A multi-split ac-dc step-up / down transformer control system and method

Abstract

This invention provides a control system and method for a multi-split AC / DC step-up / step-down transformer, belonging to the field of power conversion and energy storage control technology. By adding a first set of secondary coils and a second set of secondary coils to the existing step-up transformer, and coordinating with a rectifier, inverter, energy storage device, and parallel switch group, the system retains the original main and secondary coils' step-up and grid-connection functions while further enabling step-down energy storage during surplus power generation and energy storage and step-up grid connection during insufficient power generation. This allows step-up grid connection, step-down energy storage, and energy storage feedback to be achieved within the same transformer system, and enables distributed energy storage for single or multiple generator units at the generator end. Furthermore, in scenarios involving multiple coils, multiple branch options, and fluctuating mode boundaries in actual operation, the system improves control continuity, coil group matching, and long-term operational stability, reduces equipment investment and site occupation, and enhances the synergistic operation of energy storage and grid connection in new energy power plants.

Description

Technical Field

[0001] This invention relates to the field of power conversion and energy storage control technology, specifically to a control system and method for a multi-split AC / DC step-up / step-down transformer. Background Technology

[0002] In wind farms, photovoltaic power plants, hydropower stations, and other new energy power generation sites, the output power of the generation side typically exhibits significant fluctuations. On the one hand, when the power generation equipment has sufficient or excessive load, it is often necessary to transfer excess electricity to energy storage devices; on the other hand, when the output of the power generation equipment is insufficient or temporarily interrupted, energy storage devices are needed to replenish energy to the system side to maintain the continuity of power supply. Traditional implementation methods often separate the step-up transformer, step-down energy storage interface, and energy storage grid connection interface. This not only results in a large number of devices and a large site area, but also disperses the control links, making it difficult to simultaneously handle multiple operating states such as normal step-up grid connection, surplus energy extraction and storage, and energy storage back-feeding grid connection under the same control framework. Furthermore, due to site or space limitations at some power generation ends, it is often difficult to achieve distributed energy storage for single or multiple power generation devices.

[0003] Meanwhile, in traditional control methods, the common practice is to directly switch between charging and discharging based on the power difference between the generation side and the load side, or to perform coarse-grained activation and deactivation control based solely on the state of charge of the energy storage device. While this approach can achieve basic energy transfer in conventional single-coil or single-channel scenarios, for multi-split AC / DC step-up / step-down transformers with both a first and second set of secondary coils, the first and second sets of secondary coils may each contain multiple additional coil branches. Furthermore, different branch combinations correspond to different voltage level matching relationships, different current carrying capacities, and different activation / deactivation boundary states. If control is based solely on basic power balance logic and simple switching activation / deactivation logic, although the basic functions of surplus energy extraction and insufficient energy replenishment can be achieved, problems may still arise near the mode switching boundary under the condition of multiple coil combinations. These problems include repeated changes in the target coil combination, large fluctuations in reference values ​​between continuous control cycles, and a particular combination being continuously selected despite operating in a high-deviation state for an extended period. This can affect the stability of energy storage charging and the continuity of step-up grid connection.

[0004] Therefore, it is necessary to establish a computational control method adapted to this integrated structure, based on the construction of a multi-split AC / DC step-up / step-down transformer integrated system architecture that breaks through the basic structural limitations of traditional discrete equipment and drives the energy conversion between multiple AC / DC voltage levels to be concentrated in the same multi-split AC / DC step-up / step-down transformer system. This method would enable the participation relationship between the first and second sets of secondary coils under different operating scenarios, the target coil combination selection relationship, the switching on / off relationship, and the mode switching boundary relationship to be organized with a unified and continuous data processing link. This would improve the overall stability, coordination, and engineering feasibility of the system during surplus power generation energy storage, grid connection energy supplementation for insufficient power generation, and multi-voltage level switching processes. Summary of the Invention

[0005] The purpose of this invention is to provide a control method for multi-split AC / DC step-up / step-down transformers, which at least solves the problems of existing transformer schemes being unable to simultaneously take into account multiple operating states such as normal step-up grid connection, surplus energy extraction and storage, and energy storage back-to-grid connection under the same control framework, as well as the energy storage of single or multiple power generation devices at the generator end, and the difficulty in simultaneously taking into account power balance determination, coil combination selection, and continuous control of mode switching under a multi-split coil structure.

[0006] To achieve the above objectives, a first aspect of the present invention provides a control system for a multi-split AC / DC step-up / step-down transformer, comprising: A multi-split AC / DC step-up / step-down transformer includes a primary main coil, a primary secondary coil, a first set of secondary coils, and a second set of secondary coils. The first set of secondary coils includes n sets of additional coils disposed on the primary side and N sets of additional coils disposed on the secondary side. The second set of secondary coils includes m sets of additional coils disposed on the primary side and M sets of additional coils disposed on the secondary side. The primary main coil and the primary secondary coil are configured to maintain a conventional boost grid connection channel. The first set of secondary coils is configured to perform step-down energy extraction when the power generation equipment has redundant load. The second set of secondary coils is configured to perform boost energy delivery when the power generation equipment has insufficient load or stops. A rectifier is connected to n additional coils on the primary side of the first set of secondary coils, and is used to convert the alternating current corresponding to the first set of secondary coils into direct current required for charging the energy storage device. An inverter, which is connected to m additional coils on the primary side of the second set of secondary coils, is used to convert the DC power output by the energy storage device into AC power required for the second set of secondary coils to be boosted and connected to the grid. An energy storage device is disposed between the rectifier and the inverter, for storing the DC power output by the rectifier and providing discharge DC power to the inverter; A parallel switch group, comprising at least a rectifier switch disposed between the rectifier and the energy storage device, an inverter switch disposed between the inverter and the energy storage device, a grid disconnect switch disposed on N sets of auxiliary coils on the secondary side of the first set of secondary coils, and a grid connection switch disposed on M sets of auxiliary coils on the secondary side of the second set of secondary coils, wherein the parallel switch group is configured to switch the on / off states of the first set of secondary coils and the second set of secondary coils; The computing and control equipment is electrically or communicatively connected to the multi-split AC / DC step-up / step-down transformer, rectifier, inverter, energy storage device, and parallel switch group, respectively. It is configured to collect operating data from the generation side, system side, energy storage side, and each coil branch to form control result data corresponding to the current operating mode, and coordinate the control timing of the rectifier, inverter, and parallel switch group based on the control result data to realize step-down energy storage control when there is surplus power generation and step-up grid connection control when there is insufficient power generation.

[0007] A second aspect of the present invention provides a control method for a multi-split AC / DC step-up / step-down transformer, used in a computing and control device within a multi-split AC / DC step-up / step-down transformer control system as described in any of the preceding claims, the control method comprising: Acquire the output data from the power generation side, the bus data from the system side, the energy storage status data, the branch sampling data from the first and second sets of auxiliary coils, and the status data of the parallel switch group, and construct the current control status dataset; Based on the current control state dataset, calculate the power balance results and mode constraint results to determine the target operating mode data, and filter the target coil combination data based on the target operating mode data; Based on the target operating mode data and target coil combination data, rectifier reference data or inverter reference data is generated, and mode switching boundary continuity verification data is generated. Based on the rectifier reference data or inverter reference data, the mode switching boundary continuity verification data, and the parallel switch group status data, coordinate execution command data corresponding to the rectifier, inverter, and parallel switch group is generated; Obtain the execution feedback data corresponding to the coordinated execution command data, perform consistency correction on the execution feedback data and the coordinated execution command data, and update the current control state dataset for the next control cycle based on the correction result.

[0008] Through the above technical solution, this invention proposes a control system and method for a multi-split AC / DC step-up / step-down transformer. By adding a first set of secondary coils and a second set of secondary coils to the original step-up transformer, and cooperating with a rectifier, inverter, energy storage device, and parallel switch group, the system retains the original main coil and secondary coil step-up and grid connection functions, while further enabling step-down energy storage when power generation is excessive and energy storage and step-up grid connection when power generation is insufficient. This allows step-up grid connection, step-down energy storage, and energy storage feedback to be realized in the same transformer system. Furthermore, in the face of scenarios such as multiple coil participation, multiple branch selection, and easily fluctuating mode boundaries in actual operation, a continuous control link is constructed, consisting of the current control state dataset, target operating mode data, target coil combination data, mode switching boundary continuity verification data, coordinated execution command data, and execution feedback correction data. This allows the computational control device to more effectively select different additional coil combinations based on the multi-split AC / DC step-up / step-down transformer, smooth the reference value changes at the mode switching boundary, and perform constraint updates on continuous periodic deviations. Therefore, this invention can not only realize the integrated operation of multi-split AC / DC step-up and step-down transformers, but also further improve the control continuity, coil group matching and long-term operation stability in the process of surplus energy extraction and insufficient energy replenishment. Thus, while reducing equipment investment and site occupation, it enhances the engineering application effect of energy storage and grid-connected collaborative operation of new energy power stations, and can effectively solve the problem of energy storage for single or multiple power generation devices at the power generation end.

[0009] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0010] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a system structure diagram of a multi-split AC / DC step-up / step-down transformer control system provided in one embodiment of the present invention.

[0011] Figure 2 This is a control architecture diagram of a multi-split AC / DC step-up / step-down transformer control system provided in one embodiment of the present invention.

[0012] Figure 3 This is a schematic diagram of a distributed energy storage architecture supported by a multi-split AC / DC step-up / step-down transformer control system, provided in one embodiment of the present invention.

[0013] Figure 4 This is a flowchart of the steps of a multi-split AC / DC step-up / step-down transformer control method provided in one embodiment of the present invention.

[0014] Explanation of reference numerals in the attached figures: 100 - Multi-split AC / DC step-up / step-down transformer; 200 - Rectifier; 300 - Inverter; 400 - Energy storage equipment; 500 - Parallel switchgear; 600 - Computing and control equipment; 101 - Primary main coil; 102 - Primary secondary coil; 103 - First group of secondary coils; 104 - Second group of secondary coils; Additional coils for group 1031-n; additional coils for group 1032-N; additional coils for group 1041-m; additional coils for group 1042-M; 501 - Rectifier switch; 502 - Inverter switch; 503 - Off-grid switch; 504 - On-grid switch. Detailed Implementation

[0015] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0016] like Figure 1 and Figure 2 As shown in the figure, an embodiment of the present invention provides a control system for a multi-split AC / DC step-up / step-down transformer. The control system includes a multi-split AC / DC step-up / step-down transformer 100, a rectifier 200, an inverter 300, an energy storage device 400, a parallel switch group 500, and a computing and control device 600.

[0017] Specifically, the multi-split AC / DC step-up / step-down transformer 100 includes a primary main coil 101, a primary secondary coil 102, a first set of secondary coils 103, and a second set of secondary coils 104. The primary main coil 101 and the primary secondary coils 102 are used to retain the basic step-up grid connection channel. That is to say, in the entire technical route of this invention, the primary main coil 101 and the primary secondary coil 102 are not replaced by newly added secondary coil structures, but continue to exist as components of the system's original step-up grid connection capability. The advantage of this design is that the equipment does not need to lose its original main transformer operating capability due to the introduction of energy storage, thus maintaining the continuous inheritance relationship of equipment functions between different operating scenarios.

[0018] The first set of secondary coils 103 includes n sets of auxiliary coils 1031 disposed on the primary side and N sets of auxiliary coils 1032 disposed on the secondary side. It is mainly used to step down the voltage to extract energy when there is surplus power generation, and then provide charging power to the energy storage device 400 via the rectifier 200. The second set of secondary coils 104 includes m sets of auxiliary coils 1041 disposed on the primary side and M sets of auxiliary coils 1042 disposed on the secondary side. It is mainly used to receive the AC output from the inverter 300 and step up the voltage to supply energy to the system side when power generation is insufficient or stopped. It should be noted that the first set of secondary coils 103 and the second set of secondary coils 104 may each include one or more auxiliary coil units, and their number is not limited to a fixed value. n, N, m, and M can be set according to the actual voltage level, capacity level, equipment layout, and whether a distributed or centralized energy storage scheme is adopted.

[0019] Furthermore, such as Figure 3 As shown, in one executable implementation, the multi-split AC / DC step-up / step-down transformer control system of the present invention is also applicable to scenarios where it is difficult to add a separate energy storage transformer and electrical bays for a single or multiple power generation devices due to space constraints. Specifically, the existing step-up transformer can be used as the basis for modification. Without changing the original step-up and grid-connection main channel functions of the original main coil 101 and the original auxiliary coil 102, a first set of auxiliary coils 103, a second set of auxiliary coils 104, and corresponding rectifiers 200, inverters 300, energy storage devices 400, parallel switch groups 500, and computing and control devices 600 are added to the existing step-up transformer, thereby forming a distributed energy storage access structure for on-site deployment at the power generation end. In this way, the energy storage device 400 does not need to be configured with a separate energy storage transformer and electrical bays, but directly uses the modified multi-split AC / DC step-up / step-down transformer 100 to complete the energy coupling between the power generation side and the energy storage side, as well as the step-up and grid connection between the energy storage side and the system side.

[0020] In this embodiment of the invention, when the power generation end is a single power generation device, the original connection relationship between the single power generation device and the input side of the original step-up transformer can be maintained unchanged, and a local energy storage device 400 can be configured near the multi-split AC / DC step-up transformer 100 after the original step-up transformer has been modified. It is easy to understand that when the single power generation device has short-term output redundancy and cannot build a new independent energy storage step-up unit due to site limitations, the computing and control device 600 can control the first set of secondary coils 103 to start operation, so that the surplus power on the power generation side is stepped down by the first set of secondary coils 103 and converted by the rectifier 200 before being written into the energy storage device 400; when the output of the single power generation device decreases, fluctuates, or is shut down for a short time, the computing and control device 600 then controls the second set of secondary coils 104 to start operation, so that the energy storage device 400 performs step-up energy transmission through the inverter 300 and the second set of secondary coils 104, and continues to use the original step-up grid connection channel to supplement energy to the system side. Therefore, without the need to add a complete and independent energy storage transformer and electrical bay on the side of a single power generation device, distributed energy storage can be configured locally and the original step-up grid connection path can be reused.

[0021] In this embodiment of the invention, when there are multiple power generation devices at the power generation end, these devices can first be connected to the same multi-split AC / DC step-up transformer 100 (modified from an existing step-up transformer) via a collection line or parallel connection point. Then, the multi-split AC / DC step-up transformer 100 and the locally configured energy storage device 400 form a shared distributed energy storage unit. It should be noted that the distributed energy storage here is not limited to each power generation device having its own completely independent energy storage device 400. Alternatively, after several power generation devices are aggregated, one or more energy storage devices 400 can be configured near the aggregation point and connected to the modified original step-up transformer structure via the first set of secondary coils 103 and the second set of secondary coils 104. The advantage of this configuration is that it allows for the local absorption of surplus power from multiple power generation devices and local compensation for insufficient power generation, without significantly expanding the existing step-up substation site, existing outgoing line channels, and existing grid connection facilities. This enables multiple power generation devices to still be configured with energy storage and maintain good grid connection flexibility even under space constraints.

[0022] Furthermore, the beneficial effect of the solution described in this invention in site-constrained scenarios is that it eliminates the need to construct a separate, independent energy storage station near the power generation end. Instead, it transforms the existing step-up transformer into a multi-split AC / DC step-up / step-down transformer 100, allowing the energy flow path between the power generation equipment, energy storage equipment 400, and the system side to be organized within the same transformer system. This reduces the footprint of new equipment, the amount of civil engineering modifications, and the expansion of electrical bays. Simultaneously, it retains the existing step-up and grid-connection functions of the original main coil 101 and the original auxiliary coil 102. The computational control device 600 enables the orderly commissioning and decommissioning of the first set of auxiliary coils 103 and the mode switching of the second set of auxiliary coils 104. This ensures that distributed energy storage has good adaptability and engineering implementation value in scenarios involving a single power generation device, multiple power generation devices converging, and on-site modification of the original step-up station, and can significantly improve the economic efficiency of power generation by approximately 10-20%.

[0023] Furthermore, in one executable implementation, the multi-split AC / DC step-up / step-down transformer 100 can be either a single-phase structure or a three-phase structure. The operating principle and connection logic under the three-phase structure can be extended accordingly according to the single-phase structure.

[0024] The rectifier 200 is connected to the primary side of the first set of secondary coils 103 with n sets of auxiliary coils 1031, and the inverter 300 is connected to the primary side of the second set of secondary coils 104 with m sets of auxiliary coils 1041. The energy storage device 400 is disposed between the rectifier 200 and the inverter 300. It should be noted that the rectifier 200 and inverter 300 in this invention not only perform the energy conversion function between AC and DC, but also serve as the execution terminals for control feedback in the first set of secondary coils 103 and the second set of secondary coils 104, respectively. Therefore, in practical applications, the rectifier 200 and inverter 300 not only receive the electrical side power reference value, but also receive the mode tag, target current reference value, target voltage reference value, or target coil combination association identifier issued by the computing control device 600. Thus, the energy converter of this invention is no longer a simple passively responding power device, but rather, together with the multi-split secondary coils, constitutes an execution object that can be uniformly scheduled.

[0025] The energy storage device 400 is used to store the DC power output by the rectifier 200 and provide DC power for discharge to the inverter 300. It should be noted that the energy storage device 400 can be a battery pack, a supercapacitor pack, a lithium iron phosphate energy storage unit, a sodium-ion energy storage unit, a lead-carbon energy storage unit, or a composite energy storage system formed by combining multiple energy storage units; its corresponding battery management system can adopt conventional implementation methods in the art. This invention does not regard the energy storage device 400 itself as the core innovation point, but rather considers the energy storage device 400 as an energy cache link incorporated into the overall structure of the control system, and its state data is further uniformly accessed by the data processing link in the overall flow of the control method.

[0026] The parallel switch group 500 includes at least a rectifier switch 501, an inverter switch 502, a grid-connected switch 503, and a grid-connected switch 504. The rectifier switch 501 is located between the rectifier 200 and the energy storage device 400; the inverter switch 502 is located between the inverter 300 and the energy storage device 400; the grid-connected switch 503 is located on the secondary side of the first group of secondary coils 103, consisting of N groups of auxiliary coils 1032; and the grid-connected switch 504 is located on the secondary side of the second group of secondary coils 104, consisting of M groups of auxiliary coils 1042. It should be understood that in this invention, the parallel switch group 500 is not simply a switching device, but rather a fundamental execution component for establishing the mode-switching topology. That is, whether the first group of secondary coils 103 participates in charging mode, whether the second group of secondary coils 104 participates in discharging mode, and whether there are topological conflicts between charging and discharging modes, all need to be orderly realized through the parallel switch group 500 under the coordinated execution command data generated by the computing and control device 600.

[0027] The computing and control device 600 establishes electrical or communication connections with the multi-split AC / DC step-up / step-down transformer 100, rectifier 200, inverter 300, energy storage device 400, and parallel switch group 500. Unlike conventional controllers, the computing and control device 600 in this invention does not directly determine charging or discharging based solely on a threshold value. Instead, it establishes a more complete chain around the participation characteristics of the multi-split secondary coil structure, encompassing operational data acquisition, operational mode determination, target coil combination screening, reference value generation, boundary continuity verification, execution feedback correction, and historical deviation constraint update. Thus, the overall structure of the control system provides an integrated equipment foundation, while the overall control method process enables this integrated equipment foundation to operate more stably in complex operating scenarios. Together, they constitute the complete technical solution of this invention.

[0028] In a typical operating scenario, when the output of the power generation equipment exceeds the real-time demand on the system side, the computing and control equipment 600 controls the first set of secondary coils 103 to operate, the rectifier 200 to work, the rectifier switch 501 and the grid connection switch 503 to be turned on, the second set of secondary coils 104 to be deactivated, and the inverter switch 502 and the grid connection switch 504 to be disconnected. Thus, the first set of secondary coils 103 forms a step-down energy extraction path to charge the energy storage device 400. Simultaneously, the original main coil 101 and the original secondary coil 102 can still maintain their conventional step-up grid connection functions. Conversely, when the output of the power generation equipment is lower than the system side demand or the power generation equipment stops, the computing and control equipment 600 controls the second set of secondary coils 104 to operate, the inverter 300 to work, the inverter switch 502 and the grid connection switch 504 to be turned on, the first set of secondary coils 103 to be deactivated, and the rectifier switch 501 and the grid connection switch 503 to be disconnected. Thus, the second set of secondary coils 104 forms an energy storage discharge step-up grid connection path. It should be noted that, in some embodiments, the first set of secondary coils 103 and the second set of secondary coils 104 can also be used in conjunction with a bidirectional converter.

[0029] like Figure 4 As shown, this invention provides a control method for a multi-split AC / DC step-up / step-down transformer, used in the computing and control equipment of the multi-split AC / DC step-up / step-down transformer control system as described in any of the preceding claims. The control method includes: S10: Acquire the output data from the generator side, the bus data from the system side, the energy storage status data, the branch sampling data of the first and second auxiliary coils, and the status data of the parallel switch group, and construct the current control status dataset.

[0030] Specifically, the following data are collected: power output data from the generator side, voltage data from the generator side, bus voltage data from the system side, frequency data from the system side, state of charge data from the energy storage device, terminal voltage data from the energy storage device, voltage and current sampling values ​​from each branch of the first and second secondary coils, and state values ​​from the parallel switch group, as raw operating data. The raw operating data undergoes timestamp alignment, outlier removal, and dimensional normalization to form a data sequence corresponding to each sampling time. Based on the data sequence, the equivalent voltage level data, available current margin data, and allowable charge / discharge window data for each branch are calculated. The equivalent voltage level data, available current margin data, and allowable charge / discharge window data are then associated and combined with the data sequence to establish the current control state dataset corresponding to the current control cycle.

[0031] In this embodiment of the invention, by acquiring the output data of the power generation side, the bus data of the system side, the energy storage status data, the branch sampling data of the first group of auxiliary coils and the second group of auxiliary coils, and the status data of the parallel switch group, and constructing the current control status dataset based on the above data, the subsequent mode judgment, target coil combination screening, reference value generation and execution feedback correction can all be based on a unified and continuous data foundation.

[0032] It should be noted that the calculation and control equipment 600 synchronously collects the following data according to a preset control cycle: power output data from the generator side, voltage data from the generator side, bus voltage data from the system side, frequency data from the system side, state of charge data of the energy storage device, terminal voltage data of the energy storage device, voltage and current sampling values ​​of each branch of the first group of secondary coils 103 and the second group of secondary coils 104, and state values ​​of the parallel switch group 500. This data is then used as the raw operating data. This synchronous collection does not require absolutely simultaneous physical sampling; rather, it requires that all data be grouped under the same control cycle index before entering subsequent calculations.

[0033] Subsequently, the computing and control device 600 performs timestamp alignment, outlier removal, and dimensional normalization on the raw operating data. This processing is necessary because generation-side measurements, energy storage-side measurements, and switch status readbacks typically originate from different acquisition links. These links differ in sampling delay, noise levels, and calibration methods. Without initial standardization, the power balance and mode constraint results obtained in the next step will be mismatched. For example, if the system-side bus voltage data belongs to the previous control cycle, while the energy storage device's state of charge data belongs to the current control cycle, the seemingly rechargeable state may no longer meet the conditions in actual operation.

[0034] After completing the aforementioned basic processing, the computational control device 600 further calculates the equivalent voltage level data, available current margin data, and energy storage allowable charge / discharge window data for each branch based on the data sequence. It is important to note that the equivalent voltage level data characterizes the voltage conversion level relationship that different additional coil branches or combinations of additional coils can provide under the current operating conditions; the available current margin data characterizes the margin of each branch from its maximum allowable current; and the energy storage allowable charge / discharge window data reflects how much charging power the energy storage device can still receive or how much discharging power it can still output under the current state of charge, voltage, and temperature conditions. Finally, the computational control device 600 uniformly correlates the equivalent voltage level data, available current margin data, and energy storage allowable charge / discharge window data with the original operating data sequence to form the current control state dataset corresponding to the current control cycle.

[0035] S20: Calculate the power balance result and mode constraint result based on the current control state dataset to determine the target operating mode data, and filter the target coil combination data based on the target operating mode data.

[0036] Specifically, the power balance difference is calculated based on the power output data from the generation side and the load demand data from the system side; the executable power amount is obtained by performing executable constraint processing on the power balance difference based on the allowable charge and discharge window data of the energy storage; when the power balance difference is greater than the charging judgment threshold and the state of charge of the energy storage device is less than the upper limit threshold of the state of charge, charging mode data is generated; when the power balance difference is less than the negative number of the discharging judgment threshold, discharging mode data is generated; in other cases, standby mode data is generated; the executable power amount is associated with the charging mode data, discharging mode data, or standby mode data to form target operating mode data.

[0037] Furthermore, based on the target operating mode data, multiple candidate coil combinations are extracted from the operational additional coil combinations corresponding to the first or second set of auxiliary coils; a target voltage reference value for the current control cycle is generated based on the system-side bus voltage data, energy storage device terminal voltage data, and equivalent voltage level data; the target-side output voltage and branch predicted current corresponding to each candidate coil combination are predicted respectively, and the matching evaluation value of each candidate coil combination is calculated according to the following formula; the candidate coil combination with the smallest matching evaluation value is selected as the target coil combination data.

[0038] It should be noted that step S20 addresses two closely related questions in the control scenario of multi-split AC / DC step-up / step-down transformers: which operating mode should be entered and which set of additional coils should participate in the current operating mode. These two questions are not independent sequential decisions in this invention, but rather a continuous derivation based on the same current control state dataset. That is, the target operating mode is first determined by the power balance relationship and energy storage constraint relationship, and then the target operating mode is used to conversely limit the range of candidate coil combinations for screening.

[0039] In this embodiment of the invention, the calculation and control device 600 first calculates the power balance difference based on the power output data from the generation side and the load demand data from the system side: ; in, This represents the power balance difference in the t-th control cycle. This represents the power output from the generator side during the t-th control cycle. This represents the system-side load demand power during the t-th control cycle.

[0040] Using this formula, the calculation control device 600 can clearly determine whether the power generation side is in a state of power surplus or power shortage relative to the system side during the current control cycle. If If positive, it means that the current output from the generation side is greater than the system load demand; if... A negative value indicates that the current output from the generation side is lower than the system load demand. However, based solely on... The sign of the value is not enough to directly determine whether to charge or discharge, because the energy storage device 400 may not meet the conditions for further power reception or output at the current moment. Therefore, it is necessary to combine the allowable charge and discharge window data of the energy storage for feasible constraints.

[0041] To this end, the computational control device 600 further performs executability constraint processing on the power balance difference based on the energy storage allowable charge and discharge window data to obtain the executable power quantity: ; in, Let represent the executable power quantity in the t-th control cycle. This represents the upper limit of allowable power in the t-th control cycle, which is determined by the state of charge, terminal voltage, and allowable current of the energy storage device.

[0042] Based on this, when > and < When, generate charging mode data; when < and > In the current case, discharge mode data is generated; in other cases, standby mode data is generated. and These represent the charging and discharging thresholds, respectively. Indicates the current state of charge of the energy storage device. and These represent the upper and lower threshold values ​​for the state of charge, respectively. It should be noted that setting... and The purpose is to avoid the system repeatedly switching between charging and discharging modes when the power balance difference is close to zero, thereby providing a first layer of buffer for subsequent boundary continuity control.

[0043] After obtaining charging mode data, discharging mode data, or standby mode data, the computing and control device 600 associates the executable power quantity with the corresponding mode data to form target operating mode data. At this point, the target operating mode data is no longer just a simple mode label, but a combined control result containing the target mode and the corresponding executable power quantity.

[0044] Subsequently, the calculation and control device 600 enters the target coil combination data screening process. The first group of auxiliary coils 103 or the second group of auxiliary coils 104 often correspond to more than a single fixed additional coil structure, especially in scenarios with multiple voltage levels and multiple capacities, where there are often multiple operable coil combinations. If they are randomly selected without screening, the overall engineering usability of the control system structure itself will be weakened.

[0045] In one executable implementation, when the target operating mode data is charging mode data, the computing control device 600 extracts multiple candidate coil combinations only from the operable additional coil combinations corresponding to the first group of secondary coils 103; when the target operating mode data is discharging mode data, it extracts multiple candidate coil combinations only from the operable additional coil combinations corresponding to the second group of secondary coils 104; when the target operating mode data is standby mode data, no new coil operation combinations are generated, and only the previous cycle state is retained or the system enters an idle state.

[0046] Furthermore, the calculation and control device 600 generates a target voltage reference value for the current control cycle based on the system-side bus voltage data, the energy storage device terminal voltage data, and the equivalent voltage level data. And predict the target-side output voltage corresponding to each candidate coil combination. Predicted current of branches Then, calculate the matching evaluation value for each candidate coil combination according to the following formula: ; in, This represents the matching evaluation value of the i-th candidate coil combination. This represents the predicted output voltage on the target side for the i-th candidate coil combination. Indicates the target voltage reference value. This represents the predicted branch current for the i-th candidate coil combination. This represents the maximum allowable current in the branch corresponding to the i-th candidate coil combination. and This represents the weighting coefficient.

[0047] Through the above-described matching evaluation value calculation process, the calculation control device 600 considers both the deviation between the candidate coil combination and the target voltage reference value, as well as the current safety margin of the corresponding branch of the candidate coil combination. Therefore, the final selected target coil combination data can simultaneously consider voltage matching and current carrying capacity, rather than making a selection based solely on a single indicator. Finally, the calculation control device 600 selects the candidate coil combination with the smallest matching evaluation value as the target coil combination data and uses it in the reference value generation process of step S30.

[0048] S30: Generate rectifier reference data or inverter reference data based on the target operating mode data and target coil combination data, and generate mode switching boundary continuity verification data.

[0049] Specifically, when the target operating mode data is charging mode data, the charging power reference value and the rectified current reference value are calculated; when the target operating mode data is discharging mode data, the discharging power reference value and the inverter current reference value are calculated; the corresponding power reference value, current reference value, target voltage reference value and target coil combination data are correlated to form rectified reference data or inverter reference data.

[0050] Furthermore, the system reads the executed target voltage reference value, executed current reference value, and executed coil combination data from the previous control cycle, and extracts the target voltage reference value, current current reference value, and equivalent number of engaged coils corresponding to the current coil combination for the current control cycle. Based on the reference change between the current control cycle and the previous control cycle, it calculates the mode switching boundary continuity index. When the mode switching boundary continuity index is greater than the continuity judgment threshold, it generates transition target voltage reference value and transition current reference value. When the mode switching boundary continuity index does not exceed the continuity judgment threshold, it keeps the target voltage reference value and current reference value of the current control cycle unchanged, and uses the corresponding results as mode switching boundary continuity verification data.

[0051] It should be noted that step S30 is performed after the target operating mode data and target coil combination data have been obtained in step S20. Its purpose is to further refine the mode judgment result and coil selection result into reference data that can directly drive the rectifier 200, inverter 300 and subsequent parallel switch group 500 to perform actions, and introduce mode switching boundary continuity verification in this process.

[0052] In this embodiment of the invention, when the target operating mode data is charging mode data, the calculation and control device 600 first calculates the executable power quantity. Maximum allowable charging power of energy storage devices and the maximum allowable transmission power of the first set of secondary coils in the target coil combination. Calculate the reference value for charging power: ; This formula ensures that the final charging power reference value does not exceed the current power surplus level, the allowable charging capacity of the energy storage device 400, or the transmission capacity of the current target coil combination on the first set of secondary coils 103.

[0053] Subsequently, the calculation and control device 600 further calculates the rectified current reference value: ; in, This indicates the reference value for the rectified current. This indicates the current terminal voltage of the energy storage device. From this, the rectified reference data corresponding to the charging mode and the current target coil combination data can be obtained.

[0054] Correspondingly, when the target operating mode data is discharge mode data, the calculation control device 600 calculates the executable power quantity. Maximum allowable discharge power of energy storage devices and the maximum allowable transmission power of the second set of auxiliary coils in the target coil combination. Calculate the reference value for discharge power: ; Further calculation of the inverter current reference value: ; in, This represents the inverter current reference value. This forms the inverter reference data corresponding to the discharge mode and the current target coil combination data.

[0055] After completing the basic generation of rectifier reference data or inverter reference data, this invention further introduces a mode switching boundary continuity verification data generation process. Specifically, the calculation control device 600 reads the executed target voltage reference value, executed current reference value, and executed coil combination data from the previous control cycle, and extracts the target voltage reference value, current current reference value, and the equivalent number of engaged coils corresponding to the current coil combination for the current control cycle. Then calculate the mode switching boundary continuity index: ; in, This represents the continuity index of the mode switching boundary in the t-th control cycle. and These represent the target voltage reference values ​​for the current control cycle and the previous control cycle, respectively. and These represent the current reference values ​​for the current control cycle and the previous control cycle, respectively. Indicates the rated voltage. Indicates the rated current. and These represent the equivalent number of engaged coils in the current control cycle and the previous control cycle, respectively. This indicates the maximum number of equivalent coils allowed. , and This represents the weighting coefficient.

[0056] In an embodiment of the present invention, if > This indicates a significant change in the target voltage, target current, or number of engaged coils compared to the previous control cycle. In this case, directly using the target reference value for the current cycle, while still satisfying the mode determination logic from a single-cycle perspective, may cause insufficient smoothness in the instantaneous response of the rectifier 200, inverter 300, and parallel switch group 500 at the physical execution level, and may even lead to frequent switching of certain coil combinations within adjacent cycles. Therefore, the calculation control device 600 further generates transition target voltage reference values ​​and transition current reference values: ; ; The transition target voltage reference value and transition current reference value are used as the actual execution reference values ​​for the current control cycle boundary stage, thereby forming a transition zone between the current cycle reference value and the previous cycle reference value. ≤ If the difference between the current cycle and the previous cycle is within the allowable range, then the target voltage reference value and current reference value of the current control cycle are kept unchanged, and the corresponding results are used as the continuity verification data for the mode switching boundary.

[0057] Through the above processing, the overall flow of the control method will not reduce the control smoothness near the mode switching boundary due to the increase in the degree of freedom of path switching.

[0058] S40: Based on the rectifier reference data or inverter reference data, the mode switching boundary continuity verification data, and the parallel switch group status data, generate coordinated execution command data corresponding to the rectifier, inverter, and parallel switch group.

[0059] Specifically, a switching command vector for a parallel switch group is constructed; when the target operating mode data is charging mode data, a first switching command vector is generated; when the target operating mode data is discharging mode data, a second switching command vector is generated; when the target operating mode data is standby mode data, a third switching command vector is generated; a topology mutual exclusion check value is calculated based on the corresponding switching command vector; and when the topology mutual exclusion check value satisfies the constraints, the switching command vector, rectifier reference data or inverter reference data, and mode switching boundary continuity check data are associated and encapsulated to form coordinated execution command data.

[0060] It should be noted that step S40 is used to convert the aforementioned data processing results into command data that can be directly invoked by the execution layer. In this invention, the coordinated execution command data is not the control quantity of a single device, but a composite control result jointly generated for the rectifier 200, inverter 300, and parallel switch group 500. Its goal is to ensure that multiple devices coordinate their actions around the same control cycle result without causing conflicts between control contents.

[0061] In this embodiment of the invention, the switching command vector of the parallel switch group 500 is first constructed: ; in, This represents the rectifier switch command value in the t-th control cycle. Indicates the inverter switch command value. This indicates the value of the offline switch command. This indicates the command value for switching the internet connection on / off.

[0062] Furthermore, when the target operating mode data is charging mode data, generate =[1,0,1,0]; When the target operating mode data is discharge mode data, generate =[0,1,0,1]; When the target operating mode data is standby mode data, generate =[0,0,0,0]. This shows that there is a one-to-one correspondence between the generated switch command vector and the aforementioned target operating mode data.

[0063] After obtaining the switch command vector, the calculation control device 600 further calculates the topology mutual exclusion check value: ; in, This represents the topology mutual exclusion check value for the t-th control cycle. When... When =0, it means that there is no conflict between the current rectifier switch and the inverter switch being put into operation at the same time, and there is also no conflict between the grid-connected switch and the grid-connected switch being put into operation at the same time. Therefore, it can be determined that the current switch command vector satisfies the mutual exclusion constraint.

[0064] In practical applications, the mutual exclusion constraint verification is not merely to check for switch conflicts, but more importantly, to ensure that the first set of secondary coils 103 and the second set of secondary coils 104 do not simultaneously form unreasonable parallel paths due to control logic mismatch within the same control cycle. If the mutual exclusion constraint is not satisfied, even if steps S20 and S30 appear numerically reasonable, their execution results may still pose a risk to the overall topology security. Therefore, this step plays a crucial role in mapping the mode judgment result to a physically executable result.

[0065] After confirming that the topological mutual exclusion constraint is satisfied, the computing control device 600 associates and encapsulates the switching command vector, rectifier reference data or inverter reference data, and mode switching boundary continuity verification data to form coordinated execution command data. In one executable implementation, the coordinated execution command data includes at least a target mode identifier, a target coil combination identifier, a switching command vector, a target voltage reference value, a target current reference value, a power reference value, and a boundary transition identifier. Subsequently, the rectifier 200, inverter 300, and parallel switch group 500 respectively call the corresponding fields and complete the action execution within a unified control cycle.

[0066] S50: Obtain the execution feedback data corresponding to the coordinated execution command data, perform consistency correction on the execution feedback data and the coordinated execution command data, and update the current control state dataset for the next control cycle based on the correction result.

[0067] Specifically, the execution feedback data is acquired, which includes at least the actual transmission power, the actual target side voltage, and the actual switching state vector; based on the target power reference value, the target voltage reference value, and the switching command vector in the coordinated execution command data, a consistency deviation value is calculated; when the consistency deviation value is greater than the consistency correction threshold, the compensation coefficient is updated; based on the updated compensation coefficient, the target power reference value, the target voltage reference value, or the candidate coil combination screening conditions for the next control cycle are corrected, and the correction result is written into the current control state dataset for the next control cycle.

[0068] In addition, the method further includes: storing the consistency deviation values ​​of m consecutive control cycles to form a historical deviation sequence; calculating the rolling deviation mean based on the historical deviation sequence and updating the adaptive constraint threshold; when the rolling deviation mean is greater than the adaptive constraint threshold of the next control cycle, marking the target coil combination corresponding to the current control cycle as a temporary suppression combination and removing the temporary suppression combination from the candidate coil combinations of the next control cycle; when the rolling deviation mean does not exceed the adaptive constraint threshold of the next control cycle, keeping the target coil combination corresponding to the current control cycle in an optional state and updating the current control state dataset of the next control cycle.

[0069] It should be noted that step S50 further addresses the issue of whether the path maintains the expected effect throughout continuous execution. Without this step, although the aforementioned steps can complete pattern determination and command generation, it is difficult to detect deviations between the actual execution and the target result in a timely manner, and it is also impossible to suppress the accumulation of deviations within continuous cycles.

[0070] In this embodiment of the invention, the computing control device 600 acquires execution feedback data, which includes at least the actual transmission power. Actual target side voltage and the actual switching state vector The actual transmission power here The actual target-side voltage is used to reflect the actual level of energy transfer completed within the current cycle. This is used to reflect the actual voltage state formed on the target side under the current target coil combination and the current reference value, while the actual switching state vector... This is used to reflect whether the parallel switch group 500 is consistent with the command level at the physical execution level.

[0071] Subsequently, the calculation control device 600 calculates the consistency deviation value based on the target power reference value, target voltage reference value, and switching command vector in the coordinated execution command data: ; in, This represents the consistency deviation value in the t-th control cycle. Indicates the target power reference value. Indicates the actual transmission power. Indicates the target voltage reference value. Indicates the actual target-side voltage. Indicates the power reference value. Indicates the voltage reference value. Indicates based on the actual switch state vector With the switch command vector The calculated inconsistency of switch states , and This represents the weighting coefficient.

[0072] Using this consistency deviation value, the control device 600 can simultaneously measure the execution result of the current control cycle from three dimensions: power deviation, voltage deviation, and switching state deviation, instead of relying solely on a single physical quantity as the basis for correction. > If this is the case, it indicates that the execution effect of the current cycle deviates significantly from the command target. In this case, the compensation coefficient is updated according to the following formula: ; in, and represents the compensation coefficients for the current control cycle and the next control cycle, respectively, and λ represents the compensation update coefficient. The updated compensation coefficients are used to correct the target power reference value, target voltage reference value, or candidate coil combination screening conditions for the next control cycle, and the correction results are written into the current control state dataset for the next control cycle.

[0073] It should be further explained that the above consistency correction still mainly targets the deviation in a single control cycle. However, in the scenario of multiple split additional coil combinations, there is a more subtle problem: although the deviation value of a certain target coil combination in a single cycle does not significantly exceed the limit, if a moderate level of deviation continues to occur in multiple consecutive control cycles, it may cause instability at the mode switching boundary in a cumulative sense. Traditional methods are usually difficult to handle this type of problem because in traditional single-channel scenarios, there is usually no complex situation where multiple additional coil combinations are repeatedly selected in rotation. Therefore, this invention further adds a historical deviation constraint update process on the basis of consistency correction.

[0074] Specifically, the calculation control device 600 stores the consistency deviation values ​​for m consecutive control cycles, forming a historical deviation sequence; subsequently, the rolling deviation mean is calculated based on the historical deviation sequence. ; in, This represents the average rolling deviation corresponding to the t-th control cycle. Let m represent the consistency deviation value in the j-th control cycle, and m represent the length of the historical deviation sequence.

[0075] Furthermore, the calculation control device 600 updates the adaptive constraint threshold based on the mean rolling deviation: ; in, and These represent the adaptive constraint thresholds for the current control cycle and the next control cycle, respectively. This represents the threshold retention coefficient.

[0076] when > When this occurs, it indicates that the overall execution stability of the current target coil combination is poor across multiple consecutive control cycles. Even if it does not necessarily trigger a serious fault in a single cycle, it is no longer suitable as a priority combination for the next cycle. Therefore, the calculation control device 600 marks the target coil combination corresponding to the current control cycle as a temporary suppression combination and removes the temporary suppression combination from the candidate coil combinations for the next control cycle; when ≤ If the current target coil combination is in an optional state, the current control state dataset for the next control cycle is updated.

[0077] Through this process, the present invention establishes a cross-cycle historical constraint layer in addition to the real-time correction in the current cycle. This historical constraint, through continuous cycle deviation statistics, adaptive threshold updates, and combined temporary suppression actions, can effectively suppress control oscillations caused by the repeated selection of certain combinations near the mode boundary.

[0078] In one specific implementation, suppose the new energy power station is currently in a fluctuating output state. During several consecutive control cycles, the power output from the generation side fluctuates around the system's demand power, while the state of charge of the energy storage equipment remains in the middle range. Therefore, the system frequently oscillates between the edge of charging mode and the edge of standby mode. If only the basic structure and simple power difference judgment logic provided by the overall control system structure are used, although the equipment already has the capability for step-down energy storage and step-up grid connection, it may still cause the two adjacent target coil combinations in the first set of secondary coils 103 to repeatedly switch within several control cycles. At this time, the present invention, through the mode switching boundary continuity check in step S30, first implements a smooth transition for changes in reference values ​​and the number of coils in operation; then, through the historical deviation constraint update in step S50, it temporarily suppresses the target coil combinations that perform poorly within consecutive cycles. Thus, the system can not only maintain the integrated energy allocation capability achieved by the overall control system structure, but also make the control process more stable under the overall flow of the control method, reducing unnecessary switching actions and reference value fluctuations.

[0079] In summary, the specific implementation of this invention shows that: the overall structure of the control system, through the integrated structure of multiple split AC / DC step-up and step-down transformers, realizes the unified integration of the original main and auxiliary coil step-up grid connection function and the auxiliary coil step-down energy storage and energy storage step-up grid connection function; the overall control method further focuses on the operating characteristics of this integrated structure under the condition of multiple auxiliary coils, and constructs a continuous control link consisting of the current control state dataset, target operating mode data, target coil combination data, mode switching boundary continuity verification data, coordinated execution command data, and execution feedback correction data, and improves the control stability in the continuous operation stage through the historical deviation constraint update mechanism.

[0080] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0081] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe the various possible combinations.

[0082] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. A control system for a multi-split AC / DC step-up / step-down transformer, characterized in that, include: A multi-split AC / DC step-up / step-down transformer includes a primary main coil, a primary secondary coil, a first set of secondary coils, and a second set of secondary coils. The first set of secondary coils includes n sets of additional coils disposed on the primary side and N sets of additional coils disposed on the secondary side. The second set of secondary coils includes m sets of additional coils disposed on the primary side and M sets of additional coils disposed on the secondary side. The primary main coil and the primary secondary coil are configured to maintain a conventional boost grid connection channel. The first set of secondary coils is configured to perform step-down energy extraction when the power generation equipment has redundant load. The second set of secondary coils is configured to perform boost energy delivery when the power generation equipment has insufficient load or stops. A rectifier is connected to n additional coils on the primary side of the first set of secondary coils, and is used to convert the alternating current corresponding to the first set of secondary coils into direct current required for charging the energy storage device. An inverter, which is connected to m additional coils on the primary side of the second set of secondary coils, is used to convert the DC power output by the energy storage device into AC power required for the second set of secondary coils to be boosted and connected to the grid. An energy storage device is disposed between the rectifier and the inverter, for storing the DC power output by the rectifier and providing discharge DC power to the inverter; A parallel switch group, comprising at least a rectifier switch disposed between the rectifier and the energy storage device, an inverter switch disposed between the inverter and the energy storage device, a grid disconnect switch disposed on N sets of auxiliary coils on the secondary side of the first set of secondary coils, and a grid connection switch disposed on M sets of auxiliary coils on the secondary side of the second set of secondary coils, wherein the parallel switch group is configured to switch the on / off states of the first set of secondary coils and the second set of secondary coils; The computing and control equipment is electrically or communicatively connected to the multi-split AC / DC step-up / step-down transformer, rectifier, inverter, energy storage device, and parallel switch group, respectively. It is configured to collect operating data from the generation side, system side, energy storage side, and each coil branch to form control result data corresponding to the current operating mode, and coordinate the control timing of the rectifier, inverter, and parallel switch group based on the control result data to realize step-down energy storage control when there is surplus power generation and step-up grid connection control when there is insufficient power generation.

2. A control method for a multi-split AC / DC step-up / step-down transformer, characterized in that, The computational control device used in the multi-split AC / DC step-up / step-down transformer control system as described in claim 1, wherein the control method includes: Acquire the output data from the power generation side, the bus data from the system side, the energy storage status data, the branch sampling data from the first and second sets of auxiliary coils, and the status data of the parallel switch group, and construct the current control status dataset; Based on the current control state dataset, calculate the power balance results and mode constraint results to determine the target operating mode data, and filter the target coil combination data based on the target operating mode data; Based on the target operating mode data and target coil combination data, rectifier reference data or inverter reference data is generated, and mode switching boundary continuity verification data is generated. Based on the rectifier reference data or inverter reference data, the mode switching boundary continuity verification data, and the parallel switch group status data, coordinate execution command data corresponding to the rectifier, inverter, and parallel switch group is generated; Obtain the execution feedback data corresponding to the coordinated execution command data, perform consistency correction on the execution feedback data and the coordinated execution command data, and update the current control state dataset for the next control cycle based on the correction result.

3. The control method for multi-split AC / DC step-up / step-down transformers according to claim 2, characterized in that, Acquire power generation side output data, system side bus data, energy storage status data, branch sampling data of the first and second sets of auxiliary coils, and parallel switch group status data, and construct the current control status dataset, including: The system collects the following data as raw operating data: power output data from the generator side, voltage data from the generator side, bus voltage data from the system side, frequency data from the system side, state of charge data from the energy storage device, terminal voltage data from the energy storage device, voltage and current sampling values ​​of each branch of the first and second secondary coils, and state values ​​of the parallel switch group. The original running data is processed by timestamp alignment, outlier removal and unit normalization to form a data sequence corresponding to each sampling time. Based on the data sequence, calculate the equivalent voltage level data, available current margin data, and allowable charge / discharge window data for each branch; The equivalent voltage level data, available current margin data, and energy storage allowable charge / discharge window data are associated and combined with the data sequence to establish the current control state dataset corresponding to the current control cycle.

4. The control method for multi-split AC / DC step-up / step-down transformers according to claim 3, characterized in that, Based on the current control state dataset, power balance results and mode constraint results are calculated to determine the target operating mode data, including: The power balance difference is calculated based on the power output data from the generation side and the load demand data from the system side. Based on the energy storage allowable charge and discharge window data, the power balance difference is subjected to executability constraint processing to obtain the executable power amount; When the power balance difference is greater than the charging determination threshold and the state of charge of the energy storage device is less than the upper limit threshold of the state of charge, charging mode data is generated; when the power balance difference is less than the negative number of the discharging determination threshold, discharging mode data is generated; otherwise, standby mode data is generated. The executable power quantity is associated with the charging mode data, discharging mode data, or standby mode data to form target operating mode data.

5. The control method for multi-split AC / DC step-up / step-down transformers according to claim 4, characterized in that, Filtering target coil combination data based on the target operating mode data includes: Based on the target operating mode data, multiple candidate coil combinations are extracted from the operational additional coil combinations corresponding to the first group of secondary coils or the second group of secondary coils. The target voltage reference value for the current control cycle is generated based on the system-side bus voltage data, energy storage device terminal voltage data, and equivalent voltage level data. Predict the target side output voltage and branch predicted current for each candidate coil combination, and calculate the matching evaluation value for each candidate coil combination according to the following formula; The candidate coil combination with the smallest matching evaluation value is selected as the target coil combination data.

6. The control method for multi-split AC / DC step-up / step-down transformers according to claim 2, characterized in that, Based on the target operating mode data and target coil combination data, rectifier reference data or inverter reference data is generated, including: When the target operating mode data is charging mode data, calculate the charging power reference value and the rectified current reference value; When the target operating mode data is discharge mode data, calculate the discharge power reference value and the inverter current reference value; The corresponding power reference value, current reference value, target voltage reference value, and target coil combination data are correlated to form rectifier reference data or inverter reference data.

7. The control method for multi-split AC / DC step-up / step-down transformers according to claim 6, characterized in that, Generate mode switching boundary continuity verification data, including: Read the executed target voltage reference value, executed current reference value, and executed coil combination data from the previous control cycle, and extract the target voltage reference value, current current reference value, and equivalent number of engaged coils corresponding to the current coil combination for the current control cycle; The continuity index of the mode switching boundary is calculated based on the reference change between the current control cycle and the previous control cycle. When the continuity index of the mode switching boundary is greater than the continuity judgment threshold, a transition target voltage reference value and a transition current reference value are generated. When the continuity index of the mode switching boundary does not exceed the continuity judgment threshold, the target voltage reference value and current reference value of the current control cycle remain unchanged, and the corresponding results are used as the continuity verification data of the mode switching boundary.

8. The control method for multi-split AC / DC step-up / step-down transformers according to claim 2, characterized in that, Based on the rectifier reference data or inverter reference data, the mode switching boundary continuity verification data, and the parallel switch group status data, coordinated execution command data corresponding to the rectifier, inverter, and parallel switch group is generated, including: Construct the switching command vector for the parallel switch group; When the target operating mode data is charging mode data, a first switch command vector is generated; when the target operating mode data is discharging mode data, a second switch command vector is generated; when the target operating mode data is standby mode data, a third switch command vector is generated. Calculate the topology mutual exclusion check value based on the corresponding switch command vector; When the topology mutual exclusion check value satisfies the constraints, the switching command vector, rectifier reference data or inverter reference data, and mode switching boundary continuity check data are associated and encapsulated to form coordinated execution command data.

9. The control method for multi-split AC / DC step-up / step-down transformers according to claim 2, characterized in that, Obtain the execution feedback data corresponding to the coordinated execution command data, perform consistency correction between the execution feedback data and the coordinated execution command data, and update the current control state dataset for the next control cycle based on the correction result, specifically including: Acquire execution feedback data, which includes at least the actual transmission power, the actual target-side voltage, and the actual switching state vector; Based on the target power reference value, target voltage reference value, and switching command vector in the coordinated execution command data, calculate the consistency deviation value; When the consistency deviation value is greater than the consistency correction threshold, the compensation coefficient is updated; The target power reference value, target voltage reference value, or candidate coil combination screening conditions for the next control cycle are corrected based on the updated compensation coefficients, and the correction results are written into the current control state dataset for the next control cycle.

10. The control method for multi-split AC / DC step-up / step-down transformers according to claim 9, characterized in that, The method further includes: Store the consistency deviation values ​​for m consecutive control cycles to form a historical deviation sequence. Calculate the rolling deviation mean based on the historical deviation sequence and update the adaptive constraint threshold. When the average rolling deviation is greater than the adaptive constraint threshold of the next control cycle, the target coil combination corresponding to the current control cycle is marked as a temporary suppression combination, and the temporary suppression combination is removed from the candidate coil combination of the next control cycle. When the average rolling deviation does not exceed the adaptive constraint threshold of the next control cycle, the target coil combination corresponding to the current control cycle is kept in the selectable state, and the current control state dataset of the next control cycle is updated.

Images