Method, device and storage medium for simulating and calculating overvoltage of circuit breaker under multiple lightning strikes

Abstract

The present invention relates to the technical field of lightning protection for substation equipment in power systems, and discloses a simulation calculation method, device and storage medium for circuit breaker overvoltage under multiple lightning strikes. The present invention establishes a simulation calculation model for circuit breaker overvoltage based on in-station equipment data, determines the minimum lightning strike time interval and the maximum lightning current amplitude according to the historical lightning strike data in the area where the circuit breaker is located, uses two counterattack lightning currents to simulate the counterattack on the incoming line tower in the model, and uses two shielding failure lightning currents to simulate the shielding failure on the incoming line conductor. Among them, the minimum lightning strike time interval is used as the return stroke interval, the first counterattack lightning current is set according to the maximum lightning current recommended value and the maximum lightning current amplitude recommended by the national standard, and the second counterattack lightning current and the second shielding failure lightning current are set based on the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval. The present invention takes into account the actual lightning current situation in the area where the circuit breaker is located, so that the simulation calculation results of overvoltage can conform to the actual situation.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning protection for substation equipment in power systems, and particularly to a simulation calculation method, device, and storage medium for circuit breaker overvoltage under multiple lightning strikes. Background Art

[0002] After a lightning strike on the line, when the circuit breaker cuts off the short-circuit current, if a lightning flashover occurs again, it will cause the arc to reignite, thus triggering a power accident and seriously threatening the safe and stable operation of the power grid. Simulating and calculating the lightning overvoltage of the circuit breaker and taking lightning protection measures for the equipment in advance according to the simulation calculation results can reduce the incidence of power accidents caused by multiple lightning strikes.

[0003] Currently, when simulating and modeling the lightning overvoltage of a circuit breaker, the selection of the counterattack lightning current and the shielding failure lightning current directly uses the fixed values in the existing regulations. This value does not consider the actual lightning current situation in the area where the circuit breaker is located, resulting in the simulation calculation results of the circuit breaker overvoltage under multiple lightning strikes not conforming to the actual situation and unable to provide meaningful reference data for the layout of lightning protection measures. Summary of the Invention

[0004] The present invention provides a simulation calculation method, device, and storage medium for circuit breaker overvoltage under multiple lightning strikes, which solves the technical problem that the existing simulation method for circuit breaker overvoltage under multiple lightning strikes cannot conform to the actual situation due to unreasonable lightning current values.

[0005] The first aspect of the present invention provides a simulation calculation method for circuit breaker overvoltage under multiple lightning strikes, including:

[0006] Collecting the data required for circuit breaker simulation, where the data required for circuit breaker simulation includes in-station equipment data and historical lightning strike data within a preset time period in the area where the circuit breaker is located. The in-station equipment data includes relevant parameters of the line, tower, insulator string, terrain, substation electrical floor plan, and equipment;

[0007] Establishing a simulation calculation model for circuit breaker overvoltage in the electromagnetic transient program according to the in-station equipment data;

[0008] Determining the minimum lightning strike time interval and the maximum lightning current amplitude according to the historical lightning strike data, and using two counterattack lightning currents to simulate the counterattack on the incoming line tower in the simulation calculation model of the circuit breaker overvoltage to obtain the counterattack overvoltage result of the circuit breaker; where the minimum lightning strike time interval is used as the return interval of the two counterattack lightning currents, the first counterattack lightning current is set according to the maximum recommended lightning current value recommended by the national standard and the maximum lightning current amplitude, and the second counterattack lightning current is set according to the first counterattack lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval;

[0009] In the overvoltage simulation calculation model of the circuit breaker, the two-stroke lightning current is used to simulate the shielding failure of the incoming line conductor to obtain the shielding failure overvoltage result of the circuit breaker; wherein, the minimum lightning strike time interval is used as the return stroke interval of the two-stroke lightning current, the maximum shielding failure lightning current of the incoming line tower calculated according to the electrical geometric model of the tower is used as the first-stroke lightning current, and the second-stroke lightning current is set according to the maximum lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval.

[0010] Determine the circuit breaker overvoltage according to the circuit breaker backflashover overvoltage result and the circuit breaker shielding failure overvoltage result.

[0011] According to an implementable manner of the first aspect of the present invention, the establishment of the circuit breaker overvoltage simulation calculation model in the electromagnetic transient program according to the in-station equipment data includes:

[0012] Establish a lightning current model using the Heidler wave in the electromagnetic transient program;

[0013] Establish a line tower model using the multi-wave impedance model in the electromagnetic transient program;

[0014] Establish an insulator string flashover model using the leader development method in the electromagnetic transient program;

[0015] Establish a tower grounding resistance model using the concentrated resistance model in the electromagnetic transient program;

[0016] In the electromagnetic transient program, simulate each in-station equipment using the one-line-one-variable operation mode, equivalently simulate each in-station equipment using the entrance capacitance, equivalently simulate the connection lines between in-station equipment using the wave impedance, and establish an in-station equipment model;

[0017] Combine the lightning current model, the line tower model, the insulator string flashover model, the tower grounding resistance model and the in-station equipment model to establish a circuit breaker overvoltage simulation calculation model.

[0018] According to an implementable manner of the first aspect of the present invention, the setting of the first backflashover lightning current according to the recommended maximum lightning current recommended value of the national standard and the maximum lightning current amplitude includes:

[0019] When the maximum lightning current amplitude is greater than the recommended maximum lightning current recommended value, set the amplitude of the first backflashover lightning current to the maximum lightning current amplitude;

[0020] When the maximum lightning current amplitude is not greater than the recommended maximum lightning current recommended value, set the amplitude of the first backflashover lightning current to the recommended maximum lightning current recommended value.

[0021] According to an implementable manner of the first aspect of the present invention, setting the first back-strike lightning current according to the maximum lightning current recommended value and the maximum lightning current amplitude recommended by the national standard includes:

[0022] Determining the first back-strike lightning current by weighting the maximum lightning current recommended value and the maximum lightning current amplitude.

[0023] According to an implementable manner of the first aspect of the present invention, setting the second back-strike lightning current according to the first back-strike lightning current and the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval includes:

[0024] Calculating the current amplitude decrease ratio according to the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval:

[0025]

[0026] In the formula, a represents the current amplitude decrease ratio, I 1 is the lightning current amplitude of the first lightning strike corresponding to the minimum lightning strike time interval, I 2 is the lightning current amplitude of the second lightning strike corresponding to the minimum lightning strike time interval, max(I 1 , I 2 ) represents taking the maximum value from I 1 , I 2 ;

[0027] When the current amplitude decrease ratio is not greater than the decrease ratio threshold, setting the amplitude of the second back-strike lightning current as:

[0028] I x2 = I x1 ×(1 - a)

[0029] When the current amplitude decrease ratio is greater than the decrease ratio threshold, setting the amplitude of the second back-strike lightning current as:

[0030] I x2 = I xmax ×(1 - a T )

[0031] In the formula, I x1 is the amplitude of the first back-strike lightning current, I x2 is the amplitude of the second back-strike lightning current, a T is the decrease ratio threshold, and I xma is the maximum lightning current recommended value.

[0032] According to an implementable manner of the first aspect of the present invention, setting the second shielding failure lightning current according to the lightning current amplitudes of two lightning strikes corresponding to the maximum shielding failure lightning current and the minimum lightning strike time interval includes:

[0033] When the current amplitude decrease ratio is not greater than the decrease ratio threshold, setting the amplitude of the second shielding failure lightning current as:

[0034] I y2 = I yma ×(1 - a)

[0035] When the current amplitude decrease ratio is greater than the decrease ratio threshold, setting the amplitude of the second shielding failure lightning current as:

[0036] I y2 = I ymax ×(1 - a T )

[0037] Wherein, I y2 is the amplitude of the second shielding failure lightning current, and I ymax is the amplitude of the maximum shielding failure lightning current.

[0038] According to an implementable manner of the first aspect of the present invention, setting the second back - flashover lightning current according to the first back - flashover lightning current and the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval further includes:

[0039] Setting the decrease ratio threshold as 20%.

[0040] The second aspect of the present invention provides a simulation calculation method for circuit breaker over - voltage under multiple lightning strikes, which is characterized by including:

[0041] A data acquisition module, configured to acquire data required for circuit breaker simulation. The data required for circuit breaker simulation includes in - station equipment data and historical lightning strike data within a preset time period in the area where the circuit breaker is located. The in - station equipment data includes relevant parameters of lines, towers, insulator strings, terrain and landforms, substation electrical floor plans, and equipment;

[0042] A model establishment module, configured to establish a simulation calculation model for circuit breaker over - voltage in an electromagnetic transient program according to the in - station equipment data;

[0043] A lightning counterattack simulation module, which is used to determine the minimum lightning strike time interval and the maximum lightning current amplitude according to the historical lightning strike data, and perform a counterattack simulation on the incoming line tower by using two counterattack lightning currents in the circuit breaker overvoltage simulation calculation model to obtain the circuit breaker counterattack overvoltage result; wherein, the minimum lightning strike time interval is used as the strike interval of the two counterattack lightning currents, the first counterattack lightning current is set according to the maximum lightning current recommended value recommended by the national standard and the maximum lightning current amplitude, and the second counterattack lightning current is set according to the first counterattack lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval;

[0044] A lightning shielding failure simulation module, which is used to perform a shielding failure simulation on the incoming line conductor by using two shielding failure lightning currents in the circuit breaker overvoltage simulation calculation model to obtain the circuit breaker shielding failure overvoltage result; wherein, the minimum lightning strike time interval is used as the strike interval of the two shielding failure lightning currents, the maximum shielding failure lightning current of the incoming line tower calculated according to the electrical geometric model of the tower is used as the first shielding failure lightning current, and the second shielding failure lightning current is set according to the maximum shielding failure lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval;

[0045] A circuit breaker overvoltage determination module, which is used to determine the circuit breaker overvoltage according to the circuit breaker counterattack overvoltage result and the circuit breaker shielding failure overvoltage result.

[0046] According to an implementable manner of the second aspect of the present invention, the model establishment module includes:

[0047] Establish a lightning current model by using the Heidler wave in the electromagnetic transient program;

[0048] A first model establishment unit, which is used to establish a line tower model by using a multi-wave impedance model in the electromagnetic transient program;

[0049] A second model establishment unit, which is used to establish an insulator string flashover model by using the leader development method in the electromagnetic transient program;

[0050] A third model establishment unit, which is used to establish a tower grounding resistance model by using a concentrated resistance model in the electromagnetic transient program;

[0051] A fourth model establishment unit, which is used to simulate each device in the substation by using the operation mode of one line and one transformer in the electromagnetic transient program, equivalently simulate each device in the substation by using the entrance capacitance, and equivalently simulate the connection line between devices in the substation by using the wave impedance to establish a substation device model;

[0052] A fifth model establishment unit, which is used to establish a circuit breaker overvoltage simulation calculation model by combining the lightning current model, the line tower model, the insulator string flashover model, the tower grounding resistance model and the substation device model.

[0053] According to an implementable manner of the second aspect of the present invention, the lightning back-strike simulation module includes:

[0054] A first back-strike lightning current setting unit, configured to set the amplitude of the first back-strike lightning current to the maximum lightning current amplitude when the maximum lightning current amplitude is greater than the recommended maximum lightning current value;

[0055] A second back-strike lightning current setting unit, configured to set the amplitude of the first back-strike lightning current to the recommended maximum lightning current value when the maximum lightning current amplitude is not greater than the recommended maximum lightning current value.

[0056] According to an implementable manner of the second aspect of the present invention, the lightning back-strike simulation module includes:

[0057] A third back-strike lightning current setting unit, configured to determine the first back-strike lightning current by weighting the recommended maximum lightning current value and the maximum lightning current amplitude.

[0058] According to an implementable manner of the second aspect of the present invention, the lightning shielding failure simulation module includes:

[0059] A calculation unit, configured to calculate the current amplitude decrease ratio according to the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval:

[0060]

[0061] where a represents the current amplitude decrease ratio, I 1 is the lightning current amplitude of the first lightning strike corresponding to the minimum lightning strike time interval, I 2 is the lightning current amplitude of the second lightning strike corresponding to the minimum lightning strike time interval, max(I 1 , I 2 ) represents taking the maximum value from I 1 , I 2 ;

[0062] A fourth back-strike lightning current setting unit, configured to set the amplitude of the second back-strike lightning current to:

[0063] I x2 = I x1 ×(1 - a)

[0064] A fifth back-strike lightning current setting unit, configured to set the amplitude of the second back-strike lightning current to:

[0065] I x2 = I xmax×(1 - a T )

[0066] Wherein, I x1 is the amplitude of the first back - strike lightning current, I x2 is the amplitude of the second back - strike lightning current, a T is the falling - ratio threshold, and I xmax is the recommended value of the maximum lightning current.

[0067] According to an implementable manner of the second aspect of the present invention, the lightning shielding failure simulation module includes:

[0068] The first shielding - failure lightning - current setting unit is configured to set the amplitude of the second shielding - failure lightning current as:

[0069] I y2 = I ymax ×(1 - a)

[0070] The second shielding - failure lightning - current setting unit is configured to set the amplitude of the second shielding - failure lightning current as:

[0071] I y2 = I ymax ×(1 - a T )

[0072] Wherein, I y2 is the amplitude of the second shielding - failure lightning current, and I ymax is the amplitude of the maximum shielding - failure lightning current.

[0073] According to an implementable manner of the second aspect of the present invention, the lightning back - strike simulation module further includes:

[0074] The threshold - setting unit is configured to set the falling - ratio threshold to 20%.

[0075] The third aspect of the present invention provides a circuit - breaker over - voltage simulation calculation device under multiple lightning strikes, including:

[0076] A memory for storing instructions; wherein, the instructions are used to implement the circuit - breaker over - voltage simulation calculation method according to any one of the above - mentioned implementable manners;

[0077] A processor for executing the instructions in the memory.

[0078] In a fourth aspect of the present invention, a computer-readable storage medium stores a computer program thereon. When the computer program is executed by a processor, it implements the method for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes as described in any one of the above-mentioned implementable manners.

[0079] As can be seen from the above technical solutions, the present invention has the following advantages:

[0080] The present invention establishes a simulation calculation model for the overvoltage of a circuit breaker in an electromagnetic transient program based on the in-station equipment data, determines the minimum lightning strike time interval and the maximum lightning current amplitude according to the historical lightning strike data in the area where the circuit breaker is located, uses two counterattack lightning currents to simulate the counterattack on the incoming line tower in the simulation calculation model, and uses two shielding failure lightning currents to simulate the shielding failure on the incoming line conductor. Among them, the minimum lightning strike time interval is used as the return stroke interval, the first counterattack lightning current is set according to the recommended maximum lightning current value and the maximum lightning current amplitude recommended by the national standard, and the maximum shielding failure lightning current of the incoming line tower calculated according to the electrical geometric model of the tower is used as the first shielding failure lightning current, and the second counterattack lightning current and the second shielding failure lightning current are set based on the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval. The present invention combines the historical lightning strike data in the area where the circuit breaker is located to set the counterattack lightning current and the shielding failure lightning current, considers the actual lightning current situation in the area where the circuit breaker is located, enables the simulation calculation result of the overvoltage to fit the actual situation, and provides meaningful reference data for the layout of lightning protection measures. Description of the Drawings

[0081] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0082] Figure 1 It is a flowchart of a method for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes provided for an optional embodiment of the present invention;

[0083] Figure 2 It is a principle block diagram of a device for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes provided for an optional embodiment of the present invention.

[0084] Reference Signs:

[0085] 1 - Data Acquisition Module; 2 - Model Establishment Module; 3 - Lightning Counterattack Simulation Module; 4 - Lightning Shielding Failure Simulation Module; 5 - Circuit Breaker Overvoltage Determination Module. Detailed Embodiments

[0086] The embodiments of the present invention provide a method, device and storage medium for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes, which are used to solve the technical problem that the overvoltage simulation calculation results of the existing circuit breaker overvoltage simulation method under multiple lightning strikes cannot conform to the actual situation due to unreasonable lightning current values.

[0087] In order to make the invention objectives, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0088] The present invention provides a method for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes.

[0089] Please refer to Figure 1 , Figure 1 which shows a flowchart of a method for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes provided by the embodiments of the present invention.

[0090] A method for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes provided by the embodiments of the present invention includes steps S1 - S5.

[0091] Step S1: Collect the data required for circuit breaker simulation. The data required for circuit breaker simulation includes in - station equipment data and historical lightning strike data within a preset time period in the area where the circuit breaker is located. The in - station equipment data includes relevant parameters of lines, towers, insulator strings, terrain, substation electrical floor plans and equipment.

[0092] When collecting the in - station equipment data, it is preferable to collect data such as all lines, towers, insulator strings, terrain, substation electrical floor plans and equipment relevant parameters within 2 km of the substation incoming line section.

[0093] When collecting the historical lightning strike data, the data can be obtained from the lightning location system detection stations that have been built and put into operation. Among them, the specific value of this preset time period can be determined according to the actual situation. For example, the preset time period is set to be within the past year. Specifically, the area where the circuit breaker is located can be set as the area within 1 km on both sides along the overhead transmission line.

[0094] Step S2: Establish a simulation calculation model for the overvoltage of the circuit breaker in the electromagnetic transient program according to the in - station equipment data.

[0095] In an implementable manner, the establishing a simulation calculation model for the overvoltage of the circuit breaker in the electromagnetic transient program according to the in - station equipment data includes:

[0096] In the electromagnetic transient program, the Heidler wave is used to establish the lightning current model;

[0097] In the electromagnetic transient program, the multi-wave impedance model is used to establish the line tower model;

[0098] In the electromagnetic transient program, the leader development method is used to establish the insulator string flashover model;

[0099] In the electromagnetic transient program, the concentrated resistance model is used to establish the tower grounding resistance model;

[0100] In the electromagnetic transient program, the operation mode of one line and one transformer is adopted to simulate each device in the substation. The entrance capacitance is used to equivalently simulate each device in the substation, and the wave impedance is used to equivalently simulate the connection lines between devices in the substation to establish the substation device model;

[0101] Combined with the lightning current model, the line tower model, the insulator string flashover model, the tower grounding resistance model and the substation device model, a circuit breaker overvoltage simulation calculation model is established.

[0102] In the calculation of lightning intrusion overvoltage, the functions describing the lightning current waveform mainly include the ramp wave, the Heidler wave and the double exponential wave. In this embodiment, the Heidler wave is selected to establish the lightning current model, and the Heidler wave can obtain the current peak value, the half-peak time and the current steepness of the lightning current by adjusting parameters. As a specific implementation manner, the Heidler wave with a lightning current waveform of 2.6 / 50 μs is used to establish the lightning current model.

[0103] In this embodiment, considering the influence of factors such as the tower cross arm and bracket on the tower impedance, the multi-wave impedance model is used to establish the line tower model, and the line tower model is composed of three parts: the tower body, the bracket and the cross arm.

[0104] The insulator string flashover criterion determines the magnitude and waveform of the overvoltage invading the substation. Therefore, the accurate simulation of the insulator string is crucial. In this embodiment, the leader development method that can reflect the insulator string flashover characteristics under any discharge waveform is used to establish the insulator string flashover model.

[0105] When the line tower is struck by lightning and the lightning current flows into the grounding body, the grounding body presents a resistive state, and the impulse impedance of the grounding body is significantly affected by the current amplitude and frequency flowing through it, showing strong non-linear characteristics. The tower grounding device should be equivalently represented by a concentrated parameter resistance, and the resistance value is equal to the tower impulse grounding resistance value. Therefore, in this embodiment, the concentrated resistance model is used to establish the tower grounding resistance model.

[0106] When carrying out the analysis and calculation of lightning overvoltage in a substation, it should be determined in combination with the actual operation situation of the specific project. If there are many outgoing lines, the incoming wave overvoltage is generally relatively low, and the probability of a fault in the outgoing line of the circuit breaker is relatively low. The wiring mode of one line and one transformer (i.e., one circuit and one transformer) is the most severe wiring mode in the general operation mode. Based on this, in this embodiment, the operation mode of one line and one transformer is adopted to simulate each device in the substation.

[0107] Since the lightning transient process is very short and the frequency of the lightning shock wave is very high, the resistance and inductance effects of the electrical equipment in the substation are not established in time during lightning strikes. In this embodiment, the entrance capacitance is used to equivalently simulate each device in the substation, and the wave impedance is used to equivalently simulate the connection lines between the devices in the substation.

[0108] Among them, the entrance capacitance of each device can be set according to the measured value.

[0109] As a specific implementation manner, when using the wave impedance to equivalently simulate the connection lines between the devices in the substation, the magnitude of the wave impedance can be calculated according to the following formula:

[0110]

[0111] In the formula, Z c is the wave impedance of the conductor in the substation, with the unit of Ω, h c is the height of the conductor, with the unit of m, r e is the equivalent radius of the conductor, with the unit of m.

[0112] In the embodiment of the present invention, the lightning current model, the line tower model, the insulator string flashover model, the tower grounding resistance model, and the substation equipment model are established in combination with the above factors, and a circuit breaker overvoltage simulation calculation model is established based on each model, which can make the established circuit breaker overvoltage simulation calculation model have a high simulation accuracy.

[0113] Step S3, determine the minimum lightning strike time interval and the maximum lightning current amplitude according to the historical lightning strike data, and use two counterattack lightning currents in the circuit breaker overvoltage simulation calculation model to simulate the counterattack of the incoming line tower to obtain the circuit breaker counterattack overvoltage result; among them, use the minimum lightning strike time interval as the strike interval of the two counterattack lightning currents, set the first counterattack lightning current according to the maximum lightning current recommended value recommended by the national standard and the maximum lightning current amplitude, and set the second counterattack lightning current according to the first counterattack lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval.

[0114] In a feasible manner, the setting of the first counterattack lightning current according to the maximum lightning current recommended value recommended by the national standard and the maximum lightning current amplitude includes:

[0115] When the maximum lightning current amplitude is greater than the recommended value of the maximum lightning current, set the amplitude of the first counterattack lightning current to the maximum lightning current amplitude;

[0116] When the maximum lightning current amplitude is not greater than the recommended value of the maximum lightning current, set the amplitude of the first counterattack lightning current to the recommended value of the maximum lightning current.

[0117] The embodiment of the present invention can ensure the rationality of setting the amplitude of the first counterattack lightning current.

[0118] In another implementable way, setting the first counterattack lightning current according to the recommended value of the maximum lightning current recommended by the national standard and the maximum lightning current amplitude includes:

[0119] Determine the first counterattack lightning current by weighting the recommended value of the maximum lightning current and the maximum lightning current amplitude.

[0120] The weighting coefficients of the recommended value of the maximum lightning current and the maximum lightning current amplitude can be set respectively according to actual needs.

[0121] As a specific implementation manner, set the amplitude of the first counterattack lightning current according to the following formula:

[0122] I x1 = k 1 I xma + k 2 I max

[0123] In the formula, I x1 is the amplitude of the first counterattack lightning current, I xmax is the recommended value of the maximum lightning current, I max is the maximum lightning current amplitude, k 1 is the weighting coefficient of the recommended value of the maximum lightning current, k 2 is the weighting coefficient of the maximum lightning current amplitude.

[0124] Preferably, k 1 = 0.3, k 2 = 0.7.

[0125] In an implementable way, setting the second counterattack lightning current according to the first counterattack lightning current and the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval includes:

[0126] Calculate the current amplitude decrease ratio according to the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval:

[0127]

[0128] Wherein, a represents the proportion of the current amplitude decrease, and I 1 is the lightning current amplitude of the first lightning strike corresponding to the minimum lightning strike time interval, and I 2 is the lightning current amplitude of the second lightning strike corresponding to the minimum lightning strike time interval. max(I 1 , I 2 ) represents taking the maximum value from I 1 , I 2 ;

[0129] When the proportion of the current amplitude decrease is not greater than the decrease proportion threshold, set the amplitude of the second back-strike lightning current as:

[0130] I x2 = I x1 ×(1 - a)

[0131] When the proportion of the current amplitude decrease is greater than the decrease proportion threshold, set the amplitude of the second back-strike lightning current as:

[0132] I x2 = I xmax ×(1 - a T )

[0133] Wherein, I x1 is the amplitude of the first back-strike lightning current, I x2 is the amplitude of the second back-strike lightning current, a T is the decrease proportion threshold, and I xmax is the recommended value of the maximum lightning current.

[0134] In a preferred embodiment, set the decrease proportion threshold to 20%.

[0135] Step S4, in the circuit breaker overvoltage simulation calculation model, use the two shielding failure lightning currents to simulate the shielding failure of the incoming line conductor to obtain the circuit breaker shielding failure overvoltage result; wherein, use the minimum lightning strike time interval as the return stroke interval of the two shielding failure lightning currents, use the maximum shielding failure lightning current of the incoming line tower calculated according to the tower electrical geometry model as the first shielding failure lightning current, and set the second shielding failure lightning current according to the maximum shielding failure lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval.

[0136] When setting the second shielding failure lightning current according to the maximum shielding failure lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval, the setting method of the second back-strike lightning current can be referred to.

[0137] In an achievable manner, setting the second shielding failure lightning current according to the maximum shielding failure lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval includes:

[0138] When the decrease ratio of the current amplitude is not greater than the decrease ratio threshold, set the amplitude of the second side-stroke lightning current as:

[0139] I y2 = I ymax ×(1 - a)

[0140] When the decrease ratio of the current amplitude is greater than the decrease ratio threshold, set the amplitude of the second side-stroke lightning current as:

[0141] I y2 = I ymax ×(1 - a T )

[0142] In the formula, I y2 is the amplitude of the second side-stroke lightning current, and I ymax is the amplitude of the maximum side-stroke lightning current.

[0143] Step S5, determine the breaker overvoltage according to the breaker back-stroke overvoltage result and the breaker side-stroke overvoltage result.

[0144] The present invention also provides a breaker overvoltage simulation calculation device under multiple lightning strikes.

[0145] Please refer to Figure 2 , Figure 2 which shows a schematic block diagram of a breaker overvoltage simulation calculation device provided by an embodiment of the present invention.

[0146] An embodiment of the present invention provides a breaker overvoltage simulation calculation device under multiple lightning strikes, including:

[0147] A data acquisition module 1, configured to acquire data required for breaker simulation. The data required for breaker simulation includes in-station equipment data and historical lightning strike data within a preset time period in the area where the breaker is located. The in-station equipment data includes relevant parameters of lines, towers, insulator strings, terrain and landforms, substation electrical floor plans, and equipment;

[0148] A model establishment module 2, configured to establish a breaker overvoltage simulation calculation model in an electromagnetic transient program according to the in-station equipment data;

[0149] The lightning counterattack simulation module 3 is used to determine the minimum lightning strike time interval and the maximum lightning current amplitude according to the historical lightning strike data, and perform a counterattack simulation on the incoming line tower using two counterattack lightning currents in the circuit breaker overvoltage simulation calculation model to obtain the circuit breaker counterattack overvoltage result; wherein, the minimum lightning strike time interval is used as the strike interval of the two counterattack lightning currents, the first counterattack lightning current is set according to the maximum lightning current recommended value recommended by the national standard and the maximum lightning current amplitude, and the second counterattack lightning current is set according to the first counterattack lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval;

[0150] The lightning shielding failure simulation module 4 is used to perform a shielding failure simulation on the incoming line conductor using two shielding failure lightning currents in the circuit breaker overvoltage simulation calculation model to obtain the circuit breaker shielding failure overvoltage result; wherein, the minimum lightning strike time interval is used as the strike interval of the two shielding failure lightning currents, the maximum shielding failure lightning current of the incoming line tower calculated according to the electrical geometric model of the tower is used as the first shielding failure lightning current, and the second shielding failure lightning current is set according to the maximum shielding failure lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval;

[0151] The circuit breaker overvoltage determination module 5 is used to determine the circuit breaker overvoltage according to the circuit breaker counterattack overvoltage result and the circuit breaker shielding failure overvoltage result.

[0152] In an implementable manner, the model establishment module 2 includes:

[0153] Establish a lightning current model using the Heidler wave in the electromagnetic transient program;

[0154] The first model establishment unit is used to establish a line tower model using the multi-wave impedance model in the electromagnetic transient program;

[0155] The second model establishment unit is used to establish an insulator string flashover model using the leader development method in the electromagnetic transient program;

[0156] The third model establishment unit is used to establish a tower grounding resistance model using the concentrated resistance model in the electromagnetic transient program;

[0157] The fourth model establishment unit is used to simulate each device in the substation using the operation mode of one line and one transformer in the electromagnetic transient program, perform equivalent simulation on each device in the substation using the entrance capacitance, perform equivalent simulation on the connection lines between devices in the substation using the wave impedance, and establish a substation device model;

[0158] The fifth model establishment unit is used to establish a circuit breaker overvoltage simulation calculation model by combining the lightning current model, the line tower model, the insulator string flashover model, the tower grounding resistance model and the substation device model.

[0159] In an implementable manner, the lightning counterattack simulation module 3 includes:

[0160] A first counterattack lightning current setting unit, configured to set the amplitude of the first counterattack lightning current to the maximum lightning current amplitude when the maximum lightning current amplitude is greater than the recommended maximum lightning current value;

[0161] A second counterattack lightning current setting unit, configured to set the amplitude of the first counterattack lightning current to the recommended maximum lightning current value when the maximum lightning current amplitude is not greater than the recommended maximum lightning current value.

[0162] In an implementable manner, the lightning counterattack simulation module 3 includes:

[0163] A third counterattack lightning current setting unit, configured to determine the first counterattack lightning current by weighting the recommended maximum lightning current value and the maximum lightning current amplitude.

[0164] In an implementable manner, the lightning shielding failure simulation module 4 includes:

[0165] A calculation unit, configured to calculate the current amplitude decrease ratio according to the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval:

[0166]

[0167] In the formula, a represents the current amplitude decrease ratio, I 1 is the lightning current amplitude of the first lightning strike corresponding to the minimum lightning strike time interval, I 2 is the lightning current amplitude of the second lightning strike corresponding to the minimum lightning strike time interval, max(I 1 , I 2 ) represents taking the maximum value from I 1 , I 2 ;

[0168] A fourth counterattack lightning current setting unit, configured to set the amplitude of the second counterattack lightning current to:

[0169] I x2 = I x1 ×(1 - a)

[0170] A fifth counterattack lightning current setting unit, configured to set the amplitude of the second counterattack lightning current to:

[0171] I x2 = I xmax ×(1 - a T )

[0172] Wherein, I x1 is the amplitude of the first counterattack lightning current, I x2 is the amplitude of the second counterattack lightning current, a T is the falling ratio threshold, I xmax is the recommended value of the maximum lightning current.

[0173] In an implementable manner, the lightning shielding failure simulation module 4 includes:

[0174] The first shielding failure lightning current setting unit is configured to set the amplitude of the second shielding failure lightning current as:

[0175] I y2 = I ymax × (1 - a)

[0176] The second shielding failure lightning current setting unit is configured to set the amplitude of the second shielding failure lightning current as:

[0177] I y2 = I ymax × (1 - a T )

[0178] Wherein, I y2 is the amplitude of the second shielding failure lightning current, I ymax is the amplitude of the maximum shielding failure lightning current.

[0179] In an implementable manner, the lightning counterattack simulation module 3 further includes:

[0180] The threshold setting unit is configured to set the falling ratio threshold to 20%.

[0181] The present invention further provides a circuit breaker overvoltage simulation calculation device under multiple lightning strikes, including:

[0182] A memory for storing instructions; wherein, the instructions are used to implement the circuit breaker overvoltage simulation calculation method under multiple lightning strikes described in any one of the above embodiments;

[0183] A processor for executing the instructions in the memory.

[0184] The present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the circuit breaker overvoltage simulation calculation method under multiple lightning strikes described in any one of the above embodiments.

[0185] In the above embodiments of the present invention, the counter-attack lightning current and the shielding failure lightning current are set by combining the historical lightning strike data in the area where the circuit breaker is located, taking into account the actual lightning current situation in the area where the circuit breaker is located, so that the overvoltage simulation calculation results can conform to the actual situation and provide meaningful reference data for the layout of lightning protection measures.

[0186] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described devices and modules can refer to the corresponding processes in the foregoing method embodiments, and the specific beneficial effects of the above-described devices and modules can refer to the corresponding beneficial effects in the foregoing method embodiments, which will not be elaborated herein.

[0187] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0188] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0189] In addition, in each embodiment of the present invention, the functional modules can be integrated in a processing module, or each module can exist physically alone, or two or more modules can be integrated in one module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules.

[0190] When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs.

[0191] As described above, the above embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of various embodiments of the present invention.

Claims

1. A simulation calculation method for circuit breaker overvoltage under multiple lightning strikes, characterized in that, it includes: Collect data required for circuit breaker simulation, where the data required for circuit breaker simulation includes in-station equipment data and historical lightning strike data within a preset time period in the area where the circuit breaker is located. The in-station equipment data includes relevant parameters of lines, towers, insulator strings, terrain, substation electrical floor plans, and equipment; Establish a simulation calculation model for circuit breaker overvoltage in the electromagnetic transient program according to the in-station equipment data; Determine the minimum lightning strike time interval and the maximum lightning current amplitude according to the historical lightning strike data. Use two counterattack lightning currents in the circuit breaker overvoltage simulation calculation model to simulate the counterattack on the incoming line tower to obtain the circuit breaker counterattack overvoltage result. Among them, use the minimum lightning strike time interval as the strike interval of the two counterattack lightning currents. Set the first counterattack lightning current according to the maximum lightning current recommended value recommended by the national standard and the maximum lightning current amplitude. Set the second counterattack lightning current according to the first counterattack lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval; Use two shielding failure lightning currents in the circuit breaker overvoltage simulation calculation model to simulate the shielding failure of the incoming line conductor to obtain the circuit breaker shielding failure overvoltage result. Among them, use the minimum lightning strike time interval as the strike interval of the two shielding failure lightning currents. Use the maximum shielding failure lightning current of the incoming line tower calculated according to the electrical geometric model of the tower as the first shielding failure lightning current. Set the second shielding failure lightning current according to the maximum shielding failure lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval; Determine the circuit breaker overvoltage according to the circuit breaker counterattack overvoltage result and the circuit breaker shielding failure overvoltage result.

2. The simulation calculation method for circuit breaker overvoltage under multiple lightning strikes according to claim 1, characterized in that, The step of establishing a simulation calculation model for circuit breaker overvoltage in the electromagnetic transient program according to the in-station equipment data includes: Establish a lightning current model using the Heidler wave in the electromagnetic transient program; Establish a line tower model using a multi-wave impedance model in the electromagnetic transient program; Establish an insulator string flashover model using the leader development method in the electromagnetic transient program; Establish a tower grounding resistance model using a concentrated resistance model in the electromagnetic transient program; Use the operation mode of one line and one transformer in the electromagnetic transient program to simulate each in-station equipment. Use the entrance capacitance to equivalently simulate each in-station equipment. Use the wave impedance to equivalently simulate the connection lines between in-station equipment to establish an in-station equipment model; Combine the lightning current model, the line tower model, the insulator string flashover model, the tower grounding resistance model, and the in-station equipment model to establish a simulation calculation model for circuit breaker overvoltage.

3. The simulation calculation method for circuit breaker overvoltage under multiple lightning strikes according to claim 1, characterized in that, The step of setting the first counterattack lightning current according to the maximum lightning current recommended value recommended by the national standard and the maximum lightning current amplitude includes: When the maximum lightning current amplitude is greater than the recommended value of the maximum lightning current, set the amplitude of the first back-strike lightning current to the maximum lightning current amplitude; When the maximum lightning current amplitude is not greater than the recommended value of the maximum lightning current, set the amplitude of the first back-strike lightning current to the recommended value of the maximum lightning current.

4. The method for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes according to claim 1, characterized in that, the setting of the first back-strike lightning current according to the recommended value of the maximum lightning current recommended by the national standard and the maximum lightning current amplitude includes: determining the first back-strike lightning current by weighting the recommended value of the maximum lightning current and the maximum lightning current amplitude.

5. The method for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes according to claim 1, characterized in that, the setting of the second back-strike lightning current according to the first back-strike lightning current and the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval includes: calculating the current amplitude decrease ratio according to the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval: where a represents the proportion of the current amplitude drop, and I 1 is the lightning current amplitude of the first lightning strike corresponding to the minimum lightning strike time interval, and I 2 is the lightning current amplitude of the second lightning strike corresponding to the minimum lightning strike time interval, and max(I 1 , I 2 ) represents taking the maximum value from I 1 , I 2 ; when the current amplitude decrease ratio is not greater than the decrease ratio threshold, set the amplitude of the second back-strike lightning current to: I x2 = I x1 × (1 - a) when the current amplitude decrease ratio is greater than the decrease ratio threshold, set the amplitude of the second back-strike lightning current to: I x2 = I xmax × (1 - a T ) Where, I x1 is the amplitude of the first counterattack lightning current, I x2 is the amplitude of the second counterattack lightning current, a T is the decline ratio threshold, and I xmax is the recommended value of the maximum lightning current.

6. The method for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes according to claim 5, characterized in that, the setting of the second shielding failure lightning current according to the maximum shielding failure lightning current and the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval includes: when the current amplitude decrease ratio is not greater than the decrease ratio threshold, set the amplitude of the second shielding failure lightning current to: I y2 = I ymax × (1 - a) when the current amplitude decrease ratio is greater than the decrease ratio threshold, set the amplitude of the second shielding failure lightning current to: I y2 = I ymax × (1 - a T ) where I y2 is the amplitude of the second side-stroke lightning current, and I ymax is the amplitude of the maximum side-stroke lightning current.

7. The method for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes according to claim 5, characterized in that, the setting of the second back-strike lightning current according to the first back-strike lightning current and the lightning current amplitudes of two lightning strikes corresponding to the minimum lightning strike time interval further includes: set the decrease ratio threshold to 20%.

8. A device for simulating and calculating the overvoltage of a circuit breaker under multiple lightning strikes, characterized in that, it includes: a data acquisition module, configured to acquire data required for circuit breaker simulation, where the data required for circuit breaker simulation includes in-station equipment data and historical lightning strike data within a preset time period in the area where the circuit breaker is located, and the in-station equipment data includes relevant parameters of lines, towers, insulator strings, terrain and landforms, substation electrical floor plans, and equipment; a model establishment module, configured to establish a simulation calculation model for the overvoltage of a circuit breaker in an electromagnetic transient program according to the in-station equipment data; A lightning counterattack simulation module, which is used to determine the minimum lightning strike time interval and the maximum lightning current amplitude according to the historical lightning strike data, and perform a counterattack simulation on the incoming line tower using two counterattack lightning currents in the circuit breaker overvoltage simulation calculation model to obtain the circuit breaker counterattack overvoltage result; wherein the minimum lightning strike time interval is used as the strike interval of the two counterattack lightning currents, the first counterattack lightning current is set according to the maximum lightning current recommended value recommended by the national standard and the maximum lightning current amplitude, and the second counterattack lightning current is set according to the first counterattack lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval; A lightning shielding failure simulation module, which is used to perform a shielding failure simulation on the incoming line conductor using two shielding failure lightning currents in the circuit breaker overvoltage simulation calculation model to obtain the circuit breaker shielding failure overvoltage result; wherein the minimum lightning strike time interval is used as the strike interval of the two shielding failure lightning currents, the maximum shielding failure lightning current of the incoming line tower calculated according to the electrical geometric model of the tower is used as the first shielding failure lightning current, and the second shielding failure lightning current is set according to the maximum shielding failure lightning current and the lightning current amplitudes of the two lightning strikes corresponding to the minimum lightning strike time interval; A circuit breaker overvoltage determination module, which is used to determine the circuit breaker overvoltage according to the circuit breaker counterattack overvoltage result and the circuit breaker shielding failure overvoltage result.

9. A circuit breaker overvoltage simulation calculation device under multiple lightning strikes, characterized in that, it includes: a memory, which is used to store instructions; wherein, the instructions are used to implement the circuit breaker overvoltage simulation calculation method according to any one of claims 1-7; a processor, which is used to execute the instructions in the memory.

10. A computer-readable storage medium, characterized in that, a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, it implements the circuit breaker overvoltage simulation calculation method according to any one of claims 1-7.

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