Ac-dc complementary resonance detection method and device, storage medium and computer device

Abstract

The application provides a kind of AC-DC complementary resonance detection method, device, storage medium and computer equipment.The method comprises: obtaining the system stability parameter model of DC power transmission system;Obtain the AC harmonic impedance curve and AC impedance phase angle curve of AC side in the preset first frequency range;Obtain the DC harmonic impedance curve and DC impedance phase angle curve of DC side in the preset second frequency range;Calculate the trigger angle and commutation overlap angle of converter when DC side works at target power;Using system stability parameter model, calculate system stability parameter;If system stability parameter is less than 0, it is determined that there is complementary resonance risk when system works at target power, and AC side works at first target frequency, and DC side works at second target frequency.The application can analyze the operation risk of system in advance.

Description

Technical Field

[0001] This application relates to the field of DC power transmission technology, and in particular to an AC / DC complementary resonance detection method, device, storage medium, and computer equipment. Background Technology

[0002] When a conventional DC transmission system is in operation, based on the modulation effect of the converter, the harmonics on both sides of the converter (i.e., the DC side and the AC side) can be repeatedly transmitted to each other. The key to achieving this repeated transmission is the fundamental frequency impedance on the DC side and the second harmonic impedance on the AC side.

[0003] If the fundamental frequency impedance on the DC side is low, the fundamental frequency harmonic voltage will generate a large fundamental frequency harmonic current on the DC side. This current, after modulation by the converter, will generate a large second-sequence harmonic current on the AC side. If the second-sequence harmonic impedance on the AC side is high, the second-sequence harmonic current will generate a large second-sequence harmonic voltage. This results in a gradually increasing second-sequence harmonic component on the AC side and a gradually increasing power frequency component on the DC side during repeated transmission, leading to harmonic instability, i.e., AC / DC complementary resonance, and consequently, system instability. Currently, conventional complementary resonance detection is based on post-hoc analysis, which is not conducive to ensuring system stability. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, device, storage medium, and computer equipment for detecting AC / DC complementary resonance that can perform pre-analysis, addressing the aforementioned technical problems.

[0005] This application provides a method for detecting AC / DC complementary resonance, the method comprising:

[0006] Obtain the system stability parameter model of the DC transmission system;

[0007] Obtain the AC harmonic impedance curve and AC impedance phase angle curve on the AC side within a preset first frequency range;

[0008] Obtain the DC harmonic impedance curve and DC impedance phase angle curve on the DC side within a preset second frequency range; the upper limit of the second frequency range is the upper limit of the first frequency range minus the power frequency.

[0009] Calculate the firing angle and commutation overlap angle of the converter when the DC side is operating at the target power.

[0010] Using the system stability parameter model, the system stability parameters are calculated based on the firing angle, the commutation overlap angle, the AC harmonic impedance and AC impedance phase angle at the first target frequency, and the DC harmonic impedance and DC impedance phase angle at the second target frequency; the difference between the first target frequency and the second target frequency is equal to the power frequency; the first target frequency is any frequency in the first frequency range, and the second target frequency is any frequency in the second frequency range;

[0011] If the system stability parameter is less than 0, then it is determined that when the system is at the target power and operates at the first target frequency on the AC side and the second target frequency on the DC side, there is a risk of complementary resonance.

[0012] In one embodiment, the system stability parameter model is:

[0013]

[0014] Among them, Z acnx For negative-sequence AC harmonic impedance, Z acpx For positive-sequence AC harmonic impedance, Z acp Z is the sum of the positive-sequence AC harmonic impedance and the impedance of the transformer in the DC transmission system. acn Z is the sum of the negative-sequence AC harmonic impedance and the AC side impedance of the transformer in the DC transmission system. dcn Where is the DC-side impedance of the transformer, N is the transformer turns ratio, A is the transfer coefficient of the converter in the DC transmission system, α0 is the firing angle of the converter, μ0 is the commutation overlap angle of the converter, and L... m X is the equivalent reactance of the transformer, and X is the transformer saturation coefficient.

[0015] In one embodiment, the transfer coefficient of the converter is calculated according to the following formula:

[0016]

[0017] Where μ0 is the commutation overlap angle of the converter.

[0018] In one embodiment, obtaining the AC harmonic impedance curve and AC impedance phase angle curve on the AC side within a preset first frequency range includes:

[0019] Starting from the lower limit of the first frequency range, the AC harmonic impedance and AC impedance phase angle on the AC side are obtained according to a preset step size until the frequency is equal to the upper limit of the first frequency range.

[0020] In one embodiment, obtaining the DC harmonic impedance curve and DC impedance phase angle curve on the DC side within a preset second frequency range includes:

[0021] Starting from the lower limit of the second frequency range, the DC harmonic impedance and DC impedance phase angle on the DC side are obtained according to a preset step size until the frequency is equal to the lower limit of the second frequency range.

[0022] In one embodiment, the preset step size is less than or equal to 1 Hz.

[0023] In one embodiment, calculating the firing angle and commutation overlap angle of the converter when the DC side operates at the target power includes:

[0024] Based on the preset power step size and starting from the initial power, calculate the firing angle and commutation overlap angle of the converter at different target powers;

[0025] The calculation of system stability parameters using the system stability parameter model, based on the firing angle, the commutation overlap angle, the AC harmonic impedance and AC impedance phase angle at the first target frequency, and the DC harmonic impedance and DC impedance phase angle at the second target frequency, includes:

[0026] Starting from the initial power, the system stability parameters are calculated according to the power step size at different target power levels, with the AC side operating at the first target frequency and the DC side operating at the second target frequency.

[0027] This application also provides an AC / DC complementary resonance detection device, comprising:

[0028] The model acquisition module is used to acquire the system stability parameter model of the DC transmission system.

[0029] The AC side parameter acquisition module is used to acquire the AC harmonic impedance curve and AC impedance phase angle curve of the AC side within a preset first frequency range.

[0030] The DC-side parameter acquisition module is used to acquire the DC harmonic impedance curve and DC impedance phase angle curve of the DC side within a preset second frequency range; the upper limit of the second frequency range is the upper limit of the first frequency range minus the power frequency.

[0031] The first calculation module is used to calculate the firing angle and commutation overlap angle of the converter when the DC side is operating at the target power.

[0032] The second calculation module is used to calculate system stability parameters based on the firing angle, the commutation overlap angle, the AC harmonic impedance and AC impedance phase angle at the first target frequency, and the DC harmonic impedance and DC impedance phase angle at the second target frequency using the system stability parameter model; the difference between the first target frequency and the second target frequency is equal to the power frequency; the first target frequency is any frequency in the first frequency range, and the second target frequency is any frequency in the second frequency range;

[0033] The risk assessment module is used to determine whether there is a complementary resonance risk when the system is at the target power and the AC side is operating at the first target frequency and the DC side is operating at the second target frequency, when the system stability parameter is less than 0.

[0034] This application also provides a storage medium storing computer-readable instructions that, when executed by one or more processors, cause the one or more processors to perform the steps of the AC / DC complementary resonance detection method as described in any of the above embodiments.

[0035] This application also provides a computer device, including: one or more processors, and memory;

[0036] The memory stores computer-readable instructions, which, when executed by the one or more processors, perform the steps of the AC / DC complementary resonance detection method as described in any of the above embodiments.

[0037] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0038] The AC / DC complementary resonance detection method, device, storage medium, and computer equipment provided in this application acquire the AC harmonic impedance curve and AC impedance phase angle curve of the AC side in a first frequency range, and the DC harmonic impedance curve and DC impedance phase angle curve of the DC side in a second frequency range. They then calculate the firing angle and commutation overlap angle of the converter when the DC side of the DC transmission system operates at the target power. Based on the system stability parameter model of the DC transmission system, and using the AC harmonic impedance curve, AC impedance phase angle curve, DC harmonic impedance curve, and DC impedance phase angle curve, they calculate whether the system stability parameters are less than 0 when the AC side and DC side operate at different frequencies at the target power. If the system stability parameters are less than 0 when the AC side operates at the first target frequency and the DC side operates at the second target frequency, then a complementary resonance risk is identified. This pre-analysis method acquires the physical parameters of the DC transmission system under different conditions and uses the system stability parameter model for judgment, avoiding detection after a fault occurs. This proactive approach can prevent system faults caused by complementary resonance, thus improving system stability. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart illustrating an AC / DC complementary resonance detection method in one embodiment.

[0041] Figure 2 This is a block diagram of the AC / DC complementary resonant detection device in one embodiment;

[0042] Figure 3 This is a diagram of the internal structure of a computer device in one embodiment. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] like Figure 1 As shown, this application provides an AC / DC complementary resonance detection method, including steps S101 to S106, wherein:

[0045] Step S101: Obtain the system stability parameter model of the DC transmission system.

[0046] The system stability parameter model refers to the equivalent model that the DC transmission system will satisfy when complementary resonance does not occur. Based on the equivalent circuit of the system's positive feedback resonance, the negative sequence current model on the transformer secondary side can be derived:

[0047] I acnt =e -(a+bj)

[0048] Among them, I acntLet a+bj be the negative sequence current on the secondary side of the transformer, where a represents the real part of the change and b represents the imaginary part. a represents the forced decay component, and b represents the periodic component of the sinusoidal change. The system stability parameter model can be obtained by simplifying the above model. Since the simplification methods used in the equivalent treatment differ, the obtained system stability parameter model may also differ. It can be derived based on the considerations of those skilled in the art regarding the parameters affecting system stability.

[0049] Step S102: Obtain the AC harmonic impedance curve and AC impedance phase angle curve of the AC side within the preset first frequency range.

[0050] The preset first frequency range is a pre-defined frequency range that may occur during the operation of the AC side of the DC transmission system. The AC harmonic impedance curve and AC impedance phase angle curve within the first frequency range represent the AC harmonic impedance and AC impedance phase angle that may occur during the operation of the DC transmission system. Specifically, the AC harmonic impedance curve and AC impedance phase angle curve within the first frequency range can be obtained through simulation calculation using AC impedance calculation software.

[0051] Step S103: Obtain the DC harmonic impedance curve and DC impedance phase angle curve on the DC side within the preset second frequency range.

[0052] The upper limit of the second frequency range is the upper limit of the first frequency range minus the power frequency. The preset second frequency range is a pre-defined range of possible frequencies during the operation of the DC side of the DC transmission system. The DC harmonic impedance curve and DC impedance phase angle curve within the second frequency range represent the DC harmonic impedance and DC impedance phase angle that may occur during the operation of the DC transmission system. Specifically, the DC harmonic impedance curve and DC impedance phase angle curve within the second frequency range can be obtained through harmonic impedance scanning.

[0053] Step S104: Calculate the firing angle and commutation overlap angle of the converter when the DC side is operating at the target power.

[0054] The formula for calculating the firing angle of the converter is as follows:

[0055]

[0056] The formula for calculating the commutation overlap angle is as follows:

[0057]

[0058] Among them, U dc U is the DC side voltage. di0 The open-circuit voltage, X c For commutation reactance, I dcE11 is the rated AC valve-side line voltage, where E11 is the DC-side current. The target power is equal to the ratio of the DC-side voltage to the DC-side current.

[0059] Step S105: Using the system stability parameter model, calculate the system stability parameters based on the firing angle, commutation overlap angle, AC harmonic impedance and AC impedance phase angle at the first target frequency, and DC harmonic impedance and DC impedance phase angle at the second target frequency.

[0060] The difference between the first target frequency and the second target frequency is equal to the power frequency; the first target frequency is any frequency within a first frequency range, and the second target frequency is any frequency within a second frequency range. The system stability parameters are calculated using a system stability parameter model. When the system stability parameters are greater than 0, the system is considered to have no complementary resonance risk; when the system stability parameters are less than 0, the system is considered to have complementary resonance risk.

[0061] Step S106: If the system stability parameter is less than 0, it is determined that when the system is at the target power and operates at the first target frequency on the AC side and the second target frequency on the DC side, there is a risk of complementary resonance.

[0062] The AC / DC complementary resonance detection method provided in this application obtains the AC harmonic impedance curve and AC impedance phase angle curve on the AC side within a first frequency range, and the DC harmonic impedance curve and DC impedance phase angle curve on the DC side within a second frequency range. It then calculates the firing angle and commutation overlap angle of the converter when the DC side of the DC transmission system operates at the target power. Based on the system stability parameter model of the DC transmission system, and using the AC harmonic impedance curve, AC impedance phase angle curve, DC harmonic impedance curve, and DC impedance phase angle curve, it calculates whether the system stability parameters are less than 0 when the AC side operates at the first target frequency and the DC side operates at the second target frequency. If the system stability parameters are less than 0 when the AC side operates at the first target frequency and the DC side operates at the second target frequency, then a complementary resonance risk is identified. This method obtains the physical parameters of the DC transmission system under different conditions through pre-analysis and uses the system stability parameter model for judgment, avoiding detection after a fault occurs. This proactive approach can prevent system faults caused by complementary resonance, thus improving system stability. Furthermore, this application also considers the impedance phase angles of the AC and DC sides for analysis, improving the accuracy of complementary resonance detection.

[0063] In one embodiment, the system stability parameter model is:

[0064]

[0065] Among them, Z acnx For negative-sequence AC harmonic impedance, Z acpxFor positive-sequence AC harmonic impedance, Z acp Z is the sum of the positive-sequence AC harmonic impedance and the impedance of the transformer in the DC transmission system. acn Z is the sum of the negative-sequence AC harmonic impedance and the AC side impedance of the transformer in the DC transmission system. dcn Where is the DC-side impedance of the transformer, N is the transformer turns ratio, A is the transfer coefficient of the converter in the DC transmission system, α0 is the firing angle of the converter, μ0 is the commutation overlap angle of the converter, and L... m X is the equivalent reactance of the transformer, and X is the transformer saturation coefficient.

[0066] In one embodiment, the transfer factor of the converter is calculated according to the following formula:

[0067]

[0068] Where μ0 is the commutation overlap angle of the converter.

[0069] In one embodiment, obtaining the AC harmonic impedance curve and AC impedance phase angle curve on the AC side within a preset first frequency range includes:

[0070] Starting from the lower limit of the first frequency range, the AC harmonic impedance and AC impedance phase angle on the AC side are obtained according to a preset step size until the frequency equals the upper limit of the first frequency range.

[0071] Within the first frequency range, there are an infinite number of frequency values. By setting a preset step size, some frequencies can be selected to calculate the AC harmonic impedance and AC impedance phase angle. Since the changes in AC harmonic impedance and AC impedance phase angle are related to the frequency, the AC harmonic impedance curve and AC impedance phase angle curve can be constructed by calculating several AC harmonic impedances and AC impedance phase angles.

[0072] In one embodiment, obtaining the DC harmonic impedance curve and DC impedance phase angle curve on the DC side within a preset second frequency range includes:

[0073] Starting from the lower limit of the second frequency range, the DC harmonic impedance and DC impedance phase angle on the DC side are obtained according to a preset step size until the frequency is equal to the lower limit of the second frequency range.

[0074] Within the second frequency range, there are an infinite number of frequency values. By setting a preset step size, some frequencies can be selected to scan the DC harmonic impedance and DC impedance phase angle. Since the changes in DC harmonic impedance and DC impedance phase angle are related to the frequency, the DC harmonic impedance curve and DC impedance phase angle curve can be constructed by scanning several DC harmonic impedances and DC impedance phase angles.

[0075] In one embodiment, the preset step size is less than or equal to 1 Hz.

[0076] In one embodiment, calculating the firing angle and commutation overlap angle of the converter when the DC side operates at the target power includes:

[0077] Based on the preset power step size and starting from the initial power, calculate the firing angle and commutation overlap angle of the converter at different target powers;

[0078] Using the system stability parameter model, the system stability parameters are calculated based on the firing angle, commutation overlap angle, AC harmonic impedance and AC impedance phase angle at the first target frequency, and DC harmonic impedance and DC impedance phase angle at the second target frequency. These parameters include:

[0079] Starting from the initial power, the system stability parameters are calculated according to the power step size at different target power levels, with the AC side operating at the first target frequency and the DC side operating at the second target frequency.

[0080] In this embodiment, starting from the initial power, the firing angle and commutation overlap angle are calculated for power at preset power step intervals. Then, for each power, the system stability parameter model is calculated when the AC side operates at the first target frequency and the DC side operates at the second target frequency. This analysis examines at which target power the DC transmission system has, the AC side operates at the first target frequency, and the DC side operates at the second target power, where there is a risk of complementary resonance. This approach avoids risky operating parameters, reduces the occurrence of complementary resonance faults in the DC transmission system, and improves system stability.

[0081] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0082] The text processing apparatus provided in the embodiments of this application is described below. The text processing apparatus described below and the text processing method described above can be referred to in correspondence.

[0083] like Figure 2As shown, in one embodiment, this application also provides an AC / DC complementary resonance detection device 200, comprising:

[0084] Model acquisition module 201 is used to acquire the system stability parameter model of the DC transmission system;

[0085] The AC side parameter acquisition module 202 is used to acquire the AC harmonic impedance curve and AC impedance phase angle curve of the AC side within a preset first frequency range.

[0086] The DC side parameter acquisition module 203 is used to acquire the DC harmonic impedance curve and DC impedance phase angle curve of the DC side within a preset second frequency range; the upper limit of the second frequency range is the upper limit of the first frequency range minus the power frequency.

[0087] The first calculation module 204 is used to calculate the firing angle and commutation overlap angle of the converter when the DC side is operating at the target power.

[0088] The second calculation module 205 is used to calculate system stability parameters using the system stability parameter model based on the firing angle, the commutation overlap angle, the AC harmonic impedance and AC impedance phase angle at the first target frequency, and the DC harmonic impedance and DC impedance phase angle at the second target frequency; the difference between the first target frequency and the second target frequency is equal to the power frequency; the first target frequency is any frequency in the first frequency range, and the second target frequency is any frequency in the second frequency range;

[0089] Risk assessment module 206 is used to determine, when the system stability parameter is less than 0, that the system has a complementary resonance risk at the target power, and when the AC side operates at the first target frequency and the DC side operates at the second target frequency.

[0090] Each module in the aforementioned AC / DC complementary resonant detection device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0091] In one embodiment, this application also provides a storage medium storing computer-readable instructions that, when executed by one or more processors, cause the one or more processors to perform the steps of the AC / DC complementary resonance detection method as described in any of the above embodiments.

[0092] In one embodiment, this application also provides a computer device storing computer-readable instructions that, when executed by one or more processors, cause the one or more processors to perform the steps of the AC / DC complementary resonance detection method as described in any of the above embodiments.

[0093] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 3 As shown, the computer device includes a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements an AC / DC complementary resonance detection method. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0094] Those skilled in the art will understand that Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0095] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0096] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0097] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0098] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0099] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An AC-DC complementary resonance detection method, characterized in that, The method comprises: obtaining a system stability parameter model of a direct current power transmission system; obtaining an alternating current harmonic impedance curve and an alternating current impedance phase angle curve of an alternating current side in a preset first frequency range; obtaining a direct current harmonic impedance curve and a direct current impedance phase angle curve of a direct current side in a preset second frequency range; an upper limit value of the second frequency range is an upper limit value of the first frequency range minus a power frequency; calculating a trigger angle and a commutation overlap angle of a converter when the direct current side works at a target power; calculating a system stability parameter according to the trigger angle, the commutation overlap angle, an alternating current harmonic impedance at a first target frequency, an alternating current impedance phase angle, a direct current harmonic impedance at a second target frequency and a direct current impedance phase angle by using the system stability parameter model; a difference between the first target frequency and the second target frequency is equal to the power frequency; the first target frequency is any one frequency in the first frequency range, and the second target frequency is any one frequency in the second frequency range; if the system stability parameter is less than 0, determining that there is a complementary resonance risk when the system works at the target power, the alternating current side works at the first target frequency and the direct current side works at the second target frequency; the system stability parameter model is: wherein, is the AC harmonic impedance for negative sequence, is the AC harmonic impedance for positive sequence, is the sum of the AC harmonic impedance for positive sequence and the impedance of the transformer in the DC power transmission system, is the sum of the AC harmonic impedance for negative sequence and the AC side impedance of the transformer in the DC power transmission system, is the DC side impedance of the transformer, N is the transformation ratio of the transformer, A is the transfer coefficient of the converter in the DC power transmission system, is the firing angle of the converter, is the commutation overlap angle of the converter, is the equivalent reactance of the transformer, X is the saturation coefficient of the transformer; a transfer coefficient of the converter is calculated according to the following formula: wherein is the commutation overlap angle of the converter.

2. The AC-DC complementary resonance detection method of claim 1, wherein, the obtaining of the alternating current harmonic impedance curve and the alternating current impedance phase angle curve of the alternating current side in the preset first frequency range comprises: starting from a lower limit value frequency of the first frequency range, obtaining the alternating current harmonic impedance and the alternating current impedance phase angle of the alternating current side according to a preset step length until the frequency is equal to an upper limit value of the first frequency range.

3. The AC-DC complementary resonance detection method of claim 1, wherein, the obtaining of the direct current harmonic impedance curve and the direct current impedance phase angle curve of the direct current side in the preset second frequency range comprises: starting from a lower limit value frequency of the second frequency range, obtaining the direct current harmonic impedance and the direct current impedance phase angle of the direct current side according to a preset step length until the frequency is equal to a lower limit value of the second frequency range.

4. The AC-DC complementary resonance detection method according to claim 2 or 3, characterized in that, the preset step length is less than or equal to 1 Hz.

5. The AC-DC complementary resonance detection method of claim 1, wherein, the calculating of the trigger angle and the commutation overlap angle of the converter when the direct current side works at the target power comprises: starting from an initial power according to a preset power step length, calculating the trigger angle and the commutation overlap angle of the converter at different target powers respectively; the calculating of the system stability parameter according to the trigger angle, the commutation overlap angle, the alternating current harmonic impedance at the first target frequency, the alternating current impedance phase angle, the direct current harmonic impedance at the second target frequency and the direct current impedance phase angle by using the system stability parameter model comprises: starting from the initial power, calculating the system stability parameter at different target powers respectively according to the power step length, when the alternating current side works at the first target frequency and the direct current side works at the second target frequency.

6. An AC-DC complementary resonance detection device, characterized by comprising: comprise: a model obtaining module configured to obtain a system stability parameter model of a direct current power transmission system; an alternating current side parameter obtaining module configured to obtain an alternating current harmonic impedance curve and an alternating current impedance phase angle curve of an alternating current side in a preset first frequency range; The direct current side parameter acquisition module is configured to acquire a direct current harmonic impedance curve and a direct current impedance phase angle curve of the direct current side in a preset second frequency range; an upper limit value of the second frequency range is an upper limit value of the first frequency range minus a power frequency; The first calculation module is configured to calculate a firing angle and a commutation overlap angle of the converter when the direct current side works at the target power; The second calculation module is configured to calculate a system stability parameter by using the system stability parameter model according to the firing angle, the commutation overlap angle, an alternating current harmonic impedance at a first target frequency, an alternating current impedance phase angle, a direct current harmonic impedance at a second target frequency, and a direct current impedance phase angle; a difference between the first target frequency and the second target frequency is equal to a power frequency; the first target frequency is any one frequency in the first frequency range, and the second target frequency is any one frequency in the second frequency range; The risk determination module is configured to determine that there is a complementary resonance risk when the system works at the target power, the alternating current side works at the first target frequency, and the direct current side works at the second target frequency, when the system stability parameter is less than 0. The system stability parameter model is: wherein, is the AC harmonic impedance for negative sequence, is the AC harmonic impedance for positive sequence, is the sum of the AC harmonic impedance for positive sequence and the impedance of the transformer in the DC power transmission system, is the sum of the AC harmonic impedance for negative sequence and the AC side impedance of the transformer in the DC power transmission system, is the DC side impedance of the transformer, N is the transformation ratio of the transformer, A is the transfer coefficient of the converter in the DC power transmission system, is the firing angle of the converter, is the commutation overlap angle of the converter, is the equivalent reactance of the transformer, X is the saturation coefficient of the transformer; The transfer coefficient of the converter is calculated according to the following formula: wherein is the commutation overlap angle of the converter.

7. A storage medium characterized by: The storage medium stores computer readable instructions, and the computer readable instructions are executed by one or more processors to make the one or more processors execute the steps of the AC-DC complementary resonance detection method in any one of claims 1 to 5.

8. A computer device, comprising: Comprises: One or more processors, and a memory; The memory stores computer readable instructions, and the computer readable instructions are executed by the one or more processors to execute the steps of the AC-DC complementary resonance detection method in any one of claims 1 to 5.

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