A method for simulating analysis of influence of lightning arrester cut-off characteristic on lightning intrusion wave
By establishing a simulation model to analyze the cutoff characteristics of multi-gap surge arresters, the problem of the impact of multi-gap surge arresters on the insulation of wind turbine transformer windings was solved, application guidance was provided, and the threat of lightning intrusion waves to the insulation of transformer windings was reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ELECTRIC POWER RES INST OF GUANGXI POWER GRID CO LTD
- Filing Date
- 2022-12-06
- Publication Date
- 2026-05-15
AI Technical Summary
In the existing technology, the wave interception of multi-gap surge arresters during operation may threaten the insulation of the wind turbine transformer windings, and its impact needs to be analyzed.
By establishing a simulation model, the impact of the cutoff characteristics of multi-gap surge arresters on lightning intrusion waves is analyzed using the ATP-EMTP program. Overvoltage and current waveforms under different installation methods are considered, and the equipment insulation coordination is verified.
It provides guidance on the application of multi-gap surge arresters in distribution networks, effectively reducing the threat of lightning surge waves to transformer winding insulation, and the simulation results are more in line with reality.
Smart Images
Figure CN115795887B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of simulation analysis technology, and in particular relates to a method for simulation analysis of the influence of surge arrester cutoff characteristics on lightning intrusion waves. Background Technology
[0002] Wind power is a green energy source that has received strong government support and has developed rapidly in my country in recent years. Large-scale wind power projects have been built in parts of Northwest my country and the coast. The power generated by wind turbines is transmitted to the power grid through collector towers. It is necessary to consider the lightning protection near the wind turbines. According to relevant regulations, zinc oxide surge arresters are generally recommended to be installed at the outlet of the wind turbine power generation cable and the three phases of the collector tower. However, due to lightning overvoltage, zinc oxide surge arresters are often damaged. This not only requires more money to replace the zinc oxide surge arresters, but also, if the damaged zinc oxide surge arresters are not replaced in time, it may even endanger the safety of the wind turbine.
[0003] Currently, installing multi-gap surge arresters on three phases of the tower following the collector tower works well with zinc oxide surge arresters, reducing system failures caused by arrester malfunctions. However, multi-gap surge arresters have a large current capacity and low residual voltage during operation, inevitably generating chopped waves. These chopped waves travel along the line to the wind turbine transformer, potentially threatening the insulation of the transformer windings. Therefore, it is necessary to analyze the chopped wave overvoltage of the multi-gap surge arresters to determine whether it will affect the insulation of the wind turbine transformer windings.
[0004] To address this issue, a simulation analysis method is provided to analyze the impact of surge arrester cutoff characteristics on lightning intrusion waves, thereby resolving the aforementioned impact of cutoff waves on the insulation of wind turbine transformer windings. Summary of the Invention
[0005] To address or mitigate the impact of surge arrester cutoff on the insulation of wind turbine transformer windings, this invention provides a method for simulation analysis of the influence of surge arrester cutoff characteristics on lightning intrusion waves. The specific technical solution is as follows:
[0006] This invention provides a method for simulation analysis of the influence of surge arrester cutoff characteristics on lightning intrusion waves, comprising the following steps:
[0007] S1, perform calculation condition analysis and setting for lightning intrusion wave overvoltage;
[0008] S2. Based on the acquisition of wind farm system parameters, a simulation model of the overvoltage of lightning intrusion wave considering the interception characteristics of multi-gap surge arresters is established.
[0009] S3. Run the simulation model to obtain the voltage and current waveforms at each device under the action of backflash lightning and lightning bypass chopped overvoltage. Calculate the voltage and current values at each device under the action of backflash lightning and lightning bypass chopped overvoltage. Compare and analyze the influence law of chopped overvoltage under different installation methods and draw reasonable conclusions.
[0010] Preferably, in S1, to verify whether the chopped overvoltage of the multi-gap surge arrester may threaten the insulation of the wind turbine transformer box, the installation method of the zinc oxide surge arrester and the multi-gap surge arrester is considered in the calculation.
[0011] Preferably, the installation method is the conventional installation method, that is, installing zinc oxide surge arresters on the collector tower and multi-gap surge arresters on the next level tower.
[0012] Preferably, the installation method is the extreme installation method, that is, multi-gap surge arresters are installed on the collector tower, and no surge arresters are installed from the next level tower onwards.
[0013] Preferably, in S2, the system parameters are acquired and the simulation model is established using the internationally recognized graphical power system electromagnetic transient calculation program ATP-EMTP to establish a simulation model that considers the interception characteristics of multi-gap surge arresters on the overvoltage of lightning intrusion waves.
[0014] Preferably, in S3, the voltage and current waveforms and amplitudes at each device under the action of backflash lightning and lightning bypass overvoltage should be considered under different installation methods, and the insulation coordination of each device should be checked.
[0015] Preferably, the simulation model includes electrical equipment model, cable model, surge arrester module model, and other module models.
[0016] Preferably, the insulation coordination of electrical equipment is checked. When calculating the insulation coordination margin for lightning overvoltage, the impact of aging on the withstand voltage of the equipment needs to be considered. The degradation factor is calculated according to the external insulation degradation factor of 1.05 recommended by IEC60071.
[0017] The beneficial effects of this invention are as follows: By establishing and running a simulation model considering the cutoff characteristics of multi-gap surge arresters on lightning surge overvoltage, this invention analyzes the cutoff overvoltage of multi-gap surge arresters and determines whether it will affect the insulation of wind turbine transformer windings. The simulation results can provide guidance for the application of multi-gap surge arresters in distribution networks, effectively reducing the threat of lightning surges to transformer winding insulation. This invention, based on the ATP-EMTP simulation model considering the impact of multi-gap surge arrester cutoff characteristics on lightning surge overvoltage, can accurately obtain the influence law of multi-gap surge arresters on lightning surge overvoltage, which is more realistic than commonly used engineering methods for calculating lightning surge overvoltage. Attached Figure Description
[0018] Figure 1 This is a flowchart of the present invention;
[0019] Figure 2 It is an ATP interface overhead circuit module;
[0020] Figure 3 It refers to the surge arrester module and surge arrester parameter setting window on the ATP interface;
[0021] Figure 4 This is the volt-ampere characteristic curve of a zinc oxide surge arrester;
[0022] Figure 5 These are the surge arrester module and surge arrester volt-ampere characteristic curves on the ATP interface;
[0023] Figure 6 It is a simulation model of chopped overvoltage;
[0024] Figure 7 These are the chopped overvoltage waveforms at various power equipment locations. Detailed Implementation
[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0026] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.
[0027] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.
[0028] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.
[0029] To address the impact of wave chokes on the insulation of wind turbine transformer windings, the following measures are proposed: Figure 1The method shown here is a simulation analysis of the influence of surge arrester cutoff characteristics on lightning intrusion waves, including the following steps:
[0030] S1, perform calculation condition analysis and setting for lightning intrusion wave overvoltage;
[0031] S2. Based on the acquisition of wind farm system parameters, a simulation model of the overvoltage of lightning intrusion wave considering the interception characteristics of multi-gap surge arresters is established.
[0032] S3. Run the simulation model to obtain the voltage and current waveforms at each device under the action of backflash lightning and lightning bypass chopped overvoltage. Calculate the voltage and current values at each device under the action of backflash lightning and lightning bypass chopped overvoltage. Compare and analyze the influence law of chopped overvoltage under different installation methods and draw reasonable conclusions.
[0033] This invention proposes a simulation analysis method considering the impact of the cutoff characteristics of multi-gap surge arresters on lightning surge overvoltage. First, the invention analyzes and sets the calculation conditions for lightning surge overvoltage, including both conventional and extreme installation methods for surge arresters. Second, based on the acquisition of wind farm system parameters, an ATP-EMTP simulation model considering the impact of the cutoff characteristics of multi-gap surge arresters on lightning surge overvoltage is established. Finally, the voltage and current waveforms and amplitudes at various equipment are considered under different installation methods, including backflashover and lightning strike cutoff overvoltages, and the insulation coordination of each device is verified. This invention can provide effective guidance for the application of multi-gap surge arresters in distribution network lightning protection.
[0034] As a specific embodiment of the present invention, in S1, in order to verify whether the chopped overvoltage of the multi-gap surge arrester may threaten the insulation of the wind turbine transformer box, the calculation considers the installation methods of the zinc oxide surge arrester and the multi-gap surge arrester. The installation methods include: conventional installation method, that is, installing the zinc oxide surge arrester on the collector tower and installing the multi-gap surge arrester on the next level tower; extreme installation method, that is, installing the multi-gap surge arrester on the collector tower and not installing surge arrester protection from the next level tower.
[0035] The relevant conditions for the calculation are as follows:
[0036] 1) Wind power is transmitted to the load center via 35kV overhead transmission lines.
[0037] 2) Each group of wind turbines is individually stepped up to 35kV via a wind turbine box transformer, and then connected to an overhead line via a cable.
[0038] 3) Without considering the length of the busbar on the fan side, the cable connected to each fan group is uniformly set to 150m.
[0039] 4) Install ZnO surge arresters at both ends of the cable.
[0040] Both calculation conditions consider the most severe scenario: since each group of wind turbines will shunt the overvoltage from the intercepted lightning, only the overvoltage level when one group of wind turbines is online is set to be the highest; it is assumed that the lightning strikes the first tower after the collector tower, and the subsequent span is set to be long enough so that there is no wave reflection on the non-wind turbine side within the calculation range; the wind turbine side is not energized, that is, it is directly grounded after the transformer. According to the reflection theorem, the wave will undergo total reflection at the end, and the current value will rise to twice the original value. At this time, the overvoltage value borne by the insulation of the wind turbine box transformer is the highest.
[0041] As a specific embodiment of the present invention, in S2, the system parameters are acquired and the simulation model is established using the internationally recognized graphical power system electromagnetic transient calculation program ATP-EMTP. This program is used to establish a simulation model that considers the interception characteristics of multi-gap surge arresters on the overvoltage of lightning intrusion waves. The simulation model includes electrical equipment models, cable models, surge arrester module models, and other module models, as detailed below:
[0042] 1. Models of electrical equipment such as transformers
[0043] Due to the high-frequency characteristics of lightning waves, substation equipment such as transformers, circuit breakers, current transformers, and disconnect switches exhibit a significant capacitive effect under the influence of high-frequency voltage waves. Therefore, they can all be approximated by using an equivalent input capacitance.
[0044] According to the formula for the equivalent input capacitance of a transformer derived by Soviet scholars:
[0045]
[0046] (1) In the formula, C is the equivalent inlet capacitance of the transformer and S is the three-phase capacity of the transformer.
[0047] The parameters of wind turbine transformer boxes vary depending on the model. Taking the ZGS11-ZF-2200 / 35 model as an example, for this transformer, K is 350, n is 3, and the three-phase capacity of the wind turbine transformer box is 2200kVA. Based on this, the equivalent inlet capacitance of the wind turbine transformer box can be calculated. Similarly, by consulting relevant literature, the equivalent inlet capacitance of other 35kV electrical equipment can be found as shown in Table 1 below.
[0048] Table 1 Equivalent inlet capacitance of each electrical device
[0049] equipment Fan box transformer breaker Current transformer disconnect switch Voltage transformer Input capacitance (pF) 455 500 200 100 400
[0050] The relevant equipment was previously connected via an overhead line with a wave impedance of 400Ω and a wave speed of light. The model in ATP is as follows: Figure 2 .
[0051] 2. Cable Model
[0052] The collector cable is a 35kV three-core cross-linked polyethylene insulated power cable, commonly model YJV22. Without considering cable grounding, equivalent surge impedance can also be used. YJV22 cable parameters are shown in Tables 2 and 3.
[0053] Table 2 Structural parameters of YJV22 power cable
[0054]
[0055] Table 3 Electrical parameters of YJV22 power cable
[0056] AC resistance of conductor (Ω / km) Capacitance uF / km Reactance Ω / km Current carrying capacity A (in the soil) 0.196 0.16 0.135 350
[0057] The wave impedance and wave velocity of the power cable can be calculated from the following equations (2) to (4):
[0058]
[0059]
[0060]
[0061] 3. Lightning arrester module model
[0062] Zinc oxide surge arresters are simulated using a nonlinear resistor in series with a small inductor. Typical parameters for a 35kV zinc oxide surge arrester are shown in Table 4. The surge arrester module and parameter setting window on the ATP interface are shown below. Figure 3 As shown, the surge arrester's volt-ampere characteristic curve is as follows: Figure 4 As shown
[0063] Table 4 Parameters of 35kV Zinc Oxide Surge Arrester
[0064]
[0065] Multi-gap surge arresters are simulated using a voltage-controlled switch in series with a nonlinear resistor and then in series with a small inductor. When the voltage across the arrester exceeds 240kV, the voltage-controlled switch activates, causing the arrester to operate. The residual voltage of the MGA-I type multi-gap surge arrester is 10kV. The surge arrester module and the surge arrester's volt-ampere characteristic curves on the ATP interface are shown below. Figure 5 As shown.
[0066] 4. Other module models
[0067] The tower model uses a lumped parameter inductor model to simulate the distribution line tower, which meets the simulation accuracy requirements, with an inductance value of 0.84uH / m per unit length; the overhead collector line model uses the JMarti frequency characteristic overhead line model with parameters varying with frequency; the lightning current uses the Heidler model, with a waveform of 2.6 / 50μs; and the insulator module is simulated using the intersection method.
[0068] Combining the above components yields a simulation model for analyzing the impact of the choke wave of a multi-gap surge arrester on the insulation of the wind turbine transformer windings, as shown below. Figure 6 .
[0069] As a specific embodiment of the present invention, the overvoltage analysis of cutoff lightning is considered under conventional and extreme installation methods. The effects of backflash lightning overvoltage and lightning strike overvoltage are considered under the two different installation methods. The simulation model is run to obtain the voltage and current waveforms at each device under the action of backflash lightning and lightning strike cutoff lightning overvoltages. The voltage and current values at each device under the action of backflash lightning and lightning strike cutoff lightning overvoltages are calculated. The influence law of cutoff lightning overvoltage under different installation methods is compared and analyzed, and reasonable conclusions are drawn. The amplitude of the backflash lightning current can be taken as -80kA, -100kA, and -120kA respectively. According to the electrical geometry model, the maximum lightning strike current of each phase conductor is calculated as follows: Phase A 4.097kA; Phase B 1.166kA; Phase C 2.4775kA. The maximum value is taken as the lightning strike current of Phase A. Based on this, the insulation coordination of electrical equipment needs to be checked. When calculating the insulation coordination margin for lightning overvoltage, the impact of aging on the withstand voltage of the equipment needs to be considered. The degradation factor is calculated according to the external insulation degradation factor of 1.05 recommended by IEC60071.
[0070] Taking the voltage and current waveforms at various equipment points under the action of backflash lightning overvoltage in extreme installation mode as an example:
[0071] A backflash lightning strike occurred on the next lower tower (tower 2) of the collector tower. The lightning overvoltage intruded into tower 1, causing the multi-gap surge arrester on that tower to trip, limiting the backflash lightning overvoltage to a residual voltage of 10kV. The overvoltage situation was analyzed with a lightning current amplitude of -80kA. The overvoltage curves of each device on the wind turbine's output line are shown below. Figure 7 .
[0072] Those skilled in the art will recognize that the units of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of the invention.
[0073] In the embodiments provided in this application, it should be understood that the division of units is only a logical functional division. In actual implementation, there may be other division methods, such as multiple units can be combined into one unit, one unit can be split into multiple units, or some features can be ignored.
[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.
Claims
1. A method for simulation analysis of the influence of surge arrester cutoff characteristics on lightning intrusion waves, characterized in that, Includes the following steps: S1, perform calculation condition analysis and setting for lightning intrusion wave overvoltage; specifically: To verify whether the chopped overvoltage of the multi-gap surge arrester might threaten the insulation of the wind turbine transformer box, the calculations consider the installation methods of the zinc oxide surge arrester and the multi-gap surge arrester. The surge arrester installation methods include conventional installation methods and extreme installation methods. The conventional installation method refers to installing zinc oxide surge arresters on the collector tower and multi-gap surge arresters on the next level tower; the extreme installation method refers to installing multi-gap surge arresters on the collector tower and not installing surge arresters for protection from the next level tower onwards. S2. Based on the acquisition of wind farm system parameters, a simulation model of the overvoltage of lightning intrusion wave considering the interception characteristics of multi-gap surge arresters is established. S3. Run the simulation model to obtain the voltage and current waveforms at each device under the action of backflash lightning and lightning bypass chopped overvoltage. Calculate the voltage and current values at each device under the action of backflash lightning and lightning bypass chopped overvoltage. Compare and analyze the influence law of chopped overvoltage under different installation methods and draw reasonable conclusions.
2. The method for simulation analysis of the influence of surge arrester cutoff characteristics on lightning intrusion waves according to claim 1, characterized in that: In S2, system parameter acquisition and simulation model establishment are carried out using the internationally recognized graphical power system electromagnetic transient calculation program ATP-EMTP to establish a simulation model that considers the interception characteristics of multi-gap surge arresters on the overvoltage of lightning intrusion waves.
3. The method for simulation analysis of the influence of surge arrester cutoff characteristics on lightning intrusion waves according to claim 1, characterized in that: In S3, it is necessary to consider the voltage and current waveforms and amplitudes at each device under the action of backflash lightning and lightning bypass overvoltage under different installation methods, and to check the insulation coordination of each device.
4. The method for simulation analysis of the influence of surge arrester cutoff characteristics on lightning intrusion waves according to claim 2, characterized in that: The simulation model includes electrical equipment models, cable models, and surge arrester module models.
5. The method for simulation analysis of the influence of surge arrester cutoff characteristics on lightning intrusion waves according to claim 3, characterized in that: The insulation coordination of electrical equipment should be checked. When calculating the insulation coordination margin for lightning overvoltage, the effect of aging on the withstand voltage of the equipment should be considered. The degradation factor should be calculated according to the external insulation degradation factor of 1.05 recommended by IEC60071.