Power distribution network uninterrupted load transfer control method, system and device based on series compensation and storage medium

Abstract

The invention discloses a series compensation-based uninterrupted load transfer control method and system for a power distribution network, and solves the related problems of instantaneous impact of loop closing, short-time power failure of a user and the like. The invention provides a topological structure of a non-power-cut load transfer system, introduces the working principle of the system, utilizes the voltage amplitude and phase angle compensation function provided by series compensation to realize sewing-ring-free control, and further adopts an impedance compensation function to realize smooth load transfer control. According to the method, the impact influence of voltage and current at the moment of loop closing can be avoided, the power supply transfer process is stable, power-off-free power supply transfer is realized, the application range of loop closing power supply transfer is expanded, and the safety and reliability of loop closing power supply transfer are improved.

Description

Technical Field

[0001] The present invention relates to a method, system, equipment and storage medium for controlling load transfer in a power distribution network without power outages based on series compensation, and belongs to the technical field of power distribution automation. Background Art

[0002] The distribution network is a key link in ensuring the power supply and service quality of users, and people have higher and higher requirements for its power supply reliability. In recent years, with the advancement of the construction of intelligent distribution networks and the development of distribution automation technology, the power supply reliability of the distribution network has gradually received attention from the distribution department, breaking the original situation of "focusing on transmission and neglecting distribution". At first, people only paid attention to long-term power outages with a power outage time of more than 3 minutes. However, with the increase of important loads, a short power outage will inevitably bring significant economic losses, and short-term power outage time (less than 3 minutes) has also become an indicator for the power department to measure power supply reliability.

[0003] In order to reduce costs and improve the convenience of operation and management, most distribution networks adopt the power supply mode of "closed-loop design and open-loop operation". On the basis of open-loop operation, the distribution department improves the power supply reliability of the distribution network by implementing feeder automation, load transfer and other measures. However, with the development of distribution network energy storage, large-scale distributed power sources, and the access of flexible loads, the traditional distribution network is transforming into an active distribution network with complex multiple sources and multi-coordinated source, grid, load and storage. Therefore, how to improve the power supply reliability and service quality of the distribution network is a challenge facing the current distribution network. Closing and power supply is an effective measure to improve the power supply reliability of the distribution network. When the upper power grid needs to be planned for maintenance, the load on the side to be shut down is directly transferred to the other side of the power grid by closing the tie switch between the two substations. If the closing operation is performed between two different substations, due to the voltage difference between different power supply points, the direct closing operation will generate a large impact current. In order to avoid the risk of closing the loop, the closing and power supply is only implemented in a few power supply areas that meet the closing conditions. Most areas still adopt the method of power outage first and then power supply, which cannot meet people's growing demand for power supply reliability.

[0004] The prior art document (CN202110524738.8) discloses a distribution network closing and unclosing method based on decoupling voltage regulation, including: a voltage regulating phase shifter, a control system, a voltage collection device and a closing switch; the voltage collection device collects the voltage signals on both sides of the closing switch that performs the closing and unclosing operation, and transmits them to the control system; the control system calculates the compensation voltage amplitude and phase angle according to the voltage signal, and issues instructions to the voltage regulating phase shifter according to the compensation voltage amplitude and phase angle; the voltage regulating phase shifter outputs the compensation voltage amplitude and phase angle to compensate for the voltage difference on both sides of the closing switch according to the instructions issued by the control system. This prior art solves the closing and unclosing operation in scenarios where the voltage amplitude and phase angle of the distribution network bus are greatly different. However, this solution requires a complex control system and multiple transformers to realize the decoupling control of voltage and phase angle, and the structure is relatively complex, resulting in high initial investment costs, and relatively high operation 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 the power quality needs to be improved.

[0005] The prior art document (CN202110267788.2) discloses a method for seamlessly closing and transferring power in a low-voltage distribution network based on a parallel converter, which determines the load to be transferred, the original power supply bus and the capacity of the load, selects a transfer bus with sufficient capacity, and connects the closing device in parallel between the feeder of the original power supply bus and the transfer bus; first close the first switch to make the converter take power from the transfer bus and adjust the output voltage, and when the amplitude difference and phase angle difference of the voltage on both sides of the second switch meet the preset closing conditions, close the second switch to make the load powered by the original power supply bus and the transfer bus at the same time; control the output power of the converter to rise step by step until the output current of the original power supply bus is zero, the converter supplies power to the load alone, and cuts off the original power supply bus to stop supplying power to the load; adjust the output voltage of the converter to make it track the transfer bus voltage until the voltage on both sides of the converter meets the preset closing conditions, and then close the closing switch. This patented technology solves the problem that the non-stop closing method generates impact current during the closing period and the closing process takes too long. However, this prior art solution involves the use of power electronic devices (such as rectifiers and inverters) to control the flow of current, thereby achieving the regulation of grid parameters. This structure is not only relatively complex, but also requires precise control of the states of multiple switches and the handling of harmonic problems generated thereby. At the same time, the cost of long-term operation and maintenance may also be higher because of the need to purchase and maintain expensive power electronic devices.

[0006] Therefore, how to achieve the safety and reliability of distribution network power supply through a relatively simple structure and realize 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 the present invention is to solve the deficiencies in the prior art and to provide a method and system for controlling load transfer without power outages in a distribution network based on series compensation.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for controlling load transfer without power outage in a distribution network based on series compensation, characterized in that it comprises the following steps:

[0010] Step 1: Receive the planned power outage instruction issued by the master station, determine the two substations that need to be closed and determine the closing point;

[0011] Step 2: Connect an uninterrupted power supply device between the closing points. The uninterrupted power supply device 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 and the second switch K2; the bypass switch K, the first switch K1 and the second switch K2 are all in the disconnected state in the initial state;

[0012] Step 3: Detect and calculate the voltage difference ΔU, phase angle difference δ between the two areas' closing points, and the load rates of the two areas, i.e., the load rate μ of the transfer area. 转 and the load factor μ of the planned outage area 停 ;

[0013] Step 4: When the seamless loop condition is met, go 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 closing loop condition is met, close the first switch K1 and the second switch K2 to complete the online connection of the seamless closing loop load transfer device.

[0015] Step 6: Real-time adjustment of compensation voltage source u through control strategy c The output of the closed loop current is controlled to increase slowly from zero to the load current;

[0016] Step 7: After detecting that the load transfer is completed, disconnect the outgoing circuit breaker of the distribution transformer in the planned outage area, and the planned outage area will be seamlessly shut down;

[0017] Step 8: Adjust the compensation supply voltage u c The working mode makes the voltage amplitude and phase angle on both sides of the bypass switch K smaller 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 adjust the compensation voltage source u c The operation mode is set so that the interconnection line current is less than the set current threshold, and then the first switch K1 and the second switch K2 are disconnected to complete the load transfer without power outage in the distribution network.

[0020] More preferably,

[0021] In step 4, the ring closing condition is as follows:

[0022] And the load rate of the area after the transfer is less than 1,

[0023] Among them, U max is the maximum amplitude difference allowed for loop closing, δ max is the maximum phase angle difference allowed for closing the loop; u cM is the maximum voltage value of the compensation power supply, δ cM To compensate for the maximum phase angle that the power supply can compensate.

[0024] More preferably,

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

[0026]

[0027] Where: Z eq To compensate for the equivalent impedance of the power supply, R C is the compensation resistor value, L C To compensate the inductance value of the inductor, They are the voltages at the closing points of the transfer station area and the planned outage station area, To compensate 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 current threshold is set to 0.1 times the rated current.

[0032] In a second aspect, the present invention provides a non-stop load transfer control system for a distribution network based on the control method, including a planned power outage instruction receiving module, a non-stop 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 station area exit control module, and a compensation power supply exit control module; characterized in that:

[0033] The planned power outage instruction receiving module receives the planned power outage instruction issued by the master station and determines the two substations that need to be closed and determines the closing point;

[0034] After the uninterruptible power supply transfer device is connected to the control module and the bypass switch K, the first switch K1 and the second switch K2 are disconnected, the uninterruptible power supply transfer device is connected to the closing 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 condition;

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

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

[0038] After the load transfer detection module detects that the load transfer is completed, the planned outage area exit control module disconnects the outgoing circuit breaker of the distribution transformer in the planned outage area;

[0039] After the planned outage area is exited, the loop condition judgment and adjustment module adjusts the compensation power supply voltage u c The working mode makes the voltage amplitude and phase angle on both sides of the bypass switch K less than the set voltage difference threshold and phase angle difference threshold, and the compensation power supply exit control module controls the bypass switch K to close;

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

[0041] More preferably,

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

[0043] And the load rate of the area after the transfer is less than 1,

[0044] Among them, U max is the maximum amplitude difference allowed for loop closing, δ max is the maximum phase angle difference allowed for closing the loop; u cM is the maximum voltage value of the compensation power supply, δ cM To compensate for the maximum phase angle that the power supply can compensate.

[0045] More preferably,

[0046] When adjusting the closed-loop current, it is determined according to the following formula:

[0047]

[0048] Where: Z eq To compensate for the equivalent impedance of the power supply, R C is the compensation resistor value, L C To compensate the inductance value of the inductor, They are the voltages at the closing points of the transfer station area and the planned outage station area, To compensate the power supply output voltage.

[0049] In a third aspect, the present invention provides a non-stop load transfer control device for a distribution network based on series compensation, including a storage medium and a processor;

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

[0051] The processor is used to operate according to the instructions to execute the steps of any of the aforementioned methods.

[0052] In a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any of the aforementioned methods.

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

[0054] The present invention has a simple structure and is easy to implement. It does not require human intervention and can safely, reliably and flexibly complete the seamless transfer of loads automatically. The present invention is applicable to various power systems, especially in situations where rapid response and precise control are required. It can effectively solve the problem of power flow in the control line and improve the stability and reliability of the power grid. The invention uses the voltage amplitude and phase angle compensation functions provided by series compensation to achieve seamless loop closing operation, and further uses the impedance compensation function to achieve load transfer operation. This method can not only achieve instantaneous impact-free loop closing, a smooth power transfer process and non-stop power transfer, but also expand the scope of application of loop-closing power transfer and improve the safety and reliability of loop-closing power transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is an architecture diagram of a load transfer control system for a distribution network without power outages based on series compensation according to the present invention;

[0056] Figure 2 It is a flow chart of the operation steps of a method for controlling load transfer in a distribution network without power outages based on series compensation of the present invention; DETAILED DESCRIPTION

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

[0058] The present invention discloses a method for controlling load transfer of a distribution network without power outages based on series compensation. The structure diagram of the load transfer device to be connected is as follows: Figure 1 As shown, the seamless loop power supply system consists of a series compensation voltage source u c , series compensation resistor R c , Compensation reactance L c , the first switch K1, the second switch K2 and the tie switch K are connected to the distribution system with voltages U1 and U2 on both sides of the closing point through the access switch. The tie switch is used to bypass the non-stop power supply system and connect the two substations. The amplitude difference and phase angle difference of U1 and U2 are represented by ΔU and δ respectively. The current flowing through the two distribution transformers is represented by i s1 and i s2 Indicated by i, load current l1 and i l2 The current flowing through the non-stop power supply system is represented by i c Resistor R C Simulate the active power loss of the non-stop power supply system, inductance L C Mainly used to limit current.

[0059] This embodiment discloses a method for controlling load transfer without power outages in a distribution network based on series compensation. The voltage amplitude and phase angle compensation functions provided by the series compensation are used to achieve seamless closed-loop operation, and the impedance compensation function is used to achieve load transfer operation. This solves the problem of load transfer without power outages, expands the scope of application of closed-loop power supply, eliminates closed-loop impact current, and improves the safety and reliability of closed-loop power supply. The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The flow chart of the operating steps of the method for controlling load transfer without power outages is shown in the figure. Figure 2 As shown,

[0060] Assume that the distribution transformer substation 2 on the main supply side needs maintenance, and the load L2 needs to be transferred to the backup supply side through the non-stop power supply transfer system. The operation of the non-stop power supply transfer system is divided into three stages, namely seamless loop closing, load transfer and live exit. During normal operation, first select the two substations to be closed according to the planned power outage instructions of the substation, and judge whether the voltage difference and phase angle difference on both sides of the closing point are within the range allowed by the system. Secondly, check the load rate of the distribution transformer, and estimate whether the distribution transformer on the main supply side can bear the load of the two substations after the power transfer. The specific operation process includes:

[0061] Step 1: Receive the planned power outage instruction issued by the master station, determine the two substations that need to be closed and determine the closing point;

[0062] Step 2: Connect an uninterrupted power supply device between the closing points. The uninterrupted power supply device 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 and the second switch K2; the bypass switch K, the first switch K1 and the second switch K2 are all in the disconnected state in the initial state;

[0063] Step 3: Detect and calculate the voltage difference ΔU, phase angle difference δ between the two areas' closing points, and the load rates of the two areas, i.e., the load rate μ of the transfer area. 转 and the load factor μ of the planned outage area 停 ;

[0064] Step 4: When the seamless loop condition is met, go to step 5, otherwise, adjust the load rate of the two zones and return to step 3:;

[0065] The closing condition is as follows:

[0066] And the load rate of the area after the transfer is less than 1,

[0067] Among them, U max is the maximum amplitude difference allowed for loop closing, δ max is the maximum phase angle difference allowed for closing the loop; u cM is the maximum voltage value of the compensation power supply, δ cM To compensate for the maximum phase angle that the power supply can compensate.

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

[0069] According to the voltage difference ΔU, phase angle difference δ between the two areas, and the load rate of the two areas, that is, the load rate μ of the transfer area 转 and the load factor μ of the planned outage area 停 , determine whether conditions 1 and 2 are met. If they are met, allow the next step of contract operation.

[0070] Condition 1:

[0071] Condition 2:

[0072] Among them, U maxis the maximum amplitude difference allowed for loop closing, δ max is the maximum phase angle difference allowed for closing the loop; u cM is the maximum voltage value of the compensation power supply, δ cM To compensate for the maximum phase angle that the power supply can compensate;

[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 of 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 closing loop condition is met, close the first switch K1 and the second switch K2 to complete the online connection of the seamless closing loop load transfer device.

[0077] Step 6: Real-time adjustment of compensation voltage source u through control strategy c The output of the closed loop current is controlled to increase slowly from zero to the load current;

[0078] When adjusting the closed-loop current, it is determined according to the following formula:

[0079]

[0080] Where: Z eq To compensate for the equivalent impedance of the power supply, R C is the compensation resistor value, L C To compensate the inductance value of the inductor, They are the voltages at the closing points of the transfer station area and the planned outage station area, To compensate the power supply output voltage.

[0081] Step 7: After detecting that the load transfer is completed, disconnect the outgoing circuit breaker of the distribution transformer in the planned outage area, and the planned outage area will be seamlessly shut down;

[0082] Step 8: Adjust the compensation supply voltage u c The working mode makes the voltage amplitude and phase angle on both sides of the bypass switch K smaller 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 adjust the compensation voltage source u c The operation mode is set so that the interconnection line current is less than the set current threshold, and then the first switch K1 and the second switch K2 are disconnected to complete the load transfer without power outage in the distribution network.

[0086] The current threshold is preferably set to 0.1 times the rated current.

[0087] The present application also discloses a distribution network non-stop load transfer control system of the control method, including a planned power outage instruction receiving module, an non-stop power transfer device access control module, a loop condition judgment and adjustment module, a loop closing operation module, a load transfer detection module, a planned power outage station area exit control module, and a compensation power supply exit control module.

[0088] The planned power outage instruction receiving module receives the planned power outage instruction issued by the master station and determines the two substations that need to be closed and determines the closing point; after the uninterrupted power supply transfer device access control module disconnects the bypass switch K, the first switch K1 and the second switch K2, the uninterrupted power supply transfer device is connected to the closing point; the closing condition judgment and adjustment module judges and adjusts the output voltage and phase angle of the compensation power supply to meet the closing condition; after the closing condition is met, the closing operation module closes the first switch K1 and the second switch K2; after the closing condition is successfully closed, the closing condition judgment and adjustment module adjusts the compensation voltage source u in real time c The output of the loop current is controlled to increase slowly from zero to the load current; after the load transfer detection module detects that the load transfer is completed, the planned outage area exit control module disconnects the outgoing line circuit breaker of the planned outage area distribution transformer; after the planned outage area exits, the loop condition judgment and adjustment module adjusts the compensation power supply voltage u c The working mode makes the voltage amplitude and phase angle on both sides of the bypass switch K less than the set voltage difference threshold and phase angle difference threshold, and the compensation power supply exit control module controls the bypass switch K to close; after the bypass switch K is closed, the closing condition judgment and adjustment module continues to adjust the compensation power supply voltage u c In the working mode, the interconnection line current is less than the set current threshold, and then the compensation power supply exit control module disconnects the first switch K1 and the second switch K2.

[0089] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the aforementioned control method are implemented.

[0090] In summary, the present invention provides a method, system, device and storage medium for non-stop load transfer control in a distribution network based on series compensation, and proposes a method for non-stop load transfer control in a distribution network based on series compensation, which solves the problem of excessive impact power caused by the large voltage difference on both sides of the closing point. The present invention provides a topological structure of a seamless closing-loop power supply system and analyzes the working principle of the system, including utilizing the voltage amplitude and phase angle compensation functions provided by series compensation to achieve seamless closing-loop operation, and then utilizing the impedance compensation function to achieve load transfer operation. This method can not only achieve non-stop power supply, but also expand the scope of application of closing-loop power supply, eliminate the closing-loop impact current, achieve smooth switching of the closing process of the distribution network, and improve the safety and reliability of the closing-loop power supply.

[0091] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0092] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0093] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0094] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for controlling load transfer in a distribution network without power outage based on series compensation, characterized in that: The steps include: Step 1: Receive the planned power outage instruction from the master station, determine the two substations that need to be closed and determine the closing point; Step 2: Connect an uninterrupted power supply device between the closing points. The uninterrupted power supply device 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 and the second switch K2; the bypass switch K, the first switch K1 and the second switch K2 are all in the disconnected state in the initial state; Step 3: Detect and calculate the voltage difference ΔU, phase angle difference δ between the two areas' closing points, and the load rates of the two areas, i.e., the load rate μ of the transfer area. 转 and the load factor μ of the planned outage area 停 ; Step 4: When the seamless loop condition is met, go to step 5, otherwise, adjust the load rate of the two zones and return to step 3:; Step 5: Adjust the output voltage and phase angle difference of the compensation power supply. When the closing loop condition is met, close the first switch K1 and the second switch K2 to complete the online connection of the seamless closing loop load transfer device. Step 6: Real-time adjustment of compensation voltage source u through control strategy c The output of the closed loop current is controlled to increase slowly from zero to the load current; Step 7: After detecting that the load transfer is completed, disconnect the outgoing circuit breaker of the distribution transformer in the planned outage area, and the planned outage area will be seamlessly shut down; Step 8: Adjust the compensation supply voltage u c The working mode makes the voltage amplitude and phase angle on both sides of the bypass switch K smaller 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 adjust the compensation voltage source u c The operation mode is set so that the interconnection line current is less than the set current threshold, and then the first switch K1 and the second switch K2 are disconnected to complete the load transfer without power outage in the distribution network.

2. According to claim 1, the method for controlling load transfer in a distribution network without power outage based on series compensation is characterized in that: In step 4, the ring closing condition is as follows: And the load rate of the area after the transfer is less than 1, Among them, U max is the maximum amplitude difference allowed for loop closing, δ max is the maximum phase angle difference allowed for closing the loop; u cM is the maximum voltage value of the compensation power supply, δ cM To compensate for the maximum phase angle that the power supply can compensate.

3. The method for controlling load transfer in a distribution network without power outage based on series compensation according to claim 1 is characterized in that: In step 6, the closed-loop current can be determined according to the following formula: Where: Z eq To compensate for the equivalent impedance of the power supply, R C is the compensation resistor value, L C To compensate the inductance value of the inductor, They are the voltages at the closing points of the transfer station area and the planned outage station area, To compensate the power supply output voltage.

4. The method for controlling load transfer in a distribution network without power outage based on series compensation according to claim 2 is 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 .

5. The method for controlling load transfer in a distribution network without power outages based on series compensation according to claim 4 is characterized in that: In step 10, the current threshold is set to 0.1 times the rated current.

6. A distribution network non-stop load transfer control system based on the control method according to any one of claims 1 to 5, comprising a planned power outage instruction receiving module, a non-stop 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 station area exit control module, and a compensation power source exit control module; characterized in that: The planned power outage instruction receiving module receives the planned power outage instruction issued by the master station and determines the two substations that need to be closed and determines the closing point; After the uninterruptible power supply transfer device is connected to the control module and the bypass switch K, the first switch K1 and the second switch K2 are disconnected, the uninterruptible power supply transfer device is connected to the closing 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 condition; After the loop closing condition is met, the loop closing operation module closes the first switch K1 and the second switch K2; After the loop closing condition judgment and adjustment module is successfully closed, the compensation voltage source u is adjusted in real time. c The output of the closed loop current is controlled to increase slowly from zero to the load current; After the load transfer detection module detects that the load transfer is completed, the planned outage area exit control module disconnects the outgoing circuit breaker of the distribution transformer in the planned outage area; After the planned outage area is exited, the loop condition judgment and adjustment module adjusts the compensation power supply voltage u c The working mode makes the voltage amplitude and phase angle on both sides of the bypass switch K less than the set voltage difference threshold and phase angle difference threshold, and the compensation power supply exit control module controls the bypass switch K to close; After the bypass switch K is closed, the loop condition judgment and adjustment module continues to adjust the compensation power supply voltage u c In the working mode, the interconnection line current is less than the set current threshold, and then the compensation power supply exit control module disconnects the first switch K1 and the second switch K2.

7. The non-stop load transfer control system for the power distribution network according to claim 6, characterized in that: In the loop closing condition judgment and adjustment module, the loop closing condition is as follows: And the load rate of the area after the transfer is less than 1, Among them, U max is the maximum amplitude difference allowed for loop closing, δ max is the maximum phase angle difference allowed for closing the loop; u cM is the maximum voltage value of the compensation power supply, δ cM To compensate for the maximum phase angle that the power supply can compensate.

8. The non-stop load transfer control system for distribution network according to claim 6, characterized in that: When adjusting the closed-loop current, it is determined according to the following formula: Where: Z eq To compensate for the equivalent impedance of the power supply, R C is the compensation resistor value, L C To compensate the inductance value of the inductor, They are the voltages at the closing points of the transfer station area and the planned outage station area, To compensate the power supply output voltage.

9. A load transfer control system for a distribution network without power outages based on series compensation, characterized in that: including storage media and processors; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the steps of the method according to claims 1-5.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to claims 1 to 5 are implemented.

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