CN113449946A - Risk assessment method and device for relay protection setting system - Google Patents

Risk assessment method and device for relay protection setting system Download PDF

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CN113449946A
CN113449946A CN202010231446.0A CN202010231446A CN113449946A CN 113449946 A CN113449946 A CN 113449946A CN 202010231446 A CN202010231446 A CN 202010231446A CN 113449946 A CN113449946 A CN 113449946A
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CN113449946B (en
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黄超
蒙亮
田君杨
杨彦
刘斌
何洪
李海勇
覃丙川
巫聪云
韩冰
秦蓓
孙翔
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Guangxi Power Grid Co Ltd
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Guangxi Power Grid Co Ltd
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Abstract

The application discloses a risk assessment method and device of a relay protection setting system. The method comprises the following steps: determining at least one protection device to be evaluated and a false action source thereof; calculating the probability of each hardware system failure of each protection device to be evaluated; traversing all the protections in the false activation source corresponding to each protection device to be evaluated, and calculating the probability of each principle failure of each protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to each protection device to be evaluated; determining the failure probability of each protection device to be evaluated according to the probability of each hardware system failure and the probability of each principle failure of each protection device to be evaluated; calculating the loss load quantity of each protection device to be evaluated after each failure; and performing risk assessment on the relay protection setting system according to the failure probability and the loss load. The method and the device can accurately reflect the relay protection characteristics and actual operating environment risk factors.

Description

Risk assessment method and device for relay protection setting system
Technical Field
The application relates to the technical field of power systems, in particular to a risk assessment method and a risk assessment device for a relay protection setting system.
Background
As a first line of defense for protecting the safety of a power grid, the reliable operation of a relay protection system has important significance on the safety and the stability of a power system, but the refusal action and the misoperation of the relay protection system are also one of important factors for triggering and accelerating the system disturbance. With the increasing requirements of power systems on secondary automatic devices, the technology and management level of protection reliability and risk assessment are still to be improved, and the systematic implementation of measures for accumulation and mining of basic data of protection reliability, reliability and risk assessment and reliability enhancement, and the establishment and research of the measures have important significance for enhancing the protection reliability and operation level and protecting the safe operation of a power grid.
The relay protection is often in the form of protection devices in the power grid, and most of the protection devices are in coordination with the upper and lower stages, and the failure or misoperation of one protection device may cause the sequential actions of other protection devices and even cause the risk of tripping in chain. For a relay protection setting system, if only the traditional certainty criterion is analyzed and improved, the complexity and randomness of a power system are difficult to consider, and only probabilistic risk calculation is properly introduced, the possibility of failure of the protection system and the severity of failure consequences can be enhanced. Therefore, the research of the risk assessment method capable of quantitatively reflecting various failure modes of the relay protection system is of great significance.
Disclosure of Invention
The object of the present application is to solve at least to some extent one of the above mentioned technical problems.
Therefore, a first objective of the present application is to provide a risk assessment method for a relay protection setting system. The method can accurately reflect the relay protection characteristics and the actual operation environment risk factors.
The second purpose of the present application is to provide a risk assessment device for a relay protection setting system.
In order to achieve the above object, an embodiment of the present application provides a risk assessment method for a relay protection setting system, including: determining at least one protection device to be evaluated and a false action source of each protection device to be evaluated according to the power grid topological structure; calculating the probability of each hardware system failure of each protection device to be evaluated; traversing all the protections in the false activation source corresponding to each protection device to be evaluated, and calculating the probability of each principle failure of each protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to each protection device to be evaluated; determining the failure probability of each failure of each protection device to be evaluated according to the probability of each hardware system failure of each protection device to be evaluated and the probability of each principle failure of each protection device to be evaluated; calculating the loss load quantity of each to-be-evaluated protection device after each failure according to the protection device failure possible loss evaluation model; and performing risk assessment on the relay protection setting system according to the failure probability of each failure of each protection device to be assessed and the loss load quantity caused by each failure of each protection device to be assessed.
In order to achieve the above object, an embodiment of the second aspect of the present application provides a risk assessment apparatus for a relay protection setting system, including: the determining module is used for determining at least one to-be-evaluated protection device and a false action source of each to-be-evaluated protection device according to the power grid topological structure; the data acquisition module is used for acquiring measured values of the characteristic quantities corresponding to each protection device to be evaluated; the hardware system failure probability calculation module is used for calculating the probability of each hardware system failure of each protection device to be evaluated; the principle failure probability calculation module is used for traversing all the protections in the false activation source corresponding to each protection device to be evaluated, and calculating the probability of each principle failure of each protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to each protection device to be evaluated; the failure probability determining module is used for determining the failure probability of each failure of each to-be-evaluated protection device according to the probability of each hardware system failure of each to-be-evaluated protection device and the probability of each principle failure of each to-be-evaluated protection device; the loss load calculation module is used for calculating the loss load of each to-be-evaluated protection device after each failure according to the protection device failure possible loss evaluation model; and the risk evaluation module is used for carrying out risk evaluation on the relay protection setting system according to the failure probability of each failure of each protection device to be evaluated and the loss load quantity caused by each failure of each protection device to be evaluated.
According to the risk assessment method and the wind direction assessment device of the relay protection setting system, at least one protection device to be assessed and a malfunction source of each protection device to be assessed can be determined according to a power grid topological structure, the probability of each hardware system failure of each protection device to be assessed is calculated, all protection in the malfunction source corresponding to each protection device to be assessed is traversed, the probability of each principle failure of each protection device to be assessed is calculated according to a fixed value and an actual measured value of a characteristic quantity corresponding to each protection device to be assessed, then the failure probability of each protection device to be assessed is determined according to the probability of each hardware system failure of each protection device to be assessed and the probability of each principle failure, the loss load quantity caused by each protection device to be assessed after each failure is calculated, and then, and performing risk assessment on the relay protection setting system according to the failure probability and the loss load. The embodiment of the application provides a novel risk evaluation mode of a relay protection setting system, and a principle failure risk analysis mode of typical stage type backup protection is introduced mainly, so that the system mainly focuses on aspects of system software, hardware, a protection configuration scheme, hidden faults and the like, and in view of the fact that the current relay protection configuration strengthens main protection and simplifies backup protection, the reliability of the main protection is relatively high, and failure analysis is relatively simple; in addition, the influence of the actual operation environment of the relay protection on the relay protection device is considered, the actual operation risk of the relay protection device when the system mode changes is effectively reflected, and the relay protection characteristic and the actual operation environment risk factor can be accurately reflected.
Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.
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The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a flowchart of a risk assessment method of a relay protection tuning system according to an embodiment of the present application;
FIG. 2 is a flow chart of calculating a probability of principle failure according to an embodiment of the present application;
FIG. 3 is an exemplary graph of a probability distribution of over-actuated protection device I section no-start-up according to an embodiment of the present application;
FIG. 4 is a flow chart of calculating a lost load amount according to an embodiment of the present application;
FIG. 5 is an exemplary diagram of a grid architecture according to an embodiment of the present application;
fig. 6 is a schematic structural diagram of a risk assessment device of a relay protection setting system according to an embodiment of the present application.
Detailed Description
Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application and should not be construed as limiting the present application.
At present, the reliability and operation risk research of a relay protection system is mostly described by protecting indexes such as correct action rate, misoperation rate and rejection rate, and the indexes reflect the long-term average reliability of the whole relay protection from the aspect of statistics and are statistical values obtained through long-term historical data statistics. Therefore, the influence of the actual operation environment of the relay protection on the conventional risk index evaluation mode of the relay protection system is not taken into account, and the actual operation risk of the relay protection system when the system mode is changed is difficult to effectively reflect. Therefore, the application introduces a novel risk assessment method of a relay protection setting system, and the method can accurately reflect relay protection characteristics and actual operation environment risk factors.
Fig. 1 is a flowchart of a risk assessment method of a relay protection tuning system according to an embodiment of the present application. As shown in fig. 1, the risk assessment method of the relay protection setting system may include:
step 101, determining at least one protection device to be evaluated and a false action source of each protection device to be evaluated according to a power grid topological structure.
It is to be understood that the above "at least one" means one or more, and "a plurality" means at least two, e.g., two, three, etc.
That is to say, according to the topology structure of the current power grid, the protection device that needs to be evaluated in the power grid can be determined, so that the protection range to be evaluated is determined. After the protection devices to be evaluated in the power grid are determined, the false operation source of each protection device to be evaluated is determined according to the topology structure of the power grid. In the embodiment of the present application, the source of the false operation refers to two adjacent levels of protection in a matching relationship with the protection device to be evaluated.
And 102, calculating the probability of each hardware system failure of each protection device to be evaluated.
Optionally, based on the running state of the relay protection setting system, calculating the probability of each hardware system failure of the protection device to be evaluated, that is, determining the reliability of the hardware system of the protection device to be evaluated.
Step 103, traversing all the protections in the false activation source corresponding to each protection device to be evaluated, and calculating the probability of each principle failure of each protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to each protection device to be evaluated.
The characteristic quantity may be an impedance of the protection device to be evaluated. That is, for each protection device to be evaluated, all the protection devices in the malfunction source corresponding to the protection device to be evaluated can be traversed, and the probability of each principle failure of the protection device to be evaluated is calculated according to the fixed value and the measured value of the impedance corresponding to the protection device to be evaluated. In the present application, the above-described principle failures may include failures due to a refusal of action and failures due to a malfunction.
Optionally, in an embodiment of the present application, as shown in fig. 2, the specific implementation process of traversing all protections in the malfunction source corresponding to each protection device to be evaluated and calculating the probability of each principle failure of each protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to each protection device to be evaluated may include the following steps:
step 201, aiming at the ith protection device to be evaluated, determining the type of a protection element in the ith protection device to be evaluated. It can be understood that the value range of i is greater than or equal to 1 and less than or equal to the total number of the protection devices to be evaluated.
Step 202, according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated, adopting a motion rejection probability calculation formula corresponding to the type to calculate the motion rejection probability of the ith protection device to be evaluated.
In one embodiment of the present application, the types may include an under action protection type and an over action protection type. It is understood that protection devices can be broadly divided into two categories, one being underactuated protection devices, such as distance elements, low voltage elements, etc.; the other is an excessive action protection device such as a current actuated element or the like. Whether the amplitude comparison criterion or the phase comparison criterion is adopted by the elements, an action boundary, such as a circular track of the impedance element and the like, can be found according to a fixed value. In the embodiment of the application, the boundary is taken as reference, and the probability of the operation failure and the probability of the misoperation of the protection device are calculated according to the characteristic quantities of the fixed value and the measured value.
In an embodiment of the application, a specific implementation process of calculating the rejection probability of the ith protection device to be evaluated by using a rejection probability calculation formula corresponding to the type according to the fixed value and the measured value of the feature quantity corresponding to the ith protection device to be evaluated may be as follows: when the type is the underactuated protection type, calculating the probability of refusing the action of the ith protection device to be evaluated by adopting a first probability of refusing calculation formula according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated; and determining the probability of the protection device to be evaluated failing to operate according to the fixed value and the actual measured value of the characteristic quantity corresponding to the protection device to be evaluated i and the boundary activation probability reference point which is the minimum and the maximum of the corresponding characteristic quantity when the type is the excessive operation protection type. Wherein, the first action rejection probability calculation formula is:
Figure BDA0002429407400000051
wherein the content of the first and second substances,
Figure BDA0002429407400000052
the probability of the refusing action of the ith protection device to be evaluated is obtained; alpha is an offset coefficient; zsetA constant impedance of the ith protection device to be evaluated; zmFor the measured resistance of the i-th protection device to be evaluatedResisting;
Figure BDA0002429407400000053
to measure the impedance angle;
Figure BDA0002429407400000054
the maximum sensitivity angle of the ith protection device to be evaluated; pinact.minThe minimum probability of the protection device to be evaluated in the protection characteristic area is the ith protection device to be evaluated; pinact.midThe maximum probability of the protection device to be evaluated in the protection characteristic area is the ith protection device to be evaluated.
For example, for a protection device with an underactuation, a feature quantity corresponding to the protection device, for example, an impedance of a distance protection device, is first selected, and a probability variation trend is determined according to a relative position of an actually measured value of the feature quantity in the protection characteristic region of the type. Taking the directional impedance protection device with circular characteristics as an example, the probability of protection rejection (i.e. probability of no start) at the center of the circle is the minimum and is marked as Pinact.min(for example, numerical value can take 0), and the probability of refusing action on the circular track is recorded as Pinact.mid(e.g., a value of 0.5 may be desirable). The principle failure mainly considers the randomness of the matching degree of the protection principle and a specific fault. For distance protection, the randomness is influenced by factors such as transition resistance, system oscillation, power flow transfer and the like, and can be finally reflected on the characteristic quantity of the measured impedance to a great extent, the more the measured impedance deviates from the range of protection characteristics, the poorer the matching degree of the protection principle and the fault is, the higher the probability of the protection device for refusing action is, and on the other hand, the probability of the specific fault and the probability of the protection device for refusing action are in one-to-one correspondence as far as possible, so that the refusing probability and the resolution ratio of the operation risk under different fault situations are improved to the greatest extent. Combining the characteristics of the impedance circle, actually measuring the effective value and phase information of the impedance, unifying the randomness to the radial direction of the circle characteristics for comparative analysis, calculating the instantaneous rejection probability of the circle characteristic impedance protection device according to the formula (1), and limiting the numerical value to [0,1 ]]The method ensures that the correlation between the actually measured impedance and the rejection probability of the directional impedance protection device is linearly changed in the radial direction of the circle, meets the requirements and reduces the complexity of calculationAnd (4) degree. Wherein, corresponding to the three-stage impedance customization, the instantaneous rejection probability of each stage of the protection device can be calculated by the formula (1) and can be recorded as
Figure BDA0002429407400000055
For another example, for an over-actuated protection device, such as the rejection probability of a staged current protection, the processing concept is similar to that of an under-actuated protection device, and since it generally involves only amplitude comparison, the probability model is simpler than that of a distance protection. Firstly, selecting proper characteristic quantity to determine the change trend of the probability, and determining the calculation of the instantaneous probability of refusing action through the minimum and maximum characteristic quantity and the boundary starting probability reference point. Taking three-segment zero-sequence current protection as an example, the instantaneous rejection probability of the I segment
Figure BDA0002429407400000056
When the protection device actually measures zero sequence current (total current) Ik(t) satisfies
Figure BDA0002429407400000057
When the probability of motion rejection is minimum, it is recorded as P'JminAnd the value may take 0;
Figure BDA0002429407400000058
taking a fixed value of 1.3 times of zero sequence current protection I section
Figure BDA0002429407400000059
Referred to as the upper current limit. When in use
Figure BDA0002429407400000061
When the probability of motion rejection is maximum, it is recorded as P'JmaxAnd the value may take 1;
Figure BDA0002429407400000062
the maximum zero sequence current which may occur when the grounding short circuit occurs at the tail end of the line in the maximum operation mode is called as the lower limit current.
Figure BDA0002429407400000063
Then, the probability of motion rejection is recorded as P'JmidAnd may take a value of 0.5. Therefore, the I-segment motion rejection probability can be calculated according to the following formula (2), wherein the protection I-segment motion rejection probability distribution can be shown in fig. 3.
Figure BDA0002429407400000064
The method for determining the boundary corresponding to the instantaneous action rejection probability of the II section of the current protection device comprises the following steps: the lower limit current is the maximum sensitive current which flows through the protection device when the tail end of the protection range of the section I of the adjacent next-stage line is in a grounding short circuit in the maximum operation mode; the upper limit current is 1.3 times of the setting value of the zero-sequence current protection II section. Instantaneous probability of refusing action in II and III sections
Figure BDA0002429407400000065
The specific calculation idea of the method is the same as the calculation of the instantaneous probability of action rejection of the section I, and details are not repeated here.
Step 203, traversing all the protections in the false action source corresponding to the ith protection device to be evaluated, and calculating the false action probability of the ith protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated and the false action probability of the ith protection device to be evaluated.
Optionally, traversing all protections in a false action source corresponding to the ith protection device to be evaluated, and based on a protection device false action probability calculation formula, calculating the false action probability of the ith protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated and the false action probability of the ith protection device to be evaluated; wherein, the false operation probability calculation formula of the protection device is as follows:
Figure BDA0002429407400000066
wherein, PmisThe false action probability of the ith protection device to be evaluated is obtained; preclose∈(0,1]The reclosing failure probability reflects the instantaneity of the reclosing pairThe correction conditions of the conditions of faults, circuit breaker tripping and the like can be calculated by adopting statistical data in the power grid, and if reclosing is not configured, P is calculatedreclose＝1；Pf.next(j) Representing the fault probability of the jth device at the next lower level of the protected device; pw(j) The probability of false operation, P, caused by short circuit of the jth adjacent next-stage equipment when the ith protection device to be evaluated operates in the system with m adjacent equipment is shownw(j) The estimated probability is calculated based on the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be estimated and the operation rejection probability of the ith protection device to be estimated.
It can be understood that the probability of false operation P of the protection device to be evaluatedmisThe probability of the protection action is the probability of the protection action when no fault exists in the area, or the probability of the protection action of the power equipment under the condition that the adjacent equipment has faults and the protection of the adjacent equipment is not rejected. The method represents the possibility of misoperation of the protection device under the condition of a certain system running state and a protection fixed value, and the calculation formula can be shown as the formula (3). Wherein, to the syllogic protection device, also there are corresponding three probability of maloperation:
Figure BDA0002429407400000071
Pw.nf. Wherein, Pw.nfIndicating the probability of false activation of the protection in the absence of a fault. The following takes the line distance protection as an example to introduce Pw(j) The method comprises the following steps:
stage I: in the distance protection I section, when the jth adjacent next-stage line of the protected line is short-circuited and the distance protection of the adjacent line does not reject the operation, the operation belongs to false operation, and the probability can be expressed as formula (4):
Figure BDA0002429407400000072
in the formula (4), the reaction mixture is,
Figure BDA0002429407400000073
respectively protecting the refusing action probability of each section for the distance of the jth adjacent next-stage line,
Figure BDA0002429407400000074
the probability of action rejection of this protection (protection I) segment I is shown. The calculation method is the same as the formula (1), and only the fixed value of the corresponding protection needs to be selected.
The fixed value of the distance I section is generally 80% -85% of the impedance of the protected line, the probability of false operation is small, but the false operation may be caused by factors such as transition resistance and power flow transfer.
And II, section: the action time is longer than the action time of the protected line and the section I of the jth adjacent next-level line, the protected line can act on tripping only when the two sections of protection are both refused to act, and the action of the distance protection section II of the protected line can be regarded as false action only when the sections II and III of the jth adjacent next-level line are not simultaneously refused to act, and the probability is shown as the following formula (5):
Figure BDA0002429407400000075
the above two calculation ideas are also applicable to current protection.
Stage III: in case of overload or power flow transition, etc., the distance III section may be erroneously operated by the measured impedance entering the operation region. Setting false action probability P of distance protection III sectionw.nfAs shown in the following formula (6): distance protection III section constant value with actually measured impedance smaller than 0.8 times
Figure BDA0002429407400000076
When is, Pw.nfIs a constant;
Figure BDA0002429407400000077
when is, Pw.nf0; in that
Figure BDA0002429407400000078
A middle linear decreasing to ensure when
Figure BDA0002429407400000079
The false action probability is 0.5.
Figure BDA0002429407400000081
For the false action probability of the section III of the excessive protection such as the current protection, considering the false action under the condition that the system has no fault or the false action of the section III of the current protection when the adjacent line has a fault with a time coordination relationship, the analysis idea is similar to that of each section of the distance protection, wherein the false action probability of the section III of the current protection can be calculated according to the following formula (7):
Figure BDA0002429407400000082
in the formula (7), the reaction mixture is,
Figure BDA0002429407400000083
for this protection (protection I) probability of refusal of stage II, ImAs a measure of the current of the present protection,
Figure BDA0002429407400000084
and setting values for protecting the section III.
Therefore, in the process of evaluating the operation risk of the protection system, the refusal action and the misoperation of the protection need to be comprehensively considered.
And 204, determining the probability of each principle failure of the ith protection device to be evaluated according to the action rejection probability and the misoperation probability of the ith protection device to be evaluated.
Optionally, the calculated probability of the action rejection of the ith protection device to be evaluated and the probability of the false action of the ith protection device to be evaluated are unified as the principle failure probability of the ith protection device to be evaluated, so that the probability of each principle failure of the ith protection device to be evaluated can be obtained. That is, the principle failure may be failure of the protection device due to a malfunction or a malfunction, so when calculating the probability of each principle failure of the protection device, it is only necessary to calculate the malfunction probability and the malfunction probability of the protection device, and the malfunction probability are unified as the principle failure probability of the protection device.
And step 104, determining the failure probability of each failure of each protection device to be evaluated according to the probability of each hardware system failure of each protection device to be evaluated and the probability of each principle failure of each protection device to be evaluated.
It is understood that the failure modes of the protection device may include hardware system failure and principle failure, and in this step, the probability of each hardware system failure of the protection device to be evaluated and the probability of each principle failure of the protection device to be evaluated may be unified as the failure probability of each failure of the protection device to be evaluated.
It is worth noting that in the relay protection setting system, on the premise of high reliability, the main failure mode is similar to a competitive relationship. That is, for a single set of protection devices or systems, the failure mode that occurs first will most likely result in failure of the protection device or system; for the protection device with redundant configuration, the failure of the protection device is analyzed by combining the definition of false action failure and rejection failure, for example, the protection of double-set configuration, if one set of false action can trigger the false action of the protection device, and if both sets of false action trigger the protection device to reject action, and the rejection and false action modes still meet the competition relationship. The failure rate function of the relay protection setting system can be represented by the following formula (8):
Figure BDA0002429407400000091
in formula (8), λfi(t) indicates the probability of the occurrence of the i-th hardware system failure, λsj(t) represents the probability of the occurrence of the j-th principle failure, k1 is the number of classes of hardware system failure modes, and k2 is the number of classes of principle failure modes.
As shown in the formula (8), the probabilities of all kinds of hardware system failures of the protection device to be evaluated, which may occur, may be summed, the probabilities of all kinds of principle failures of the protection device to be evaluated, which may occur, may be summed, and the two sum values are summed, where the sum value obtained at this time is the failure rate of the relay protection setting system.
And 105, calculating the loss load quantity of each to-be-evaluated protection device after each failure according to the protection device failure possible loss evaluation model.
In an embodiment of the present application, as shown in fig. 4, the specific implementation process of calculating the loss load amount caused by each protection device to be evaluated after each failure according to the protection device failure possible loss evaluation model may include the following steps:
step 401, for the ith protection device to be evaluated, under the power grid topology structure, calculating a first protection false action probability in a false action source corresponding to the ith protection device to be evaluated.
And 402, cutting off the line of the ith protection device to be evaluated according to the first protection malfunction probability, and performing N-1 load flow calculation.
And 403, calculating a second protection misoperation probability in the corresponding misoperation source of the ith to-be-evaluated protection device under the new power grid topological structure and the new power flow state.
And step 404, according to the second protection misoperation probability, cutting off a line where the protection in the protection device to be evaluated corresponds to the misoperation source, and performing N-2 load flow calculation to obtain the load loss caused by the misoperation of the protection device of the current line.
Step 405, calculating load loss caused by the far backup protection action of the ith protection device to be evaluated.
And 406, calculating the loss load quantity of each protection device to be evaluated after each failure according to the load loss caused by the misoperation of the protection device of the current line and the load loss caused by the far backup protection action of the ith protection device to be evaluated.
Therefore, the loss load amount of the protection device to be evaluated after each failure can be obtained through the steps 401 and 406.
And 106, performing risk assessment on the relay protection setting system according to the failure probability of each failure of each protection device to be assessed and the loss load quantity caused by each failure of each protection device to be assessed.
Optionally, the absolute risk indicator of each protection device to be evaluated is calculated according to the failure probability of each failure of each protection device to be evaluated and the loss load amount caused by each protection device to be evaluated after each failure, and the relative risk indicator of each protection device to be evaluated is calculated according to the absolute risk indicator of each protection device to be evaluated and the load amount of each load node in each protection device to be evaluated.
It will be appreciated that the probability of failure is different for each protection device and the consequences of failure may also be different. Therefore, while considering the probability of failure of protection, a severity metric should be determined to characterize the difference in outcomes. Let P be the probability of failure of a protection device in a certain modeiTwo risk indicators are defined:
(1) absolute risk indicator
Figure BDA0002429407400000101
Wherein, I1Set of failure modes for relay protection, PiAnd SiThe occurrence probability of the ith failure mode and the corresponding loss load amount are respectively. The absolute risk index reflects the expected value of load loss caused by the failure of the relay protection device.
(2) Relative risk indicator
Figure BDA0002429407400000102
Wherein, I2Is a load node set; l isiIs the load capacity of node i.
In an embodiment of the application, the risk level of each to-be-evaluated protection device may be determined according to the relative risk indicator, each to-be-evaluated protection device may be sorted according to the risk level, and a sorting result and the risk level of each to-be-evaluated protection device may be output. That is to say, after the relative risk index is obtained, the risk level of each to-be-evaluated protection device can be determined according to the relative risk index, the to-be-evaluated protection devices are sorted according to the risk levels, and the sorting result and the risk level of the to-be-evaluated protection device are output, so that an evaluator can know the operation risk condition of the relay protection setting system based on the output result, and a new working idea is provided for research of relay protection operation risk control.
For example, to facilitate the understanding of the present application for those skilled in the art, the following describes an example of a single protection device as a basic evaluation object, and the calculation process of the risk indicator can be as follows:
(1) and determining a protection device to be evaluated and a false action source set according to the topological structure of the power grid, wherein the false action source refers to two adjacent levels of protection which have a matching relationship with the protection to be evaluated.
(2) And (3) carrying out failure classification analysis on the protection device: 1) calculating the reliability of a hardware system of the protection device to be evaluated; 2) and according to the current measured value, calculating the false action probability of the protection device to be evaluated by the protection principle failure probability model. And calculating the false action probability of the protection device according to a protection device failure probability algorithm based on failure mode competition, cutting off the line where the protection to be evaluated is located, and performing N-1 load flow calculation.
(3) And calculating the protection misoperation probability in the misoperation source set under the new power grid structure and the new power flow state.
(4) And (4) taking the protection device in the false action source into consideration, cutting off the line where the protection device is positioned according to the false action probability, and carrying out N-2 load flow calculation to obtain the load loss caused by the false action of the protection device of the current line.
(5) And calculating the non-starting probability of the protection to be evaluated, the action probability of the far backup protection and the load loss caused by the far backup action.
(6) And traversing all the protections in the false action source set, and respectively calculating the risk index corresponding to the current protection device and the total false action probability, the false action probability and the comprehensive risk index of the protection device to be evaluated according to the protection false action probability, the false action probability and the corresponding load loss.
(7) And traversing the protection device set to be evaluated, repeating the risk index calculation process to obtain the absolute risk index and the relative risk index of the whole network protection device, sequencing according to the risk size, and providing reference for judging the weakest protection link in the power grid and the like.
For example, taking the exemplary power grid diagram shown in fig. 5 as an example, it is assumed that the positive sequence impedance and the zero sequence impedance of each line are respectively as follows: z1.AB＝22.5164∠66°，Z0.AB＝35.2483∠74°，Z1.CD＝3.8∠62.1°，Z0.CD＝2.8∠62°，Z1.DE＝7.397∠61°，Z0.DE＝12.9∠75°，Z1.EF＝4.233∠79°，Z0.EF＝4.614∠60°，Z1.GH＝3.8∠76°，Z0.GH＝2.8∠75°；
The zero-sequence equivalent impedance and the positive-sequence equivalent impedance under the maximum operation mode and the minimum operation mode of each equivalent system are respectively as follows:
Z1.A.min＝0.0893∠50°，Z1.A.max＝0.4∠80°，Z0.A.min＝0.2135∠50°，Z0.A.min＝0.5∠70°；Z1.B.min＝0.0414∠90°，Z1.B.max＝0.2∠90°，Z0.B.min＝0.0788∠90°，Z0.B.max＝0.3∠90°；Z1.H.min＝0.06∠50°，Z1.H.max＝0.16∠80°，Z0.H.min＝0.08∠50°，Z0.H.max＝0.18∠80°；
the active load carried by each bus can be as follows:
LA＝50MW，LB＝125MW，LD＝30MW，LE＝20MW，LG＝20MW，LH＝15MW。
the following table 1 shows the fixed values of each section of the grounding distance protection of each line and performs correlation analysis, the distance elements all adopt the directional circle characteristic, and the fixed values of each section are respectively set according to the following principles: the section I is set according to 80% of protection of the line; section II satisfies: 1) the sensitivity is less than 1.25 when the line tail end ground fault is met by matching with the fixed value of the adjacent line grounding distance protection I/II section; and the III section meets the following conditions: 1) and 2) matching with a fixed value of a grounding distance protection II/III section of an adjacent line, 2) meeting the requirement that the sensitivity is not less than 1.5 when the tail end of the line is in a grounding fault, 3) setting according to far backup sensitivity, and matching with the adjacent line, wherein the sensitivity coefficient is not less than 1.2. The fixed values of the ground distance protection sections corresponding to the line protections 1-10 are shown in the following table 1, and the maximum sensitivity angle is the impedance angle of the protected line.
TABLE 1 ground distance protection constant
Protection number Grounding distance I section Grounding distance II section Grounding distance III section
1 18.04 28.2 33.8
2 18.04 28.2 33.8
3 3.05 7.925 11.4
4 3.05 4.77 5.72
5 5.92 10.15 12
6 5.92 9.93 10.7
7 3.39 5.29 6.35
8 3.39 8.12 11.33
9 3.05 4.77 5.73
10 3.05 4.77 5.73
With the fixed values shown in table 1 above, under the condition that each protection device is in the maximum operation mode, if a single-phase a-phase ground fault occurs at the midpoint of the line EF through the 1 Ω transition resistor, the relative risk indexes of all the protections are calculated, as shown in table 2 below:
TABLE 2 relative risk indicators for all protections
Protection number Measuring impedance RRI
1 96.23 0
2 114.44 0
3 13.94 0
4 10.17 0
5 11.29 0.0086
6 4.35 0
7 3.36 0.0606
8 3.04 0.011
9 2.41 0
10 6.23 0
As can be seen from the calculation results shown in table 2 above, when a fault occurs on the line EF, the relative risk indicator of the operational risk of the protections 7 and 8 is high, and the relative risk indicator of the operational risk of the upper-level protection 5 is high. Therefore, protection with high relay protection risk index value can become a weak link of a protection system and can be used as a decision basis of an equipment maintenance plan.
According to the risk assessment method of the relay protection setting system, at least one protection device to be assessed and a malfunction source of each protection device to be assessed can be determined according to a power grid topological structure, the probability of each hardware system failure of each protection device to be assessed is calculated, all protection in the malfunction source corresponding to each protection device to be assessed is traversed, the probability of each principle failure of each protection device to be assessed is calculated according to a fixed value and an actual measured value of a characteristic quantity corresponding to each protection device to be assessed, then the failure probability of each protection device to be assessed is determined according to the probability of each hardware system failure of each protection device to be assessed and the probability of each principle failure, the loss load quantity caused by each protection device to be assessed after each failure is calculated, and then according to the failure probability and the loss load quantity, and performing risk assessment on the relay protection setting system. The embodiment of the application provides a novel risk evaluation mode of a relay protection setting system, and a principle failure risk analysis method of typical stage type backup protection is mainly introduced, so that the method is mainly focused on aspects of system software, hardware, a protection configuration scheme, hidden faults and the like, and in view of the fact that the current relay protection configuration strengthens main protection and simplifies backup protection, the reliability of the main protection is relatively high, and failure analysis is relatively simple; in addition, the influence of the actual operation environment of the relay protection on the relay protection device is considered, the actual operation risk of the relay protection device when the system mode changes is effectively reflected, and the relay protection characteristic and the actual operation environment risk factor can be accurately reflected.
Corresponding to the risk assessment methods of the relay protection setting system provided in the above several embodiments, an embodiment of the present application also provides a risk assessment apparatus of the relay protection setting system, and since the risk assessment apparatus of the relay protection setting system provided in the embodiment of the present application corresponds to the risk assessment methods of the relay protection setting system provided in the above several embodiments, the implementation manner of the risk assessment method of the relay protection setting system is also applicable to the risk assessment apparatus of the relay protection setting system provided in the embodiment, and is not described in detail in the embodiment. Fig. 6 is a schematic structural diagram of a risk assessment device of a relay protection setting system according to an embodiment of the present application. As shown in fig. 6, the risk assessment apparatus 600 of the relay protection tuning system may include: the system comprises a determination module 610, a data acquisition module 620, a hardware system failure probability calculation module 630, a principle failure probability calculation module 640, a failure probability determination module 650, a loss load amount calculation module 660 and a risk assessment module 670.
Specifically, the determining module 610 is configured to determine at least one protection device to be evaluated and a malfunction source of each protection device to be evaluated according to a power grid topology.
The data collection module 620 is configured to collect measured values of the characteristic quantities corresponding to each protection device to be evaluated.
The hardware system failure probability calculation module 630 is configured to calculate the probability of each hardware system failure occurring for each protection device to be evaluated.
The principle failure probability calculation module 640 is configured to traverse all protections in the false activation source corresponding to each protection device to be evaluated, and calculate the probability of each principle failure occurring in each protection device to be evaluated according to the fixed value and the measured value of the feature quantity corresponding to each protection device to be evaluated. As an example, the principle failure probability calculation module 640 is specifically configured to: determining the type of a protection element in an ith protection device to be evaluated aiming at the ith protection device to be evaluated; calculating the action rejection probability of the ith protection device to be evaluated by adopting an action rejection probability calculation formula corresponding to the type according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated; traversing all protections in a false action source corresponding to the ith protection device to be evaluated, and calculating the false action probability of the ith protection device to be evaluated according to the fixed value and the actual value of the characteristic quantity corresponding to the ith protection device to be evaluated and the false action probability of the ith protection device to be evaluated; and determining the probability of each principle failure of the ith protection device to be evaluated according to the action rejection probability and the misoperation probability of the ith protection device to be evaluated.
In one embodiment of the present application, the types may include an under action protection type and an over action protection type. In an embodiment of the present application, the principle failure probability calculating module 640 calculates the failure probability of the ith protection device to be evaluated according to the fixed value and the measured value of the feature quantity corresponding to the ith protection device to be evaluated by using the failure probability calculating formula corresponding to the type described above, and the specific implementation process of calculating the failure probability of the ith protection device to be evaluated may be as follows: when the type is the underactuated protection type, calculating the probability of refusing the action of the ith protection device to be evaluated by adopting a first probability of refusing calculation formula according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated; determining the probability of the protection device to be evaluated failing to operate according to the fixed value and the actual measured value of the characteristic quantity corresponding to the protection device to be evaluated i and the minimum and maximum boundary starting probability reference points of the corresponding characteristic quantity when the type is the excessive operation protection type; wherein, the first action rejection probability calculation formula is:
Figure BDA0002429407400000141
wherein the content of the first and second substances,
Figure BDA0002429407400000142
the probability of the refusing action of the ith protection device to be evaluated is obtained; alpha is an offset coefficient; zsetA constant impedance of the ith protection device to be evaluated; zmMeasuring impedance of the ith protection device to be evaluated;
Figure BDA0002429407400000143
to measure the impedance angle;
Figure BDA0002429407400000144
the maximum sensitivity angle of the ith protection device to be evaluated; pinact.minThe minimum probability of the protection device to be evaluated in the protection characteristic area is the ith protection device to be evaluated; pinact.midThe maximum probability of the protection device to be evaluated in the protection characteristic area is the ith protection device to be evaluated.
In an embodiment of the present application, a specific implementation process of the principle failure probability calculation module 640 calculating the malfunction probability of the ith protection device to be evaluated according to the fixed value and the actual value of the feature quantity corresponding to the ith protection device to be evaluated and the malfunction probability of the ith protection device to be evaluated may be as follows: based on a protection device malfunction probability calculation formula, calculating the malfunction probability of the ith protection device to be evaluated according to the fixed value and the actual value of the characteristic quantity corresponding to the ith protection device to be evaluated and the malfunction probability of the ith protection device to be evaluated; wherein, the false operation probability calculation formula of the protection device is as follows:
Figure BDA0002429407400000151
wherein, PmisThe false action probability of the ith protection device to be evaluated is obtained; preclose∈(0,1]The reclosing failure probability is obtained; pf.next(j) Indicating the phase of a protected deviceThe fault probability of the j-th equipment at the next level; pw(j) The probability of false operation, P, caused by short circuit of the jth adjacent next-stage equipment when the ith protection device to be evaluated operates in the system with m adjacent equipment is shownw(j) The estimated probability is calculated based on the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be estimated and the operation rejection probability of the ith protection device to be estimated.
The failure probability determination module 650 is configured to determine a failure probability of each failure of each protection device to be evaluated according to a probability of each hardware system failure of each protection device to be evaluated and a probability of each principle failure of each protection device to be evaluated.
The loss load calculation module 660 is configured to calculate a loss load caused by each failure of the protection device to be evaluated according to the protection device failure possible loss evaluation model. As an example, the loss load amount calculation module 660 is specifically configured to: aiming at the ith to-be-evaluated protection device, calculating a first protection misoperation probability in a corresponding misoperation source of the ith to-be-evaluated protection device under the power grid topological structure; according to the first protection misoperation probability, cutting off a line where the ith protection device to be evaluated is located, and carrying out N-1 load flow calculation; under the condition of a new power grid topological structure and a new power flow state, calculating a second protection misoperation probability in the corresponding misoperation source of the ith protection device to be evaluated; according to the second protection misoperation probability, cutting off a line where protection in the corresponding misoperation source of the ith protection device to be evaluated is located, and performing N-2 load flow calculation to obtain the load loss caused by misoperation of the protection device of the current line; calculating load loss caused by the far backup protection action of the ith protection device to be evaluated; and calculating the loss load quantity of each protection device to be evaluated after each failure according to the load loss caused by the misoperation of the protection device of the current line and the load loss caused by the far backup protection action of the ith protection device to be evaluated.
The risk evaluation module 670 is configured to perform risk evaluation on the relay protection setting system according to the failure probability of each failure of each protection device to be evaluated and the loss load amount caused by each failure of each protection device to be evaluated. As an example, the risk assessment module 670 calculates an absolute risk indicator of each to-be-assessed protection device according to a failure probability of each failure of each to-be-assessed protection device and a loss load amount caused by each to-be-assessed protection device after each failure, and calculates a relative risk indicator of each to-be-assessed protection device according to the absolute risk indicator of each to-be-assessed protection device and a load amount of each load node in each to-be-assessed protection device.
In an embodiment of the application, the risk assessment module 670 is further configured to determine a risk level of each to-be-assessed protection device according to the relative risk indicator, sort each to-be-assessed protection device according to the risk level, and output a sorting result and the risk level of each to-be-assessed protection device.
According to the risk evaluation device of the relay protection setting system, at least one protection device to be evaluated and a malfunction source of each protection device to be evaluated can be determined according to a power grid topological structure, the probability of each hardware system failure of each protection device to be evaluated is calculated, all protections in the malfunction source corresponding to each protection device to be evaluated are traversed, the probability of each principle failure of each protection device to be evaluated is calculated according to a fixed value and an actual value of a characteristic quantity corresponding to each protection device to be evaluated, then, the failure probability of each protection device to be evaluated is determined according to the probability of each hardware system failure of each protection device to be evaluated and the probability of each principle failure, the loss load quantity caused by each protection device to be evaluated after each failure is calculated, and then, according to the failure probability and the loss load quantity, and performing risk assessment on the relay protection setting system. The embodiment of the application provides a novel risk evaluation mode of a relay protection setting system, and a principle failure risk analysis method of typical stage type backup protection is mainly introduced, so that the method is mainly focused on aspects of system software, hardware, a protection configuration scheme, hidden faults and the like, and in view of the fact that the current relay protection configuration strengthens main protection and simplifies backup protection, the reliability of the main protection is relatively high, and failure analysis is relatively simple; in addition, the influence of the actual operation environment of the relay protection on the relay protection device is considered, the actual operation risk of the relay protection device when the system mode changes is effectively reflected, and the relay protection characteristic and the actual operation environment risk factor can be accurately reflected.
In the description of the present application, it is to be understood that the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the description herein, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and the scope of the preferred embodiments of the present application includes other implementations in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present application.
The logic and/or steps represented in the flowcharts or otherwise described herein, e.g., an ordered listing of executable instructions that can be considered to implement logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.
It should be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.
It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware that is related to instructions of a program, and the program may be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.
In addition, functional units in the embodiments of the present application may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a separate product, may also be stored in a computer readable storage medium.
The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc. Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

Claims (10)

1. A risk assessment method of a relay protection setting system is characterized by comprising the following steps:
determining at least one protection device to be evaluated and a false action source of each protection device to be evaluated according to the power grid topological structure;
calculating the probability of each hardware system failure of each protection device to be evaluated;
traversing all the protections in the false activation source corresponding to each protection device to be evaluated, and calculating the probability of each principle failure of each protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to each protection device to be evaluated;
determining the failure probability of each failure of each protection device to be evaluated according to the probability of each hardware system failure of each protection device to be evaluated and the probability of each principle failure of each protection device to be evaluated;
calculating the loss load quantity of each to-be-evaluated protection device after each failure according to the protection device failure possible loss evaluation model;
and performing risk assessment on the relay protection setting system according to the failure probability of each failure of each protection device to be assessed and the loss load quantity caused by each failure of each protection device to be assessed.
2. The method according to claim 1, wherein traversing all the protections in the malfunction source corresponding to each protection device to be evaluated, and calculating the probability of each principle failure of each protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to each protection device to be evaluated comprises:
determining the type of a protection element in an ith protection device to be evaluated aiming at the ith protection device to be evaluated;
calculating the action rejection probability of the ith protection device to be evaluated by adopting an action rejection probability calculation formula corresponding to the type according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated;
traversing all protections in a false action source corresponding to the ith protection device to be evaluated, and calculating the false action probability of the ith protection device to be evaluated according to the fixed value and the actual value of the characteristic quantity corresponding to the ith protection device to be evaluated and the false action probability of the ith protection device to be evaluated;
and determining the probability of each principle failure of the ith protection device to be evaluated according to the action rejection probability and the false action probability of the ith protection device to be evaluated.
3. The method of claim 2, wherein the types include an under action protection type and an over action protection type; the calculating the motion rejection probability of the ith protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated and by using a motion rejection probability calculation formula corresponding to the type includes:
when the type is the underaction protection type, calculating the action rejection probability of the ith protection device to be evaluated by adopting a first action rejection probability calculation formula according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated; wherein, the first action rejection probability calculation formula is as follows:
Figure FDA0002429407390000021
wherein the content of the first and second substances,
Figure FDA0002429407390000022
the probability of the refusing action of the ith protection device to be evaluated is obtained; alpha is an offset coefficient; zsetSetting a constant impedance for the ith protection device to be evaluated; zmMeasuring impedance of the ith protection device to be evaluated;
Figure FDA0002429407390000023
to measure the impedance angle;
Figure FDA0002429407390000024
the maximum sensitivity angle of the ith protection device to be evaluated is obtained; pinact.minThe minimum probability of refusing to move of the ith protection device to be evaluated in the protection characteristic area is obtained; pinact.midThe maximum probability of refusing to move of the ith protection device to be evaluated in the protection characteristic area is obtained;
and when the type is the excessive action protection type, determining the motion rejection probability of the ith protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated and the minimum and maximum boundary starting probability reference points of the corresponding characteristic quantity.
4. The method according to claim 2, wherein calculating the false action probability of the ith protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated and the false action probability of the ith protection device to be evaluated comprises:
based on a protection device malfunction probability calculation formula, calculating the malfunction probability of the ith protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated and the malfunction probability of the ith protection device to be evaluated; the protection device malfunction probability calculation formula is as follows:
Figure FDA0002429407390000025
wherein, PmisThe false action probability of the ith protection device to be evaluated is obtained; preclose∈(0,1]The reclosing failure probability is obtained; pf.next(j) Representing the fault probability of the jth device at the next lower level of the protected device; pw(j) Indicating that the ith protection device to be evaluated operates in a system with m adjacent devices, and the probability of false operation caused by short circuit of the jth adjacent next-level device, Pw(j) The evaluation method is calculated based on the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated and the probability of the failure of the ith protection device to be evaluated.
5. The method according to claim 1, wherein the calculating the loss load amount of each protection device to be evaluated after each failure according to the protection device failure possible loss evaluation model comprises:
aiming at the ith to-be-evaluated protection device, calculating a first protection misoperation probability in a corresponding misoperation source of the ith to-be-evaluated protection device under the power grid topological structure;
according to the first protection misoperation probability, cutting off a line where the ith protection device to be evaluated is located, and carrying out N-1 load flow calculation;
under the condition of a new power grid topological structure and a new power flow state, calculating a second protection misoperation probability in a corresponding misoperation source of the ith protection device to be evaluated;
according to the second protection misoperation probability, cutting off a line where protection in the corresponding misoperation source of the ith protection device to be evaluated is located, and carrying out N-2 load flow calculation to obtain the load loss caused by misoperation of the protection device of the current line;
calculating load loss caused by a far backup protection action of the ith protection device to be evaluated;
and calculating the loss load quantity of each protection device to be evaluated after each failure according to the load loss caused by the misoperation of the protection device of the current line and the load loss caused by the far backup protection action of the ith protection device to be evaluated.
6. The method according to any one of claims 1 to 5, wherein the risk assessment of the relay protection setting system is performed according to the failure probability of each failure of each protection device to be assessed and the loss load amount caused by each failure of each protection device to be assessed, and comprises the following steps:
calculating an absolute risk index of each to-be-evaluated protection device according to the failure probability of each failure of each to-be-evaluated protection device and the loss load quantity of each to-be-evaluated protection device after each failure;
and calculating the relative risk index of each to-be-evaluated protection device according to the absolute risk index of each to-be-evaluated protection device and the load amount of each load node in each to-be-evaluated protection device.
7. The method of claim 6, further comprising:
determining the risk level of each to-be-evaluated protection device according to the relative risk index;
and sequencing each protection device to be evaluated according to the risk level, and outputting a sequencing result and the risk level of each protection device to be evaluated.
8. A risk assessment device of a relay protection setting system is characterized by comprising:
the determining module is used for determining at least one to-be-evaluated protection device and a false action source of each to-be-evaluated protection device according to the power grid topological structure;
the data acquisition module is used for acquiring measured values of the characteristic quantities corresponding to each protection device to be evaluated;
the hardware system failure probability calculation module is used for calculating the probability of each hardware system failure of each protection device to be evaluated;
the principle failure probability calculation module is used for traversing all the protections in the false activation source corresponding to each protection device to be evaluated, and calculating the probability of each principle failure of each protection device to be evaluated according to the fixed value and the measured value of the characteristic quantity corresponding to each protection device to be evaluated;
the failure probability determining module is used for determining the failure probability of each failure of each to-be-evaluated protection device according to the probability of each hardware system failure of each to-be-evaluated protection device and the probability of each principle failure of each to-be-evaluated protection device;
the loss load calculation module is used for calculating the loss load of each to-be-evaluated protection device after each failure according to the protection device failure possible loss evaluation model;
and the risk evaluation module is used for carrying out risk evaluation on the relay protection setting system according to the failure probability of each failure of each protection device to be evaluated and the loss load quantity caused by each failure of each protection device to be evaluated.
9. The apparatus of claim 8, wherein the principle failure probability calculation module is specifically configured to:
determining the type of a protection element in an ith protection device to be evaluated aiming at the ith protection device to be evaluated;
calculating the action rejection probability of the ith protection device to be evaluated by adopting an action rejection probability calculation formula corresponding to the type according to the fixed value and the measured value of the characteristic quantity corresponding to the ith protection device to be evaluated;
traversing all protections in a false action source corresponding to the ith protection device to be evaluated, and calculating the false action probability of the ith protection device to be evaluated according to the fixed value and the actual value of the characteristic quantity corresponding to the ith protection device to be evaluated and the false action probability of the ith protection device to be evaluated;
and determining the probability of each principle failure of the ith protection device to be evaluated according to the action rejection probability and the false action probability of the ith protection device to be evaluated.
10. The apparatus according to claim 8 or 9, wherein the risk assessment module is specifically configured to:
calculating an absolute risk index of each to-be-evaluated protection device according to the failure probability of each failure of each to-be-evaluated protection device and the loss load quantity of each to-be-evaluated protection device after each failure;
and calculating the relative risk index of each to-be-evaluated protection device according to the absolute risk index of each to-be-evaluated protection device and the load amount of each load node in each to-be-evaluated protection device.
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Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005069465A1 (en) * 2004-01-14 2005-07-28 Rotatek Finland Oy Electric machine assembly
CN102521667A (en) * 2011-12-26 2012-06-27 华北电力大学（保定） Probability assessing method for stage type protection operational risk of electric power system
CN102915515A (en) * 2012-11-10 2013-02-06 四川省电力公司资阳公司 Cascade outage recognition and risk evaluation method of power grid
CN104376507A (en) * 2014-11-18 2015-02-25 国家电网公司 Power transmission network reliability assessment method for invalid relay protection
CN105427025A (en) * 2015-11-04 2016-03-23 广东电网有限责任公司茂名供电局 Primary element and secondary element safety assessment method and system
CN106713354A (en) * 2017-01-23 2017-05-24 全球能源互联网研究院 Method for evaluating vulnerability node of electric cyber-physical system based on undetectable information attack pre-warning technology
CN107222348A (en) * 2017-06-22 2017-09-29 湘潭大学 A kind of method for reducing power information physical system cascading failure risk
CN107832984A (en) * 2017-12-19 2018-03-23 西南交通大学 Consider the tractive power supply system methods of risk assessment of reliability of relay protection
CN108802570A (en) * 2018-06-15 2018-11-13 贵州电网有限责任公司 A kind of fault detection system and detection method for alternating current-direct current series-parallel connection micro-capacitance sensor
CN109064071A (en) * 2018-09-20 2018-12-21 国网重庆市电力公司电力科学研究院 A kind of secondary system of intelligent substation methods of risk assessment based on shielding failure
CN110380447A (en) * 2019-07-22 2019-10-25 重庆大学 A kind of lower electric-gas interconnection energy resource system drop Risk Scheduling method of blower failure
CN110516287A (en) * 2019-07-09 2019-11-29 广东工业大学 It is a kind of meter and ageing failure power supply system outage probability calculation method

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005069465A1 (en) * 2004-01-14 2005-07-28 Rotatek Finland Oy Electric machine assembly
CN102521667A (en) * 2011-12-26 2012-06-27 华北电力大学（保定） Probability assessing method for stage type protection operational risk of electric power system
CN102915515A (en) * 2012-11-10 2013-02-06 四川省电力公司资阳公司 Cascade outage recognition and risk evaluation method of power grid
CN104376507A (en) * 2014-11-18 2015-02-25 国家电网公司 Power transmission network reliability assessment method for invalid relay protection
CN105427025A (en) * 2015-11-04 2016-03-23 广东电网有限责任公司茂名供电局 Primary element and secondary element safety assessment method and system
CN106713354A (en) * 2017-01-23 2017-05-24 全球能源互联网研究院 Method for evaluating vulnerability node of electric cyber-physical system based on undetectable information attack pre-warning technology
CN107222348A (en) * 2017-06-22 2017-09-29 湘潭大学 A kind of method for reducing power information physical system cascading failure risk
CN107832984A (en) * 2017-12-19 2018-03-23 西南交通大学 Consider the tractive power supply system methods of risk assessment of reliability of relay protection
CN108802570A (en) * 2018-06-15 2018-11-13 贵州电网有限责任公司 A kind of fault detection system and detection method for alternating current-direct current series-parallel connection micro-capacitance sensor
CN109064071A (en) * 2018-09-20 2018-12-21 国网重庆市电力公司电力科学研究院 A kind of secondary system of intelligent substation methods of risk assessment based on shielding failure
CN110516287A (en) * 2019-07-09 2019-11-29 广东工业大学 It is a kind of meter and ageing failure power supply system outage probability calculation method
CN110380447A (en) * 2019-07-22 2019-10-25 重庆大学 A kind of lower electric-gas interconnection energy resource system drop Risk Scheduling method of blower failure

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
习莉等: "基于Markov模型的定值失配点风险评估", 《广西电力》 *
张玉浩等: "同步异常场景下线路单元式纵联保护方案研究", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 *
陈勇等: "一种考虑变电站内部的电力系统可靠性分析", 《电力自动化设备》 *
陶旋旋: "基于电网实时运行条件的继电保护可靠性评估", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 *
黄超等: "计及母联状态的线路失灵保护整定计算研究", 《广西电力》 *

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