Control method of combined multifunctional transformer for flexible loop transfer

Abstract

The application relates to a control method and device for a combined multifunctional transformer for flexible loop transfer, computer equipment, a storage medium and a computer program product. The method comprises the following steps: acquiring an expected operating current of a looped circuit, equivalent impedance of the looped circuit, and a current voltage difference and a compensated voltage on both sides of the looped circuit; determining a first compensation voltage according to the equivalent impedance, the current voltage difference and the compensated voltage; acquiring an actual operating current of the looped circuit, and determining a second compensation voltage based on a deviation between the actual operating current and the expected operating current; generating a target compensation voltage according to the first compensation voltage and the second compensation voltage; adjusting a transformer of the looped circuit according to the target compensation voltage; and adjusting a reactor of the looped circuit to a target state. The method can effectively suppress the loop current generated in the loop operation process and reduce the influence of the loop impact current on power grid equipment.

Description

Technical Field

[0001] This application relates to the field of power distribution network technology, and in particular to a control method for a combined multifunctional transformer for flexible closed-loop power supply. Background Technology

[0002] With the continuous expansion of distribution network scale and the increasing demands for power supply reliability, closed-loop circuits have been widely used in distribution systems. During closed-loop operation, factors such as inconsistent transformer parameters on both sides of the closed-loop switch, uneven load distribution, or voltage fluctuations in the upstream grid often lead to significant circulating currents at the moment of closed-loop operation and during the operation period. Excessive circulating currents not only increase line losses but may also cause transformer overload and malfunction of protection devices, seriously threatening equipment safety and power supply stability. Existing control methods typically calculate compensation voltage based on the steady-state voltage difference before closed-loop operation and suppress circulating currents by adjusting transformer taps or connecting reactors, which can play a certain regulatory role under steady-state conditions. However, the operating environment of closed-loop circuits is complex, the load exhibits obvious time-varying characteristics, and the actual operating conditions of transformers continuously change. Relying solely on the steady-state voltage data before closed-loop operation to determine the compensation amount is insufficient to adapt to the dynamic current deviations that occur during operation after closed-loop operation, resulting in the circulating current suppression effect not meeting expectations. Summary of the Invention

[0003] Based on this, it is necessary to provide a control method, device, computer equipment, computer-readable storage medium, and computer program product for a combined multifunctional transformer with flexible loop power supply, addressing the aforementioned technical problems.

[0004] Firstly, this application provides a control method for a combined multifunctional transformer with flexible closed-loop power supply. The method includes:

[0005] Obtain the expected operating current of the closed loop, the equivalent impedance of the closed loop, and the current voltage difference and compensated voltage on both sides of the closed loop;

[0006] The first compensation voltage is determined based on the equivalent impedance, the current voltage difference, and the already compensated voltage.

[0007] Obtain the actual operating current of the closed loop, and determine the second compensation voltage based on the deviation between the actual operating current and the expected operating current;

[0008] Generate a target compensation voltage based on the first compensation voltage and the second compensation voltage;

[0009] According to the target compensation voltage, the transformer of the closed loop is adjusted; and the reactor of the closed loop is adjusted to the target state; wherein, the target state is used to suppress the circulating current generated during the closed loop operation.

[0010] In one embodiment, determining the first compensation voltage based on the equivalent impedance, the current voltage difference, and the compensated voltage includes:

[0011] Obtain the active and reactive currents of the closed loop at the current time;

[0012] Based on the equivalent impedance, the voltage difference, the compensated voltage, the active current, and the reactive current, predict the predicted active current and predicted reactive current at the next moment.

[0013] The first compensation voltage is determined based on the difference between the predicted active current and the expected active current, and the difference between the predicted reactive current and the expected reactive current.

[0014] In one embodiment, obtaining the actual operating current of the closed-loop circuit and determining the second compensation voltage based on the deviation between the actual operating current and the expected operating current specifically includes:

[0015] Obtain the active and reactive currents of the closed loop at the current time;

[0016] Based on the difference between the active current and the expected active current, and the difference between the reactive current and the expected reactive current, the active current deviation and the reactive current deviation are determined.

[0017] The initial compensation voltage is determined based on the active current deviation and reactive current deviation.

[0018] The initial compensation voltage is corrected based on the active current and reactive current to obtain the second compensation voltage.

[0019] In one embodiment, adjusting the transformer of the closed-loop circuit according to the target compensation voltage specifically includes:

[0020] Based on the target compensation voltage, obtain the basic compensation component of the transformer;

[0021] Based on the basic compensation component, the excitation voltage and series injection voltage of the transformer are adjusted to adjust the voltage relationship on both sides of the loop closing point.

[0022] In one embodiment, adjusting the reactor of the closed-loop circuit to the target state specifically includes:

[0023] Before the loop switch is closed, a first impedance adjustment command for the reactor is generated, and the equivalent inductive reactance of the reactor is adjusted to a high impedance state according to the first impedance adjustment command.

[0024] After the inrush current generated at the moment of loop closure drops to a preset threshold, a second impedance adjustment command for the reactor is generated, and the equivalent inductive reactance of the reactor is adjusted to the target impedance state according to the second impedance adjustment command.

[0025] In one embodiment, after adjusting the equivalent inductive reactance of the reactor to the target impedance state according to the second impedance adjustment command, the method further includes:

[0026] When a fault is detected in the distribution network, a third impedance adjustment command is generated for the reactor, and the impedance value of the reactor is lowered according to the third impedance adjustment command so that the power supply side outputs power to the fault side through the loop closing point.

[0027] Secondly, this application also provides a control device for a combined multifunctional transformer with flexible loop-to-circuit power supply. The device includes:

[0028] The data acquisition module is used to acquire the expected operating current of the closed loop, the equivalent impedance of the closed loop, and the current voltage difference and compensated voltage on both sides of the closed loop.

[0029] The compensation determination module is used to determine a first compensation voltage based on the equivalent impedance, the current voltage difference, and the already compensated voltage;

[0030] The compensation determination module is also used to obtain the actual operating current of the closed loop and determine the second compensation voltage based on the deviation between the actual operating current and the expected operating current.

[0031] The compensation determination module is further configured to generate a target compensation voltage based on the first compensation voltage and the second compensation voltage;

[0032] A voltage adjustment module is used to adjust the transformer of the closed loop according to the target compensation voltage; and to adjust the reactor of the closed loop to a target state; wherein the target state is used to suppress the circulating current generated during the closed loop operation.

[0033] In one embodiment, the compensation determination module is further configured to:

[0034] Obtain the active and reactive currents of the closed loop at the current time;

[0035] Based on the equivalent impedance, the voltage difference, the compensated voltage, the active current, and the reactive current, predict the predicted active current and predicted reactive current at the next moment.

[0036] The first compensation voltage is determined based on the difference between the predicted active current and the expected active current, and the difference between the predicted reactive current and the expected reactive current.

[0037] In one embodiment, the compensation determination module is further configured to:

[0038] Obtain the active and reactive currents of the closed loop at the current time;

[0039] Based on the difference between the active current and the expected active current, and the difference between the reactive current and the expected reactive current, the active current deviation and the reactive current deviation are determined.

[0040] The initial compensation voltage is determined based on the active current deviation and reactive current deviation.

[0041] The initial compensation voltage is corrected based on the active current and reactive current to obtain the second compensation voltage.

[0042] In one embodiment, the voltage adjustment module is further configured to:

[0043] Based on the target compensation voltage, obtain the basic compensation component of the transformer;

[0044] Based on the basic compensation component, the excitation voltage and series injection voltage of the transformer are adjusted to adjust the voltage relationship on both sides of the loop closing point.

[0045] In one embodiment, the voltage adjustment module is further configured to:

[0046] Before the loop switch is closed, a first impedance adjustment command for the reactor is generated, and the equivalent inductive reactance of the reactor is adjusted to a high impedance state according to the first impedance adjustment command.

[0047] After the inrush current generated at the moment of loop closure drops to a preset threshold, a second impedance adjustment command for the reactor is generated, and the equivalent inductive reactance of the reactor is adjusted to the target impedance state according to the second impedance adjustment command.

[0048] In one embodiment, the device further includes an impedance adjustment module for:

[0049] When a fault is detected in the distribution network, a third impedance adjustment command is generated for the reactor, and the impedance value of the reactor is lowered according to the third impedance adjustment command so that the power supply side outputs power to the fault side through the loop closing point.

[0050] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the control method for a combined multifunctional transformer for flexible loop-to-circuit power supply as described in any of the embodiments of this disclosure.

[0051] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the control method for a combined multifunctional transformer for flexible loop-to-circuit power supply as described in any of the embodiments of this disclosure.

[0052] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the control method for a combined multifunctional transformer for flexible loop-to-circuit power supply as described in any of the embodiments of this disclosure.

[0053] The aforementioned control method, device, computer equipment, storage medium, and computer program product for a combined multifunctional transformer used in flexible loop-closing power supply achieve a dual correction mechanism for voltage regulation during loop closure by combining a first compensation voltage calculated based on circuit parameters with a second compensation voltage based on current deviation feedback. This mechanism not only considers the static electrical characteristics of the loop closure circuit but also dynamically responds to changes in actual operating current, thereby effectively improving compensation accuracy. Simultaneously adjusting the transformer taps and coordinating the control of the reactor to the target state significantly reduces the circulating current amplitude during loop closure and steady-state operation, avoiding problems such as equipment overload, increased losses, or protection malfunctions caused by excessive circulating current, thus improving the safety and reliability of distribution network loop closure operations. Attached Figure Description

[0054] Figure 1 This is an application environment diagram of a control method for a combined multifunctional transformer with flexible loop power supply in one embodiment.

[0055] Figure 2 This is a flowchart illustrating a control method for a combined multifunctional transformer used in a flexible loop-to-power transfer configuration, as shown in one embodiment.

[0056] Figure 3 A system topology diagram illustrating a control method for a combined multifunctional transformer with flexible loop power supply in one embodiment;

[0057] Figure 4 A control block diagram illustrating an implementation of a control method for a combined multifunctional transformer with flexible loop power supply in one embodiment;

[0058] Figure 5 This is a structural block diagram of a control device for a combined multifunctional transformer used in a flexible loop-to-power supply system, as shown in one embodiment.

[0059] Figure 6 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0061] The control method for a combined multifunctional transformer with flexible closed-loop power supply provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104, or it can be located in the cloud or on another network server. The control method for the combined multifunctional transformer used for flexible loop power transfer can be executed by server 104, terminal 102, or a local controller independently located in the loop. After obtaining the operating parameters of the loop, server 104 or terminal 102 generates a target compensation voltage according to a preset control strategy and sends control commands via the network to the on-load tap changer and reactor switching or regulating actuators in the loop to coordinate the adjustment of the transformer's output voltage and the reactor's operating state. The data storage system also stores the loop's topology parameters, historical operating current data, and compensation voltage calculation models to support server 104 in data processing and command generation. The terminal 102 can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, and smart in-vehicle systems. Portable wearable devices can include smartwatches, smart bracelets, and head-mounted devices. The server 104 can be implemented using a standalone server or a server cluster consisting of multiple servers.

[0062] In one embodiment, such as Figure 2 As shown, a control method for a combined multifunctional transformer for flexible closed-loop power supply is provided, including the following steps:

[0063] Step S200: Obtain the expected operating current of the closed loop, the equivalent impedance of the closed loop, and the current voltage difference and compensated voltage on both sides of the closed loop.

[0064] The expected operating current may include the expected active current and the expected reactive current, which are determined by the distribution network dispatching department based on the load forecast results before loop closure. The equivalent impedance can be calculated in advance by the topology parameters of the loop closure circuit.

[0065] In one exemplary embodiment, the expected operating current of the closed loop, the equivalent impedance of the closed loop, and the current voltage difference and compensated voltage on both sides of the closed loop can be obtained by real-time collection of voltage and current data from a smart terminal deployed near the closed loop point, combined with load forecast information issued by the scheduling system and network topology parameters for fusion calculation. The current voltage difference may include the real-time voltage phasor difference between the feeder ports on both sides of the closed loop switch, and the compensated voltage may include the compensation amount applied in previous control cycles, which can be used to avoid repeated adjustments or overcompensation.

[0066] Step S202: Determine the first compensation voltage based on the equivalent impedance, the current voltage difference, and the compensated voltage.

[0067] The first compensation voltage can be used to feedforward compensate for potential current deviations in the closed-loop circuit at the next moment. Specifically, based on the circuit model, the theoretical expected current can be obtained by subtracting the compensated voltage from the current voltage difference and dividing by the equivalent impedance. This theoretical expected current is then compared with the expected operating current to determine the required compensation voltage. In practical applications, this process can combine real-time collected active and reactive currents, estimate the current component at the next moment using a state prediction algorithm, and then calculate the first compensation voltage based on the deviation between the predicted and target values ​​to improve the system's response to dynamic operating conditions.

[0068] In one exemplary embodiment, the active and reactive currents of the closed-loop circuit at the current time can be obtained, and a dynamic state equation can be constructed by combining the equivalent impedance, the current voltage difference, and the compensated voltage. Based on this state equation, the predicted active and reactive currents at the next moment are predicted. The predicted active current is compared with the expected active current to obtain the prediction deviation in the active direction, and the predicted reactive current is compared with the expected reactive current to obtain the prediction deviation in the reactive direction. According to the prediction deviation, a first compensation voltage for feedforward regulation is calculated using a preset proportional-integral control strategy or model predictive control algorithm. This first compensation voltage can offset the potential circulating current growth trend caused by load time-varying and grid fluctuations in advance, thereby improving the stability in the initial stage of closed-loop operation.

[0069] Step S204: Obtain the actual operating current of the closed loop, and determine the second compensation voltage based on the deviation between the actual operating current and the expected operating current.

[0070] The second compensation voltage can be used to provide feedback compensation for the actual current deviation of the closed-loop circuit at the current moment, eliminating the circulating current component generated under the current operating state, further reducing the deviation between the actual operating current and the expected operating current, and improving the stability of the closed-loop operation. Specifically, the actual operating current can be decomposed into active and reactive components, and the deviations of the two components from the corresponding expected components can be calculated separately. Then, the initial compensation voltage can be calculated by combining the impedance parameters of the closed-loop circuit. Finally, the initial compensation voltage can be corrected by combining the current actual operating current component to eliminate the calculation error caused by circuit coupling, and finally obtain a more accurate second compensation voltage to ensure the accuracy of feedback compensation.

[0071] In one exemplary embodiment, the active and reactive currents currently collected in the closed-loop circuit can be obtained, and then subtracted from the expected active and reactive currents issued by the dispatch center to obtain the active current deviation and reactive current deviation, respectively. These two deviations are then combined with equivalent impedance parameters to calculate the initial compensation voltage according to circuit relationships. Due to circuit coupling effects in the closed-loop circuit, different components can influence each other. Therefore, the initial compensation voltage needs to be coupled and corrected based on the current actual active and reactive currents to offset the calculation errors caused by component crossover, ultimately yielding the second compensation voltage. This compensation voltage, based on the current actual operational deviation, provides feedback correction, effectively eliminating the circulating current already generated and improving the stability of the closed-loop operation.

[0072] Step S206: Generate a target compensation voltage based on the first compensation voltage and the second compensation voltage.

[0073] The target compensation voltage can be a weighted sum or a direct sum of the first compensation voltage and the second compensation voltage. The weights can be dynamically adjusted according to different stages of the closed-loop operation. In the initial impact stage of the closed-loop operation, the weight of the first compensation voltage can be appropriately increased to enhance the feedforward pre-adjustment effect and suppress the rapid growth of the impact circulating current. After entering the steady-state operation stage, the weight of the second compensation voltage can be appropriately increased to enhance the deviation feedback correction and ensure the accuracy of circulating current suppression. Finally, based on the weighted summation result, the target compensation voltage value for transformer regulation is output.

[0074] In one exemplary embodiment, the weights of the first compensation voltage and the second compensation voltage can be dynamically set according to the stage of the loop-closing operation. During the initial impact stage when the loop-closing switch is just closed, the circulating current grows rapidly and has a significant impact on system stability. Therefore, a weight value greater than the first compensation voltage but less than 1 can be set greater than the weight of the second compensation voltage to fully utilize the feedforward pre-adjustment function of the first compensation voltage and suppress the growth of the impact circulating current in advance. When the loop-closing operation enters a steady state, the fluctuation amplitude of the circulating current decreases. The weight of the second compensation voltage can be increased to strengthen the feedback correction of actual operating deviations and ensure the accuracy of circulating current suppression. Finally, the weighted first compensation voltage and the second compensation voltage are added together to obtain the final target compensation voltage.

[0075] Step S208: Adjust the transformer of the closed loop according to the target compensation voltage; and adjust the reactor of the closed loop to the target state; wherein the target state is used to suppress the circulating current generated during the closed loop operation.

[0076] The adjusting transformer can include adjusting the excitation voltage and series injection voltage of the transformer based on the basic compensation component obtained from the decomposition of the target compensation voltage. This dynamically matches the voltage amplitude and phase on both sides of the loop closing point, reducing the circulating current driving source caused by the voltage difference. Simultaneously, the equivalent inductive reactance of the reactor can be controlled collaboratively according to different stages of the loop closing process. Specifically, before the loop closing switch is closed, the reactor can be adjusted to a high impedance state to limit the inrush current at the moment of loop closing. After the inrush current decays to below a preset threshold, the reactor is switched to the target impedance state. The impedance value in this state is optimized and can effectively suppress residual circulating current during steady-state operation. Furthermore, when the system detects a short circuit or other type of fault in the distribution network, an emergency response mechanism can be triggered to generate a third impedance adjustment command, rapidly reducing the reactor impedance value, enhancing the power transmission capacity of the loop closing channel, and enabling the non-faulty side power supply to provide necessary support power to the faulty area through the loop closing point, thereby improving the power supply reliability and fault ride-through capability of the distribution network.

[0077] In one exemplary embodiment, before the loop-closing switch is closed, the adjustable taps or power electronic switches of the reactor can be remotely controlled to adjust its equivalent inductive reactance to a preset high impedance threshold. At this time, the overall impedance of the loop-closing circuit is raised. When the loop-closing switch is closed, the instantaneous inrush current will be significantly weakened due to the high impedance, avoiding excessive inrush current that could cause the protection device to malfunction or damage to the power grid equipment. After the inrush current has decayed for a preset time and the amplitude of the inrush current detected in real time has dropped to within the preset safety threshold, a second impedance adjustment command is issued to gradually adjust the equivalent inductive reactance of the reactor to the target impedance state calculated in advance based on the loop-closing circuit parameters. This target impedance can ensure the continuous suppression of residual circulating current during steady-state operation without excessively raising the overall impedance of the loop-closing circuit, avoiding unnecessary additional power loss and ensuring the economy and stability of the loop-closing operation.

[0078] The control method for the combined multifunctional transformer used in flexible loop-connection power supply achieves a dual correction mechanism for voltage regulation during loop-connection by combining a first compensation voltage calculated based on circuit parameters and a second compensation voltage based on current deviation feedback. This mechanism not only considers the static electrical characteristics of the loop-connection circuit but also dynamically responds to changes in the actual operating current, thereby effectively improving compensation accuracy. Simultaneously adjusting the transformer tap and coordinating the control of the reactor to the target state significantly reduces the circulating current amplitude during both the instantaneous loop-connection and steady-state operation phases, avoiding problems such as equipment overload, increased losses, or protection malfunctions caused by excessive circulating current, thus improving the safety and reliability of the distribution network's loop-connection operation.

[0079] In one embodiment, determining the first compensation voltage based on the equivalent impedance, the current voltage difference, and the compensated voltage includes:

[0080] Obtain the active and reactive currents of the closed loop at the current time.

[0081] Based on the equivalent impedance, the voltage difference, the compensated voltage, the active current, and the reactive current, predict the predicted active current and predicted reactive current at the next moment.

[0082] The first compensation voltage is determined based on the difference between the predicted active current and the expected active current, and the difference between the predicted reactive current and the expected reactive current.

[0083] The prediction process can employ a first-order or higher-order state-space model, combining the current voltage, current, and impedance parameters at the current moment to deduce the current change trend in the next control cycle. The prediction deviation is mapped into a voltage regulation quantity via a proportional-integral (PI) controller or a model predictive control (MPC) algorithm, forming a forward-looking first compensation voltage to proactively offset the circulating current increment that may be caused by load fluctuations or grid disturbances. This approach effectively enhances the system's adaptability to dynamic operating conditions, especially in scenarios with rapid load changes or large fluctuations in distributed power output, significantly improving voltage matching accuracy and operational stability during the initial loop closure.

[0084] In one exemplary embodiment, the active current and reactive current at the current moment can be used as state variables, and a discretized state prediction equation can be constructed by combining the equivalent impedance, the current voltage difference, and the compensated voltage. The predicted active current and predicted reactive current for the next control cycle are obtained by recursive calculation. The deviation between the predicted value and the expected value are calculated separately, and the two deviations are input into a pre-designed PI controller, which outputs the compensation voltages corresponding to the active component and the reactive component, respectively. Finally, the first compensation voltage is obtained by combining the phase information.

[0085] In this embodiment, the current change trend at the next moment is predicted by the current real-time electrical parameters, and the growth direction of the circulating current is predicted in advance. This allows for pre-adjustment before the deviation actually occurs, effectively avoiding the adverse effects of the circulating current impact and improving the dynamic stability of the closed-loop operation.

[0086] In one embodiment, obtaining the actual operating current of the closed-loop circuit and determining the second compensation voltage based on the deviation between the actual operating current and the expected operating current includes:

[0087] Obtain the active and reactive currents of the closed loop at the current time.

[0088] The active current deviation and reactive current deviation are determined based on the difference between the active current and the expected active current, and the difference between the reactive current and the expected reactive current.

[0089] The initial compensation voltage is determined based on the active current deviation and reactive current deviation.

[0090] The initial compensation voltage is corrected based on the active current and reactive current to obtain the second compensation voltage.

[0091] Among them, the initial compensation voltage can be cross-coupled and corrected based on the current actual phase relationship and coupling parameters of active and reactive currents, so as to cancel the mutual interference between different components, eliminate calculation errors, obtain a more accurate second compensation voltage, ensure the accuracy of feedback compensation, and improve the circulating current suppression effect under steady-state operation.

[0092] In one exemplary embodiment, three-phase electrical parameters can be decomposed into active and reactive components through coordinate transformation, yielding the deviations between the actual active and reactive currents and their corresponding expected values. Then, based on the circuit impedance matrix in the rotating coordinate system, the active and reactive components of the initial compensation voltage are directly calculated. Subsequently, according to the current actual active and reactive operating points, coupling cross terms in the impedance matrix are extracted to correct the two initially calculated components, offsetting the calculation deviations caused by coupling, ultimately obtaining the corrected second compensation voltage. This method can eliminate the coupling effects between different components in the dq coordinate system, significantly improving the calculation accuracy of the compensation voltage and making the feedback compensation stage more precise in suppressing circulating currents.

[0093] In this embodiment, by accurately calculating the actual current deviation at the current moment and eliminating the cross-interference between different current components through coupling correction, the calculation accuracy of the second compensation voltage is effectively improved, ensuring the actual effect of feedback compensation, thereby more accurately eliminating the circulating current component that has already been generated and improving the stability of closed-loop operation.

[0094] In one embodiment, adjusting the transformer of the closed-loop circuit according to the target compensation voltage includes:

[0095] Based on the target compensation voltage, the basic compensation component of the transformer is obtained.

[0096] Based on the basic compensation component, the excitation voltage and series injection voltage of the transformer are adjusted to adjust the voltage relationship on both sides of the loop closing point.

[0097] The voltage difference between the two sides of the loop closing point can be dynamically compensated and offset, which reduces the driving force of the circulating current from the source. At the same time, the amplitude and phase of the voltage can be adjusted independently by adjusting the excitation voltage and the series injection voltage, which can not only ensure the flexibility of voltage compensation, but also adapt to different topologies and parameter types of loop closing circuits, thus improving the applicability of the device.

[0098] In one exemplary embodiment, the target compensation voltage can be decomposed into amplitude adjustment components and phase adjustment components using a decoupling control strategy, corresponding to the excitation branch and series injection branch of the transformer, respectively. Based on this decomposition, a corresponding voltage regulation command is generated to drive the on-load tap changer or power electronic voltage regulation module to adjust the excitation voltage in real time to match the voltage amplitude on both sides of the loop closing point. Simultaneously, the amplitude and phase angle of the series injection voltage are adjusted to dynamically compensate for the voltage phasor difference. This process can be combined with feedforward correction based on the actual impedance angle of the loop closing circuit to ensure that the voltage regulation direction is consistent with the circulating current suppression requirement, avoiding weakening of the compensation effect or even aggravation of circulating current due to deviation in the regulation direction.

[0099] In this embodiment, the target compensation voltage is decomposed into an excitation component related to voltage amplitude adjustment and a series injection component related to phase adjustment, which are applied to the excitation winding and series winding of the transformer, respectively, to achieve coordinated correction of the voltage amplitude difference and phase angle difference on both sides of the loop point.

[0100] In one embodiment, adjusting the reactor of the closed-loop circuit to the target state includes:

[0101] Before the loop switch is closed, a first impedance adjustment command for the reactor is generated, and the equivalent inductive reactance of the reactor is adjusted to a high impedance state according to the first impedance adjustment command.

[0102] After the inrush current generated at the moment of loop closure drops to a preset threshold, a second impedance adjustment command for the reactor is generated, and the equivalent inductive reactance of the reactor is adjusted to the target impedance state according to the second impedance adjustment command.

[0103] In this way, the equivalent impedance of the reactor can be dynamically adjusted in stages. This can limit the amplitude of the inrush current during the loop-closing impact phase, thus avoiding damage to the grid equipment caused by excessive inrush current. It can also adjust the impedance to a suitable target value during the steady-state operation phase, ensuring the residual circulating current suppression effect while avoiding additional power loss caused by excessive loop impedance, thus balancing the safety and economy of loop-closing operation.

[0104] In one exemplary embodiment, a high impedance threshold can be pre-set based on the maximum allowable inrush current of the closed loop, and the target impedance value can be calculated based on the steady-state circulating current suppression requirements and the allowable power loss range. Before the closed loop switch is closed, the reactor is adjusted to the correct position via a first impedance adjustment command. After the loop is closed, the circuit current amplitude is monitored in real time. When the current amplitude of multiple consecutive sampling cycles is lower than the preset safety threshold, a second impedance adjustment command is triggered to gradually adjust the equivalent inductive reactance of the reactor to the pre-calculated target impedance value, thus completing the staged impedance regulation.

[0105] In this embodiment, by dynamically adjusting the equivalent inductive reactance of the reactor in stages, the amplitude of the inrush current can be limited by high impedance during the loop-closing impact phase, avoiding excessive inrush current that could cause protection malfunction or equipment damage. At the same time, the impedance can be adjusted to a reasonable target value during the steady-state operation phase, ensuring that the residual circulating current is continuously suppressed while avoiding excessive power loss caused by excessive loop impedance, thus balancing the safety and economy of loop-closing operation.

[0106] In one embodiment, after adjusting the equivalent inductive reactance of the reactor to the target impedance state according to the second impedance adjustment command, the method further includes:

[0107] When a fault is detected in the distribution network, a third impedance adjustment command is generated for the reactor, and the impedance value of the reactor is lowered according to the third impedance adjustment command so that the power supply side outputs power to the fault side through the loop closing point.

[0108] In this emergency response mechanism, by reducing the impedance of the reactors, the transmission impedance loss of the closed-loop path can be minimized. This ensures that the non-faulty power supply can provide sufficient supporting power to the outage area, achieving uninterrupted power supply or short-term power transfer to the faulty area. This reduces the outage area and duration, effectively improving the power supply reliability of the distribution network. This emergency response mechanism fully utilizes the advantages of the closed-loop network structure, enabling rapid power support in fault scenarios without requiring additional changes to the network topology, thus improving the system's fault handling efficiency.

[0109] In one exemplary embodiment, after the protection device of the distribution network detects a fault, it can send a fault trigger signal to the control device. Upon receiving the signal, the control device immediately generates a third impedance adjustment command to quickly lower the equivalent impedance of the adjustable reactor to a preset low impedance value, thereby increasing the power transmission capacity of the closed loop channel. This allows the power supply on the non-faulty side to continuously supply power to the important loads in the faulty area through the closed loop channel. After the fault isolation is completed and the grid restoration operation is executed, the impedance parameters of the reactor are readjusted according to the restored operating status.

[0110] In this embodiment, by rapidly reducing the reactor impedance when a distribution network fault is detected, the power transmission capacity of the closed loop can be quickly increased, allowing the power supply in the non-faulty area to deliver sufficient supporting power to the faulty area through the closed loop point, thereby reducing the scope of the power outage, shortening the fault recovery time, and effectively improving the power supply reliability and fault response capability of the distribution network.

[0111] In one exemplary embodiment, a system topology is provided for implementing a control method for a combined multifunctional transformer with flexible loop-to-supply capability, specifically as follows: Figure 3 As shown, the power grid on side A and the power grid on side B are connected via their respective circuit breakers (K). A K B Power is supplied to loads on side A and side B, with bus voltages U on both sides respectively. A and U B The line impedances are Z A and Z B The tie switch K is located between the two busbar sections. When K is open, the circuit operates separately; when K is closed, a closed loop is formed. Before the loop is closed, the load current on side A is I. A The load current on side B is I. B After the loop is closed, due to the difference in voltage amplitude / phase on both sides, a circulating current I0 will be generated. At this time, the actual current on side A becomes I. A'=I A +I0, the actual current on side B becomes I B '=I B -I0. T in the diagram X For the transformer in the closed loop, L X The transformer and reactor are connected in series, and both participate in circulating current suppression. This diagram mainly illustrates the mechanism of circulating current generation at the moment of loop closure and the positional relationship of the transformer and reactor in circulating current suppression. Specifically, the transformer can include a combined electromagnetic multifunctional transformer, which can achieve high integration in physical topology, consisting of three units: a large-capacity phase-shifting transformer TX (composed of an excitation transformer and a series transformer), a smaller-capacity unified power flow controller (UPFC), and a controllable reactor. The excitation transformer is connected in parallel to the distribution network bus to extract the reference voltage source. The UPFC parallel-side converter is connected to the secondary side of the excitation transformer, responsible for maintaining the stability of the system's DC bus. The UPFC series-side converter outputs a high-frequency PWM wave, which seamlessly injects a precision compensation voltage vector into the main line through the series transformer. In this scheme, the transformer and a controllable reactor are connected in series to the distribution network tie point. The equivalent inductive reactance of the controllable reactor is used as a variable parameter in the voltage divider network or phase-shifting resonant network, further reducing the capacity of the power electronic equipment and improving the response speed of loop closure. The reactor includes an AC working circuit and a DC excitation control circuit. By adjusting the DC bias current, the core saturation can be changed, thereby achieving continuous, wide-range stepless control of the AC equivalent inductive reactance.

[0112] In one exemplary embodiment, a control block diagram is provided for implementing a control method for a combined multifunctional transformer with flexible loop-to-supply transmission, specifically as follows: Figure 4 As shown, a short control path architecture with feedforward prediction and shallow closed-loop control is specifically adopted. The control flow originates from the desired power command P. ref Q ref After input, the system starts by generating a current command I through a reverse derivation process of the desired steady-state current. dref I qref This instruction is fed into the discretized state-space current prediction stage, and, by combining the equivalent parameters of the closed loop with the current bus voltage difference, the reference feedforward compensation voltage U is solved. ff On the other hand, after comparing with the actual feedback current, the single-loop PI regulator outputs a deviation correction amount, and ωL is introduced into the cross-decoupling compensation stage. n I q With ωL n I d The decoupling term eliminates the mutual influence between active and reactive power, ultimately resulting in a fine-tuned compensation voltage ΔU at the output. PIThe feedforward and fine-tuning quantities are summed at the summation point to obtain the total compensation voltage requirement, which is then sent to a multi-port command shunt. The shunt is distributed to three parallel execution ports according to amplitude and response speed: a large-capacity phase-shifting transformer handles the large-amplitude fundamental voltage compensation; a controllable reactor continuously adjusts the equivalent inductive reactance via DC excitation to fill the adjustment gap; and a micro-capacity UPFC performs high-frequency PWM fine-tuning. These three components work together to achieve full-scale zero steady-state error compensation. This architecture eliminates the long path delay of traditional power, voltage, and current cascaded loops, using physical feedforward to offset most transient impacts and shallow closed-loop to eliminate residuals, ensuring a fast and smooth loop closure process.

[0113] In one exemplary embodiment, the control method for a combined multifunctional transformer with flexible closed-loop power supply can also be implemented as follows, specifically including:

[0114] Derivation of the expected steady-state current in reverse: During the preparation phase of the closed-loop power transfer, the intelligent controller obtains the preset active power P of the target power transfer load. ref Reactive power Q ref and bus target voltage U ref In the synchronously rotating dq coordinate system, based on instantaneous power theory, the desired current command I after the closed-loop steady state is derived with relatively high accuracy. dref with I qref :

[0115]

[0116] Discretized state-space current prediction: The algorithm internally constructs an equivalent distributed inductance L based on a closed-loop circuit. n With equivalent resistance R n The system employs a discretized prediction model. In the k-th sampling period, based on the current bus voltage difference and the total compensation voltage to be output by the combined transformer, the system predicts the transient current I at time k+1 in advance. d with I q :

[0117] I d,q (k+1)=(1- R n T s L n ) I d,q (k)+ T s L n [ △ U d,q (k)- U C d,q (k)]# （ 2 ）

[0118] In the formula: I d,q (k) represents the closed-loop current actually measured and calculated at the current sampling time (step k); I d,q (k+1) represents the transient current that the controller predicts will flow through the closed loop at the next sampling time (step k+1); T S The sampling period is ΔU. d,q The bus loop differential voltage refers to the projection of the voltage amplitude and phase difference between the distribution network buses on both sides of the loop point onto the dq axis at time k; U Cd,q(k): Total compensation voltage vector, referring to the total compensation voltage that the entire system needs to inject in series at time k. Let the predicted I... d,q (k+1) is forced to equal the expected I. dref I qref The system is able to inversely solve and output a reference feedforward compensation voltage U in advance at the instant the physical switch is closed. ff This feedforward command can counteract most of the closed-loop transient impact driving force in the open loop.

[0119] Single-loop PI and cross-decoupling compensation: Due to the dynamic drift of resistance caused by line heating, the fluctuation of inductance parameters caused by core nonlinearity, and measurement errors in actual power grids, simple predictive feedforward inevitably suffers from residuals due to changes in model parameters. Therefore, the system retains an extremely short shallow closed-loop network for accurate compensation. The small deviation e between the actual current and the commanded current... id With e iq The signal passes through the slow outer loop and is fed into the PI controller. Its short physical path results in a small computational delay.

[0120] Simultaneously, in a physical inductive element, the flow of alternating current generates electromagnetic induction. Mathematically, changes in the d-axis current cause a voltage drop along the q-axis, and changes in the q-axis current, in turn, cause a voltage drop along the d-axis. The coupling equation is:

[0121]

[0122] In order to achieve completely independent control of active and reactive power, the control algorithm artificially adds an opposite compensation amount to the output of the PI regulator for cross-decoupling. A feedforward term ωL is added to the d-axis compensation command. n I q In the q-axis compensation command, subtract the feedforward term ωL. n I d The final output is an extremely precise fine-tuning compensation voltage ΔU. PI Multi-port command synthesis and shallow closed-loop: The predicted feedforward quantity and the precise fine-tuning quantity are summed at the summation point to generate the total compensation voltage requirement required by the system, and then sent to the multi-port signal shunt, which distributes it to three physical execution ports with different response speeds and capacities. The transformer performs large-scale phase and voltage regulation control to meet most of the system's requirements and provide basic compensation without consuming power electronic capacity; the controllable reactor provides continuous impedance smooth regulation, filling any gaps that may exist during transformer regulation; the UPFC's SVPWM control performs high-frequency transient fine-tuning, making the final state approach zero steady-state error.

[0123] In another exemplary embodiment, when a distribution network undergoes a mode change, planned maintenance of an upstream substation, or network reconfiguration, it often needs to close two feeders that were originally in an open-loop state through a tie switch to form a temporary or long-term closed-loop network. When there is a significant difference in amplitude and phase between the voltages on both sides, direct loop closure will trigger a severe transient inrush current. The dynamic evolution of the inrush current can be precisely described by the differential equation of a first-order RL transient circuit:

[0124]

[0125] Among them, L Σ With R Σ Let denoted by , and Δu be the equivalent total inductance and total resistance of the closed loop. Analytical solutions to this differential equation reveal that the closed-loop current is a superposition of a rapidly decaying aperiodic DC component and a stable sinusoidal AC component. In traditional distribution networks, due to the extremely small and fixed leakage inductance of the lines, the peak value of the inrush current is completely uncontrolled, easily exceeding the breaking capacity limit of the circuit breaker or triggering overcurrent protection devices.

[0126] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0127] Based on the same inventive concept, this application also provides a control device for a combined multifunctional transformer with flexible loop-lock power supply, which implements the control method for the combined multifunctional transformer with flexible loop-lock power supply described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more control device embodiments for a combined multifunctional transformer with flexible loop-lock power supply provided below can be found in the limitations of the control method for the combined multifunctional transformer with flexible loop-lock power supply described above, and will not be repeated here.

[0128] In one embodiment, such as Figure 5As shown, a control device 500 for a combined multifunctional transformer with flexible loop power supply is provided, including: a data acquisition module 501, a compensation determination module 503, and a voltage adjustment module 505, wherein:

[0129] The data acquisition module is used to acquire the expected operating current of the closed loop, the equivalent impedance of the closed loop, and the current voltage difference and compensated voltage on both sides of the closed loop.

[0130] The compensation determination module is used to determine a first compensation voltage based on the equivalent impedance, the current voltage difference, and the already compensated voltage;

[0131] The compensation determination module is also used to obtain the actual operating current of the closed loop and determine the second compensation voltage based on the deviation between the actual operating current and the expected operating current.

[0132] The compensation determination module is further configured to generate a target compensation voltage based on the first compensation voltage and the second compensation voltage;

[0133] A voltage adjustment module is used to adjust the transformer of the closed loop according to the target compensation voltage; and to adjust the reactor of the closed loop to a target state; wherein the target state is used to suppress the circulating current generated during the closed loop operation.

[0134] In one embodiment, the compensation determination module is further configured to:

[0135] Obtain the active and reactive currents of the closed loop at the current time;

[0136] Based on the equivalent impedance, the voltage difference, the compensated voltage, the active current, and the reactive current, predict the predicted active current and predicted reactive current at the next moment.

[0137] The first compensation voltage is determined based on the difference between the predicted active current and the expected active current, and the difference between the predicted reactive current and the expected reactive current.

[0138] In one embodiment, the compensation determination module is further configured to:

[0139] Obtain the active and reactive currents of the closed loop at the current time;

[0140] Based on the difference between the active current and the expected active current, and the difference between the reactive current and the expected reactive current, the active current deviation and the reactive current deviation are determined.

[0141] The initial compensation voltage is determined based on the active current deviation and reactive current deviation.

[0142] The initial compensation voltage is corrected based on the active current and reactive current to obtain the second compensation voltage.

[0143] In one embodiment, the voltage adjustment module is further configured to:

[0144] Based on the target compensation voltage, obtain the basic compensation component of the transformer;

[0145] Based on the basic compensation component, the excitation voltage and series injection voltage of the transformer are adjusted to adjust the voltage relationship on both sides of the loop closing point.

[0146] In one embodiment, the voltage adjustment module is further configured to:

[0147] Before the loop switch is closed, a first impedance adjustment command for the reactor is generated, and the equivalent inductive reactance of the reactor is adjusted to a high impedance state according to the first impedance adjustment command.

[0148] After the inrush current generated at the moment of loop closure drops to a preset threshold, a second impedance adjustment command for the reactor is generated, and the equivalent inductive reactance of the reactor is adjusted to the target impedance state according to the second impedance adjustment command.

[0149] In one embodiment, the device further includes an impedance adjustment module for:

[0150] When a fault is detected in the distribution network, a third impedance adjustment command is generated for the reactor, and the impedance value of the reactor is lowered according to the third impedance adjustment command so that the power supply side outputs power to the fault side through the loop closing point.

[0151] In an exemplary embodiment, the control device for the combined multifunctional transformer used for flexible loop-connected power supply can employ a controllable reactor to implement active impedance reconfiguration. Specifically, this scheme proposes a flexible loop-connected control sequence: High impedance anti-impedance preparation: In the preparation stage before the loop-connection operation is about to start, the main loop-connection control device not only uses the transformer to initially compensate for the steady-state voltage difference and phase angle difference on both sides, but more importantly, the control system sends instructions to the power electronic converter to reduce the DC excitation current of the controllable reactor as much as possible while meeting the adjustment requirements, thereby reducing the core saturation of the controllable reactor, restoring the AC magnetic circuit to a relatively high permeability level, and causing the AC winding to exhibit a large equivalent inductive reactance value L. X1 The combined device thus enters a high-impedance state. Physical current limiting and smooth transition: At the instant the tie switch is physically closed, the huge closed-loop voltage difference attempts to drive a large transient inrush current. However, due to the total inductance L of the circuit at this time... Σ Because L X1The surge in transient current, constrained by the aforementioned differential equations, not only is the rate of increase of the inrush current, di / dt, suppressed, but the absolute peak value of the transient current is also strictly limited within the safety threshold of the power grid equipment. This direct current limiting mechanism based on electromagnetic physical properties is far simpler and more effective than pure power electronic algorithms. After the loop connection is completed and the transient decay period of the first few cycles has passed, the intelligent control system confirms the end of the transient process and then initiates a soft-start transition program, slowly and smoothly increasing the DC excitation current to drive the inductance value to smoothly fall back from the high-resistance state until it reaches the target impedance level required for steady-state power flow control, completely eliminating voltage oscillations. In addition, when a severe fault suddenly occurs on one side of the distribution network, the system can trigger an emergency transfer mode, injecting a strong excitation current into the DC winding of the controllable reactor, forcing the core to enter a deep saturation state in a short time, and the relative permeability to decrease rapidly. This physical process reduces the equivalent inductive reactance of the series AC winding, and the device is transformed into an extremely low impedance path. Relying on this extremely low impedance path, the normal-side power supply can cross the loop-closing point with a minimal voltage drop, providing supporting capacity to the fault side before the main circuit breaker on the fault side completes its mechanical trip. This rapid hot-swap mechanism enables seamless takeover of critical loads, completely eliminating the power supply gap in the traditional cold-swap mode, and making the fault switching process completely imperceptible to the user side.

[0152] The various modules in the control device for the combined multifunctional transformer used for flexible loop power supply can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0153] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 6As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements a control method for a combined multi-functional transformer used for flexible closed-loop power supply. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0154] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0155] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0156] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0157] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0158] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A control method for a combined multifunctional transformer for flexible loop-to-circuit power supply, characterized in that, The method includes: Obtain the expected operating current of the closed loop, the equivalent impedance of the closed loop, and the current voltage difference and compensated voltage on both sides of the closed loop; The first compensation voltage is determined based on the equivalent impedance, the current voltage difference, and the already compensated voltage. Obtain the actual operating current of the closed loop, and determine the second compensation voltage based on the deviation between the actual operating current and the expected operating current; Generate a target compensation voltage based on the first compensation voltage and the second compensation voltage; According to the target compensation voltage, the transformer of the closed loop is adjusted; and the reactor of the closed loop is adjusted to the target state; wherein, the target state is used to suppress the circulating current generated during the closed loop operation.

2. The method according to claim 1, characterized in that, Determining the first compensation voltage based on the equivalent impedance, the current voltage difference, and the already compensated voltage includes: Obtain the active and reactive currents of the closed loop at the current time; Based on the equivalent impedance, the voltage difference, the compensated voltage, the active current, and the reactive current, predict the predicted active current and predicted reactive current at the next moment. The first compensation voltage is determined based on the difference between the predicted active current and the expected active current, and the difference between the predicted reactive current and the expected reactive current.

3. The method according to claim 1, characterized in that, The step of obtaining the actual operating current of the closed-loop circuit and determining the second compensation voltage based on the deviation between the actual operating current and the expected operating current includes: Obtain the active and reactive currents of the closed loop at the current time; Based on the difference between the active current and the expected active current, and the difference between the reactive current and the expected reactive current, the active current deviation and the reactive current deviation are determined. The initial compensation voltage is determined based on the active current deviation and reactive current deviation. The initial compensation voltage is corrected based on the active current and reactive current to obtain the second compensation voltage.

4. The method according to claim 1, characterized in that, The step of adjusting the transformer of the closed-loop circuit according to the target compensation voltage includes: Based on the target compensation voltage, obtain the basic compensation component of the transformer; Based on the basic compensation component, the excitation voltage and series injection voltage of the transformer are adjusted to adjust the voltage relationship on both sides of the loop closing point.

5. The method according to claim 1, characterized in that, Adjusting the reactor of the closed-loop circuit to the target state includes: Before the loop switch is closed, a first impedance adjustment command for the reactor is generated, and the equivalent inductive reactance of the reactor is adjusted to a high impedance state according to the first impedance adjustment command. After the inrush current generated at the moment of loop closure drops to a preset threshold, a second impedance adjustment command for the reactor is generated, and the equivalent inductive reactance of the reactor is adjusted to the target impedance state according to the second impedance adjustment command.

6. The method according to claim 5, characterized in that, After adjusting the equivalent inductive reactance of the reactor to the target impedance state according to the second impedance adjustment command, the method further includes: When a fault is detected in the distribution network, a third impedance adjustment command is generated for the reactor, and the impedance value of the reactor is lowered according to the third impedance adjustment command so that the power supply side outputs power to the fault side through the loop closing point.

7. A control device for a combined multifunctional transformer with flexible closed-loop power supply, characterized in that, The device includes: The data acquisition module is used to acquire the expected operating current of the closed loop, the equivalent impedance of the closed loop, and the current voltage difference and compensated voltage on both sides of the closed loop. The compensation determination module is used to determine a first compensation voltage based on the equivalent impedance, the current voltage difference, and the already compensated voltage; The compensation determination module is also used to obtain the actual operating current of the closed loop and determine the second compensation voltage based on the deviation between the actual operating current and the expected operating current. The compensation determination module is further configured to generate a target compensation voltage based on the first compensation voltage and the second compensation voltage; A voltage adjustment module is used to adjust the transformer of the closed loop according to the target compensation voltage; and to adjust the reactor of the closed loop to a target state; wherein the target state is used to suppress the circulating current generated during the closed loop operation.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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