; therefore, when it is known that the protection device fails, the upper section III can be opened; The part of judging whether part of the information of the subordinate station is missing or all of the information is interrupted is that the communication failure mainly occurs within the scope of the subordinate station itself, and part of the missing information may be caused by partial damage to the communication network in the station. At this time, the busbar, transformer and the station The protection of outgoing lines will be affected, and the upper-level section III should be opened as a backup; since each station has a station domain backup protection host, the station domain host uses the centralized information of the entire station to identify faults in the station, so the characteristics of some missing information can be determined by The station domain host is detected and identified, and the judgment result is uploaded to the domain host; The power grid fault characteristic module uses the power grid fault characteristics to realize the opening or blocking of the section III protection of the upper level component, including judging whether the section III protection installation and a certain protection at the outlet of the lower station meet the action criterion part, and judging whether the bus voltage of the lower station meets the complex condition. The part of pressure condition and the part of judging whether a certain outgoing line of the subordinate station, including the line where Section III is located, is in a non-full-phase operation state; The part of judging whether the protection installation place of section III and a certain protection at the exit of the lower-level station satisfies the action criterion is that on the regional backup protection platform, the regional host has the ability to concentrate multiple information, and obtains the fault characteristics reflected by the outgoing line protection of the lower-level station; The protection criteria for the protection installation place of the above-mentioned section III and the exit of the lower-level station are as follows: I ₂ +I ₀ >0.5I ₁ (1) In the formula, I ₁ , I ₂ , and I ₀ are the positive, negative and zero-sequence currents at the place where the protection is installed, U ₁ is the positive-sequence voltage, is the angle between positive sequence voltage and positive sequence current, is the line impedance angle; if formula (1) and (2) are taken together or combined with the directional impedance relay, formula (1) can start when asymmetrical fault occurs, formula (2) can start when symmetrical fault, and overload Time formulas (1) and (2) are not activated, so as to prevent misoperation of distance protection; When a fault occurs at a certain point, the protection located on the same line as the fault point satisfies the criteria (1) and (2), and can act sensitively, and open the protection section III of the upper line to realize its remote backup function; while the upper protection Judging by criteria (1) and (2), it is helpful to sensitively open the distance section III when the superior line fails, and assist in undertaking the near-backup function; The part of judging whether the bus voltage of the lower-level station meets the revoltage condition is that the revoltage condition is composed of phase low voltage, negative sequence voltage and zero sequence voltage criteria, wherein the theoretical value of negative sequence and zero sequence voltage is zero when the line is overloaded , will not malfunction; the condition of bus repressure is: The re-voltage criterion acts sensitively when the components in the lower-level station fail, and opens the section III of the upper-level distance. When the protection of the components in the station refuses to operate, the section III can provide remote backup to remove the fault; The part of judging whether a certain outgoing line of the lower-level station including the line where Section III is located is in the non-full-phase operation state is that the high-voltage level line is often equipped with single-phase reclosing, and the non-full-phase line zero-sequence direction during single-phase reclosing The protection will be blocked, and the differential sensitivity of the zero-sequence current of adjacent lines will decrease. At this time, there is no short-circuit fault, but due to the performance degradation of the protection system, the protection of the upper stage III can also be opened to deal with possible faults at any time; except for single-phase Sneak jumping of the coincident external circuit breaker will also cause non-full-phase operation, which can be treated as the same state; since non-full-phase operation is a disconnection fault, it can be used as a kind of fault characteristic of the power grid to play an auxiliary role; The fault characteristic module of the protection system and the fault characteristic module of the power grid use the fault characteristic information collected by the regional master station to judge whether the fault characteristics of the protection system and the power grid are satisfied respectively. 2. The distance III section anti-maloperation system based on regional double-type fault characteristics according to claim 1, characterized in that, in the fault characteristic module of the protection system, it is judged whether TV and TA are disconnected in the lower station, because TV There is a special identification criterion for TA disconnection. The original protection device in the substation includes this function. The area protection host does not need to perform repeated identification, and the identification results of the fault station can be uploaded for use. 3. The anti-misoperation method of the distance section III based on the regional double-type fault characteristics, characterized in that the steps of the method are: Step 1: When the lower-level system fails, the upper-level protection device judges whether to act according to the action criterion of the distance section III; Step 2: The fault feature module of the protection system includes the part for judging whether TV and TA in the lower station are disconnected, the part for judging whether the lower station loses synchronization with the adjacent station, the part for judging whether the communication between the lower station and the adjacent station is interrupted, and the judgment for the protection of the lower station The failure part of the device and the part of judging whether part of the information of the subordinate station is missing or all the information is interrupted respectively use the fault characteristic information collected by the regional master station to judge whether the protection system is faulty; At the same time, in the fault feature module of the power grid, the section for judging whether the protection installation of section III and a certain protection at the outlet of the lower-level station meets the action criterion part, the part for judging whether the bus voltage of the lower-level station satisfies the revoltage condition, and judging the location of the lower-level station including the line where section III is located Whether a certain outgoing line is in non-full-phase operation state partly uses the fault characteristic information collected in the regional master station to judge whether the power grid is faulty; Step 3: Perform an OR operation on the output signals of the protection system fault module and the grid fault characteristic module, and send out a logic signal for blocking or opening the distance section III; Step 4: Perform an AND operation on the action signal of distance III section protection in step 1 and the logic signal in step 3 to determine whether the distance III section is delayed.