Method, device, medium and product for determining transient voltage drop of marine island power transformer

Abstract

The embodiment of the application discloses a kind of marine island power transformer transient voltage drop determination method, equipment, medium and product, comprising: obtaining power supply capacity influence factor and the internal impedance of power transformer;When power transformer is not no-load, the impedance of power transformer with load and the phase angle with load are obtained;The impedance of power transformer to be connected load and the phase angle to be connected load are obtained;According to power supply capacity influence factor, the internal impedance of power transformer, the impedance of to-be-connected load, the phase angle of to-be-connected load, the impedance with load and the phase angle with load, the transient voltage drop of power transformer is determined after to-be-connected load is connected to the power supply loop of power transformer.The method considers the influence of the power supply capacity of the upstream power supply with limited capacity on transient voltage drop, thereby, the accuracy of the determined transient voltage drop is improved.

Description

Technical Field

[0001] This invention relates to the field of marine power transformer technology, and in particular to a method, equipment, medium, and product for determining transient voltage drop of a marine island power transformer. Background Technology

[0002] With the increasing electrification of large ships, many vessels now employ a design approach where generators first supply power to power transformers, which then supply power to large loads. The transient voltage drop phenomenon of a power transformer refers to the brief, rapid decrease in its secondary voltage when subjected to a sudden change in load. Here, "large load" refers to a load with a power exceeding a certain power threshold. In engineering, it is necessary to quantify the transient voltage drop of the power transformer to assess whether it remains within acceptable limits.

[0003] Among related technologies, only the land-based calculation method is used to calculate the transient voltage drop of a power transformer under heavy load. In this calculation, the upstream power source of the power transformer is idealized and assumed to be an infinitely large power grid.

[0004] However, the land-based calculation method is not applicable to ships because ships are powered by generators with limited capacity and are considered as isolated power plants. Using existing transient voltage drop calculation methods would result in low accuracy. Summary of the Invention

[0005] This invention provides a method, equipment, medium, and product for determining transient voltage drop of a marine island power transformer, in order to solve the technical problem of low accuracy caused by the use of existing transient voltage drop calculation methods in related technologies.

[0006] According to one aspect of the present invention, a method for determining the transient voltage drop of a marine islanding power transformer is provided, the method comprising:

[0007] Obtain the power supply capacity influence factor and the internal impedance of the power transformer; wherein, the power supply capacity influence factor is used to characterize the degree of influence of the power supply capacity of the upstream power source supplying power to the power transformer on the transient voltage drop of the power transformer;

[0008] When the power transformer is not unloaded, obtain the impedance of the power transformer under load and the phase angle of the under load;

[0009] Obtain the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected;

[0010] Based on the power supply capacity influence factor, the internal impedance of the power transformer, the impedance of the load to be connected, the phase angle of the load to be connected, the impedance of the already connected load, and the phase angle of the already connected load, the transient voltage drop of the power transformer after the load to be connected is determined.

[0011] According to another aspect of the present invention, a device for determining transient voltage drop of a marine islanding power transformer is provided, the device comprising:

[0012] The first acquisition module is used to acquire the power supply capacity influence factor and the internal impedance of the power transformer; wherein, the power supply capacity influence factor is used to characterize the degree of influence of the power supply capacity of the upstream power supply supplying the power transformer on the transient voltage drop of the power transformer.

[0013] The second acquisition module is used to acquire the impedance of the power transformer under load and the phase angle of the load when the power transformer is not unloaded.

[0014] The third acquisition module is used to acquire the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected;

[0015] The first determining module is used to determine the transient voltage drop of the power transformer after the load to be connected to the power supply circuit of the power transformer, based on the power capacity influence factor, the internal impedance of the power transformer, the impedance of the load to be connected, the phase angle of the load to be connected, the impedance of the already connected load, and the phase angle of the already connected load.

[0016] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0017] At least one processor; and

[0018] A memory communicatively connected to the at least one processor; wherein,

[0019] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the transient voltage drop determination method for marine island power transformers according to any embodiment of the present invention.

[0020] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, the computer program being configured to cause a processor to execute and implement the transient voltage drop determination method for a marine islanding power transformer according to any embodiment of the present invention.

[0021] According to another aspect of the present invention, a computer program product is provided, comprising a computer program that, when executed by a processor, implements the transient voltage drop determination method for marine islanded power transformers as described in any embodiment of the present invention.

[0022] The technical solution of this invention includes: obtaining a power supply capacity influence factor and the internal impedance of a power transformer, wherein the power supply capacity influence factor is used to characterize the degree of influence of the power supply capacity of the upstream power source supplying power to the power transformer on the transient voltage drop of the power transformer; when the power transformer is not unloaded, obtaining the impedance of the power transformer under load and the phase angle of the load under load; obtaining the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected; and determining the transient voltage drop of the power transformer after the load to be connected is connected to the power supply circuit of the power transformer based on the power supply capacity influence factor, the internal impedance of the power transformer, the impedance of the load to be connected, the phase angle of the load to be connected, the impedance of the load under load, and the phase angle of the load under load. It has the following technical advantages: First, in determining the transient voltage drop of an isolated power transformer, the influence factor of power supply capacity is taken into account, which is equivalent to taking into account the influence of the power supply capacity of the upstream power source with limited capacity on the transient voltage drop, thereby improving the accuracy of the determined transient voltage drop. Second, when the power transformer is not unloaded, in determining the transient voltage drop of the power transformer, the influence of the impedance of the load and the phase angle of the load on the transient voltage drop is taken into account, thereby further improving the accuracy of the determined transient voltage drop.

[0023] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart of a method for determining the transient voltage drop of a marine island power transformer provided in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the power transformer power supply topology provided in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the circuit model of the power transformer provided in an embodiment of the present invention;

[0028] Figure 4 This is a flowchart of another method for determining the transient voltage drop of a marine island power transformer provided in an embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of a device for determining the transient voltage drop of a marine island power transformer provided in an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the electronic device for implementing the transient voltage drop determination method of a marine islanded power transformer according to an embodiment of the present invention. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0032] It should be noted that the term "comprising" and any variations thereof in the specification, claims, and accompanying drawings of this invention are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices. The acquisition, storage, use, and processing of data in the embodiments of this invention comply with the relevant provisions of national laws and regulations.

[0033] Figure 1 This is a flowchart illustrating a method for determining the transient voltage drop of a marine islanding power transformer according to an embodiment of the present invention. This embodiment is applicable to scenarios where the transient voltage drop of a marine power transformer is determined after a load to be connected to the power supply circuit of the transformer. This method can be executed by a device for determining the transient voltage drop of a marine islanding power transformer, which can be implemented in hardware and / or software. This device can be configured in a determining device. In this embodiment, the determining device can be an electronic device, such as a computer device. Figure 1 As shown, the method includes the following steps 101 to 104.

[0034] Step 101: Obtain the power supply capacity influence factor and the internal impedance of the power transformer.

[0035] Among them, the power supply capacity influence factor is used to characterize the degree of influence of the power supply capacity of the upstream power source supplying power to the power transformer on the transient voltage drop of the power transformer.

[0036] In this embodiment, the power transformer is a power transformer installed on a ship. Of course, the power transformer in this embodiment could also be a power transformer installed on other mobile devices, such as a power transformer installed on a vehicle. As long as the power transformer is essentially an islanded power transformer, its transient voltage drop can be determined using the transient voltage drop determination method provided in this embodiment. In this embodiment, an islanded power transformer refers to a power transformer in a local power grid that is disconnected from the main power grid on land and operates independently.

[0037] In this embodiment, the upstream power source is an islanded power source. The upstream power source generates electrical energy. The power transformer obtains electrical energy from the upstream power source to supply power to the downstream load. For example, the upstream power source in this embodiment can be a marine generator. More specifically, the marine generator in this embodiment can include at least one of the following: a diesel generator, a gas turbine generator, and a gas-fueled generator.

[0038] Shipboard power transformers and generators, being islanded power sources, differ from land-based power sources. Sudden changes in the load conditions of the power transformers will inevitably cause impacts. Currently, there are no theoretically sound methods for calculating the transient voltage drop of such impacts. This embodiment provides a method for determining the transient voltage drop of a shipboard islanded power transformer to address this problem.

[0039] Figure 2 This is a schematic diagram of the power transformer power supply topology provided in an embodiment of the present invention. Figure 2 As shown, 1G and 2G represent the upstream power sources that supply power to the power transformer. This represents the impedance of the load to be connected to the power transformer. This indicates the impedance of the power transformer under load. When switch 21 is open, it means that the load to be connected is not connected to the power transformer's power supply circuit; when switch 22 is closed, it means that the load to be connected is connected to the power transformer's power supply circuit.

[0040] Figure 2 The example provided uses an AC power frequency of 60Hz in an AC power distribution network. Of course, the AC power frequency can be other frequencies, and this embodiment is not limited to this.

[0041] Figure 2 In this context, TR represents a power transformer. This represents the effective value of the voltage on the primary side of the power transformer. This represents the effective value of the steady-state voltage on the secondary side of the power transformer before the load to be connected to the power supply circuit of the power transformer.

[0042] When the load on a power transformer changes, the upstream power source, being a limited capacity source, will affect the transient voltage drop of the power transformer. In this embodiment, a power supply capacity influence factor is obtained. This factor characterizes the degree to which the capacity of the upstream power source supplying the power transformer affects its transient voltage drop.

[0043] Optionally, the power supply capacity influencing factor can be determined by the non-operation characteristic coefficient of the protective circuit breaker of the power transformer. Alternatively, the power supply capacity influencing factor can be determined by the non-operation characteristic coefficient of the protective circuit breaker of the power transformer, the steady-state short-circuit current of the primary side of the power transformer, and the steady-state short-circuit current of the upstream power source.

[0044] Optionally, the power capacity influence factor in this embodiment can be a pre-determined parameter. In step 101, the power capacity influence factor can be obtained from local storage space or other devices.

[0045] The internal impedance of a power transformer also affects its transient voltage drop. Therefore, in step 101, it is also necessary to obtain the internal impedance of the power transformer from local storage space or other devices.

[0046] Step 102: When the power transformer is not unloaded, obtain the impedance of the power transformer under load and the phase angle of the load.

[0047] In this embodiment, "loaded" refers to a load that is already connected to the power supply circuit of the power transformer. For example, the "loaded" load in this embodiment can be an inductive load, such as a motor.

[0048] The impedance and phase angle of the power transformer under load can be predetermined parameters. In step 102, these two parameters are obtained from local storage or other devices.

[0049] In this embodiment, the impedance and phase angle of the loaded circuit can be theoretically calculated using the design parameters of the loaded circuit, or obtained through actual measurement. The impedance of the loaded circuit can also be referred to as the equivalent impedance.

[0050] In one implementation, the load is an inductive load. Step 102 may include: determining the impedance of the power transformer under load and the phase angle of the load based on the equivalent inductive reactance, equivalent resistance, and angular frequency of the power grid.

[0051] Furthermore, according to the formula Determine the impedance of the load using the formula. Determine the phase angle of the loaded circuit. This indicates the impedance already under load. This represents the equivalent resistance under load. This indicates the equivalent inductive reactance already under load. Represents the angular frequency of the power grid. This indicates the phase angle under load.

[0052] Step 103: Obtain the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected.

[0053] In this embodiment, the load to be connected refers to the load that will be connected to the power supply circuit of the power transformer. For example, the load to be connected in this embodiment can be an inductive load, such as a motor.

[0054] The impedance and phase angle of the load to be connected to the power transformer can be predetermined parameters. In step 103, these two parameters are obtained from local storage or other devices.

[0055] In this embodiment, the impedance and phase angle of the load to be connected can be obtained theoretically through the design parameters of the load to be connected, or through actual measurement. The impedance of the load to be connected can also be called the equivalent impedance.

[0056] In one implementation, the load to be connected is an inductive load. Step 103 may include: determining the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected based on the equivalent inductive reactance, the equivalent resistance of the load to be connected, and the angular frequency of the power grid.

[0057] Furthermore, according to the formula Determine the impedance of the load to be connected, according to the formula. Determine the phase angle of the load to be connected. Among them, This indicates the impedance of the load to be connected. This represents the equivalent resistance of the load to be connected. This represents the equivalent inductive reactance of the load to be connected. Represents the angular frequency of the power grid. This indicates the phase angle of the load to be connected.

[0058] Step 104: Based on the power supply capacity influence factor, the internal impedance of the power transformer, the impedance of the load to be connected, the phase angle of the load to be connected, the impedance of the already connected load, and the phase angle of the already connected load, determine the transient voltage drop of the power transformer after the load to be connected is connected to the power supply circuit of the power transformer.

[0059] In this embodiment, the transient voltage drop refers to the transient voltage drop caused by the impact of the load to the secondary busbar of the power transformer. The voltage drop in this embodiment can also be called voltage drop.

[0060] In one implementation, the transient voltage drop of a power transformer can be determined using a pre-trained machine learning model. The power supply capacity influence factor, the internal impedance of the power transformer, the impedance of the load to be connected, the phase angle of the load to be connected, the impedance of the already connected load, and the phase angle of the already connected load are input into the machine learning model to obtain the transient voltage drop of the power transformer output by the model.

[0061] In another implementation, according to the formula:

[0062] To determine the transient voltage drop of the power transformer. Among them, This indicates the transient voltage drop of a power transformer. This indicates the power supply capacity influencing factor. This represents the internal impedance of a power transformer. This indicates the impedance of the load to be connected. This indicates the phase angle of the load to be connected. This indicates the impedance already under load. This indicates the phase angle under load.

[0063] The derivation process of the formula for determining the transient voltage drop is described below.

[0064] Figure 3 This is a schematic diagram of the circuit model of the power transformer provided in an embodiment of the present invention. Figure 3 This example uses inductive loads, both the existing load and the load to be connected, as an example. The following description is based on... Figure 3 The circuit model is used to analyze and derive the effective value of the transient voltage drop at the power transformer terminal when the ship's power transformer is used as a power source to directly supply power to the load to be connected, and a more general calculation method is designed.

[0065] Power transformer TR, secondary busbar 31 of power transformer TR, primary busbar 32 of power transformer TR, etc. Figure 3 As shown. This represents the effective value of the voltage on the primary side of the power transformer. This represents the effective value of the steady-state voltage on the secondary side of the power transformer before the load to be connected to the power supply circuit of the power transformer. This represents the internal impedance of a power transformer. The equivalent inductive reactance under load. Equivalent resistance under load The equivalent inductive reactance of the load to be connected The equivalent resistance of the load to be connected like Figure 3 As shown. Switch 33 represents the trigger signal for starting the load to be connected. The initial state is open, and when the load to be connected is started, switch 33 is closed.

[0066] The impact of a load starting on the secondary side of a power transformer is a transient process, and the influence of line impedance can be ignored. By closing switch 33, the load is connected to the power transformer's power supply circuit, and the impedance of the load will play a significant role in the impact on the circuit.

[0067] Will Figure 3 The circuit model shown is converted into an equivalent transient voltage drop mathematical model algorithm. The input parameters required by this algorithm include the capacity of the power supply to the power transformer, the impedance and electrical parameters of the load connected to the power transformer, and the parameters of the power transformer itself related to transient analysis.

[0068] According to the definition of pressure drop: .in, This represents the transient voltage drop in this embodiment. It is the average effective value of the voltage on the secondary busbar of the power transformer from the time the load is connected to the power transformer's power supply circuit until it reaches a stable state. It is the effective value of the steady-state voltage on the secondary side of the power transformer before the load to be connected to the power supply circuit of the power transformer.

[0069] The starting capacity of the power transformer supplying the load: .in, This refers to the average current flowing through the circuit of the load to be connected during the start-up process.

[0070] During the startup process of the load to be received. It can also be expressed as: .in, The current is the current already under load. This is the internal impedance of the power transformer.

[0071] based on Figure 3 The circuit model shown establishes a calculation model for the transient voltage drop on the secondary side of the power transformer when the load to be connected starts: When switch 33 is closed, the load to be connected is connected to the power supply circuit of the power transformer, which is equivalent to a zero-state response circuit.

[0072] ; .

[0073] in, , , Peak voltage, This is the angular frequency of the power grid, also known as the common frequency of the power grid. Let be the initial phase angle of the voltage.

[0074] .

[0075] Solving equations (4) and (6), we get:

[0076] ;

[0077] ;

[0078] .

[0079] Among them, the phase angle of the load to be connected time constant The impedance of the load to be connected. The phase angle of the load is already set. time constant Impedance already under load .

[0080] Substituting formulas (7) and (8) into formula (3), we get:

[0081] .

[0082] Substituting formula (9) into formula (1):

[0083] .

[0084] To determine the maximum value of the pressure drop, let We can obtain:

[0085] .

[0086] To determine the maximum pressure drop, let At the same time, the time constant as well as In general, since the effective resistance of an inductive load approaches zero, the time constant is... as well as Approaching infinity, therefore, as well as Approaching 0, and thus, as well as All are equal to 1.

[0087] Therefore, we can obtain .

[0088] Ultimately obtainable .

[0089] After considering the power supply capacity factor, we can obtain:

[0090] .

[0091] In the above implementation process, the transient voltage drop of power transformers in islanded power supply is modeled. A transient voltage drop calculation method applicable to ship power transformers is obtained. Subsequently, this algorithm can be used to rationally select and design the ship's power station capacity, transformer capacity, and load equipment, thereby improving the stability of the power system operation and the ability to prevent potential fault risks.

[0092] The method for determining the transient voltage drop of a marine island power transformer provided in this invention includes: obtaining a power supply capacity influence factor and the internal impedance of the power transformer, wherein the power supply capacity influence factor is used to characterize the degree of influence of the power supply capacity of the upstream power source supplying power to the power transformer on the transient voltage drop of the power transformer; when the power transformer is not unloaded, obtaining the impedance of the power transformer under load and the phase angle of the load under load; obtaining the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected; and determining the transient voltage drop of the power transformer after the load to be connected is connected to the power supply circuit of the power transformer based on the power supply capacity influence factor, the internal impedance of the power transformer, the impedance of the load to be connected, the phase angle of the load to be connected, the impedance of the load under load, and the phase angle of the load under load. It has the following technical advantages: First, in determining the transient voltage drop of an isolated power transformer, the influence factor of power supply capacity is taken into account, which is equivalent to taking into account the influence of the power supply capacity of the upstream power source with limited capacity on the transient voltage drop, thereby improving the accuracy of the determined transient voltage drop. Second, when the power transformer is not unloaded, in determining the transient voltage drop of the power transformer, the influence of the impedance of the load and the phase angle of the load on the transient voltage drop is taken into account, thereby further improving the accuracy of the determined transient voltage drop.

[0093] Figure 4 This is a flowchart of another method for determining the transient voltage drop of a marine islanding power transformer provided in this embodiment of the invention. The method for determining the transient voltage drop of a marine islanding power transformer provided in this embodiment... Figure 1 Based on the illustrated embodiments and various optional implementations, this paper provides a detailed explanation of how to determine the power supply capacity influence factor and how to determine the transient voltage drop of the power transformer when it is unloaded. Figure 4 As shown, the method for determining the transient voltage drop of a marine island power transformer provided in this embodiment includes the following steps 401 to 409.

[0094] Step 401: If the steady-state short-circuit current of the upstream power source is greater than or equal to the steady-state short-circuit current of the primary side of the power transformer, then divide 1 by the quotient of the non-operation characteristic coefficient of the protection circuit breaker of the power transformer, and determine it as the power supply capacity influence factor.

[0095] Before step 401, the method provided in this embodiment further includes the following step: determining the steady-state short-circuit current of the upstream power source by multiplying the rated current of the upstream power source by a preset coefficient. The preset coefficient is a number greater than 1.

[0096] For example, electrical protection characteristics require that the upstream power source of the ship's power transformer must be able to continuously output a steady-state short-circuit current value that meets 2.5 to 3 times the rated current.

[0097] ,in, This refers to the steady-state short-circuit current of the upstream power source. This is the rated current of the upstream power source. In this example, the preset factor is 3.

[0098] Optionally, before step 401, the method provided in this embodiment further includes the following step: determining the quotient of the rated current of the primary side of the power transformer and the internal impedance of the power transformer as the steady-state short-circuit current of the primary side of the power transformer.

[0099] The impedance and rated current of an isolated power transformer together determine the output capacity of the steady-state short-circuit current on the primary side of the transformer: ,in, This refers to the steady-state short-circuit current on the primary side of the power transformer. This is the rated current of the primary side of the power transformer.

[0100] In step 401, when the steady-state short-circuit current of the upstream power source is greater than or equal to the steady-state short-circuit current of the primary side of the power transformer, i.e. At this time, the islanded power transformer has sufficient power to maintain supply. Therefore, complete selective protection between the upstream power source and the power transformer should be further considered. The protective circuit breaker of the power transformer has... The inactive characteristic is defined as follows: 'a' represents the inactive characteristic coefficient, which is a value greater than 1. For example, 'a' can be 1.2. In this scenario, a power capacity influence factor is defined. When a is 1.2, .

[0101] Step 402: If the steady-state short-circuit current of the upstream power source is less than the steady-state short-circuit current of the primary side of the power transformer, then the quotient of 1 divided by the non-operation characteristic coefficient of the protection circuit breaker of the power transformer is determined as the first factor, and the quotient of the steady-state short-circuit current of the primary side of the power transformer divided by the steady-state short-circuit current of the upstream power source is determined as the second factor.

[0102] Step 403: The product of the first factor and the second factor is determined as the power capacity influence factor.

[0103] When the steady-state short-circuit current of the upstream power source is less than the steady-state short-circuit current of the primary side of the power transformer, that is... At that time, since the protection of the upstream power source takes priority over the power transformer, it is necessary to consider the actual achievable protection. The nominal "rated value" of the power transformer is derived from this reference. At this point, it's necessary to consider incorporating the upstream power source's capacity parameters into the power transformer's impedance, effectively resulting in a new impedance value for the power transformer. At this point, the power supply capacity influence factor is: .

[0104] Step 404: Obtain the power supply capacity influence factor and the internal impedance of the power transformer.

[0105] Among them, the power supply capacity influence factor is used to characterize the degree of influence of the power supply capacity of the upstream power source supplying power to the power transformer on the transient voltage drop of the power transformer.

[0106] Step 405: When the power transformer is not unloaded, obtain the impedance of the power transformer under load and the phase angle of the load.

[0107] Step 406: Obtain the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected.

[0108] Step 407: Based on the power supply capacity influence factor, the internal impedance of the power transformer, the impedance of the load to be connected, the phase angle of the load to be connected, the impedance of the already connected load, and the phase angle of the already connected load, determine the transient voltage drop of the power transformer after the load to be connected is connected to the power supply circuit of the power transformer.

[0109] The implementation process and technical principles of steps 404, 405, 406, 103, 407, and 104 are similar and will not be repeated here.

[0110] Step 408: When the power transformer is unloaded, obtain the impedance of the load to be connected to the power transformer.

[0111] Step 409: Based on the power supply capacity influence factor, the internal impedance of the power transformer, and the impedance of the load to be connected, determine the transient voltage drop of the power transformer after the load to be connected is connected to the power supply circuit of the power transformer.

[0112] Optionally, according to the formula To determine the transient voltage drop of the power transformer. Among them, This indicates the transient voltage drop of a power transformer. This indicates the power supply capacity influencing factor. This represents the internal impedance of a power transformer. This indicates the impedance of the load to be connected.

[0113] based on Figure 1 In the embodiment shown, formula (10) is used when the power transformer is unloaded. As it approaches infinity, therefore, from formula (10) we get: After considering the influence factor of power supply capacity, It can be understood that formula (10) is the general solution and formula (11) is the special solution.

[0114] The method for determining the transient voltage drop of a marine island power transformer provided in this embodiment has two main advantages. Firstly, it addresses the relative magnitudes of the steady-state short-circuit current of the upstream power source and the steady-state short-circuit current of the power transformer's primary side by employing different methods to obtain the power capacity influence factor. This improves the accuracy of the obtained power capacity influence factor, and consequently, further enhances the accuracy of the determined transient voltage drop. Secondly, it considers the determination method for the transient voltage drop under no-load conditions of the power transformer, expanding the application scenarios of this method.

[0115] In summary, the method for determining the transient voltage drop of a marine island power transformer provided in this embodiment uses circuit transient analysis to mathematically model the transient voltage drop supplied by the island power transformer. By introducing the power capacity of the upstream power source supplying the island transformer, its influence is fed back into the transient voltage drop mathematical model, resulting in a more accurate and practical marine mathematical model than the empirical calculation formula used on land.

[0116] Figure 5 This is a schematic diagram of a device for determining the transient voltage drop of a marine island power transformer, provided in an embodiment of the present invention. Figure 5 As shown, the transient voltage drop determination device for marine island power transformers provided in this embodiment includes the following modules: a first acquisition module 51, a second acquisition module 52, a third acquisition module 53, and a first determination module 54.

[0117] The first acquisition module 51 is used to acquire the power supply capacity influence factor and the internal impedance of the power transformer.

[0118] The power supply capacity influence factor is used to characterize the degree of influence of the power supply capacity of the upstream power source supplying the power transformer on the transient voltage drop of the power transformer.

[0119] The second acquisition module 52 is used to acquire the impedance of the power transformer under load and the phase angle of the load when the power transformer is not unloaded.

[0120] The third acquisition module 53 is used to acquire the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected.

[0121] The first determining module 54 is used to determine the transient voltage drop of the power transformer after the load to be connected to the power supply circuit of the power transformer based on the power capacity influence factor, the internal impedance of the power transformer, the impedance of the load to be connected, the phase angle of the load to be connected, the impedance of the load already connected, and the phase angle of the load already connected.

[0122] In one embodiment, the device further includes a fourth acquisition module and a second determination module.

[0123] The fourth acquisition module is used to acquire the impedance of the load to be connected to the power transformer when the power transformer is unloaded.

[0124] The second determining module is used to determine the transient voltage drop of the power transformer after the load to be connected to the power supply circuit of the power transformer, based on the power capacity influence factor, the internal impedance of the power transformer, and the impedance of the load to be connected.

[0125] In one embodiment, the device further includes a third determining module, a fourth determining module, and a fifth determining module.

[0126] The third determining module is used to determine the power supply capacity influence factor by dividing 1 by the quotient of the non-operation characteristic coefficient of the protection circuit breaker of the power transformer if the steady-state short-circuit current of the upstream power source is greater than or equal to the steady-state short-circuit current of the primary side of the power transformer.

[0127] The fourth determining module is used to determine the first factor by dividing 1 by the non-operation characteristic coefficient of the protection circuit breaker of the power transformer if the steady-state short-circuit current of the upstream power source is less than the steady-state short-circuit current of the primary side of the power transformer, and to determine the second factor by dividing the steady-state short-circuit current of the primary side of the power transformer by the steady-state short-circuit current of the upstream power source.

[0128] The fifth determining module is used to determine the product of the first factor and the second factor as the power supply capacity influence factor.

[0129] In one embodiment, the device further includes a sixth determining module and a seventh determining module.

[0130] The sixth determining module is used to determine the steady-state short-circuit current of the upstream power supply by multiplying the rated current of the upstream power supply by a preset coefficient. The preset coefficient is a number greater than 1.

[0131] The seventh determining module is used to determine the quotient of the rated current of the primary side of the power transformer and the internal impedance of the power transformer as the steady-state short-circuit current of the primary side of the power transformer.

[0132] In one embodiment, the first determining module 54 is specifically used for:

[0133] According to the formula The transient voltage drop of the power transformer is determined. This represents the transient voltage drop of the power transformer. This represents the power supply capacity influence factor. This represents the internal impedance of the power transformer. This indicates the impedance of the load to be connected. This indicates the phase angle of the load to be connected. This indicates the impedance already under load. This indicates the phase angle of the loaded phase angle.

[0134] In one embodiment, the second determining module is specifically used for:

[0135] According to the formula The transient voltage drop of the power transformer is determined. This represents the transient voltage drop of the power transformer. This represents the power supply capacity influence factor. This represents the internal impedance of the power transformer. This represents the impedance of the load to be connected.

[0136] In one embodiment, both the loaded load and the load to be connected are inductive loads. The device also includes an eighth determination module and a ninth determination module.

[0137] The eighth determining module is used to determine the impedance of the power transformer under load and the phase angle of the load based on the equivalent inductive reactance of the load, the equivalent resistance of the load, and the angular frequency of the power grid.

[0138] The ninth determining module is used to determine the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected based on the equivalent inductive reactance of the load to be connected, the equivalent resistance of the load to be connected, and the angular frequency of the power grid.

[0139] The transient voltage drop determination device for marine islanded power transformers provided in this embodiment of the invention can execute the transient voltage drop determination method for marine islanded power transformers provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0140] Figure 6This is a schematic diagram of the structure of an electronic device implementing the transient voltage drop determination method for a marine islanding power transformer according to an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0141] like Figure 6 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 can also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0142] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0143] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the transient voltage drop determination method for marine islanded power transformers.

[0144] In some embodiments, the method for determining the transient voltage drop of a marine islanding power transformer can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the method for determining the transient voltage drop of a marine islanding power transformer described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the method for determining the transient voltage drop of a marine islanding power transformer by any other suitable means (e.g., by means of firmware).

[0145] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0146] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0147] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0148] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0149] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0150] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0151] This invention also provides a computer program product, including a computer program that, when executed by a processor, implements the transient voltage drop determination method for marine island power transformers as provided in any embodiment of this invention.

[0152] In the implementation of a computer program product, computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. Programming languages ​​include object-oriented programming languages ​​as well as conventional procedural programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0153] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0154] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for determining the transient voltage drop of a marine islanding power transformer, characterized in that, The method includes: Obtain the power supply capacity influence factor and the internal impedance of the power transformer; wherein, the power supply capacity influence factor is used to characterize the degree of influence of the power supply capacity of the upstream power source supplying power to the power transformer on the transient voltage drop of the power transformer; When the power transformer is not unloaded, obtain the impedance of the power transformer under load and the phase angle of the under load; Obtain the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected; Based on the power capacity influence factor, the internal impedance of the power transformer, the impedance of the load to be connected, the phase angle of the load to be connected, the impedance of the already connected load, and the phase angle of the already connected load, the transient voltage drop of the power transformer after the load to be connected is determined. When the power transformer is unloaded, obtain the impedance of the load to be connected to the power transformer; Based on the power supply capacity influence factor, the internal impedance of the power transformer, and the impedance of the load to be connected, determine the transient voltage drop of the power transformer after the load to be connected is connected to the power supply circuit of the power transformer. Before obtaining the power capacity influence factor, the method further includes: If the steady-state short-circuit current of the upstream power source is greater than or equal to the steady-state short-circuit current of the primary side of the power transformer, then the quotient of 1 divided by the non-operation characteristic coefficient of the protection circuit breaker of the power transformer is determined as the power source capacity influence factor. If the steady-state short-circuit current of the upstream power source is less than the steady-state short-circuit current of the primary side of the power transformer, then the quotient of 1 divided by the non-operation characteristic coefficient of the protection circuit breaker of the power transformer is determined as the first factor, and the quotient of the steady-state short-circuit current of the primary side of the power transformer divided by the steady-state short-circuit current of the upstream power source is determined as the second factor; the product of the first factor and the second factor is determined as the power supply capacity influence factor.

2. The method according to claim 1, characterized in that, The method further includes: The product of the rated current of the upstream power source and a preset coefficient is determined as the steady-state short-circuit current of the upstream power source; wherein, the preset coefficient is a number greater than 1. The quotient of the rated current on the primary side of the power transformer and the internal impedance of the power transformer is determined as the steady-state short-circuit current on the primary side of the power transformer.

3. The method according to claim 1 or 2, characterized in that, The step of determining the transient voltage drop of the power transformer after the load to be connected to the power supply circuit of the power transformer, based on the power capacity influence factor, the internal impedance of the power transformer, the impedance of the load to be connected, the phase angle of the load to be connected, the impedance of the already connected load, and the phase angle of the already connected load, includes: According to the formula Determine the transient voltage drop of the power transformer; wherein, This represents the transient voltage drop of the power transformer. This represents the power supply capacity influence factor. This represents the internal impedance of the power transformer. This indicates the impedance of the load to be connected. This indicates the phase angle of the load to be connected. This indicates the impedance already under load. This indicates the phase angle of the loaded phase angle.

4. The method according to claim 1, characterized in that, The step of determining the transient voltage drop of the power transformer after the load to be connected to the power supply circuit of the power transformer, based on the power capacity influence factor, the internal impedance of the power transformer, and the impedance of the load to be connected, includes: According to the formula Determine the transient voltage drop of the power transformer; wherein, This represents the transient voltage drop of the power transformer. This represents the power supply capacity influence factor. This represents the internal impedance of the power transformer. This represents the impedance of the load to be connected.

5. The method according to claim 1 or 2, characterized in that, Both the loaded load and the load to be connected are inductive loads; Before obtaining the impedance of the power transformer under load and the phase angle of the load, the method further includes: Based on the equivalent inductive reactance of the load, the equivalent resistance of the load, and the angular frequency of the power grid, determine the impedance of the power transformer under load and the phase angle of the load. Before obtaining the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected, the method further includes: Based on the equivalent inductive reactance of the load to be connected, the equivalent resistance of the load to be connected, and the angular frequency of the power grid, the impedance of the load to be connected to the power transformer and the phase angle of the load to be connected are determined.

6. An electronic device, characterized in that, The electronic device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the method for determining transient voltage drop of a marine island power transformer as described in any one of claims 1 to 5.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method for determining transient voltage drop of a marine island power transformer as described in any one of claims 1 to 5.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for determining transient voltage drop of a marine island power transformer as described in any one of claims 1 to 5.

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