A power distribution network non-power-off load transfer control method, system and device based on series compensation and a storage medium

Abstract

The application discloses a power distribution network non-stop load transfer control method and system based on series compensation, solves the problems of loop closing transient impact, user short-time power failure and the like. The application gives a topology structure of the non-stop load transfer system, introduces the working principle of the system, utilizes the voltage amplitude and phase angle compensation function provided by the series compensation, realizes seamless loop closing control, and further realizes load smooth transfer control by using impedance compensation function. The above method can not only realize that the loop closing moment is not affected by voltage and current impact, the transfer process is stable, and the non-stop load transfer, but also expands the application range of loop closing transfer power, and improves the safety and reliability of loop closing transfer power.

Description

Technical Field

[0001] This invention relates to a method, system, equipment, and storage medium for uninterrupted load transfer control in a power distribution network based on series compensation, belonging to the field of power distribution automation technology. Background Technology

[0002] The power distribution network is a crucial link in ensuring power supply and service quality for users, and people have increasingly higher requirements for its power supply reliability. In recent years, with the advancement of smart distribution network construction and the development of distribution automation technology, the power supply reliability of the distribution network has gradually received attention from distribution departments, breaking the previous situation of "emphasizing transmission while neglecting distribution." Initially, people only focused on long-term power outages lasting more than 3 minutes. However, with the growth of important loads, even a short-term power outage will inevitably lead to significant economic losses, and short-term power outage time (less than 3 minutes) has also become an indicator for power departments to measure power supply reliability.

[0003] To reduce costs and improve operational efficiency, most distribution networks adopt a "closed-loop design, open-loop operation" power supply mode. Based on open-loop operation, distribution departments improve power supply reliability through measures such as feeder automation and load transfer. However, with the development of distribution network energy storage, large-scale distributed power sources, and the integration of flexible loads, traditional distribution networks are transforming into complex, multi-source, and multi-coordinated active distribution networks. Therefore, improving the reliability and service quality of distribution network power supply is a current challenge. Loop-connected power transfer is an effective measure to improve the reliability of distribution network power supply. When the upstream grid needs planned maintenance, the load on the side to be de-energized is directly switched to the other grid by closing the interconnection switch between two substations. However, if loop-connected operation is performed between two different substations, a large inrush current will be generated due to the voltage difference between the different power sources. To avoid the risks of loop-connected operation, it is only implemented in a few power supply areas that meet the loop-connection conditions. Most areas still use the method of first de-energizing and then transferring power, which cannot meet the growing demand for reliable power supply.

[0004] Existing technical document (CN202110524738.8) discloses a distribution network loop closing and opening method based on decoupled voltage regulation, including: a voltage regulator phase shifter, a control system, a voltage acquisition device, and a loop closing switch; the voltage acquisition device acquires the voltage signals on both sides of the loop closing switch performing the loop closing and opening operation, and transmits them to the control system; the control system calculates the compensation voltage amplitude and phase angle based on the voltage signals, and issues instructions to the voltage regulator phase shifter based on the compensation voltage amplitude and phase angle; the voltage regulator phase shifter outputs the compensation voltage amplitude and phase angle to compensate for the voltage difference on both sides of the loop closing switch according to the instructions issued by the control system. This existing technology solves the loop closing and opening operation in scenarios where the voltage amplitude and phase angle of the distribution network bus are significantly different. However, this scheme requires a complex control system and multiple transformers to achieve decoupled control of voltage and phase angle, resulting in a complex structure, high initial investment costs, and relatively high operating and maintenance costs. Due to its structural and cost limitations, its usage is relatively low. It is more often used in situations where there are special requirements for voltage and phase angle or where power quality needs to be improved.

[0005] Existing technical document (CN202110267788.2) discloses a seamless loop-connection method for low-voltage distribution networks based on a parallel converter. The method involves determining the load to be transferred, the original power supply bus, and the load's capacity; selecting a transfer bus with sufficient capacity; and connecting the loop-connection device in parallel between the feeders of the original power supply bus and the transfer bus. First, a first switch is closed, allowing the converter to draw power from the transfer bus and adjust its output voltage. When the amplitude difference and phase angle difference of the voltages on both sides of a second switch meet preset closing conditions, the second switch is closed, allowing the load to be powered simultaneously by both the original power supply bus and the transfer bus. The converter's output power is controlled to gradually increase until the output current of the original power supply bus is zero, at which point the converter supplies power to the load alone, and the original power supply bus is disconnected to stop supplying power to the load. The converter's output voltage is adjusted to track the transfer bus voltage until the voltages on both sides of the converter meet preset loop-connection conditions, at which point the loop-connection switch is closed. This patented technology solves the problems of inrush current during loop-connection and excessively long loop-connection processes in uninterrupted loop-connection methods. However, this existing technical solution involves using power electronic devices (such as rectifiers and inverters) to control the flow of current, thereby regulating grid parameters. This structure is not only complex, but also requires precise control of the states of multiple switches and handling the resulting harmonic problems. Furthermore, the need to purchase and maintain expensive power electronic equipment can lead to higher long-term operating and maintenance costs.

[0006] Therefore, how to achieve the safety and reliability of the power supply in a loop-type distribution network through a relatively simple structure, and to ensure uninterrupted power supply to users, has become an urgent problem to be solved in the current distribution network. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a method and system for uninterrupted load transfer control in distribution networks based on series compensation.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for uninterrupted load transfer control in a distribution network based on series compensation, characterized by comprising the following steps:

[0010] Step 1: Receive the planned power outage command from the master station, determine the two transformer substations that need to be looped together, and determine the looping point;

[0011] Step 2: Connect the uninterruptible power supply (UPS) at the loop connection point. The UPS includes a bypass switch K and a voltage compensation branch connected in parallel. The voltage compensation branch includes a first switch K1 and a compensation inductor L connected in series. C Compensation resistor R C Compensation power supply u C The first switch K1 and the second switch K2 are all initially in the open state;

[0012] Step 3: Detect and calculate the voltage difference ΔU, phase angle difference δ, and load rate (i.e., the transfer load rate μ) between the two transformer substations at the loop connection point. 转 and planned shutdown area load rate μ 停 ;

[0013] Step 4: If the seamless loop closure condition is met, proceed to Step 5; otherwise, adjust the load rate of the two zones and return to Step 3.

[0014] Step 5: Adjust the output voltage and phase angle difference of the compensation power supply. When the loop closing conditions are met, close the first switch K1 and the second switch K2 to complete the online connection of the seamless loop load transfer device.

[0015] Step 6: Adjust the compensation voltage source u in real time using a control strategy. c The output of the loop current is controlled to slowly increase from zero to the load current;

[0016] Step 7: After the load transfer is detected, disconnect the outgoing circuit breaker of the transformer in the planned shutdown area, and the planned shutdown area will be seamlessly taken out of operation;

[0017] Step 8: Adjust the compensation power supply voltage u c The operating mode ensures that the voltage amplitude and phase angle on both sides of the bypass switch K are less than the set voltage difference threshold and phase angle difference threshold.

[0018] Step 9: Close the bypass switch K;

[0019] Step 10: Continue to adjust the strategy to regulate the compensation voltage source u c The operating mode ensures that the current in the connecting line is less than the set current threshold, and then the first switch K1 and the second switch K2 are disconnected to complete the uninterrupted load transfer of the distribution network.

[0020] More preferably,

[0021] In step 4, the loop closure condition is as follows:

[0022] Furthermore, the load factor of the transformer area after the power transfer is less than 1.

[0023] Among them, U max To allow the maximum amplitude difference between the closed loops, δ max The maximum allowable phase angle difference between closed loops; u cM To compensate for the maximum voltage value of the power supply, δ cM This is to compensate for the maximum phase angle that the power supply can compensate for.

[0024] More preferably,

[0025] In step 6, the magnitude of the loop current can be determined according to the following formula:

[0026]

[0027] In the formula: Z eq To compensate for the equivalent impedance of the power supply, R C To compensate for the resistance value, L C To compensate for the inductance value of the inductor, These are the voltages at the loop connection points of the power supply area and the planned power outage area, respectively. To compensate for the power supply output voltage.

[0028] More preferably,

[0029] In step 8, the voltage difference threshold is 0.3 times U. max The phase angle difference threshold is 0.15 times δ. max .

[0030] More preferably,

[0031] In step 10, the set current threshold is 0.1 times the rated current.

[0032] Secondly, the present invention provides a power distribution network uninterrupted load transfer control system based on the aforementioned control method, comprising a planned power outage command receiving module, an uninterrupted load transfer device access control module, a loop closing condition judgment and adjustment module, a loop closing operation module, a load transfer detection module, a planned power outage area exit control module, and a compensation power supply exit control module; characterized in that:

[0033] The planned power outage command receiving module receives the planned power outage command issued by the master station, determines the two transformer areas that need to be looped together, and determines the looping point.

[0034] After disconnecting the bypass switch K, the first switch K1, and the second switch K2 from the control module of the uninterruptible power supply device, connect the uninterruptible power supply device to the loop connection point.

[0035] The loop closing condition judgment and adjustment module judges and adjusts the output voltage and phase angle of the compensation power supply to meet the loop closing conditions.

[0036] After the loop closing conditions are met, the loop closing operation module closes the first switch K1 and the second switch K2;

[0037] After successful loop closure, the loop closure condition judgment and adjustment module adjusts the compensation voltage source u in real time. c The output of the loop current is controlled to slowly increase from zero to the load current;

[0038] After the load transfer detection module completes the load transfer detection, the planned shutdown transformer exit control module disconnects the outgoing circuit breaker of the transformer in the planned shutdown transformer area.

[0039] After the planned shutdown of the radio station area, the loop closing condition judgment and adjustment module adjusts the compensation power supply voltage u. c The operating mode causes the voltage amplitude and phase angle on both sides of the bypass switch K to be less than the set voltage difference threshold and phase angle difference threshold, and the compensation power supply exits the control module to control the bypass switch K to close.

[0040] After the bypass switch K is closed, the loop closing condition judgment and adjustment module continues to adjust the compensation power supply voltage u. c In the working mode, when the current in the connecting line is less than the set current threshold, the compensation power supply exits the control module and disconnects the first switch K1 and the second switch K2.

[0041] More preferably,

[0042] In the loop closure condition judgment and adjustment module, the loop closure condition is as follows:

[0043] Furthermore, the load factor of the transformer area after the power transfer is less than 1.

[0044] Among them, U max To allow the maximum amplitude difference between the closed loops, δ max The maximum allowable phase angle difference between closed loops; u cM To compensate for the maximum voltage value of the power supply, δ cM This is to compensate for the maximum phase angle that the power supply can compensate for.

[0045] More preferably,

[0046] When adjusting the loop current, it should be determined according to the following formula:

[0047]

[0048] In the formula: Z eq To compensate for the equivalent impedance of the power supply, R C To compensate for the resistance value, L C To compensate for the inductance value of the inductor, These are the voltages at the loop connection points of the power supply area and the planned power outage area, respectively. To compensate for the power supply output voltage.

[0049] Thirdly, the present invention provides a power distribution network uninterrupted load transfer control device based on series compensation, including a storage medium and a processor;

[0050] The storage medium is used to store instructions.

[0051] The processor is configured to operate according to the instructions to perform the steps of any of the preceding methods.

[0052] Fourthly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in any of the preceding claims.

[0053] Compared with the prior art, the present invention has the following beneficial technical effects.

[0054] This invention features a simple and easy-to-implement structure, requiring no manual intervention, and can safely, reliably, and flexibly complete seamless load transfer automatically. Applicable to various power systems, especially in applications requiring rapid response and precise control, this invention effectively solves power flow problems in control lines, improving the stability and reliability of the power grid. It employs series compensation to provide voltage amplitude and phase angle compensation for seamless loop closing operation, and further utilizes impedance compensation to achieve load transfer operation. This method not only achieves shock-free loop closing and smooth, uninterrupted power transfer, but also expands the applicability of loop-based power transfer and improves its safety and reliability. Attached Figure Description

[0055] Figure 1 This is a diagram illustrating the architecture of a power distribution network uninterrupted load transfer control system based on series compensation, according to the present invention.

[0056] Figure 2 This is a flowchart of the operation steps of a power distribution network uninterrupted load transfer control method based on series compensation according to the present invention. Detailed Implementation

[0057] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other.

[0058] This invention discloses a power distribution network uninterruptible load transfer control method based on series compensation, and the architecture diagram of the uninterruptible load transfer device to be connected is shown below. Figure 1 As shown, the seamless loop power supply system consists of a series compensated voltage source u c Series compensation resistor R c Compensating reactance L c The system consists of a first switch K1, a second switch K2, and a tie switch K, which connect to the power distribution systems with voltages U1 and U2 on either side of the loop connection point. The tie switch is used to bypass the uninterruptible power supply system and connect the two substations. The amplitude difference and phase angle difference between U1 and U2 are represented by ΔU and δ, respectively. The currents flowing through the two transformers are represented by i. s1 and i s2 The load current is represented by i. l1 and i l2 The current flowing through the uninterruptible power supply system is represented by i. c Representation. Resistance R C Simulates the active power loss of an uninterruptible power supply system, inductance L C It is mainly used for rate limiting.

[0059] This embodiment discloses a power distribution network uninterrupted load transfer control method based on series compensation. It utilizes the voltage amplitude and phase angle compensation functions provided by series compensation to achieve seamless loop-closing operation, and then utilizes impedance compensation to achieve load transfer operation. This solves the problem of uninterrupted load transfer, expands the applicability of loop-closing power transfer, eliminates loop-closing inrush current, and improves the safety and reliability of loop-closing power transfer. The invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The flowchart of the uninterrupted loop-closing load transfer control method is shown below. Figure 2 As shown,

[0060] Assuming that transformer substation 2 on the main power supply side needs maintenance, load L2 needs to be transferred to the backup power supply side via an uninterruptible power transfer system. The operation of the uninterruptible power transfer system consists of three stages: seamless loop closing, load transfer, and live-line disconnection. During normal operation, firstly, based on the planned power outage command, two transformer substations to be looped are selected. It is then determined whether the voltage difference and phase angle difference on both sides of the loop closing point are within the system's allowable operating range. Secondly, the load rate of the transformers is checked to estimate whether the main power supply side transformers can handle the load of the two substations after the power transfer. The specific operation procedure includes:

[0061] Step 1: Receive the planned power outage command from the master station, determine the two transformer substations that need to be looped together, and determine the looping point;

[0062] Step 2: Connect the uninterruptible power supply (UPS) at the loop connection point. The UPS includes a bypass switch K and a voltage compensation branch connected in parallel. The voltage compensation branch includes a first switch K1 and a compensation inductor L connected in series. C Compensation resistor R C Compensation power supply u C The first switch K1 and the second switch K2 are all initially in the open state;

[0063] Step 3: Detect and calculate the voltage difference ΔU, phase angle difference δ, and load rate (i.e., the transfer load rate μ) between the two transformer substations at the loop connection point. 转 and planned shutdown area load rate μ 停 ;

[0064] Step 4: If the seamless loop closure condition is met, proceed to Step 5; otherwise, adjust the load rate of the two zones and return to Step 3.

[0065] The condition for closing the loop is shown in the following equation:

[0066] Furthermore, the load factor of the transformer area after the power transfer is less than 1.

[0067] Among them, U max To allow the maximum amplitude difference between the closed loops, δ max The maximum allowable phase angle difference between closed loops; u cM To compensate for the maximum voltage value of the power supply, δ cM This is to compensate for the maximum phase angle that the power supply can compensate for.

[0068] It should be noted that, in order to prevent the impact on the power grid caused by the access of the planned outage area load, in the preferred embodiment of the present invention, the loop closing condition should preferably satisfy the following conditions 1 and 2 simultaneously.

[0069] Based on the voltage difference ΔU, phase angle difference δ, and the respective load rates of the two transformer substations (i.e., the load rate of the transfer substations) between the two loop points, the power supply substation load rate μ is calculated. 转 and planned shutdown area load rate μ 停 Determine whether conditions 1 and 2 are met. If they are met, proceed to the next step of the contract operation.

[0070] Condition 1:

[0071] Condition 2:

[0072] Among them, U maxTo allow the maximum amplitude difference between the closed loops, δ max The maximum allowable phase angle difference between closed loops; u cM To compensate for the maximum voltage value of the power supply, δ cM To compensate for the maximum phase angle that the power supply can compensate for;

[0073] y = μ 停 ;

[0074] a = e (x-0.7) , x = μ 转 ,y=μ 停 ;

[0075] H is a unit step function, which takes the value 1 when the independent variable is greater than 1, and 0 otherwise.

[0076] Step 5: Adjust the output voltage and phase angle difference of the compensation power supply. When the loop closing conditions are met, close the first switch K1 and the second switch K2 to complete the online connection of the seamless loop load transfer device.

[0077] Step 6: Adjust the compensation voltage source u in real time using a control strategy. c The output of the loop current is controlled to slowly increase from zero to the load current;

[0078] When adjusting the loop current, it should be determined according to the following formula:

[0079]

[0080] In the formula: Z eq To compensate for the equivalent impedance of the power supply, R C To compensate for the resistance value, L C To compensate for the inductance value of the inductor, These are the voltages at the loop connection points of the power supply area and the planned power outage area, respectively. To compensate for the power supply output voltage.

[0081] Step 7: After the load transfer is detected, disconnect the outgoing circuit breaker of the transformer in the planned shutdown area, and the planned shutdown area will be seamlessly taken out of operation;

[0082] Step 8: Adjust the compensation power supply voltage u c The operating mode ensures that the voltage amplitude and phase angle on both sides of the bypass switch K are less than the set voltage difference threshold and phase angle difference threshold.

[0083] The voltage difference threshold is 0.3 times U. max The phase angle difference threshold is 0.15 times δ. max .

[0084] Step 9: Close the bypass switch K;

[0085] Step 10: Continue to adjust the strategy to regulate the compensation voltage source u c The operating mode ensures that the current in the connecting line is less than the set current threshold, and then the first switch K1 and the second switch K2 are disconnected to complete the uninterrupted load transfer of the distribution network.

[0086] The preferred current threshold is 0.1 times the rated current.

[0087] This application also discloses a power distribution network uninterrupted load transfer control system based on the control method, including a planned power outage command receiving module, an uninterrupted power transfer device access control module, a loop closing condition judgment and adjustment module, a loop closing operation module, a load transfer detection module, a planned power outage area exit control module, and a compensation power supply exit control module.

[0088] The planned power outage command receiving module receives the planned power outage command issued by the master station, identifies the two transformer substations requiring loop closure, and determines the loop closure point. The uninterruptible power transfer device connection control module disconnects the bypass switch K, the first switch K1, and the second switch K2, then connects the uninterruptible power transfer device to the loop closure point. The loop closure condition judgment and adjustment module judges and adjusts the output voltage and phase angle of the compensation power supply to meet the loop closure conditions. After the loop closure conditions are met, the loop closure operation module closes the first switch K1 and the second switch K2. After successful loop closure, the loop closure condition judgment and adjustment module adjusts the compensation voltage source u in real time. c The output of the circuit breaker causes the closed-loop current to slowly increase from zero to the load current. After the load transfer detection module detects the completion of the load transfer, the planned shutdown area exit control module disconnects the outgoing circuit breaker of the transformer in the planned shutdown area. After the planned shutdown area exits, the closed-loop condition judgment and adjustment module adjusts the compensation power supply voltage u. c In the operating mode, when the voltage amplitude and phase angle on both sides of the bypass switch K are less than the set voltage difference threshold and phase angle difference threshold, the compensation power supply exit control module controls the bypass switch K to close; after the bypass switch K closes, the loop closing condition judgment and adjustment module continues to adjust the compensation power supply voltage u. c In the working mode, when the current in the connecting line is less than the set current threshold, the compensation power supply exits the control module and disconnects the first switch K1 and the second switch K2.

[0089] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the aforementioned control method.

[0090] In summary, this invention provides a method, system, equipment, and storage medium for uninterrupted load transfer control in distribution networks based on series compensation. It proposes a method for uninterrupted load transfer control in distribution networks based on series compensation, solving the problem of excessive inrush power caused by large voltage differences across the loop connection point. This invention presents the topology of a seamless loop transfer system and analyzes its working principle, including utilizing the voltage amplitude and phase angle compensation functions provided by series compensation to achieve seamless loop connection operation, and then utilizing impedance compensation to achieve load transfer operation. This method not only enables uninterrupted power transfer but also expands the applicability of loop transfer, eliminates loop inrush current, achieves smooth switching during the distribution network loop connection process, and improves the safety and reliability of loop transfer.

[0091] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0092] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0093] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0094] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for uninterrupted load transfer control in a distribution network based on series compensation, characterized in that, Includes the following steps: Step 1: Receive the planned power outage command from the master station, determine the two transformer substations that need to be looped together, and determine the looping point; Step 2: Connect the uninterruptible power supply (UPS) at the loop connection point. The UPS includes a bypass switch K and a voltage compensation branch connected in parallel. The voltage compensation branch includes a first switch K1 and a compensation inductor L connected in series. C Compensation resistor R C Compensation power supply u C The first switch K1 and the second switch K2 are all initially in the open state; Step 3: Detect and calculate the voltage difference ΔU, phase angle difference δ, and load rate (i.e., the transfer load rate μ) between the two transformer substations at the loop connection point. 转 and planned shutdown area load rate μ 停 ; Step 4: If the seamless loop closure condition is met, proceed to Step 5; otherwise, adjust the load rate of the two zones and return to Step 3. The loop closure condition is shown in the following formula: Furthermore, the load factor of the transformer area after the power transfer is less than 1. Among them, U max To allow the maximum amplitude difference between the closed loops, δ max The maximum allowable phase angle difference between closed loops; u cM To compensate for the maximum voltage value of the power supply, δ cM To compensate for the maximum phase angle that the power supply can compensate for; Step 5: Adjust the output voltage and phase angle difference of the compensation power supply. When the loop closing conditions are met, close the first switch K1 and the second switch K2 to complete the online connection of the seamless loop load transfer device. Step 6: Adjust the compensation voltage source u in real time using a control strategy. c The output of the loop current is controlled to slowly increase from zero to the load current; Step 7: After the load transfer is detected, disconnect the outgoing circuit breaker of the transformer in the planned shutdown area, and the planned shutdown area will be seamlessly taken out of operation; Step 8: Adjust the compensation power supply voltage u c The operating mode ensures that the voltage amplitude and phase angle on both sides of the bypass switch K are less than the set voltage difference threshold and phase angle difference threshold. Step 9: Close the bypass switch K; Step 10: Continue to adjust the strategy to regulate the compensation voltage source u c The operating mode ensures that the current in the connecting line is less than the set current threshold, and then the first switch K1 and the second switch K2 are disconnected to complete the uninterrupted load transfer of the distribution network.

2. The uninterrupted load transfer control method for distribution networks based on series compensation according to claim 1, characterized in that: In step 6, the magnitude of the loop current can be determined according to the following formula: In the formula: Z eq To compensate for the equivalent impedance of the power supply, R C To compensate for the resistance value, L C To compensate for the inductance value of the inductor, These are the voltages at the loop connection points of the power supply area and the planned power outage area, respectively. To compensate for the power supply output voltage.

3. The uninterrupted load transfer control method for distribution networks based on series compensation according to claim 1, characterized in that: In step 8, the voltage difference threshold is 0.3 times U. max The phase angle difference threshold is 0.15 times δ. max .

4. The uninterrupted load transfer control method for distribution networks based on series compensation according to claim 3, characterized in that: In step 10, the set current threshold is 0.1 times the rated current.

5. A power distribution network uninterrupted load transfer control system based on the control method of any one of claims 1-4, comprising a planned power outage command receiving module, an uninterrupted load transfer device access control module, a loop closing condition judgment and adjustment module, a loop closing operation module, a load transfer detection module, a planned power outage area exit control module, and a compensation power supply exit control module; characterized in that: The planned power outage command receiving module receives the planned power outage command issued by the master station, determines the two transformer areas that need to be looped together, and determines the looping point. After disconnecting the bypass switch K, the first switch K1, and the second switch K2 from the control module of the uninterruptible power supply device, connect the uninterruptible power supply device to the loop connection point. The loop closing condition judgment and adjustment module judges and adjusts the output voltage and phase angle of the compensation power supply to meet the loop closing conditions. After the loop closing conditions are met, the loop closing operation module closes the first switch K1 and the second switch K2; After successful loop closure, the loop closure condition judgment and adjustment module adjusts the compensation voltage source u in real time. c The output of the loop current is controlled to slowly increase from zero to the load current; After the load transfer detection module completes the load transfer detection, the planned shutdown transformer exit control module disconnects the outgoing circuit breaker of the transformer in the planned shutdown transformer area. After the planned shutdown of the radio station area, the loop closing condition judgment and adjustment module adjusts the compensation power supply voltage u. c The operating mode causes the voltage amplitude and phase angle on both sides of the bypass switch K to be less than the set voltage difference threshold and phase angle difference threshold, and the compensation power supply exits the control module to control the bypass switch K to close. After the bypass switch K is closed, the loop closing condition judgment and adjustment module continues to adjust the compensation power supply voltage u. c In the working mode, when the current in the connecting line is less than the set current threshold, the compensation power supply exits the control module and disconnects the first switch K1 and the second switch K2.

6. The uninterrupted power supply control system for power distribution networks according to claim 5, characterized in that: In the loop closure condition judgment and adjustment module, the loop closure condition is as follows: Furthermore, the load factor of the transformer area after the power transfer is less than 1. Among them, U max To allow the maximum amplitude difference between the closed loops, δ max The maximum allowable phase angle difference between closed loops; u cM To compensate for the maximum voltage value of the power supply, δ cM This is to compensate for the maximum phase angle that the power supply can compensate for.

7. The uninterrupted power supply control system for power distribution networks according to claim 5, characterized in that: When adjusting the loop current, it should be determined according to the following formula: In the formula: Z eq To compensate for the equivalent impedance of the power supply, R C To compensate for the resistance value, L C To compensate for the inductance value of the inductor, These are the voltages at the loop connection points of the power supply area and the planned power outage area, respectively. To compensate for the power supply output voltage.

8. A power distribution network uninterruptible load transfer control system based on series compensation, characterized in that, Including storage media and processor; The storage medium is used to store instructions. The processor is configured to operate according to the instructions to perform the steps of the method according to any one of claims 1-4.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method according to any one of claims 1-4.

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