Visualization-based double-frequency circulating current suppression method and system

Abstract

The invention relates to the technical field of power electronics, in particular to a visualization-based double-frequency circulating current suppression method and system, and the method comprises the steps: setting a circulating current suppression visual structure with a circulating current suppression module; setting the position of a visual background, and updating visual data of the circulating current suppression module after circulating current suppression; through a containerization deployment platform, input parameters and output parameters of circulation suppression are obtained online; acquiring an input parameter of circulating current suppression, performing circulating current suppression reference voltage calculation, and storing the reference voltage after each circulating current suppression to a cloud data center; the optimal circulation parameters are automatically learned in the cloud data center; and after the optimal circulating current parameter is obtained, continuously operating the system, and if an abnormal condition occurs, updating the optimal circulating current parameter. According to the invention, a visually programmed circulating current suppression structure is arranged, and rapid debugging of circulating current suppression is realized through online adjustment.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and more specifically, to a method and system for suppressing double-frequency circulating current based on visualization. Background Art

[0002] During the control process of power electronic equipment, multiple harmonics are generally generated due to voltage and current fluctuations of the equipment. Among them, double-frequency harmonics are the most likely to appear because voltage fluctuations and current fluctuations are often out of sync, resulting in energy fluctuations at twice the frequency, which in turn causes extremely strong double-frequency circulating current in power electronic equipment. This situation is particularly common in modular multilevel flexible DC transmission.

[0003] Before the technology of the present invention, in the prior art during flexible DC transmission, the three-phase units of the converter are connected in parallel to the DC bus. During operation, since the DC voltages generated by the phase units are difficult to keep consistent, there will be a flow between the three phase units. This current is generally twice the power frequency of 50 Hz, so it is called double-frequency circulating current. If the double-frequency circulating current is larger, it will have a great impact on the life of the equipment and the stability of the system. The reason for affecting the equipment life is that the double frequency will increase the current stress, thereby leading to an increase in losses. The reason for affecting stability is that waveform distortion is likely to cause system fluctuations and affect stability. However, the prior art all pre-sets the suppression of circulating current and cannot be adjusted online. Summary of the Invention

[0004] In view of the above problems, the present invention proposes a method and system for suppressing double-frequency circulating current based on visualization, which sets a circulating current suppression structure with visual programming and realizes rapid debugging of circulating current suppression through online adjustment.

[0005] According to the first aspect of an embodiment of the present invention, there is provided a method for suppressing double-frequency circulating current based on visualization, including:

[0006] Setting a visual structure for circulating current suppression with a circulating current suppression module;

[0007] Setting the position of the visual background and updating the visual data after circulating current suppression by the circulating current suppression module;

[0008] Obtaining the input parameters and output parameters of circulating current suppression online through a containerized deployment platform;

[0009] Calculating a reference voltage for circulating current suppression according to the obtained input parameters of circulating current suppression, and storing the reference voltage after each circulating current suppression in a cloud data center;

[0010] Automatically learning the optimal circulating current parameters based on the visual data in the cloud data center;

[0011] After obtaining the optimal circulating current parameters, the system operation is continuously carried out. If an abnormal situation occurs, the optimal circulating current parameters are updated.

[0012] Furthermore, the setting of the circulating current suppression visualization structure specifically includes:

[0013] Set up a visualization programming platform based on the Internet of Things cloud platform, where the visualization programming platform is used to encapsulate the circulating current suppression module;

[0014] Set the initial parameters of the circulating current suppression module, where the initial parameters include the preset initial values of the first control parameter, the second control parameter, and the third control parameter.

[0015] Furthermore, the setting of the position of the visualization background and the update of the visualization data specifically include:

[0016] Set the visualization programming platform to be able to obtain the effective value of the current circulating current online, and use the effective value of the circulating current after circulating current suppression with a period of 1 minute as the standard circulating current parameter;

[0017] After each update of the standard circulating current parameter, the updated standard circulating current parameter is uploaded to the cloud data center as visualization data through the visualization programming platform.

[0018] Furthermore, the online acquisition of the input parameters and output parameters of the circulating current suppression through the containerized deployment platform specifically includes:

[0019] Set the input parameters of the adaptive adjustment of the circulating current suppression strategy interface as the arm current, the virtual potential, and the DC voltage, where the arm current is the real-time value of the current of the upper arm and the lower arm, the virtual potential is half of the difference between the voltage of the upper arm and the lower arm of the corresponding phase voltage, and the DC voltage is the rated DC voltage of the modular multilevel converter;

[0020] Set the first control parameter, the second control parameter, and the third control parameter as input parameters, where the first control parameter is a preset proportional coefficient, the second control parameter is a preset integral coefficient, and the third control parameter is a preset differential coefficient;

[0021] Set the voltage correction amount of the upper and lower arms as the output parameter of the circulating current suppression.

[0022] Furthermore, the acquisition of the input parameters of the circulating current suppression, the calculation of the reference voltage for circulating current suppression, and the storage of the reference voltage after each circulating current suppression into the cloud data center specifically include:

[0023] Obtain the arm current value and calculate the circulating current using the second calculation formula;

[0024] Calculate the second-harmonic D-axis component and the second-harmonic Q-axis component according to the current circulating current value using the third calculation formula;

[0025] Calculate the circulating current suppression reference voltage according to the first control parameter, the second control parameter, and the third control parameter using the fourth calculation formula;

[0026] Generate the reference voltage after circulating current suppression using the fifth calculation formula;

[0027] The second calculation formula is:

[0028] I Cj = 0.5×(IPj + INj)

[0029] where, IPj is the current of the upper bridge arm of phase j, INj is the current of the lower bridge arm of phase j, and ICj is the circulating current value of phase j; the third calculation formula is:

[0030]

[0031] where, ID is the second-harmonic D-axis component, IQ is the second-harmonic Q-axis component, IC1, IC2, and IC3 are the circulating current values of phase A, phase B, and phase C respectively, F1() is the extraction function of the D-axis component, and F2 is the extraction function of the Q-axis component;

[0032] The fourth calculation formula is:

[0033]

[0034] where, Ucirj3 is the circulating current suppression reference voltage of three phases a, b, and c, pk, pi, and pd are the first control parameter, the second control parameter, and the third control parameter respectively, FF() is the function that converts the dq-axis components into the circulating current suppression reference voltage of phase j, and FF() will calculate the circulating current suppression reference voltage of three phases a, b, and c;

[0035] The fifth calculation formula is:

[0036] Upj = 0.5×UD - Uj - Ucirj

[0037] Unj = 0.5×UD - Uj - Ucirj

[0038] where, UD is the rated voltage, Uj is the voltage reference value, Upj is the upper bridge arm voltage reference value, Unj is the lower bridge voltage reference value, and Ucirj is a certain phase among a, b, and c, defined as the circulating current suppression reference voltage of phase j.

[0039] Further, in the cloud data center, automatically learn the optimal circulating current parameters, specifically including:

[0040] In the cloud data center, several kinds of circulating current suppression parameters are set, where the circulating current suppression parameters are the first control parameter, the second control parameter, and the third control parameter;

[0041] Extract the standard circulating current parameters in the past period of time, and extract whether the standard circulating current parameters satisfy the sixth calculation formula. If satisfied, stop updating the circulating current suppression parameters. If not satisfied, replace an unused circulating current suppression parameter every minute;

[0042] Until satisfied, stop updating the circulating current suppression parameters, then no longer continue to update the circulating current suppression parameters, and use the current circulating current suppression parameters as the optimal circulating current parameters;

[0043] The sixth calculation formula is:

[0044] ccc < 0.1×EE

[0045] Where EE is the reference value of the rated current, and ccc is the standard circulating current parameter.

[0046] Further, after obtaining the optimal circulating current parameters, continuously run the system. If an abnormal situation occurs, update the optimal circulating current parameters, specifically including:

[0047] After obtaining the optimal circulating current parameters, continuously run the system. If the standard circulating current parameters cannot satisfy the seventh calculation formula within 20 consecutive seconds, continue to start replacing an unused circulating current suppression parameter; until the sixth calculation formula is satisfied, stop updating the circulating current suppression parameters, then no longer continue to update the circulating current suppression parameters, and use the current circulating current suppression parameters as the optimal circulating current parameters;

[0048] The seventh calculation formula is:

[0049] ccc < 0.15×EE

[0050] Where EE is the reference value of the rated current, and ccc is the standard circulating current parameter.

[0051] A visualization-based double-frequency circulating current suppression system, which is used to implement the method described above. The system includes:

[0052] A circulating current regulation visualization structure module, which is used to set a circulating current suppression visualization structure with a circulating current suppression module;

[0053] A visualization setting module, which is used to set the position of the visualization background and update the visualization data after the circulating current suppression module performs circulating current suppression;

[0054] A circulating current parameter acquisition module, which is used to online acquire the input parameters and output parameters of circulating current suppression through a containerized deployment platform;

[0055] An adaptive adjustment of the circulating current suppression strategy module is used to calculate the reference voltage for suppressing the circulating current according to the obtained input parameters for suppressing the circulating current, and store the reference voltage after each suppression of the circulating current in the cloud data center;

[0056] The cloud optimal learning module is used to automatically learn the optimal circulating current parameters based on the visualization data in the cloud data center;

[0057] The optimal parameter update module is used to continuously run the system after obtaining the optimal circulating current parameters, and update the optimal circulating current parameters if an abnormal situation occurs.

[0058] A computer-readable storage medium stores computer program instructions thereon, wherein the computer program instructions, when executed by a processor, implement the method described above.

[0059] An electronic device includes a memory and a processor, wherein the memory is used to store one or more computer program instructions, and the one or more computer program instructions are executed by the processor to implement the method described above.

[0060] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0061] In this solution, a method for suppressing the circulating current based on visual programming is provided to achieve efficient and convenient suppression of the circulating current.

[0062] In this solution, through the adaptive analysis of the parameters of the circulating current process, accurate tracking and adjustment of the circulating current are achieved.

[0063] Other features and advantages of the present invention will be described in the following description of the specification, and will be partially obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structures specifically pointed out in the written description, claims, and drawings.

[0064] The following will further describe the technical solutions of the present invention in detail through the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the following drawings are only some embodiments of the present invention, and those skilled in the art can obtain other drawings without creative efforts based on these drawings.

[0066] Figure 1 is a flowchart of a method for suppressing the second-harmonic circulating current based on visualization according to an embodiment of the present invention.

[0067] Figure 2 It is a flowchart of setting a circulating current suppression visualization structure in a visualization-based second-harmonic circulating current suppression method according to an embodiment of the present invention.

[0068] Figure 3 It is a flowchart of setting the position of a visualization background and updating visualization data in a visualization-based second-harmonic circulating current suppression method according to an embodiment of the present invention.

[0069] Figure 4 It is a flowchart of obtaining input parameters and output parameters of circulating current suppression online through a containerized deployment platform in a visualization-based second-harmonic circulating current suppression method according to an embodiment of the present invention.

[0070] Figure 5 It is a flowchart of obtaining the input parameters of the circulating current suppression, calculating a reference voltage for circulating current suppression, and storing the reference voltage after each circulating current suppression in a cloud data center in a visualization-based second-harmonic circulating current suppression method according to an embodiment of the present invention.

[0071] Figure 6 It is a flowchart of automatically learning optimal circulating current parameters in a cloud data center in a visualization-based second-harmonic circulating current suppression method according to an embodiment of the present invention.

[0072] Figure 7 It is a flowchart of continuously operating the system after obtaining the optimal circulating current parameters and updating the optimal circulating current parameters if an abnormal situation occurs in a visualization-based second-harmonic circulating current suppression method according to an embodiment of the present invention.

[0073] Figure 8 It is a structural diagram of a visualization-based second-harmonic circulating current suppression system according to an embodiment of the present invention.

[0074] Figure 9 It is a structural diagram of an electronic device according to an embodiment of the present invention. Detailed implementation manners

[0075] In some of the processes described in the specification, claims, and the above-mentioned drawings of the present invention, a plurality of operations appear in a specific order. However, it should be clearly understood that these operations may not be executed in the order in which they appear herein or may be executed in parallel. The serial numbers of the operations, such as 101, 102, etc., are only used to distinguish different operations, and the serial numbers themselves do not represent any execution order. In addition, these processes may include more or fewer operations, and these operations may be executed in sequence or in parallel. It should be noted that the descriptions such as "first" and "second" herein are used to distinguish different messages, devices, modules, etc., do not represent a sequence, and do not limit that "first" and "second" are of different types.

[0076] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0077] During the control process of power electronic equipment, multiple harmonics are generally generated due to voltage and current fluctuations of the equipment. Among them, the second-harmonic is the most likely to appear because the voltage fluctuation and current fluctuation are often out of sync, which will generate a 2-fold frequency fluctuation in energy, and then cause a strong second-harmonic circulating current in the power electronic equipment. This situation is particularly common in modular multilevel flexible DC transmission.

[0078] Before the technology of the present invention, in the prior art of flexible DC transmission, the three-phase units of the converter are connected in parallel to the DC bus. During operation, since it is difficult to keep the DC voltages generated by the phase units consistent, there will be a flow between the three phase units. This current is generally twice the power frequency of 50 Hz, so it is called the second-harmonic circulating current. If the second-harmonic circulating current is larger, it will have a great impact on the life of the equipment and the system stability. The reason for affecting the equipment life is that the second-harmonic will increase the current stress, thereby leading to an increase in losses. The reason for affecting the stability is that the waveform distortion is likely to cause system fluctuations and affect the stability. However, the prior art has preset the circulating current suppression and cannot be adjusted online.

[0079] In the embodiments of the present invention, a method and system for suppressing the second-harmonic circulating current based on visualization are provided. This solution sets up a circulating current suppression structure with visual programming and realizes the rapid debugging of circulating current suppression through online adjustment.

[0080] According to the first aspect of the embodiments of the present invention, a method for suppressing the second-harmonic circulating current based on visualization is provided.

[0081] Figure 1 It is a flowchart of a visualization-based second-harmonic circulating current suppression method according to an embodiment of the present invention.

[0082] In one or more embodiments, preferably, the visualization-based second-harmonic circulating current suppression method includes:

[0083] S101. Set a circulating current suppression visualization structure with a circulating current suppression module;

[0084] S102. Set the position of the visualization background and update the visualization data after the circulating current suppression module performs circulating current suppression;

[0085] S103. Through the containerized deployment platform, online obtain the input parameters and output parameters of the circulating current suppression;

[0086] S104. According to the obtained input parameters of the circulating current suppression, calculate the reference voltage for circulating current suppression, and store the reference voltage after each circulating current suppression in the cloud data center;

[0087] S105. In the cloud data center, automatically learn the optimal circulating current parameters based on the visualization data;

[0088] S106. After obtaining the optimal circulating current parameters, continuously run the system, and update the optimal circulating current parameters if an abnormal situation occurs.

[0089] In the embodiment of the present invention, according to existing engineering experience, it is known that through visual programming, the circulating current can be automatically suppressed within 15% of the rated current, and the control algorithm can be executed efficiently and reliably.

[0090] Figure 2 It is a flowchart of setting the circulating current suppression visualization structure in a visualization-based second-harmonic circulating current suppression method according to an embodiment of the present invention.

[0091] As Figure 2 shown, in one or more embodiments, preferably, the setting of the circulating current suppression visualization structure specifically includes:

[0092] S201. Set a visualization programming platform based on the Internet of Things cloud platform, wherein the visualization programming platform is used to encapsulate the circulating current suppression module;

[0093] S202. Set the initial parameters of the circulating current suppression module, wherein the initial parameters include the preset initial values of the first control parameter, the second control parameter, and the third control parameter.

[0094] In an embodiment of the present invention, first, a mature Internet of Things (IoT) cloud platform, such as AWS IoT, is selected because it provides a wide range of device connection, data processing, and visualization tools. Secondly, using the development tools provided by the cloud platform, a user-friendly visual programming interface is created. This interface allows users to build a circulating current suppression strategy by dragging and dropping different functional modules without writing code. Furthermore, the circulating current suppression algorithm is split into configurable modules, such as a current detection module, a control algorithm module, etc., and a visual representation of these modules is implemented on the cloud platform. On this basis, the connection between the cloud platform and the field devices is configured to ensure that data can be received in real time and control commands can be sent. This may involve installing appropriate communication protocols and interfaces. Further, the control parameters affecting the circulating current suppression are clearly defined, and initial values are set according to known operating conditions and empirical data. For example, the first control parameter may be a current threshold, and the second control parameter may be a suppression response time. In the visual programming environment, tools such as sliders or input boxes are provided to allow users to easily adjust these parameters according to the actual operating conditions. Finally, a highly configurable and interactive circulating current suppression system is established through the above steps. The system utilizes modern IoT technology to achieve precise control and suppression of the double-frequency circulating current in power electronic devices. Through the data analysis capabilities of the cloud platform, the system continuously optimizes the control parameters to adapt to changing operating conditions, thereby improving the stability and efficiency of the device.

[0095] Figure 3 It is a flowchart of setting the position of the visual background and updating the visual data in a method for suppressing double-frequency circulating current based on visualization according to an embodiment of the present invention.

[0096] As Figure 3 shown, in one or more embodiments, preferably, setting the position of the visual background and updating the visual data specifically includes:

[0097] S301. Set that the visual programming platform can obtain the effective value of the current circulating current online, and use the effective value of the circulating current after circulating current suppression with a 1-minute period as the standard circulating current parameter;

[0098] S302. After each update of the standard circulating current parameter, upload the updated standard circulating current parameter to the cloud data center as visual data through the visual programming platform.

[0099] In the embodiments of the present invention, by setting up a visualization backend, the dynamic monitoring and management of circulating current suppression are ensured. First, determine the deployment location of the visualization backend, which is usually on an easily accessible and secure cloud server. Subsequently, through a real-time update mechanism, this backend can continuously receive and display the current circulating current data. On this basis, a visualization programming platform is established, which has the ability to obtain the effective value of the real-time circulating current online. This means that the platform can directly read the circulating current data from the power system and calculate the accurate effective value of the circulating current in real time. To achieve the dynamic optimization of circulating current suppression, the platform is set to automatically perform circulating current suppression processing every minute, and store and reference the processed effective value of the circulating current as the standard circulating current parameter. Whenever the standard circulating current parameter is updated, the visualization programming platform will automatically upload these parameters to the cloud data center. This makes the parameters not only available in real time in the local system, but also backed up and further analyzed in the cloud. The cloud data center can thus use these data for more extensive data analysis, such as trend prediction, performance evaluation, or fault diagnosis, etc. The entire system is set up to improve the monitorability, adjustability, and reliability of circulating current suppression through visualization and cloud technologies, thereby ensuring the stable operation and performance optimization of the power electronic system. This integrated and automated strategy ensures that the circulating current suppression measures can promptly adapt to changes in the system state, improving the overall efficiency and safety.

[0100] Figure 4 It is a flowchart of obtaining the input parameters and output parameters of circulating current suppression online through a containerized deployment platform in a visualization-based double-frequency circulating current suppression method according to an embodiment of the present invention.

[0101] As Figure 4 shown, in one or more embodiments, preferably, obtaining the input parameters and output parameters of circulating current suppression online through the containerized deployment platform specifically includes:

[0102] S401. Set the input parameters of the adaptive adjustment circulating current suppression strategy interface as the arm current, virtual potential, and DC voltage, where the arm current is the real-time value of the current of the upper arm and the lower arm, the virtual potential is half of the difference between the voltages of the upper arm and the lower arm of the corresponding phase voltage, and the DC voltage is the rated DC voltage of the modular multilevel converter;

[0103] S402. Set the first control parameter, the second control parameter, and the third control parameter as input parameters, where the first control parameter is a pre-set proportional coefficient, the second control parameter is a pre-set integral coefficient, and the third control parameter is a pre-set differential coefficient;

[0104] S403. Set the voltage correction amount of the upper and lower arms as the output parameter of circulating current suppression.

[0105] In the embodiment of the present invention, the core reason for generating the circulating current is that the upper and lower bridge arms should generate voltage values exactly the same as the virtual electromotive force, but in actual operation, they are different. Therefore, a pressure difference will be generated due to the first calculation formula. In the first calculation formula, UcA is the internal unbalanced voltage of phase A, L0 is the arm reactance, and R0 is the arm resistance. By controlling the output parameters online, the voltage imbalance on any phase can be automatically cancelled out.

[0106] Figure 5 It is a flowchart of obtaining the input parameters for suppressing the circulating current, calculating the reference voltage for suppressing the circulating current, and storing the reference voltage after each suppression of the circulating current in the cloud data center in a method for suppressing the double-frequency circulating current based on visualization according to an embodiment of the present invention.

[0107] As Figure 5 shown, in one or more embodiments, preferably, the steps of obtaining the input parameters for suppressing the circulating current, calculating the reference voltage for suppressing the circulating current, and storing the reference voltage after each suppression of the circulating current in the cloud data center specifically include:

[0108] S501. Obtain the arm current value and calculate the circulating current using the second calculation formula;

[0109] S502. Calculate the double-frequency D-axis component and the double-frequency Q-axis component according to the current circulating current value using the third calculation formula;

[0110] S503. Calculate the reference voltage for suppressing the circulating current according to the first control parameter, the second control parameter, and the third control parameter using the fourth calculation formula;

[0111] S504. Generate the reference voltage after suppressing the circulating current using the fifth calculation formula;

[0112] The second calculation formula is:

[0113] I Cj = 0.5×(IPj + INj)

[0114] where IPj is the current of the upper arm of phase j, INj is the current of the lower arm of phase j, and ICj is the circulating current value of phase j. The third calculation formula is:

[0115]

[0116] where ID is the double-frequency D-axis component, IQ is the double-frequency Q-axis component, IC1, IC2, and IC3 are the circulating current values of phase A, phase B, and phase C respectively, F1() is the extraction function of the D-axis component, and F2 is the extraction function of the Q-axis component;

[0117] The fourth calculation formula is:

[0118]

[0119] Among them, Ucirj3 is the circulating current suppression reference voltage of three phases a, b, and c. pk, pi, and pd are the first control parameter, the second control parameter, and the third control parameter respectively. FF() is a function that converts the dq-axis components into the circulating current suppression reference voltage of the j-th phase. Among them, FF() will calculate the circulating current suppression reference voltages of three phases a, b, and c.

[0120] The fifth calculation formula is as follows:

[0121] Upj = 0.5 × UD - Uj - Ucirj

[0122] Unj = 0.5 × UD - Uj - Ucirj

[0123] Among them, UD is the rated voltage, Uj is the voltage reference value, Upj is the upper bridge arm voltage reference value, Unj is the lower bridge voltage reference value, and Ucirj is a certain phase among a, b, and c, defined as the circulating current suppression reference voltage of the j-th phase.

[0124] In an embodiment of the present invention, through a series of precise calculation steps, effective suppression of the double - frequency circulating current in the power electronic system is achieved. First, the system obtains the arm current values, which are realized by measuring the currents of the upper arm and the lower arm. Using the second calculation formula \(I_{Cj}=0.5\times(I_{Pj} + I_{Nj})\), the system calculates the circulating current value of each phase, where \(I_{Pj}\) and \(I_{Nj}\) are the currents of the upper arm and the lower arm of the j - phase respectively. Subsequently, based on the current circulating current value, the system uses the third calculation formula to calculate the double - frequency D - axis component and the double - frequency Q - axis component. These two components are extracted through functions \(F1()\) and \(F2()\), which respectively process the component extraction of the D - axis and the Q - axis, ensuring that the required frequency components can be accurately separated from the circulating current value. Next, the system uses the fourth calculation formula \(U_{cirj3}=p_k\times I_D + p_i\times I_Q + p_d\) to calculate the reference voltage for circulating current suppression. In this step, \(p_k\), \(p_i\), and \(p_d\) are used as the first control parameter, the second control parameter, and the third control parameter respectively to determine the response characteristics of the control strategy. The setting of these parameters depends on the specific requirements and operating conditions of the system. The function \(FF()\) further converts the DQ - axis components into the reference voltages for circulating current suppression of the a, b, and c three - phases, which is to ensure that each phase can obtain appropriate voltage adjustment to suppress the circulating current. Finally, the system generates the reference voltage after circulating current suppression through the fifth calculation formula \(U_{Pj}=0.5\times U_D - U_j - U_{cirj}\) and \(U_{Nj}=0.5\times U_D - U_j - U_{cirj}\). Here, \(U_D\) is the rated voltage, \(U_j\) is the voltage reference value, and \(U_{cirj}\) is the reference voltage for circulating current suppression of the j - phase in a, b, and c. Through this step, the system ensures that the voltage finally applied to the power electronic converter can effectively reduce the circulating current while maintaining the stable operation of the system. After each calculation, the system stores the reference voltage after circulating current suppression in the cloud data center. This not only provides long - term data records for easy analysis and optimization but also ensures the security and accessibility of the data. In this way, the system realizes the automation and intelligence of circulating current suppression, significantly improving the performance and reliability of the power electronic system.

[0125] Figure 6 It is a flowchart of automatically learning the optimal circulating current parameters in the cloud data center in a method for suppressing double - frequency circulating current based on visualization according to an embodiment of the present invention.

[0126] As Figure 6 shown, in one or more embodiments, preferably, the automatically learning the optimal circulating current parameters in the cloud data center specifically includes:

[0127] S601. In the cloud data center, several kinds of circulating current suppression parameters are set, where the circulating current suppression parameters are the first control parameter, the second control parameter, and the third control parameter;

[0128] S602. Extract the standard circulation parameters over a past period of time, and check whether the standard circulation parameters satisfy the sixth calculation formula. If they satisfy, stop updating the circulation suppression parameters; if not, replace with an unused circulation suppression parameter every minute.

[0129] S603. Stop updating the circulation suppression parameters until they satisfy, and no longer continue to update the circulation suppression parameters. Then, use the current circulation suppression parameters as the optimal circulation parameters.

[0130] The sixth calculation formula is:

[0131] ccc < 0.1×EE

[0132] where EE is the reference value of the rated current and ccc is the standard circulation parameter.

[0133] In an embodiment of the present invention, an automatic learning system is configured to optimize the circulation suppression parameters. The core of this system depends on three control parameters: the first control parameter, the second control parameter, and the third control parameter. These parameters define the behavior and effect of the circulation suppression strategy. To achieve automatic learning of the optimal circulation parameters, the system first extracts the standard circulation parameter data over a past period of time. These data are calculated by the aforementioned circulation suppression system and uploaded to the cloud. The system then checks whether these standard circulation parameters satisfy a specific condition, i.e., the sixth calculation formula ccc < 0.1×EE. Here, EE is the reference value of the rated current, and ccc is the standard circulation parameter. This condition ensures that the circulation value is controlled within 10% of the rated current, which is a key performance indicator. If the current standard circulation parameters satisfy this condition, the system determines that the current circulation suppression parameters are optimal and stops further parameter updates. This means that the current circulation suppression strategy is already effective enough and does not require further adjustment. If the condition is not satisfied, the system will automatically replace with an unused circulation suppression parameter, changing the parameter every minute and recalculating the new standard circulation parameters. This process continues until a set of parameters is found such that the standard circulation parameters satisfy the condition. At this time, the system determines this set of parameters as the optimal circulation parameters and fixedly applies them to subsequent circulation suppression operations. In this way, the cloud data center can not only automatically learn and optimize the circulation suppression parameters but also ensure that the operation efficiency and stability of the power electronic system are always in the best state. This automated optimization process reduces the need for manual intervention and improves the overall intelligence level and operation efficiency of the system.

[0134] Figure 7 It is a flowchart of a method for suppressing the second-harmonic circulation based on visualization in an embodiment of the present invention. After obtaining the optimal circulation parameters, the system continues to run. If an abnormal situation occurs, the optimal circulation parameters are updated.

[0135] As Figure 7 shown, in one or more embodiments, preferably, after obtaining the optimal circulating current parameters, the system continues to operate. If an abnormal situation occurs, the updated optimal circulating current parameters are as follows:

[0136] S701. After obtaining the optimal circulating current parameters, the system continues to operate. If the standard circulating current parameters within 20 consecutive seconds cannot satisfy the seventh calculation formula, then continue to start replacing an unused circulating current suppression parameter;

[0137] S702. Stop updating the circulating current suppression parameter until the sixth calculation formula is satisfied, then no longer continue to update the circulating current suppression parameter, and use the current circulating current suppression parameter as the optimal circulating current parameter;

[0138] The seventh calculation formula is:

[0139] ccc < 0.15 × EE

[0140] where EE is the reference value of the rated current and ccc is the standard circulating current parameter.

[0141] In the embodiments of the present invention, after obtaining and applying the optimal circulating current parameters, the system enters a continuous operation mode. In this stage, the main task of the system is to monitor the standard circulating current parameters to ensure that they continuously meet the performance standards, and at the same time respond to possible abnormal situations. The standard circulating current parameters continuously monitored by the system are evaluated by the seventh calculation formula ccc < 0.15 × EE, where EE is the reference value of the rated current and ccc is the standard circulating current parameter. This formula sets a stricter threshold (15% of the rated current) than normal operation to ensure that the system can maintain good performance even under non-ideal conditions. If the monitored standard circulating current parameters cannot meet the conditions of the seventh calculation formula within 20 consecutive seconds, the system will automatically start an abnormal response process. This process includes replacing an unused circulating current suppression parameter, and then continuing to monitor the performance of the circulating current parameters. This process will continue until a new parameter configuration is found such that the standard circulating current parameters again meet the sixth calculation formula ccc < 0.1 × EE. Once this condition is met, the system will stop updating the circulating current suppression parameter and fix the current parameter configuration as the new optimal circulating current parameter. This mechanism ensures that the system can adaptively adjust its operating parameters to cope with possible performance degradation or external condition changes, thereby continuously maintaining the optimal operating state of the system. Through continuous monitoring and automatic parameter adjustment, the system can achieve high stability and reliability, reduce the need for manual intervention, and improve the overall operating efficiency.

[0142] According to the second aspect of the embodiments of the present invention, a visualization-based double-frequency circulating current suppression system is provided.

[0143] Figure 8 It is a structural diagram of a visualization-based second-harmonic circulating current suppression system according to an embodiment of the present invention.

[0144] In one or more embodiments, preferably, the visualization-based second-harmonic circulating current suppression system includes:

[0145] The circulating current regulation visualization structure module 801 is used to set a circulating current suppression visualization structure with a circulating current suppression module;

[0146] The visualization setting module 802 is used to set the position of the visualization background and update the visualization data after the circulating current suppression module performs circulating current suppression;

[0147] The circulating current parameter acquisition module 803 is used to online acquire the input parameters and output parameters of the circulating current suppression through a containerized deployment platform;

[0148] The adaptive adjustment of the circulating current suppression strategy module 804 is used to calculate the reference voltage for circulating current suppression according to the acquired input parameters of the circulating current suppression, and store the reference voltage after each circulating current suppression in the cloud data center;

[0149] The cloud optimal learning module 805 is used to automatically learn the optimal circulating current parameters based on the visualization data in the cloud data center;

[0150] The optimal parameter update module 806 is used to continuously run the system after obtaining the optimal circulating current parameters, and update the optimal circulating current parameters if an abnormal situation occurs.

[0151] In the embodiment of the present invention, through a series of modular designs, a system applicable to different structures is realized, and the system can achieve closed-loop, reliable, and efficient execution through collection, analysis, and control.

[0152] According to the third aspect of the embodiment of the present invention, there is provided a computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are executed by a processor, the method described in any one of the first aspects of the embodiment of the present invention is implemented.

[0153] According to the fourth aspect of the embodiment of the present invention, there is provided an electronic device. Figure 9 It is a structural diagram of an electronic device in an embodiment of the present invention. Figure 9The electronic device shown is a general visualization-based second-harmonic circulating current suppression device, which includes a general computer hardware structure, and at least includes a processor 901 and a memory 902. The processor 901 and the memory 902 are connected through a bus 903. The memory 902 is adapted to store instructions or programs executable by the processor 901. The processor 901 can be an independent microprocessor or a set of one or more microprocessors. Thus, by executing the instructions stored in the memory 902, the processor 901 implements the processing of data and the control of other devices by executing the method flow of the embodiment of the present invention as described above. The bus 903 connects the above-mentioned multiple components together, and at the same time connects the above-mentioned components to a display controller 904, a display device, and an input / output (I / O) device 905. The input / output (I / O) device 905 can be a mouse, a keyboard, a modem, a network interface, a touch input device, a body-sensing input device, a printer, and other devices well-known in the art. Typically, the input / output device 905 is connected to the system through an input / output (I / O) controller 906.

[0154] The technical solutions provided by the embodiments of the present invention may include the following beneficial effects:

[0155] In this solution, a circulating current suppression method based on visual programming is provided to achieve efficient and convenient circulating current suppression.

[0156] In this solution, through the parameter adaptive analysis of the circulating current process, accurate circulating current tracking adjustment is achieved.

[0157] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0158] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, and the combination of processes and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate for implementing in the process Figure 1 one process or multiple processes and / or blocks Figure 1a device for the functions specified in one or more boxes.

[0159] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured article including an instruction device that implements the functions specified in one Figure 1 process or more processes and / or boxes Figure 1 a box or more boxes.

[0160] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to produce a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one Figure 1 process or more processes and / or boxes Figure 1 a box or more boxes.

[0161] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. A visualization-based double frequency circulation suppression method, characterized in that: The method includes: Setting up a circulation suppression visualization structure with a circulation suppression module; Set the location of the visualization background and update the visualization data after the circulation suppression module performs circulation suppression; Through the containerized deployment platform, the input and output parameters of circulation suppression are obtained online; Calculating a reference voltage for circulating current suppression according to the input parameters of the circulating current suppression obtained, and storing the reference voltage after each circulating current suppression in a cloud data center; In the cloud data center, the optimal circulation parameters are automatically learned based on the visualized data; After obtaining the optimal circulation parameters, the system continues to operate, and if an abnormal situation occurs, the optimal circulation parameters are updated.

2. A visualization-based double frequency circulating current suppression method as claimed in claim 1, characterized in that: The setting of the circulation suppression visualization structure specifically includes: Setting up a visual programming platform based on the Internet of Things cloud platform, wherein the visual programming platform is used to seal the circulation suppression module; The initial parameters of the circulation suppression module are set, wherein the initial parameters include preset initial values ​​of the first control parameter, the second control parameter, and the third control parameter.

3. A visualization-based double frequency circulating current suppression method as claimed in claim 1, characterized in that: The setting of the location of the visualization background and updating of the visualization data specifically includes: Set the visual programming platform online to obtain the effective value of the current circulation, and use the effective value of the circulation after the circulation is suppressed in a period of 1 minute as the standard circulation parameter; After each update of the standard circulation parameters, the updated standard circulation parameters are uploaded to the cloud data center as visualization data through a visualization programming platform.

4. A visualization-based double frequency circulating current suppression method as claimed in claim 2, characterized in that: The input parameters and output parameters of circulation suppression are obtained online through the containerized deployment platform, specifically including: The input parameters of the adaptive adjustment of circulating current suppression strategy interface are set to bridge arm current, virtual potential and DC voltage, where the bridge arm current is the real-time value of the current of the upper bridge arm and the lower bridge arm, the virtual potential is half of the difference between the voltage of the upper bridge arm and the voltage of the lower bridge arm of the corresponding phase voltage, and the DC voltage is the rated DC voltage of the modular multilevel converter; Setting a first control parameter, a second control parameter and a third control parameter as input parameters, wherein the first control parameter is a preset proportional coefficient, the second control parameter is a preset integral coefficient, and the third control parameter is a preset differential coefficient; Set the voltage correction of the upper and lower bridge arms as the output parameter of circulating current suppression.

5. A visualization-based double frequency circulating current suppression method as claimed in claim 4, characterized in that: The obtaining of the input parameters of the circulating current suppression, calculating the circulating current suppression reference voltage, and storing the reference voltage after each circulating current suppression in a cloud data center specifically includes: Obtain the bridge arm current value, and calculate the circulating current using the second calculation formula; Calculate the double frequency D-axis component and the double frequency Q-axis component according to the current circulating current value using the third calculation formula; Calculate the circulating current suppression reference voltage using a fourth calculation formula according to the first control parameter, the second control parameter and the third control parameter; Generate a reference voltage after circulating current suppression using the fifth calculation formula; The second calculation formula is: ICj=0.5×(IPj+INj) Among them, IPj is the current of the upper bridge arm of phase j, INj is the current of the lower bridge arm of phase j, and ICj is the circulating current value of phase j; The third calculation formula is: Among them, ID is the double frequency D-axis component, IQ is the double frequency Q-axis component, IC1, IC2, IC3 are the circulating current values ​​of phase A, phase B and phase C respectively, F1() is the extraction function of the D-axis component, and F2 is the extraction function of the Q-axis component; The fourth calculation formula is: Wherein, Ucirj3 is the circulating current suppression reference voltage of the three phases a, b and c, pk, pi and pd are the first control parameter, the second control parameter and the third control parameter respectively, FF() is a function for converting the dq axis component into the circulating current suppression reference voltage of the jth phase, wherein FF() will calculate the circulating current suppression reference voltage of the three phases a, b and c; The fifth calculation formula is: Upj=0.5×UD-Uj-Ucirj Unj=0.5×UD-Uj-Ucirj Among them, UD is the rated voltage, Uj is the voltage reference value, Upj is the upper bridge arm voltage reference value, Unj is the lower bridge voltage reference value, and Ucirj is a phase among a, b and c, which is defined as the circulating current suppression reference voltage of the jth phase.

6. A visualization-based double frequency circulating current suppression method as claimed in claim 1, characterized in that: The automatic learning of optimal circulation parameters in the cloud data center specifically includes: In the cloud data center, several circulation suppression parameters are set, wherein the circulation suppression parameters are a first control parameter, a second control parameter, and a third control parameter; Extract standard circulation parameters in the past period of time, and extract whether the standard circulation parameters satisfy the sixth calculation formula. If so, stop updating the circulation suppression parameters. If not, replace a circulation suppression parameter that has not been used every one minute. Until the condition is met, the updating of the circulation suppression parameters is stopped, and the circulation suppression parameters are no longer updated, and the current circulation suppression parameters are used as the optimal circulation parameters; The sixth calculation formula is: ccc<0.1×EE Among them, EE is the reference value of rated current, and ccc is the standard circulating current parameter.

7. The visualization-based double frequency circulating current suppression method according to claim 1, characterized in that: After obtaining the optimal circulation parameters, the system continues to operate, and if an abnormal situation occurs, the optimal circulation parameters are updated, specifically including: After obtaining the optimal circulation parameters, the system continues to operate. If the standard circulation parameters cannot satisfy the seventh calculation formula for 20 consecutive seconds, a circulation suppression parameter that has not been used will be started and replaced. The circulation suppression parameters will be stopped until the sixth calculation formula is satisfied. The circulation suppression parameters will no longer be updated, and the current circulation suppression parameters will be used as the optimal circulation parameters. The seventh calculation formula is: ccc<0.15×EE Among them, EE is the reference value of rated current, and ccc is the standard circulating current parameter.

8. A visualization-based double frequency circulation suppression system, characterized in that: The system is used to implement the method according to any one of claims 1 to 7, and the system comprises: A circulation regulation visualization structure module is used to set a circulation suppression visualization structure having a circulation suppression module; The visualization setting module is used to set the location of the visualization background and update the visualization data after the circulation suppression module performs circulation suppression; The circulation parameter acquisition module is used to obtain the input and output parameters of circulation suppression online through the containerized deployment platform; An adaptive circulation suppression strategy module is used to calculate a circulation suppression reference voltage according to the input parameters of the circulation suppression obtained, and store the reference voltage after each circulation suppression in a cloud data center; The cloud-based optimal learning module is used to automatically learn the optimal circulation parameters based on visual data in the cloud data center; The optimal parameter updating module is used to continue the system operation after obtaining the optimal circulation parameters, and to update the optimal circulation parameters if an abnormal situation occurs.

9. A computer-readable storage medium storing computer program instructions, characterized in that: The computer program instructions implement the method according to any one of claims 1 to 7 when executed by a processor.

10. An electronic device comprising a memory and a processor, characterized in that: The memory is used to store one or more computer program instructions, wherein the one or more computer program instructions are executed by the processor to implement the method according to any one of claims 1-7.

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