Compensation method for hybrid distribution transformer

Abstract

This invention discloses a compensation method for a hybrid distribution transformer, relating to the field of transformer technology. It is applicable to interconnected transformers consisting of a first hybrid distribution transformer, an energy storage control device, and a second hybrid distribution transformer connected in sequence. The method involves acquiring the first three-phase operating data of the first hybrid distribution transformer, the second three-phase operating data of the second hybrid distribution transformer, and the current energy storage information of the energy storage control device based on a preset sampling period. Based on the first and second three-phase operating data, compensation information for the first and second hybrid distribution transformers is calculated. Based on the compensation information and the current energy storage information of the energy storage control device, the conduction direction and power flow direction of the energy storage control device are determined. The switching on and off of the interconnected transformers is then controlled based on the conduction direction and power flow direction to complete the compensation.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and in particular to a compensation method for a hybrid distribution transformer. Background Technology

[0002] With the large-scale grid connection of distributed photovoltaic (PV) power, loads are exhibiting nonlinearity, imbalance, and significantly enhanced volatility. Furthermore, users' demands for power quality continue to rise, making the distribution network's regulation capabilities increasingly inadequate. Excessive power quality not only affects users' production and daily lives but may also trigger distributed PV disconnection from the grid, thereby restricting the absorption capacity of renewable energy.

[0003] A hybrid distribution transformer (HDT) adds a power electronic converter of a certain capacity to a traditional power frequency transformer. Compared to a traditional power frequency transformer, an HDT has significant advantages in voltage regulation, harmonic mitigation, imbalance suppression, and transient support. Its transient support for the distribution network covers voltage, current, inertia, and frequency. Regarding voltage support, when system faults such as lightning strikes, equipment insulation aging, or external damage cause voltage asymmetry on the distribution network side, the HDT can introduce a compensation voltage through its series compensation section, blocking the asymmetrical components from severely impacting the normal production of sensitive users within its service area. Simultaneously, the parallel compensation section of the HDT can respond to voltage dips in a short time, outputting reactive power to support the distribution network voltage and accelerating voltage recovery after fault clearance.

[0004] Existing hybrid distribution transformers, due to their limited capacity, are unable to provide sufficient compensation when there is a large three-phase imbalance disturbance. This results in poor compensation effect of the transformer, making it difficult to effectively suppress the three-phase voltage and current imbalance, leading to an increase in phase-to-phase voltage deviation and imbalance indicators, and a decline in the quality of power distribution operation. Summary of the Invention

[0005] This invention provides a compensation method for hybrid distribution transformers to improve adaptive compensation of the transformer and enhance transformer stability.

[0006] To address the aforementioned technical problems, embodiments of the present invention provide a compensation method for a hybrid distribution transformer, applicable to interconnected transformers. The interconnected transformer includes a first hybrid distribution transformer, an energy storage control device, and a second hybrid distribution transformer connected in sequence. The compensation method includes: The first three-phase operating data of the first hybrid distribution transformer, the second three-phase operating data of the second hybrid distribution transformer, and the current energy storage information of the energy storage control device are obtained based on a preset sampling period. The compensation information for the first hybrid distribution transformer and the second hybrid distribution transformer is calculated based on the first three-phase operating data and the second three-phase operating data, respectively. Based on the information to be compensated and the current energy storage information of the energy storage control device, the conduction direction and power flow direction of the energy storage control device are determined, and the switching on and off of the interconnecting transformer is controlled based on the conduction direction and the power flow direction to complete the compensation.

[0007] This invention is applicable to systems consisting of a first hybrid distribution transformer, an energy storage control device, and a second hybrid distribution transformer interconnected sequentially. By placing the compensation target within the overall architecture of the interconnected transformers, it achieves coordinated allocation of energy and information among the transformers, providing a system-level physical and control foundation for joint compensation across devices, and improving the coverage and coordination of compensation. Three-phase operating data and energy storage information from each end are acquired based on a preset sampling period. Periodic synchronous sampling provides time-consistent and comparable real-time operating data for compensation decisions, ensuring a reliable data foundation for compensation calculations and facilitating real-time response. Furthermore, the compensation information is calculated based on the three-phase operating data of the transformers on both sides, allowing for independent assessment of the compensation needs of each transformer. This clarifies local imbalances or reactive and active power deviations, ensuring the accuracy of the compensation target. Next, the energy storage conduction direction and power flow direction are determined based on the compensation information, and the interconnected transformer switches are controlled. The calculation results are directly converted into control commands for switching and power paths, achieving closed-loop control from decision-making to execution. This enables rapid and controllable targeted compensation for transformers with compensation needs, improving power quality and operational stability.

[0008] Furthermore, the step of calculating the compensation information for the first hybrid distribution transformer and the second hybrid distribution transformer based on the first three-phase operating data and the second three-phase operating data respectively includes: The first operating characteristics of the first hybrid distribution transformer are calculated based on the first three-phase operating data; The second operating characteristics of the second hybrid distribution transformer are calculated based on the second three-phase operating data; Based on the first operating characteristics, the first operating status information and the first compensation requirement information of the first hybrid distribution transformer are determined; The second operating status information and the second compensation requirement information of the second hybrid distribution transformer are determined based on the second operating characteristics. Compensation information is generated based on the first operating status information, the first compensation requirement information, the second operating status information, and the second compensation requirement information.

[0009] This invention acquires three-phase operating data and current energy storage information from both transformers based on a preset sampling period to ensure the consistency of data acquisition timing and the up-to-dateness of energy storage status, providing a unified input for subsequent feature extraction and decision-making. Furthermore, by extracting the operating characteristics of the first and second hybrid distribution transformers, their operating status can be quantified and used as a scalar basis for diagnostic and compensation decisions. Subsequently, based on the operating characteristics of both transformers, operating status information and compensation demand information are determined, transforming the original characteristics into clear operating status and compensation demands. This enables compensation scheduling to make decisions in a state-driven and demand-oriented manner, thereby improving the targeting and effectiveness of compensation. Based on the operating status, compensation demands, and energy storage information, compensation information is generated. Taking into account load-side demand and energy storage availability, executable compensation instructions are formed, optimizing energy storage resource utilization and reducing the risk of erroneous compensation or conflicting operations.

[0010] Furthermore, after generating the compensation information based on the first operating status information, the first compensation requirement information, the second operating status information, and the second compensation requirement information, the method further includes: Based on the operating status information and compensation demand information of each hybrid distribution transformer, control each hybrid distribution transformer to perform internal compensation, and obtain the remaining available compensation capacity and real-time compensation demand of each hybrid distribution transformer. The information to be compensated is updated based on the remaining available compensation capacity and real-time compensation requirements.

[0011] This invention controls internal compensation based on the operating status information and compensation requirements of each transformer, obtaining the remaining available compensation capacity and real-time compensation demand information. It prioritizes localized compensation using the series and parallel compensation units of each transformer, reducing reliance on external resources and providing accurate resource availability data for system-level scheduling by acquiring remaining capacity. The compensation list is dynamically updated based on the remaining available compensation capacity and real-time compensation requirements, ensuring that scheduling decisions reflect the latest resource status and demand changes. This enhances the adaptability and robustness of the compensation strategy and reduces scheduling errors caused by inconsistent information.

[0012] Furthermore, the step of determining the conduction direction and power flow direction of the energy storage control device based on the information to be compensated and the current energy storage information of the energy storage control device, and controlling the switching on and off of the interconnecting transformer based on the conduction direction and the power flow direction to complete the compensation, includes: The transformer to be compensated is determined based on the real-time compensation requirement; wherein, the transformer to be compensated is a hybrid distribution transformer with a real-time compensation requirement greater than 0. The external compensation source is determined based on the current energy storage information of the energy storage control device and the remaining available compensation capacity of the non-compensated transformer. The conduction direction and power flow direction of the energy storage control device are set based on the external compensation source and the transformer to be compensated. The switching on and off of the interconnecting transformer is controlled based on the conduction direction and the power flow direction in order to compensate the transformer to be compensated.

[0013] This invention identifies the transformers to be compensated based on real-time compensation needs, clearly defining the target equipment requiring real-time external support. This allows the control strategy to concentrate resources to prioritize addressing actual gaps and improve compensation efficiency. Furthermore, it determines external compensation sources based on the current state of energy storage and the remaining available compensation capacity of non-compensated transformers. The external compensation planning simultaneously considers the available capacity of energy storage and other transformers, achieving synergy between resource optimization and distributed compensation, improving overall utilization and avoiding excessive use of single resources. Based on the external compensation source and the transformers to be compensated, the energy storage conduction direction and power flow direction are set. By pre-setting the conduction and flow directions, the energy transmission path and control logic can be clearly defined, reducing control conflicts and ensuring power is transmitted in the desired direction. Then, based on the conduction and power flow directions, the switching on and off of interconnected transformers is controlled, translating the power path into specific switching actions. This ensures that the compensation energy flows safely and reliably to the transformers to be compensated within the power grid, completing the directional correction of voltage or power deviations.

[0014] Furthermore, the control of the switching on and off of the interconnecting transformer based on the conduction direction and the power flow direction to compensate the transformer to be compensated includes: The switching on and off of the energy storage control device is controlled based on the conduction direction and the power flow direction, so that the power after the interconnecting transformer is turned on flows in the direction from the external compensation source to the transformer to be compensated, thereby completing the compensation of the transformer to be compensated.

[0015] This invention controls the switching on and off of the energy storage control device based on the conduction direction and power flow direction, so that after the interconnecting transformer is turned on, the power flows in the direction from the external compensation source to the transformer to be compensated; furthermore, by directly controlling the switch on the energy storage side, the controlled directional transmission of power can be achieved, which can effectively prevent energy backflow, avoid grid connection conflicts, and ensure that the power flow direction during the compensation process is clear and controllable, thereby improving the safety and determinism of compensation execution.

[0016] Furthermore, the energy storage control device includes a first interconnection control device, an energy storage device, and a second interconnection control device; The first end of the first interconnection control device is connected to the first hybrid distribution transformer; the second end of the first interconnection control device is connected to the energy storage device; the first end of the second interconnection control device is connected to the second hybrid distribution transformer; and the second end of the second interconnection control device is connected to the energy storage device.

[0017] The energy storage control device of the present invention consists of a first interconnection control device, an energy storage device, and a second interconnection control device. The first interconnection control device and the second interconnection control device are respectively connected to the corresponding transformer and the energy storage device. Through a modular interconnection control structure, the energy storage and each transformer are coupled through independent control units, which improves the system's controllability, scalability, and fault isolation capability. In the event of a local fault or when expansion is required, flexible maintenance and upgrades can be achieved by replacing or independently configuring the interconnection control units, thereby enhancing the system's reliability and maintenance convenience.

[0018] Furthermore, the first hybrid distribution transformer includes a first main transformer and a first series-parallel compensation module; The first parallel compensation module includes a first AC / DC converter, a first DC / AC converter, and a first capacitor; The AC terminal of the first AC / DC converter is coupled to the input terminal of the first main transformer, and the DC terminal of the first AC / DC converter is connected to the DC terminal of the first DC / AC converter; the AC terminal of the first DC / AC converter is coupled to the output terminal of the first main transformer. The first capacitor is connected in parallel with the first AC / DC converter, and the first capacitor is also connected in parallel with the first DC / AC converter.

[0019] The first hybrid distribution transformer of the present invention includes a first main transformer and a first series-parallel compensation module. The coupling between the series-parallel compensation module and the main transformer constitutes an active power quality conditioning unit, which can realize the rapid injection or absorption of active / reactive power. The topology of the first AC / DC converter, the first DC / AC converter and the first capacitor connected in parallel provides bidirectional energy conversion and energy buffering functions. It can not only absorb instantaneous disturbances to enhance system stability, but also support energy recovery from the main transformer to the compensation module, thereby improving the overall energy utilization efficiency and dynamic response speed.

[0020] Furthermore, the second hybrid distribution transformer includes: a second main transformer and a second series parallel compensation module; The second series-parallel compensation module includes a second AC / DC converter, a second DC / AC converter, and a second capacitor; The AC terminal of the second AC / DC converter is coupled to the input terminal of the second main transformer, and the DC terminal of the second AC / DC converter is connected to the DC terminal of the second DC / AC converter; the AC terminal of the second DC / AC converter is coupled to the output terminal of the second main transformer. The first capacitor is connected in parallel with the second AC / DC converter, and the second capacitor is connected in parallel with the first DC / AC converter.

[0021] The second hybrid distribution transformer of the present invention includes a second main transformer and a second series-parallel compensation module; the series-parallel compensation module provides symmetrical local compensation capability to the second side, thereby achieving equality and coordination in compensation strategy between the two sides; at the same time, the parallel configuration of capacitors and converters across the sides establishes a more flexible DC / AC energy exchange channel, which helps to share short-term energy more efficiently between the two sides, alleviate transient pressure on one side and reduce stress on a single DC link, thereby improving the system's coordinated compensation capability and fault tolerance.

[0022] Furthermore, the first interconnection control device includes a third AC / DC converter; The AC terminal of the third AC / DC converter is connected in parallel with the first capacitor; the DC terminal of the third AC / DC converter is connected with the energy storage device. The first interconnection control device of the present invention includes a third AC / DC converter, whose AC terminal is connected in parallel to the first capacitor and its DC terminal is connected to the energy storage device. Through the third AC / DC converter, a direct bidirectional energy channel is realized between the capacitor on the first transformer side and the energy storage, enabling the energy storage to quickly participate in the active and reactive power regulation of the first side and coordinate with the charging and discharging of the capacitor. This not only expands the local energy buffer capacity, but also provides or recovers energy with a low delay when external support is needed, thereby improving compensation efficiency and dynamic response performance.

[0023] Furthermore, the second interconnect control device includes a third DC / AC converter; The AC terminal of the third DC / AC converter is connected in parallel with the second capacitor; the DC terminal of the third DC / AC converter is connected to the energy storage device.

[0024] The second interconnection control device of the present invention includes a third DC / AC converter, whose AC terminal is connected in parallel to a second capacitor and whose DC terminal is connected to an energy storage device. Through this, the third DC / AC converter provides a direct AC injection path for the energy storage to the second transformer side. In conjunction with the second capacitor, it can realize rapid active / reactive power support and power quality improvement for the output of the second side. This configuration enhances the controllable influence of energy storage on the output of the two transformers, thereby improving the flexibility of cross-side compensation and the system's recovery capability under disturbances. Attached Figure Description

[0025] Figure 1 A schematic flowchart of a compensation method for a hybrid distribution transformer provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of an interconnecting transformer provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of another structure of an interconnected transformer provided in an embodiment of the present invention; The reference numerals for the accompanying drawings in the specification are as follows: 11. First hybrid distribution transformer; 12. Second hybrid distribution transformer; 13. Energy storage device; 14. First interconnection control device; 15. Second interconnection control device; 20. First AC / DC converter; 21. First DC / AC converter; 22. Second AC / DC converter; 23. Second DC / AC converter; 24. Third AC / DC converter; 25. Third DC / AC converter; 26. First switch; 27. Second switch; 28. Third switch; 29. ​​Fourth switch. Detailed Implementation

[0026] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0027] The terms "first" and "second," etc., in the specification, claims, and drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] Example 1 See Figure 1 , Figure 1 This is a schematic flowchart of a compensation method for a hybrid distribution transformer provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of an interconnected transformer provided by an embodiment of the present invention. The present invention provides a compensation method for a hybrid distribution transformer, applicable to interconnected transformers. The interconnected transformer includes a first hybrid distribution transformer, an energy storage control device, and a second hybrid distribution transformer connected in sequence. The method includes steps 101 to 103, as detailed below: Step 101: Based on a preset sampling period, acquire the first three-phase operating data of the first hybrid distribution transformer, the second three-phase operating data of the second hybrid distribution transformer, and the current energy storage information of the energy storage control device; In this embodiment, voltage and current sensors distributed on the primary and secondary sides of each hybrid distribution transformer are used to synchronously collect the first three-phase operating data of the first hybrid distribution transformer, the second three-phase operating data of the second hybrid distribution transformer, and the current energy storage information of the energy storage device according to a preset sampling period. The three-phase operating data includes time-series quantities such as voltage amplitude, phase, frequency, harmonic content, current amplitude and direction of each phase, and the sampling is aligned under the same time reference to meet the time-series consistency of subsequent comparison and coupling calculation.

[0030] Step 102: Calculate the compensation information for the first hybrid distribution transformer and the second hybrid distribution transformer based on the first three-phase operating data and the second three-phase operating data, respectively; In this embodiment, the step of calculating the compensation information for the first hybrid distribution transformer and the second hybrid distribution transformer based on the first three-phase operating data and the second three-phase operating data respectively includes: The first operating characteristics of the first hybrid distribution transformer are calculated based on the first three-phase operating data; The second operating characteristics of the second hybrid distribution transformer are calculated based on the second three-phase operating data; Based on the first operating characteristics, the first operating status information and the first compensation requirement information of the first hybrid distribution transformer are determined; The second operating status information and the second compensation requirement information of the second hybrid distribution transformer are determined based on the second operating characteristics. Compensation information is generated based on the first operating status information, the first compensation requirement information, the second operating status information, and the second compensation requirement information.

[0031] In this embodiment, after obtaining the raw data, feature extraction is performed on the first three-phase operating data to calculate the first operating features, such as: voltage deviation values ​​of each phase, three-phase unbalance, instantaneous active and reactive voltage components that need to be compensated and their corresponding reference phases, and harmonic content indicators obtained from harmonic analysis. Similarly, the second operating features are calculated on the second three-phase operating data. Subsequently, based on the first and second operating features and combined with preset thresholds and compensation rules, the operating status information and compensation demand information of the two transformers are determined, and the above operating status and compensation demand, along with the current energy storage information of the energy storage device, are input into the compensation scheduling module to generate information to be compensated.

[0032] In this embodiment, the operating status information may include: normal, slight imbalance, severe imbalance, transient drop, etc.; the compensation requirement information includes the required compensation voltage amplitude, phase, compensation current or power quantization value for each phase.

[0033] In this embodiment, three-phase operating data and current energy storage information of both transformers are acquired based on a preset sampling period to ensure the consistency of data acquisition timing and the up-to-dateness of energy storage status, providing a unified input for subsequent feature extraction and decision-making. Furthermore, by extracting the operating characteristics of the first and second hybrid distribution transformers, their operating status can be quantified and used as a scalar basis for diagnostic and compensation decisions. Then, based on the operating characteristics of both transformers, operating status information and compensation demand information are determined, transforming the original characteristics into clear operating status and compensation demands. This enables compensation scheduling to make decisions in a state-driven and demand-oriented manner, thereby improving the targeting and effectiveness of compensation. Based on the operating status, compensation demands, and energy storage information, compensation information is generated. Taking into account load-side demand and energy storage availability, executable compensation instructions are formed, optimizing energy storage resource utilization and reducing the risk of erroneous compensation or conflicting operations.

[0034] In this embodiment, after generating the compensation information based on the first operating status information, the first compensation requirement information, the second operating status information, and the second compensation requirement information, the method further includes: Based on the operating status information and compensation demand information of each hybrid distribution transformer, control each hybrid distribution transformer to perform internal compensation, and obtain the remaining available compensation capacity and real-time compensation demand of each hybrid distribution transformer. The information to be compensated is updated based on the remaining available compensation capacity and real-time compensation requirements.

[0035] In this embodiment, after initially generating compensation information based on operating status information, compensation demand information, and current energy storage information of the energy storage device, internal compensation commands are issued to the two hybrid distribution transformers respectively using a "local first, external later" strategy.

[0036] In this embodiment, firstly, based on their respective operating status information and compensation requirement information, the compensation amount that each hybrid distribution transformer can be directly provided by its series-parallel compensation module (i.e., its respective AC / DC converter, DC / AC converter, and parallel capacitor) is calculated. This compensation amount is then mapped to a corresponding control quantity and sent to the corresponding converter to implement internal compensation. This control quantity includes the duty cycle of each phase switch, the PWM / hysteresis current reference of the IGBT half-bridge, or the conduction sequence of the three-phase switches.

[0037] In this embodiment, during the internal compensation execution, real-time feedback is continuously obtained through voltage and current sensors and SOC sampling, and the used capacity of each transformer is calculated and returned in real time, thereby obtaining the remaining available compensation capacity a, b of each hybrid distribution transformer and its latest real-time compensation demand information, such as the compensation voltage and current or power values ​​of each phase that are not yet covered by internal compensation.

[0038] In this embodiment, the remaining available compensation capacities a and b, the remaining energy storage capacity c, and the energy transfer efficiencies n1 (between transformers) and n2 (between energy storage and any transformer) are used as inputs to recalculate the equivalent remaining capacity and update the compensation information. Specifically, the portion of the original compensation information that has been satisfied by internal compensation is removed, and the portion that still requires external support is marked as external compensation demand. A new external compensation allocation scheme is generated according to priority and available capacity allocation rules. If the equivalent remaining capacity is insufficient to fully cover the remaining demand, a corresponding external compensation control command is generated; if the equivalent remaining capacity is sufficient, the allocation result is converted into control commands for the conduction direction and power flow direction of the energy storage control device, thereby completing cross-station complementarity.

[0039] In this embodiment, internal compensation is controlled based on the operating status information and compensation requirements of each transformer. The remaining available compensation capacity and real-time compensation demand information are obtained. Local compensation is prioritized using the series and parallel compensation units of each transformer itself, reducing reliance on external resources. Furthermore, the remaining capacity provides accurate resource availability data for system-level scheduling. The compensation list is dynamically updated based on the remaining available compensation capacity and real-time compensation demands, ensuring that scheduling decisions reflect the latest resource status and demand changes. This enhances the adaptability and robustness of the compensation strategy and reduces scheduling errors caused by inconsistent information.

[0040] Step 103: Determine the conduction direction and power flow direction of the energy storage control device based on the information to be compensated, and control the switching on and off of the interconnecting transformer based on the conduction direction and power flow direction to complete the compensation.

[0041] In this embodiment, determining the conduction direction and power flow direction of the energy storage control device based on the information to be compensated and the current energy storage information of the energy storage control device, and controlling the switching on and off of the interconnecting transformer based on the conduction direction and the power flow direction to complete the compensation, includes: The transformer to be compensated is determined based on the real-time compensation requirement; wherein, the transformer to be compensated is a hybrid distribution transformer with a real-time compensation requirement greater than 0. The external compensation source is determined based on the current energy storage information of the energy storage control device and the remaining available compensation capacity of the non-compensated transformer. The conduction direction and power flow direction of the energy storage control device are set based on the external compensation source and the transformer to be compensated. The switching on and off of the interconnecting transformer is controlled based on the conduction direction and the power flow direction in order to compensate the transformer to be compensated.

[0042] In this embodiment, the real-time compensation requirement is determined based on the updated information to be compensated and the voltage / current status obtained from real-time sampling. When the real-time compensation requirement of a hybrid distribution transformer is greater than zero, that transformer is identified as a "transformer to be compensated". Subsequently, the scheduling logic identifies available external compensation sources based on the current energy storage information of the energy storage device (e.g., SOC or remaining power c) and the remaining available compensation capacity of non-compensated transformers (e.g., a or b derived from the compensation formula).

[0043] In this embodiment, the remaining available capacity of the non-compensated transformer is used first (to maximize the use of the local series-parallel compensation module). When the local remaining capacity is insufficient, the available energy of the energy storage device is called up, or the two are combined to form an equivalent external compensation capacity.

[0044] In this embodiment, after determining the external compensation source, the required power and direction are calculated based on the location of the external source, the location of the target to be compensated, and the energy transmission efficiency between the two sides, and the "conduction direction" and target power flow direction of the first interconnection control device and the second interconnection control device are set.

[0045] In this embodiment, the transformers to be compensated are determined based on real-time compensation needs, and the target equipment requiring real-time external support is clearly identified. This allows the control strategy to concentrate resources to prioritize addressing actual gaps and improve compensation efficiency. Furthermore, external compensation sources are determined based on the current state of energy storage and the remaining available compensation capacity of non-compensated transformers. The external compensation planning simultaneously considers the available capacity of energy storage and other transformers, achieving synergy between resource optimization and distributed compensation, improving overall utilization and avoiding excessive use of a single resource. Based on the external compensation source and the transformers to be compensated, the energy storage conduction direction and power flow direction are set. By pre-setting the conduction and flow directions, the energy transmission path and control logic can be clearly defined, reducing control conflicts and ensuring power is transmitted in the desired direction. Then, based on the conduction and power flow directions, the switching on and off of the interconnecting transformers is controlled, translating the power path into specific switching actions. This ensures that the compensation energy flows safely and reliably to the transformers to be compensated within the power grid, completing the directional correction of voltage or power deviations.

[0046] In this embodiment, controlling the switching on and off of the interconnecting transformer based on the conduction direction and the power flow direction to compensate the transformer to be compensated includes: The switching on and off of the energy storage control device is controlled based on the conduction direction and the power flow direction, so that the power after the interconnecting transformer is turned on flows in the direction from the external compensation source to the transformer to be compensated, thereby completing the compensation of the transformer to be compensated.

[0047] This invention controls the switching on and off of the energy storage control device based on the conduction direction and power flow direction, so that after the interconnecting transformer is turned on, the power flows in the direction from the external compensation source to the transformer to be compensated; furthermore, by directly controlling the switch on the energy storage side, the controlled directional transmission of power can be achieved, which can effectively prevent energy backflow, avoid grid connection conflicts, and ensure that the power flow direction during the compensation process is clear and controllable, thereby improving the safety and determinism of compensation execution.

[0048] Please refer to Figure 3 , Figure 3 This is a schematic diagram of another structure of an interconnected transformer provided in an embodiment of the present invention.

[0049] In this embodiment, the interconnected transformer includes a first hybrid distribution transformer, an energy storage control device, and a second hybrid distribution transformer connected in sequence.

[0050] In this embodiment, the energy storage control device includes a first interconnection control device, an energy storage device, and a second interconnection control device; The first end of the first interconnection control device is connected to the first hybrid distribution transformer; the second end of the first interconnection control device is connected to the energy storage device; the first end of the second interconnection control device is connected to the second hybrid distribution transformer; and the second end of the second interconnection control device is connected to the energy storage device.

[0051] In this embodiment, the first interconnection control device and the second interconnection control device are respectively connected to two hybrid distribution transformers, and complementary energy dispatch is achieved through bidirectional connection with the energy storage device. In actual operation, when one of the hybrid distribution transformers (e.g., the first transformer) generates a compensation demand due to voltage sag or power imbalance, the energy storage device can supply energy to the first hybrid distribution transformer through the first interconnection control device according to the compensation demand; at the same time, the status of the second hybrid distribution transformer is also monitored, and the remaining energy of the energy storage device is dispatched to the second transformer for its compensation demand through the second interconnection control device. Through such a bidirectional connection and dispatch mechanism, the system can ensure that the two hybrid distribution transformers can compensate for each other's insufficient energy under different operating conditions, providing continuous and stable voltage and current support.

[0052] In this embodiment, during compensation, the transformers requiring compensation are first identified based on real-time operating status information and compensation needs, and compensation information is generated. Through this energy storage control device, the conduction direction and power flow of the first and second interconnection control devices can be controlled according to the compensation information to ensure effective energy flow between the two transformers, thereby completing the compensation for the transformers to be compensated. This structure ensures that the energy storage device can not only independently support the local compensation needs of each transformer but also achieve dynamic energy allocation between the two transformers, optimizing overall compensation performance and improving system reliability and flexibility.

[0053] In this embodiment, the energy storage control device consists of a first interconnection control device, an energy storage device, and a second interconnection control device. The first interconnection control device and the second interconnection control device are respectively connected to the corresponding transformer and the energy storage device. Through a modular interconnection control structure, the energy storage and each transformer are coupled through independent control units, which improves the system's controllability, scalability, and fault isolation capability. When a local fault occurs or expansion is required, flexible maintenance and upgrades can be achieved by replacing or independently configuring the interconnection control units, thereby enhancing the system's reliability and maintenance convenience.

[0054] In this embodiment, the first hybrid distribution transformer includes a first main transformer and a first series-parallel compensation module; The first parallel compensation module includes a first AC / DC converter, a first DC / AC converter, and a first capacitor; The AC terminal of the first AC / DC converter is coupled to the input terminal of the first main transformer, and the DC terminal of the first AC / DC converter is connected to the DC terminal of the first DC / AC converter; the AC terminal of the first DC / AC converter is coupled to the output terminal of the first main transformer. The first capacitor is connected in parallel with the first AC / DC converter, and the first capacitor is also connected in parallel with the first DC / AC converter.

[0055] In this embodiment, the first hybrid distribution transformer consists of a first main transformer and a first series-parallel compensation module. The first series-parallel compensation module includes a first AC / DC converter, a first DC / AC converter, and a first capacitor. The AC terminal of the first AC / DC converter is coupled to the input terminal of the first main transformer, converting the AC power supply into DC power; the DC terminal of the first AC / DC converter is connected to the DC terminal of the first DC / AC converter, ensuring that the DC power can be transmitted to the DC / AC converter for inversion; the AC terminal of the first DC / AC converter is coupled to the output terminal of the first main transformer, converting the DC power back into AC power and outputting it to the secondary side of the transformer.

[0056] In this embodiment, the first capacitor is connected in parallel with the first AC / DC converter to provide smoothing filtering and reduce current fluctuations. Simultaneously, the first capacitor is also connected in parallel with the first DC / AC converter to further balance and stabilize the voltage waveform, reducing voltage fluctuations and harmonics in the system. This parallel compensation module configuration enables the first hybrid distribution transformer to achieve rapid reactive power regulation and effectively suppress voltage sags or fluctuations in the power grid. Through this structure, the first hybrid distribution transformer can independently or in conjunction with other transformers perform functions such as voltage balancing, power compensation, and transient voltage recovery, ensuring the stable operation of the distribution network.

[0057] In this embodiment, during the compensation process, when a voltage sag or power imbalance is detected in a hybrid distribution transformer (e.g., the first transformer), the transformer to be compensated is first determined based on real-time collected three-phase operating data. Then, based on the compensation requirement information of the first transformer, the controller controls the conversion efficiency of the first AC / DC converter and the first DC / AC converter, and adjusts the compensation voltage and current to compensate for the voltage sag and power imbalance. The first capacitor plays a smoothing role in the compensation process, optimizing power quality and ensuring the smoothness of voltage recovery. Through this control method, the compensation module of the first hybrid distribution transformer effectively adjusts and feeds energy back to the load, completing rapid voltage recovery and power balance compensation, improving the reliability and response speed of the system.

[0058] In this embodiment, the first hybrid distribution transformer includes a first main transformer and a first series-parallel compensation module. The coupling between the series-parallel compensation module and the main transformer constitutes an active power quality conditioning unit, which can realize the rapid injection or absorption of active / reactive power. The topology of the first AC / DC converter, the first DC / AC converter and the first capacitor connected in parallel provides bidirectional energy conversion and energy buffering functions. It can not only absorb transient disturbances to enhance system stability, but also support energy recovery from the main transformer to the compensation module, thereby improving the overall energy utilization efficiency and dynamic response speed.

[0059] In this embodiment, the second hybrid distribution transformer includes: a second main transformer and a second series parallel compensation module; The second series-parallel compensation module includes a second AC / DC converter, a second DC / AC converter, and a second capacitor; The AC terminal of the second AC / DC converter is coupled to the input terminal of the second main transformer, and the DC terminal of the second AC / DC converter is connected to the DC terminal of the second DC / AC converter; the AC terminal of the second DC / AC converter is coupled to the output terminal of the second main transformer. The first capacitor is connected in parallel with the second AC / DC converter, and the second capacitor is connected in parallel with the first DC / AC converter.

[0060] In this embodiment, the second hybrid distribution transformer includes a second main transformer and a second series parallel compensation module. The second series parallel compensation module consists of a second AC / DC converter, a second DC / AC converter, and a second capacitor. The AC terminal of the second AC / DC converter is coupled to the input terminal of the second main transformer, receiving AC power from the primary side of the main transformer and converting it into DC power. The DC terminal of the second AC / DC converter is connected to the DC terminal of the second DC / AC converter, ensuring that the DC power can be transmitted to the DC / AC converter for inversion. The AC terminal of the second DC / AC converter is coupled to the output terminal of the second main transformer, converting the DC power back to AC power and outputting it to the secondary side of the transformer.

[0061] In this embodiment, the second capacitor is connected in parallel with the second AC / DC converter to provide smoothing filtering and reduce current fluctuations. Simultaneously, the second capacitor is also connected in parallel with the second DC / AC converter to further balance and stabilize the voltage waveform, reducing voltage fluctuations and harmonics in the system. This parallel compensation module enables the second hybrid distribution transformer to flexibly adjust the power factor, suppress voltage sags and voltage imbalances, and enhance the stability of the power system.

[0062] In this embodiment, during system operation, when the second transformer experiences voltage dips, power imbalances, or load fluctuations, the compensation requirements of the second hybrid distribution transformer are calculated and determined based on real-time monitored three-phase operating data. On this basis, the voltage and current are precisely regulated through the second AC / DC converter and the second DC / AC converter to ensure the transformer receives the necessary compensation. The second capacitor works in conjunction to optimize power quality, suppress harmonics, and smooth voltage fluctuations. Through this control method, the second hybrid distribution transformer can quickly respond to changes in the grid's demands, restoring voltage and current balance, thereby improving system stability and power quality.

[0063] In this embodiment, the second hybrid distribution transformer includes a second main transformer and a second series-parallel compensation module. The series-parallel compensation module provides symmetrical local compensation capability to the second side, thereby achieving equality and coordination in compensation strategies between the two sides. At the same time, the parallel configuration of capacitors and converters across the sides establishes a more flexible DC / AC energy exchange channel, which helps to share short-term energy more efficiently between the two sides, alleviate transient pressure on one side, and reduce the stress of a single DC link, thereby improving the system's coordinated compensation capability and fault tolerance.

[0064] In this embodiment, the first interconnection control device includes a third AC / DC converter; The AC terminal of the third AC / DC converter is connected in parallel with the first capacitor; the DC terminal of the third AC / DC converter is connected to the energy storage device.

[0065] In this embodiment, the first interconnection control device includes a third AC / DC converter, the AC terminal of which is connected in parallel with the first capacitor, and the DC terminal of which is connected to the energy storage device.

[0066] In this embodiment, the third AC / DC converter, as part of the first interconnection control device, is responsible for enabling bidirectional energy flow between the energy storage device and the first hybrid distribution transformer. The AC terminal of the third AC / DC converter is connected to the first capacitor, and the parallel connection across the capacitor filters and smooths the voltage waveform, reducing high-frequency noise and harmonics caused by grid fluctuations, thus ensuring stable energy transmission. When the first hybrid distribution transformer requires compensation, the third AC / DC converter obtains electrical energy from the AC side and converts it into DC current to charge the energy storage device.

[0067] In this embodiment, during system operation, when a voltage sag or imbalance is detected in the first hybrid distribution transformer, the controller first determines its compensation needs and, based on real-time three-phase current and voltage data, decides whether to activate the energy storage device for compensation. If the energy storage device has sufficient charge, the third AC / DC converter connects the energy storage device to the first capacitor, adjusting the energy flow by controlling the converter's operating state. The energy storage device releases its stored energy through the third AC / DC converter, supplying the series-parallel compensation module of the first hybrid distribution transformer, thereby stabilizing the voltage, suppressing current imbalance, and providing the required power support. During this process, the third AC / DC converter not only supports the charging and discharging of the energy storage device but also, through its parallel connection with the capacitor, ensures effective filtering and stabilization of electrical energy during flow, making the compensation process more efficient and stable. With this configuration, the first hybrid distribution transformer can achieve rapid compensation under grid load fluctuations or sudden faults, improving the stability and reliability of the grid.

[0068] In this embodiment, the first interconnection control device includes a third AC / DC converter, whose AC terminal is connected in parallel to the first capacitor and its DC terminal is connected to the energy storage device. Through the third AC / DC converter, a direct bidirectional energy channel is realized between the first transformer-side capacitor and the energy storage, enabling the energy storage to quickly participate in the active and reactive power regulation of the first side and coordinate with the capacitor charging and discharging. This not only expands the local energy buffer capacity, but also provides or recovers energy with a low delay when external support is needed, thereby improving compensation efficiency and dynamic response performance.

[0069] In this embodiment, the second interconnection control device includes a third DC / AC converter; The AC terminal of the third DC / AC converter is connected in parallel with the second capacitor; the DC terminal of the third DC / AC converter is connected to the energy storage device.

[0070] In this embodiment, the second interconnection control device is composed of a third DC / AC converter, whose AC terminal is connected in parallel to the second capacitor C2, and whose DC terminal is connected to the DC bus of the energy storage device.

[0071] In this embodiment, when the compensation method determines that external compensation is required for the second hybrid distribution transformer, the scheduling module will send the external compensation information to the second interconnection control device, driving the third DC / AC converter to work from the DC side to the AC side (i.e., inverter / injection mode), inverting the DC energy from the energy storage device or the DC energy allocated by the first interconnection control device and the first transformer into AC energy that is synchronized with the phase, amplitude and frequency of the secondary side of the second main transformer and injecting it into the secondary side of the second transformer, thus completing the directional compensation for the second hybrid distribution transformer; wherein the parallel second capacitor C2 plays the role of filtering and energy buffering on the AC side, weakening high-frequency harmonics, smoothing the inverter voltage and providing instantaneous energy buffering during short-term power pulsation, ensuring the quality and stability of the injected power.

[0072] In this embodiment, the third DC / AC converter achieves active and reactive power tracking by controlling the PWM duty cycle, reference current, and voltage of its internal power switches (e.g., IGBT half-bridge) and hysteresis / PI loops. Before turn-on, it performs phase detection, grid synchronization, and soft-start current limiting to avoid grid impact. During compensation, the controller continuously uses voltage, current, and energy storage SOC as closed-loop feedback to dynamically adjust the output of the third DC / AC to meet real-time compensation requirements. Simultaneously, it executes protection and isolation strategies based on overcurrent, overvoltage, reverse power, and SOC constraints. When working in conjunction with the first hybrid distribution transformer and the first interconnection control device (third AC / DC), the third DC / AC can cooperate with the first-side converter to form an energy channel via energy storage, enabling energy allocation between the two transformers: the first side rectifies AC energy and injects it into the energy storage DC bus via the third AC / DC, and then the third DC / AC inverts DC energy and injects it into the second side, thereby completing cross-unit external compensation and improving compensation flexibility and system reliability.

[0073] In this embodiment, the second interconnection control device includes a third DC / AC converter, whose AC terminal is connected in parallel to the second capacitor and its DC terminal is connected to the energy storage device. Thus, the third DC / AC converter provides a direct AC injection path for the energy storage to the second transformer side. In conjunction with the second capacitor, it can realize rapid active / reactive power support and power quality improvement for the output of the second side. This configuration enhances the controllable influence of energy storage on the output of the two transformers, thereby improving the flexibility of cross-side compensation and the system's recovery capability under disturbances.

[0074] In this embodiment, the AC terminal of the first AC / DC converter is coupled to each phase of the input terminal of the first main transformer through three first switches.

[0075] In this embodiment, the AC side of the first AC / DC converter is not directly and fixedly connected in parallel to each phase of the primary side (input terminal) of the main transformer. Instead, it is coupled to each phase of the primary side of the main transformer via three independent first switches (corresponding to phases A, B, and C respectively). These three first switches can be power semiconductor switches (such as IGBT / SiC devices) or electromechanical switches with bypass / isolation functions, and their on and off states are controlled by the controller as needed.

[0076] In this embodiment, the compensation command is mapped to the phase-level connection and rectification operation mode of the first AC / DC converter based on the compensation information (including the compensation voltage, current and phase required for each phase) calculated by the feature extraction module. When a phase needs to absorb or inject energy by the series-parallel compensation module, the first switch of the corresponding phase is turned on, so that the phase is electromagnetically coupled to the rectifier bridge of the AC / DC converter, realizing active rectification or absorption of the phase; conversely, when no compensation is needed or isolation maintenance is required, the corresponding first switch is turned off, thereby realizing electrical isolation of the phase and avoiding unnecessary power transfer or backflow.

[0077] In this embodiment, by independently controlling the three first switches, phase-by-phase fine-grained compensation can be achieved, such as single-phase injection and absorption, two-phase coupling compensation, or three-phase coordinated compensation, improving the response accuracy and compensation efficiency for three-phase unbalanced conditions. Simultaneously, in conjunction with the PWM duty cycle, hysteresis loop, and current loop control at the AC / DC terminals, the voltage / current to be compensated can be accurately converted into the conduction angle on the rectifier side and the DC side voltage, thereby completing closed-loop power distribution. To ensure switching safety and reduce switching impact, this embodiment also implements phase synchronization, soft connection / current limiting strategies, and overcurrent / undervoltage protection before the switches are turned on. When isolation maintenance or backfeed prevention is required, the disconnection of the first switches can also be used to achieve rapid isolation, thereby improving the system's reliability and maintainability.

[0078] In this embodiment, the AC terminal of the first DC / AC converter is coupled to each phase of the output terminal of the first main transformer through three second switches.

[0079] In this embodiment, the AC side of the first DC / AC converter is not directly and fixedly connected in parallel to each phase of the secondary side of the first main transformer, but is coupled to each phase of the secondary side of the main transformer through three independently set second switches (corresponding to phases A, B, and C respectively).

[0080] In this embodiment, when the compensation information determines that the first hybrid distribution transformer needs to inject or absorb compensation voltage or current onto the secondary side, the second switch of the corresponding phase is closed, electrically connecting the AC output of the first DC / AC converter to the power grid on the secondary side of the main transformer. Subsequently, under its built-in active or reactive power and current closed-loop control and PWM / space vector modulation strategy, the DC / AC converter accurately generates compensation components according to the amplitude, phase, and frequency references issued by the controller. These components may include reverse-sequence components, harmonic suppression components, or transient injection components, thereby achieving phase-by-phase or combined-phase directional compensation on the secondary side. Conversely, if a phase has no compensation requirement or needs to be isolated for maintenance or to prevent backflow, the corresponding second switch can be opened, achieving rapid electrical isolation at the phase level.

[0081] In this embodiment, to ensure grid connection safety and smooth switching, before performing the closing operation of the second switch, the controller will first complete the phase-locked loop (PLL) and amplitude synchronization detection, steady-state check of DC link voltage and capacitor C1, and soft start / current limiting settings. After closing, the controller will use closed-loop current tracking and multiple protection strategies such as overcurrent / overvoltage / reverse power and SOC to monitor and dynamically adjust the duty cycle and reference value of DC / AC in real time. In case of abnormality, the injection can be quickly stopped by disconnecting the corresponding second switch or adjusting the duty cycle.

[0082] In this embodiment, the AC terminal of the second AC / DC converter is coupled to each phase of the input terminal of the second main transformer through three third switches.

[0083] In this embodiment, the AC side of the second AC / DC converter is not directly connected in parallel to each phase of the primary side of the second main transformer. Instead, it is controllably coupled to each phase of the primary side of the second main transformer through three independent third switches (corresponding to phases A, B, and C respectively). This allows the second AC / DC converter to selectively connect or isolate phases, thus playing a flexible role in energy harvesting and rectification in the compensation method.

[0084] In this embodiment, when it is determined from the information to be compensated that external compensation energy needs to be obtained from the second side, for example, if the second transformer has a remaining available compensation capacity b and needs to provide energy to the first transformer or energy storage device, the controller issues a closing command to close the corresponding third switch, connecting the corresponding phase to the rectifier bridge of the second AC / DC converter. Subsequently, the AC / DC converter, under PWM / duty cycle and current closed-loop (hysteresis or PI) control, rectifies AC energy as needed and delivers energy to the DC side, cooperating with the DC link and the energy storage or interconnection converter to complete the transfer or injection of energy. Conversely, when the phase does not need to participate in compensation or needs to be isolated for maintenance to avoid backflow, the corresponding third switch is opened to achieve rapid electrical isolation, reducing unnecessary power flow and device stress.

[0085] In this embodiment, to ensure safety and smooth switching, phase amplitude detection and soft-start current limiting are performed before the switch is closed. During operation, overcurrent, overvoltage, reverse power, and SOC constraint protection are implemented using current, DC bus voltage, and SOC as closed-loop feedback. If an anomaly is detected, the controller can immediately reduce or cut off the rectified power by quickly disconnecting the third switch or adjusting the duty cycle. Through the independent phase-level control of the three third switches, the system can achieve phase-by-phase refined energy harvesting, dynamic remaining capacity requisition, and coordinated scheduling with the first interconnected control device / energy storage device. This improves the flexibility, compensation accuracy, and operational safety of cross-station energy allocation under the compensation strategy of "local first, external later, on-demand requisition".

[0086] In this embodiment, the AC terminal of the second DC / AC converter is coupled to each phase of the output terminal of the second main transformer through three fourth switches.

[0087] In this embodiment, the AC side of the second DC / AC converter is not connected to each phase of the secondary side of the second main transformer, but is controlled by three fourth switches corresponding to phases A, B, and C respectively. This allows the second DC / AC converter to selectively inject or isolate energy from the secondary side phase by phase under the control of the compensation method, thereby achieving refined phase-by-phase compensation.

[0088] In this embodiment, when the compensation information determines that the second transformer requires injection compensation for one or more phases on its secondary side, and this compensation should be provided by an external or internal inverter, the fourth switch of the corresponding phase is closed, electrically connecting the AC terminal of the second DC / AC converter to the secondary side of the second main transformer. Subsequently, under its vector control or hysteresis / PI closed-loop current control and PWM / space vector modulation strategy, the DC / AC converter generates the desired AC voltage / current components according to the amplitude, phase, and frequency reference issued by the controller, injecting active / reactive power into the corresponding phase as needed, thereby achieving the effect of directional compensation. Conversely, when the phase does not require compensation or for maintenance, isolation, or safety requirements such as avoiding backflow, the corresponding fourth switch can be disconnected to achieve rapid electrical isolation, avoiding unnecessary power flow and device stress.

[0089] In this embodiment, to ensure grid connection safety and smooth switching, phase synchronization, amplitude detection, DC bus voltage steady-state check, soft start, and current limiting procedures are performed before the fourth switch is closed. After closing, closed-loop current tracking and active / reactive power control are used to achieve accurate tracking and compensation targets, and the converter duty cycle and reference value are adjusted in real time with voltage, current, and energy storage SOC as feedback. At the same time, overcurrent, overvoltage, reverse power, and SOC constraint protection logic are set. When an abnormality is detected, the injection path can be cut off by changing the duty cycle or quickly disconnecting the corresponding fourth switch to protect the equipment and grid safety.

[0090] In this embodiment, the independent phase-level control of the three fourth switches, combined with the filtering / buffering capabilities of the second DC / AC and parallel capacitor C2, enables the system to achieve rapid and accurate compensation for single-phase or multi-phase unbalanced conditions under the compensation strategy of "local first, external later, and interconnection device on demand". It can also work in conjunction with the first interconnection control device and energy storage device to form a cross-platform energy transmission channel, improving compensation flexibility, dynamic response capability and overall operational reliability.

[0091] This invention is applicable to systems consisting of a first hybrid distribution transformer, an energy storage control device, and a second hybrid distribution transformer interconnected sequentially. By placing the compensation target within the overall architecture of the interconnected transformers, it achieves coordinated allocation of energy and information among the transformers, providing a system-level physical and control foundation for joint compensation across devices, and improving the coverage and coordination of compensation. Three-phase operating data and energy storage information from each end are acquired based on a preset sampling period. Periodic synchronous sampling provides time-consistent and comparable real-time operating data for compensation decisions, ensuring a reliable data foundation for compensation calculations and facilitating real-time response. Furthermore, the compensation information is calculated based on the three-phase operating data of the transformers on both sides, allowing for independent assessment of the compensation needs of each transformer. This clarifies local imbalances or reactive and active power deviations, ensuring the accuracy of the compensation target. Next, the energy storage conduction direction and power flow direction are determined based on the compensation information, and the interconnected transformer switches are controlled. The calculation results are directly converted into control commands for switching and power paths, achieving closed-loop control from decision-making to execution. This enables rapid and controllable targeted compensation for transformers with compensation needs, improving power quality and operational stability.

[0092] In this embodiment of the invention, a terminal device is also provided, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the above-described compensation method for a hybrid distribution transformer.

[0093] In this embodiment of the invention, a computer-readable storage medium is also provided, which includes a stored computer program, wherein the computer program controls the device where the computer-readable storage medium is located to execute the above-described compensation method for a hybrid distribution transformer when it is running.

[0094] For example, a computer program can be divided into one or more modules, one or more of which are stored in memory and executed by a processor to perform the present invention. The one or more modules can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in a terminal device.

[0095] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor, memory, and display. Those skilled in the art will understand that the above components are merely examples of terminal devices and do not constitute a limitation on the terminal device. It may include more or fewer components, or combinations of certain components, or different components. For example, the terminal device may also include input / output devices, network access devices, buses, etc.

[0096] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device through various interfaces and lines.

[0097] Memory can be used to store computer programs and / or modules. The processor implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory, and by accessing data stored in the memory. Memory can mainly include a program storage area and a data storage area. The program storage area can store the operating system, application programs required for at least one function (such as sound playback, text conversion, etc.), etc.; the data storage area can store data created based on the use of the mobile phone (such as audio data, text message data, etc.). In addition, memory can include high-speed random access memory, and can also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart media cards (SMC), secure digital cards (SD cards), flash cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0098] In this invention, if the module based on the compensation method for hybrid distribution transformers is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. Those skilled in the art can understand and implement this invention without any inventive effort.

[0099] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A compensation method for a hybrid distribution transformer, characterized in that, The method is applicable to interconnected transformers, wherein the interconnected transformers include a first hybrid distribution transformer, an energy storage control device, and a second hybrid distribution transformer connected in sequence; the compensation method includes: The first three-phase operating data of the first hybrid distribution transformer, the second three-phase operating data of the second hybrid distribution transformer, and the current energy storage information of the energy storage control device are obtained based on a preset sampling period. The compensation information for the first hybrid distribution transformer and the second hybrid distribution transformer is calculated based on the first three-phase operating data and the second three-phase operating data, respectively. Based on the information to be compensated and the current energy storage information of the energy storage control device, the conduction direction and power flow direction of the energy storage control device are determined, and the switching on and off of the interconnecting transformer is controlled based on the conduction direction and the power flow direction to complete the compensation.

2. The compensation method for a hybrid distribution transformer as described in claim 1, characterized in that, The calculation of the compensation information for the first hybrid distribution transformer and the second hybrid distribution transformer based on the first three-phase operating data and the second three-phase operating data includes: The first operating characteristics of the first hybrid distribution transformer are calculated based on the first three-phase operating data; The second operating characteristics of the second hybrid distribution transformer are calculated based on the second three-phase operating data; Based on the first operating characteristics, the first operating status information and the first compensation requirement information of the first hybrid distribution transformer are determined; The second operating status information and the second compensation requirement information of the second hybrid distribution transformer are determined based on the second operating characteristics. Compensation information is generated based on the first operating status information, the first compensation requirement information, the second operating status information, and the second compensation requirement information.

3. The compensation method for a hybrid distribution transformer as described in claim 2, characterized in that, After generating the compensation information based on the first operating status information, the first compensation requirement information, the second operating status information, and the second compensation requirement information, the method further includes: Based on the operating status information and compensation demand information of each hybrid distribution transformer, control each hybrid distribution transformer to perform internal compensation, and obtain the remaining available compensation capacity and real-time compensation demand of each hybrid distribution transformer. The information to be compensated is updated based on the remaining available compensation capacity and real-time compensation requirements.

4. The compensation method for a hybrid distribution transformer as described in claim 3, characterized in that, Based on the information to be compensated and the current energy storage information of the energy storage control device, the conduction direction and power flow direction of the energy storage control device are determined, and the switching on and off of the interconnecting transformer is controlled based on the conduction direction and the power flow direction to complete the compensation, including: The transformer to be compensated is determined based on the real-time compensation requirement; wherein, the transformer to be compensated is a hybrid distribution transformer with a real-time compensation requirement greater than 0. The external compensation source is determined based on the current energy storage information of the energy storage control device and the remaining available compensation capacity of the non-compensated transformer. The conduction direction and power flow direction of the energy storage control device are set based on the external compensation source and the transformer to be compensated. The switching on and off of the interconnecting transformer is controlled based on the conduction direction and the power flow direction in order to compensate the transformer to be compensated.

5. The compensation method for a hybrid distribution transformer as described in claim 4, characterized in that, The control of the switching on and off of the interconnecting transformer based on the conduction direction and the power flow direction to compensate the transformer to be compensated includes: The switching on and off of the energy storage control device is controlled based on the conduction direction and the power flow direction, so that the power after the interconnecting transformer is turned on flows in the direction from the external compensation source to the transformer to be compensated, thereby completing the compensation of the transformer to be compensated.

6. The compensation method for a hybrid distribution transformer as described in claim 1, characterized in that, The energy storage control device includes a first interconnection control device, an energy storage device, and a second interconnection control device; The first end of the first interconnection control device is connected to the first hybrid distribution transformer; the second end of the first interconnection control device is connected to the energy storage device; the first end of the second interconnection control device is connected to the second hybrid distribution transformer; and the second end of the second interconnection control device is connected to the energy storage device.

7. The compensation method for a hybrid distribution transformer as described in claim 1, characterized in that, The first hybrid distribution transformer includes a first main transformer and a first series-parallel compensation module; The first parallel compensation module includes a first AC / DC converter, a first DC / AC converter, and a first capacitor; The AC terminal of the first AC / DC converter is coupled to the input terminal of the first main transformer, and the DC terminal of the first AC / DC converter is connected to the DC terminal of the first DC / AC converter; the AC terminal of the first DC / AC converter is coupled to the output terminal of the first main transformer. The first capacitor is connected in parallel with the first AC / DC converter, and the first capacitor is also connected in parallel with the first DC / AC converter.

8. The compensation method for a hybrid distribution transformer as described in claim 7, characterized in that, The second hybrid distribution transformer includes: a second main transformer and a second series of parallel compensation modules; The second series-parallel compensation module includes a second AC / DC converter, a second DC / AC converter, and a second capacitor; The AC terminal of the second AC / DC converter is coupled to the input terminal of the second main transformer, and the DC terminal of the second AC / DC converter is connected to the DC terminal of the second DC / AC converter; the AC terminal of the second DC / AC converter is coupled to the output terminal of the second main transformer. The first capacitor is connected in parallel with the second AC / DC converter, and the second capacitor is connected in parallel with the first DC / AC converter.

9. The compensation method for a hybrid distribution transformer as described in claim 8, characterized in that, The first interconnection control device includes a third AC / DC converter; The AC terminal of the third AC / DC converter is connected in parallel with the first capacitor; the DC terminal of the third AC / DC converter is connected to the energy storage device.

10. The compensation method for a hybrid distribution transformer as described in claim 8, characterized in that, The second interconnect control device includes a third DC / AC converter; The AC terminal of the third DC / AC converter is connected in parallel with the second capacitor; the DC terminal of the third DC / AC converter is connected to the energy storage device.

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