Circuit breaker closing resistor damage impedance characteristic simulation model construction method and device

Abstract

The invention provides a circuit breaker closing resistor damage impedance characteristic simulation model construction method and device, and belongs to the technical field of circuit breaker closing resistor damage detection. Comprising the following steps: establishing a closing resistor string model based on geometric models of closing resistors in the circuit breaker; enabling a single closing resistor disc to be equivalent to a series-parallel connection form of a single RLC loop model, and building a distribution parameter model of the single closing resistor disc in the closing resistor model according to the damage type; constructing a circuit breaker closing resistor damage impedance characteristic simulation model according to a series-parallel connection relation between a closing resistor and a main port in the circuit breaker, and enabling a distribution parameter model of a single closing resistor disc to be equivalent to a lumped parameter model of each closing resistor disc in the circuit breaker closing resistor damage impedance characteristic simulation model through a vector matching method; and detecting the damage type and the actual damage condition of the closing resistor in an unknown circuit breaker by using the circuit breaker closing resistor damage impedance characteristic simulation model.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breaker closing resistor damage detection, and in particular to a method and device for constructing a circuit breaker closing resistor damage impedance characteristic simulation model. Background Art

[0002] The closing resistor of the circuit breaker is an important component of the circuit breaker. It can suppress the closing surge current and operating overvoltage during the closing process of the circuit breaker, and protect the power equipment and lines. After the circuit breaker is put into use, the huge mechanical stress and impact current during the opening and closing process will cause damage to the closing resistor in the circuit breaker. When the circuit breaker with damaged resistor is closed, it will affect the normal operation of the circuit breaker, and may cause flashover along the surface of the resistor insulation column or gap breakdown due to resistor debris, resulting in huge losses caused by circuit breaker failure or accidents, causing power outages during the operation of the circuit breaker, and having a serious impact on the reliability of power grid operation. Therefore, understanding the damage of the closing resistor is of great significance to the operation of the power grid. Summary of the invention

[0003] In view of this, the present invention provides a method and device for constructing a simulation model of the damage impedance characteristics of a circuit breaker closing resistor, so as to construct a simulation model of the damage impedance characteristics of a circuit breaker closing resistor and quickly understand the damage type and damage condition of the circuit breaker closing resistor.

[0004] The technical solution adopted by the embodiment of the present invention to solve the technical problem is:

[0005] A method for constructing a simulation model of a circuit breaker closing resistance damage impedance characteristic, comprising:

[0006] Step S1, establishing a closing resistor string model based on a geometric model of each closing resistor in the circuit breaker;

[0007] Step S2, a single closing resistor is equivalent to a series-parallel form of a single RLC loop model, and a distributed parameter model of a single closing resistor in the closing resistor model is established according to the damage type, wherein the damage type specifically includes three types: blackening and scorching, whole-piece crack, and edge drop; the blackening and scorching damage model is equivalent to a single-row series circuit of an RLC loop model with different impedance characteristics, and the whole-piece crack damage model and the edge drop damage model are both equivalent to a multi-row series circuit of an RLC loop model with the same impedance characteristics;

[0008] Step S3, constructing a simulation model of the damage impedance characteristic of the closing resistor of the circuit breaker according to the series-parallel relationship between the closing resistor and the main port in the circuit breaker, and using a vector matching method to convert the distributed parameter model of the single closing resistor into a lumped parameter model of each closing resistor in the simulation model of the damage impedance characteristic of the closing resistor of the circuit breaker; wherein, if the closing resistor and the main port are in a parallel structure, the main port is equivalent to a capacitor, and the auxiliary port is equivalent to a resistor and an inductor in series; if the closing resistor and the main port are in a series structure, the main port is equivalent to a resistor and an inductor in series, and the auxiliary port is equivalent to a capacitor;

[0009] Step S4: using the circuit breaker closing resistor damage impedance characteristic simulation model to detect the damage type and actual damage condition of the closing resistor in the unknown circuit breaker.

[0010] Preferably, the RLC loop parameters corresponding to the undamaged part of a single closing resistor are equal, wherein the calculation method of the resistance parameter R and the capacitance parameter C is:

[0011]

[0012] Where △S is the area of ​​a single loop after segmentation, △d is the width of a single loop after segmentation, ρ is the resistivity of the resistor, and ε is the dielectric constant of the resistor.

[0013] Preferably, in step S2, for the blackening and scorching damage:

[0014] According to the single loop area △S and the single loop width △d, a single closing resistor is equivalent to a parallel circuit of N1 RLC loops with the same parameters;

[0015] Determine the number of parameter loops n1 that need to be changed based on the damage area of ​​blackened and scorched damage:

[0016]

[0017] Where S1 is the total area of ​​a single closing resistor, S2 is the undamaged area of ​​a single closing resistor, and ΔS is the area of ​​a single loop set when building the model to determine the number of RLC loops; when the calculated result n1 is not an integer, n1 is rounded by adjusting ΔS;

[0018] The circuit parameter characteristics of n1 RLC circuits in the parallel form circuit of N1 RLC circuits with the same parameters are modified to obtain the blackening and scorching damage model, wherein:

[0019] The characteristic of the resistor R in the RLC circuit is that after the temperature rises to T1 and causes blackening and scorching damage, the resistance value changes to R1 and remains.

[0020] Preferably, in step S2, for the whole piece crack damage:

[0021] According to the single loop area △S and the single loop width △d, a single closing resistor is equivalent to a multi-row parallel circuit of N2×N3 RLC loops with the same parameters; according to the crack area S3 and the single loop area △S, the number of equivalent capacitors n2 required to be added is determined:

[0022] n2=S3 / △S

[0023] At the inter-row position corresponding to the actual position of the crack, an equivalent capacitor C0 is added between the upper and lower parallel RLC loops, and a total of n2 equivalent capacitors are added to obtain the whole-piece crack damage model;

[0024] The expression of inter-row capacitance C0 is defined as:

[0025]

[0026] Where k is the electrostatic force constant, which is 8.987551×10 9 N·m 2 / C2, d is the crack width.

[0027] Preferably, in step S2, for edge drop damage:

[0028] According to the single loop area △S and the single loop width △d, a single closing resistor is equivalent to a multi-row parallel circuit of N4×N5 RLC loops with the same parameters;

[0029] The actual remaining shape of the resistor is meshed according to △S and △d to obtain the edge drop damage model. In the case where the edge of the actual remaining shape of the resistor is irregular and cannot occupy a full △S, it is calculated as occupying a full grid, and an area error analysis is performed between the area S4 of the remaining shape of the resistor obtained after meshing and the area S5 of the actual remaining shape of the resistor. If the obtained area error result (S4-S5) / S5 is not lower than the area error threshold, the area error result is made lower than the area error threshold by adjusting the △S and △d values.

[0030] Preferably, in step S3, when the circuit breaker tank is at ground potential, the capacitance of a single closing resistor to the tank, i.e., the capacitance to ground C, is calculated. r The calculation method is:

[0031]

[0032] Where ε0 is the absolute dielectric constant, and the value of ε0 is 8.85×10 -12 F / m, r1 is the radius of the closing resistor, r2 is the radius of the cylindrical tank of the circuit breaker, d is the width of the closing resistor, ε ris the relative dielectric constant of the gas in the tank.

[0033] Preferably, the step S4 of detecting the damage type and damage condition of the closing resistor in the unknown circuit breaker by using the circuit breaker closing resistor damage impedance characteristic simulation model comprises:

[0034] Step S41, establishing a corresponding circuit breaker closing resistor damage impedance characteristic simulation model according to the structure of the unknown circuit breaker, making all equivalent closing resistors in the model in a lossless state, and obtaining a lossless state impedance curve, wherein the types of the lossless state impedance curve include an amplitude curve and a phase angle curve;

[0035] Step S42, obtaining an actual impedance curve of a closing resistance in an unknown circuit breaker, wherein the actual impedance curve is generated by actual measurement data;

[0036] Step S43, comparing the actual impedance curve with the lossless state impedance curve as a reference to identify the damage type of the closing resistor in the unknown circuit breaker;

[0037] Specifically, the specific impedance values ​​of the same frequency points of the lossless impedance curve and the actual impedance curve are extracted at fixed intervals, and the peak value of the amplitude curve, the peak frequency of the amplitude curve, the peak value of the phase angle curve, and the peak frequency of the phase angle curve are further obtained respectively;

[0038] When the actual impedance curve is compared with the lossless state impedance curve, when the amplitude curve peak value, the amplitude curve peak frequency, the phase angle curve peak value, and the phase angle curve peak frequency are all different, it is confirmed that the closing resistor in the unknown circuit breaker has blackening and burning damage; when the amplitude curve peak frequency is the same, and the amplitude curve peak value, the phase angle curve peak value, and the phase angle curve peak frequency are all different, it is confirmed that the closing resistor in the unknown circuit breaker has whole-piece crack damage; when the amplitude curve peak frequency, the phase angle curve peak value, and the phase angle curve peak frequency are all the same, and the amplitude curve peak frequency is different, it is confirmed that the closing resistor in the unknown circuit breaker has edge drop damage;

[0039] Step S44, calling the damage type model corresponding to the actual impedance curve, adjusting the damage area variable of each closing resistor, and making the model output impedance curve the same as the actual impedance curve under the influence of the total damage area of ​​the circuit breaker closing resistor damage impedance characteristic simulation model;

[0040] Step S45, calculating the ratio of the total damage area used by the model to the total area of ​​the closing resistor in the unknown circuit breaker as the actual damage condition of the closing resistor in the unknown circuit breaker.

[0041] The present invention provides a device for constructing a simulation model of damage impedance characteristics of a circuit breaker closing resistor, which is used to execute the above-mentioned method.

[0042] It can be seen from the above technical scheme that the method and device for constructing a simulation model of the damage impedance characteristics of the closing resistor of the circuit breaker provided by the embodiment of the present invention first establish a closing resistor series model based on the geometric model of each closing resistor in the circuit breaker; a single closing resistor piece is equivalent to the series-parallel form of a single RLC loop model, and a distributed parameter model of a single closing resistor piece in the closing resistor model is established according to the damage type, and the damage type specifically includes three types: blackening and scorching, whole piece cracks, and edge drop; a simulation model of the damage impedance characteristics of the closing resistor of the circuit breaker is constructed according to the series-parallel relationship between the closing resistor in the circuit breaker and the main port, and the distributed parameter model of the single closing resistor piece is equivalent to the lumped parameter model of each closing resistor piece in the simulation model of the damage impedance characteristics of the closing resistor of the circuit breaker through the vector matching method; the simulation model of the damage impedance characteristics of the closing resistor of the circuit breaker is used to detect the damage type and actual damage condition of the closing resistor in the unknown circuit breaker. By constructing a simulation model of the damage impedance characteristics of the closing resistor of the circuit breaker, the present invention can quickly understand the damage type and damage condition of the closing resistor of the circuit breaker, and improve the safety of power grid operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a flow chart of a method for constructing a simulation model of a circuit breaker closing resistance damage impedance characteristic.

[0044] Figure 2 A schematic diagram of a simulation model of a closing resistor damage impedance characteristic of a circuit breaker in which a closing resistor and a main port are in series relationship is provided in one embodiment of the present invention.

[0045] Figure 3 A schematic diagram of a simulation model of a closing resistor damage impedance characteristic of a circuit breaker in which a closing resistor and a main port are connected in parallel is provided in accordance with an embodiment of the present invention.

[0046] Figure 4 A schematic diagram of a distribution parameter model of damage impedance characteristics of a single closing resistor with blackened and charred damage provided by an embodiment of the present invention.

[0047] Figure 5 A schematic diagram of a distribution parameter model of damage impedance characteristics of a single closing resistor with whole-piece crack damage provided by an embodiment of the present invention.

[0048] Figure 6 A schematic diagram of a distribution parameter model of damage impedance characteristics of a single closing resistor with edge drop damage provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The technical scheme and technical effects of the present invention are further described in detail below in conjunction with the accompanying drawings of the present invention. However, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0050] refer to Figure 1 As shown, the present invention provides a method for constructing a simulation model of the damage impedance characteristics of the closing resistor of a circuit breaker, comprehensively considering the overall influence of the circuit breaker on the closing resistor, determining the model structure after judging the relationship between the closing resistor and the main break, and constructing a simulation model of the damage impedance characteristics of the closing resistor of the circuit breaker using the closing resistor pile model. The steps include:

[0051] Step S1, establishing a closing resistor string model based on a geometric model of each closing resistor in the circuit breaker;

[0052] Step S2, a single closing resistor is equivalent to a series-parallel form of a single RLC loop model, and a distributed parameter model of a single closing resistor in the closing resistor model is established according to the damage type, wherein the damage types specifically include blackening and scorching, whole-piece cracks, and edge drop; the blackening and scorching damage model is equivalent to a single-row series circuit of an RLC loop model with different impedance characteristics, and the whole-piece crack damage model and the edge drop damage model are both equivalent to a multi-row series circuit of an RLC loop model with the same impedance characteristics;

[0053] Step S3, constructing a simulation model of the damage impedance characteristic of the closing resistor of the circuit breaker according to the series-parallel relationship between the closing resistor and the main port in the circuit breaker, and using a vector matching method to convert the distributed parameter model of a single closing resistor into a lumped parameter model of each closing resistor in the simulation model of the damage impedance characteristic of the closing resistor of the circuit breaker; wherein, if the closing resistor and the main port are in a parallel structure, the main port is equivalent to a capacitor, and the auxiliary port is equivalent to a resistor and an inductor in series; if the closing resistor and the main port are in a series structure, the main port is equivalent to a resistor and an inductor in series, and the auxiliary port is equivalent to a capacitor;

[0054] Step S4, using the circuit breaker closing resistor damage impedance characteristic simulation model to detect the damage type and actual damage condition of the closing resistor in the unknown circuit breaker.

[0055] refer to Figure 2 and Figure 3 As shown, the schematic diagram of the simulation model of the closing resistance damage impedance characteristics of the circuit breaker with the closing resistance and the main port in series and parallel relationship is shown. When the closing resistance and the main port are in parallel structure, the main port is equivalent to a capacitor, and the auxiliary port is equivalent to a resistor and an inductor in series; when the closing resistance and the main port are in series structure, the main port is equivalent to a resistor and an inductor in series, and the auxiliary port is equivalent to a capacitor.

[0056] Considering the constituent phases of the Al-Si-C series closing resistor, the ceramic phase, the pores, and the graphite, the ceramic phase and the pores are both insulating phases, while the graphite is a conductive phase (semi-metal), and the electrical equivalent circuit thereof is regarded as a series of RLC circuits connected in series. Figure 2 or Figure 3 A single resistor in the resistor string is equivalent to a series-parallel form of multiple RLC circuits, such as reference Figure 4 , can be used to represent the equivalent form of a single lossless resistor. The electrical parameters of the resistor include the closing resistance conductivity, thermal expansion coefficient, density and specific heat capacity, etc. The parameters of each RLC circuit corresponding to the undamaged part of a single closing resistor are equal, where the calculation method of the resistance parameter R and the capacitance parameter C is:

[0057]

[0058]

[0059] Where △S is the area of ​​a single loop after segmentation, △d is the width of a single loop after segmentation, ρ is the resistivity of the resistor, and ε is the dielectric constant of the resistor.

[0060] The blackened and scorched damage is reflected in the model as the change of resistance or capacitance parameters in the circuit. Its structure is the same as the simulation model of the undamaged closing resistor. Figure 4 Indicates a single resistor with blackened and scorched damage. The normal closing resistor model has the same parameters in each circuit, with resistance value R and capacitance value C. When building the blackened and scorched damage model, the circuit parameters are changed, and only the RLC circuit parameters of the damaged position are changed, while the parameters of the undamaged circuit remain unchanged. According to the single circuit area △S and the single circuit width △d, the single closing resistor is equivalent to a parallel circuit of N1 RLC circuits with the same parameters;

[0061] Determine the number of parameter loops n1 that need to be changed based on the damage area of ​​blackened and scorched damage:

[0062]

[0063] Where S1 is the total area of ​​a single closing resistor, S2 is the undamaged area of ​​a single closing resistor, and ΔS is the area of ​​a single loop set when building the model to determine the number of RLC loops; when the calculated result n1 is not an integer, n1 is rounded by adjusting ΔS;

[0064] The circuit parameter characteristics of n1 RLC circuits in the parallel circuit of N1 RLC circuits with the same parameters are modified to obtain the blackening and scorching damage model, in which:

[0065] Due to oxidation, gas adsorption and desorption, carbon film defect degradation or the presence of mobile ions (such as Na, K, Cl, etc.), loose terminal joints, etc., the resistance of the resistor increases after damage. Consider the damaged part and change the resistance parameters in the RLC circuit at the corresponding position of the normally closed resistor. When the temperature rises to T1 and causes blackening and scorching damage, the corresponding circuit resistance value increases to R1. The characteristic of the resistor R in the RLC circuit is: after the temperature rises to T1 and causes blackening and scorching damage, the resistance value changes to R1 and remains.

[0066] The whole-piece crack damage is reflected in the model as a change in the equivalent circuit topology. Figure 5 The schematic diagram of the distribution parameter model of the damage impedance characteristics of a single closing resistor under the condition of crack damage is shown. The topology of the circuit model changes, and an equivalent capacitor is added at the crack damage location. To reflect the topological change, this example changes similar Figure 3 The normal resistor model structure is kept unchanged, and the model impedance characteristics are equivalent to two parallel circuits. The circuit can also be equivalent to multiple parallel circuits as needed. After the equivalent, the parameter values ​​of each circuit are still equal, and they are modified proportionally according to the length and width of the split part. Considering that there is air between the cracks, the actual cracks are regarded as a medium with the same relative dielectric constant as air during simulation.

[0067] For the whole crack damage:

[0068] According to the single loop area △S and the single loop width △d, a single closing resistor is equivalent to a multi-row parallel circuit of N2×N3 RLC loops with the same parameters; according to the crack area S3 and the single loop area △S, the number of equivalent capacitors n2 required to be added is determined:

[0069] n2=S3 / △S (4)

[0070] At the inter-row position corresponding to the actual position of the crack, an equivalent capacitor C0 is added between the upper and lower parallel RLC circuits, and a total of n2 equivalent capacitors are added to obtain the whole crack damage model;

[0071] The expression of inter-row capacitance C0 is defined as:

[0072]

[0073] Where k is the electrostatic force constant, which is 8.987551×10 9 N·m 2 / C2, d is the crack width. When the crack area S changes, it is achieved by changing the number of circuit capacitance n, and the change rule is the same as that of blackening and scorching damage; when the crack width d changes, it is achieved by changing the crack equivalent capacitance value, that is, changing the d value in the C0 formula.

[0074] Edge drop damage is reflected in the model as a change in the equivalent circuit topology. Figure 6 The schematic diagram of the distributed parameter model of the damage impedance characteristics of a single closing resistor under edge drop damage is shown. The topology of the circuit model also changes, for example, a certain number of loops in the dropped part are missing. To reflect this topological change, this example uses Figure 5 The whole crack damage model equivalent method can mesh the remaining part to form a multi-row parallel circuit. The specific operation is: according to the single circuit area △S and the single circuit width △d, a single closing resistor is equivalent to a multi-row parallel circuit of N4×N5 RLC circuits with the same parameters;

[0075] The actual remaining shape of the resistor is meshed according to △S and △d to obtain an edge drop damage model. In the case where the edge of the actual remaining shape of the resistor is irregular and cannot occupy a full △S, it is calculated as occupying a full grid, and the area error analysis is performed between the area S4 of the remaining shape of the resistor obtained after meshing and the area S5 of the actual remaining shape of the resistor. If the obtained area error result (S4-S5) / S5 is not lower than the area error threshold, the area error result is made lower than the area error threshold by adjusting the △S and △d values.

[0076] In step S3, the vector matching method first performs rational function approximation on the impedance measurement results of the distributed parameter model to obtain its poles and residues. Then, the poles and residues are classified and processed, and the parameter values ​​of the RLC series-parallel equivalent circuit of the lumped parameter model are calculated according to different categories. The implementation method of using the vector matching method to equate the distributed parameter model of a single closing resistor to the lumped parameter model of each closing resistor in the circuit breaker closing resistor damage impedance characteristic simulation model refers to any prior art solution, which will not be repeated here.

[0077] In step S3, when the circuit breaker tank is at ground potential, the capacitance of a single closing resistor to the tank, i.e., the capacitance to ground, C r The calculation method is:

[0078]

[0079] Where ε0 is the absolute dielectric constant, and the value of ε0 is 8.85×10 -12 F / m, r1 is the radius of the closing resistor, r2 is the radius of the cylindrical tank of the circuit breaker, d is the width of the closing resistor, ε r is the relative dielectric constant of the gas in the tank.

[0080] Step S4 uses the circuit breaker closing resistor damage impedance characteristic simulation model to detect the damage type and damage condition of the closing resistor in the unknown circuit breaker, including:

[0081] Step S41, establishing a corresponding simulation model of the circuit breaker closing resistance damage impedance characteristic according to the structure of the unknown circuit breaker, making all equivalent closing resistors in the model in a lossless state, and obtaining a lossless state impedance curve, wherein the types of the lossless state impedance curve include an amplitude curve and a phase angle curve;

[0082] Step S42, obtaining an actual impedance curve of the closing resistance in the unknown circuit breaker, where the actual impedance curve is generated by actual measurement data;

[0083] Step S43, comparing the actual impedance curve with the impedance curve in the intact state as a reference, and confirming the damage type of the closing resistor in the unknown circuit breaker;

[0084] Specifically, the data analysis software is used to extract the specific impedance values ​​of the same frequency points (the horizontal axis of the impedance curve is the frequency) of the lossless impedance curve and the actual impedance curve at fixed intervals, and the peak value of the amplitude curve, the peak frequency of the amplitude curve, the peak value of the phase angle curve, and the peak frequency of the phase angle curve are further obtained respectively;

[0085] When the actual impedance curve is compared with the impedance curve in the lossless state, when the peak value of the amplitude curve, the peak frequency of the amplitude curve, the peak value of the phase angle curve, and the peak frequency of the phase angle curve are all different, it is confirmed that the closing resistor in the unknown circuit breaker has blackened and burnt damage; when the peak frequency of the amplitude curve is the same, the peak value of the amplitude curve, the peak value of the phase angle curve, and the peak frequency of the phase angle curve are all different, it is confirmed that the closing resistor in the unknown circuit breaker has whole-piece crack damage; when the peak frequency of the amplitude curve, the peak value of the phase angle curve, and the peak frequency of the phase angle curve are all the same, and the peak frequency of the amplitude curve is different, it is confirmed that the closing resistor in the unknown circuit breaker has edge drop damage;

[0086] Step S44, calling the damage type model corresponding to the actual impedance curve, adjusting the damage area variable of each closing resistor, and making the model output impedance curve the same as the actual impedance curve under the influence of the total damage area of ​​the circuit breaker closing resistor damage impedance characteristic simulation model; here, since there is still a certain degree of difference between the simulation and the actual situation, when determining the degree of damage of the closing resistor through debugging, the amplitude of the approximate straight line segment frequency band in the amplitude curve can be compared, and the amplitude of the approximate straight line segment is accurate to 0.01. For example, the frequency range [1,10 3 ]Hz, the amplitude of the amplitude curve is compared, and the difference is less than 0.01;

[0087] Step S45, calculating the ratio of the total damage area used by the model to the total area of ​​the closing resistor in the unknown circuit breaker as the actual damage condition of the closing resistor in the unknown circuit breaker.

[0088] After determining the damage type, we can find a similar interval based on the existing impedance curve, and further find the impedance curve result closest to the actual impedance curve by adjusting the damage area variable. Specifically, for the blackened and scorched damage type, the variable is S1-S2; for the whole crack damage type, the variable is S3; for the edge drop damage type, the variables are △S and △d.

[0089] The present invention provides a device for constructing a simulation model of the damage impedance characteristics of a circuit breaker closing resistor, which is used to perform Figure 1 The method shown. In order to reflect the change in circuit topology when the whole piece is cracked and the edge is dropped, the single-row series RLC circuit is equivalent to a multi-row series RLC circuit with the same impedance characteristics and then the model is changed; when the whole piece is cracked, it is reflected in the circuit model, that is, an equivalent capacitor is formed at the damaged crack. Considering that there is air between the cracks, the actual crack is regarded as a medium with the same relative dielectric constant as air during simulation and the crack size is calculated; when the edge is dropped, it is reflected in the circuit model, and the remaining part is considered to be meshed, and the analysis is based on the divided part of the RLC circuit.

[0090] The present invention makes the simulation model of the circuit breaker closing resistance accurate to the distributed parameter model of a single closing resistor piece, selects three typical closing resistance damage conditions, comprehensively considers the closing resistance's own characteristics and external influences, ensures the reliability and effectiveness of the model, constructs a simulation model of the closing resistance damage impedance characteristics of circuit breakers with different damage conditions, damage degrees and different circuit breaker structures, and obtains the corresponding impedance characteristic curve. When detecting an unknown circuit breaker, a comparison and analysis can be performed through the impedance characteristic curve, and then high-precision damage degree result data can be obtained through model debugging.

[0091] According to the embodiments disclosed in the present invention, the present invention also discloses an electronic device, a readable storage medium and a computer program product. The electronic device is intended to represent various forms of digital computers, including a computing unit, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) or a computer program loaded from a storage unit into a random access memory (RAM). In the RAM, various programs and data required for the operation of the device can also be stored. The computing unit, ROM and RAM are connected to each other via a bus. The input / output (I / O) interface is also connected to the bus.

[0092] Multiple components in the device are connected to the I / O interface, including: input unit, output unit, storage unit, and communication unit. The communication unit allows the device to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0093] The computing unit may be a variety of general and / or special processing components with processing and computing capabilities to execute the various methods and processes described above, such as the GIS sub-millimeter particle defect accumulation morphology and development stage identification method.

[0094] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0095] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for constructing a simulation model of circuit breaker closing resistance damage impedance characteristics, characterized in that: include: Step S1, establishing a closing resistor string model based on a geometric model of each closing resistor in the circuit breaker; Step S2, a single closing resistor is equivalent to a series-parallel form of a single RLC loop model, and a distributed parameter model of a single closing resistor in the closing resistor model is established according to the damage type, wherein the damage type specifically includes three types: blackening and scorching, whole-piece crack, and edge drop; the blackening and scorching damage model is equivalent to a single-row series circuit of an RLC loop model with different impedance characteristics, and the whole-piece crack damage model and the edge drop damage model are both equivalent to a multi-row series circuit of an RLC loop model with the same impedance characteristics; Step S3, constructing a simulation model of the damage impedance characteristic of the closing resistor of the circuit breaker according to the series-parallel relationship between the closing resistor and the main port in the circuit breaker, and using a vector matching method to convert the distributed parameter model of the single closing resistor into a lumped parameter model of each closing resistor in the simulation model of the damage impedance characteristic of the closing resistor of the circuit breaker; wherein, if the closing resistor and the main port are in a parallel structure, the main port is equivalent to a capacitor, and the auxiliary port is equivalent to a resistor and an inductor in series; if the closing resistor and the main port are in a series structure, the main port is equivalent to a resistor and an inductor in series, and the auxiliary port is equivalent to a capacitor; Step S4: using the circuit breaker closing resistor damage impedance characteristic simulation model to detect the damage type and actual damage condition of the closing resistor in the unknown circuit breaker.

2. The method for constructing a simulation model of a circuit breaker closing resistance damage impedance characteristic according to claim 1, characterized in that: The RLC circuit parameters corresponding to the undamaged part of a single closing resistor are equal, where the calculation method of the resistance parameter R and the capacitance parameter C is: Where △S is the area of ​​a single loop after segmentation, △d is the width of a single loop after segmentation, ρ is the resistivity of the resistor, and ε is the dielectric constant of the resistor.

3. The method for constructing a simulation model of the circuit breaker closing resistance damage impedance characteristic according to claim 2, characterized in that: In step S2, for the blackening and burning damage: According to the single loop area △S and the single loop width △d, a single closing resistor is equivalent to a parallel circuit of N1 RLC loops with the same parameters; Determine the number of parameter loops n1 that need to be changed based on the damage area of ​​blackened and scorched damage: Where S1 is the total area of ​​a single closing resistor, S2 is the undamaged area of ​​a single closing resistor, and ΔS is the area of ​​a single loop set when building the model to determine the number of RLC loops; when the calculated result n1 is not an integer, n1 is rounded by adjusting ΔS; The circuit parameter characteristics of n1 RLC circuits in the parallel form circuit of N1 RLC circuits with the same parameters are modified to obtain the blackening and scorching damage model, wherein: The characteristic of the resistor R in the RLC circuit is that after the temperature rises to T1 and causes blackening and scorching damage, the resistance value changes to R1 and remains.

4. The method for constructing a simulation model of circuit breaker closing resistance damage impedance characteristics according to claim 2, characterized in that: In step S2, for the whole piece crack damage: According to the single loop area △S and the single loop width △d, a single closing resistor is equivalent to a multi-row parallel circuit of N2×N3 RLC loops with the same parameters; according to the crack area S3 and the single loop area △S, the number of equivalent capacitors n2 required to be added is determined: n2=S3 / △S At the inter-row position corresponding to the actual position of the crack, an equivalent capacitor C0 is added between the upper and lower parallel RLC loops, and a total of n2 equivalent capacitors are added to obtain the whole-piece crack damage model; The expression of inter-row capacitance C0 is defined as: Where k is the electrostatic force constant, which is 8.987551×10 9 N·m 2 / C2, d is the crack width.

5. The method for constructing a simulation model of the circuit breaker closing resistance damage impedance characteristic according to claim 2, characterized in that: In step S2, for edge drop damage: According to the single loop area △S and the single loop width △d, a single closing resistor is equivalent to a multi-row parallel circuit of N4×N5 RLC loops with the same parameters; The actual remaining shape of the resistor is meshed according to △S and △d to obtain the edge drop damage model, wherein, in the case where the edge of the actual remaining shape of the resistor is irregular and cannot occupy a full △S, it is calculated as occupying a full grid, and an area error analysis is performed between the area S4 of the remaining shape of the resistor obtained after meshing and the area S5 of the actual remaining shape of the resistor. If the obtained area error result (S4-S5) / S5 is not lower than the area error threshold, the area error result is made lower than the area error threshold by adjusting the △S and △d values.

6. The method for constructing a simulation model of a circuit breaker closing resistor damage impedance characteristic according to any one of claims 3 to 5, characterized in that: When establishing the simulation model of the damage impedance characteristic of the circuit breaker closing resistor in step S3, the closing resistor string is considered to be affected by the circuit breaker tank. When the circuit breaker tank is at ground potential, the capacitance of a single closing resistor to the tank, i.e., the capacitance to ground C, is calculated. r : Where ε0 is the absolute dielectric constant, and the value of ε0 is 8.85×10 -12 F / m, r1 is the radius of the closing resistor, r2 is the radius of the cylindrical tank of the circuit breaker, d is the width of the closing resistor, ε r is the relative dielectric constant of the gas in the tank.

7. The method for constructing a simulation model of a circuit breaker closing resistor damage impedance characteristic according to any one of claim 6, characterized in that: The step S4 uses the circuit breaker closing resistor damage impedance characteristic simulation model to detect the damage type and damage condition of the closing resistor in the unknown circuit breaker, including: Step S41, establishing a corresponding circuit breaker closing resistor damage impedance characteristic simulation model according to the structure of the unknown circuit breaker, making all equivalent closing resistors in the model in a lossless state, and obtaining a lossless state impedance curve, wherein the types of the lossless state impedance curve include an amplitude curve and a phase angle curve; Step S42, obtaining an actual impedance curve of a closing resistance in an unknown circuit breaker, wherein the actual impedance curve is generated by actual measurement data; Step S43, comparing the actual impedance curve with the lossless state impedance curve as a reference to identify the damage type of the closing resistor in the unknown circuit breaker; Specifically, the specific impedance values ​​of the same frequency points of the lossless impedance curve and the actual impedance curve are extracted at fixed intervals, and the peak value of the amplitude curve, the peak frequency of the amplitude curve, the peak value of the phase angle curve, and the peak frequency of the phase angle curve are further obtained respectively; When the actual impedance curve is compared with the lossless state impedance curve, when the amplitude curve peak value, the amplitude curve peak frequency, the phase angle curve peak value, and the phase angle curve peak frequency are all different, it is confirmed that the closing resistor in the unknown circuit breaker has blackening and burning damage; when the amplitude curve peak frequency is the same, and the amplitude curve peak value, the phase angle curve peak value, and the phase angle curve peak frequency are all different, it is confirmed that the closing resistor in the unknown circuit breaker has whole-piece crack damage; when the amplitude curve peak frequency, the phase angle curve peak value, and the phase angle curve peak frequency are all the same, and the amplitude curve peak frequency is different, it is confirmed that the closing resistor in the unknown circuit breaker has edge drop damage; Step S44, calling the damage type model corresponding to the actual impedance curve, adjusting the damage area variable of each closing resistor, and making the model output impedance curve the same as the actual impedance curve under the influence of the total damage area of ​​the circuit breaker closing resistor damage impedance characteristic simulation model; Step S45, calculating the ratio of the total damage area used by the model to the total area of ​​the closing resistor in the unknown circuit breaker as the actual damage condition of the closing resistor in the unknown circuit breaker.

8. A device for constructing a simulation model of a circuit breaker closing resistance damage impedance characteristic, characterized in that: Used to execute the method according to any one of claims 1 to 7.

9. An electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method according to any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium storing computer instructions, wherein: The computer instructions are used to cause the computer to execute the method according to any one of claims 1-7.

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