Power flow transfer method and device based on flexible loop closing device

Abstract

The invention relates to the technical field of flexible loop closing application of a power distribution network, and particularly provides a power flow transfer method and device based on a flexible loop closing device, and the method comprises the steps: transmitting a control signal for controlling an execution mechanism in the flexible loop closing device to output a compensation voltage corresponding to a power flow transfer instruction; the power flow transfer instruction is used for realizing a power flow transfer process of a power distribution network where the flexible loop closing device is located; and when the three-phase imbalance exists at the wire inlet of the flexible loop closing device, updating the compensation voltage corresponding to the power flow transfer instruction based on the voltage deviation at the wire inlet of the flexible loop closing device. According to the technical scheme provided by the invention, various complex transformations and PI closed-loop control are avoided in the aspect of three-phase imbalance control, the problem of three-phase imbalance can be effectively solved, the calculated amount is small, and the problems of overvoltage, overcurrent and the like caused by adjustment are not easy to occur.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible loop closing applications of distribution networks, and in particular to a power flow transfer method and device based on a flexible loop closing device. Background Art

[0002] In recent years, various problems of radial grids have gradually emerged in the open-loop operation mode of traditional distribution networks, and the distribution network closing technology has become a hot topic for researchers. However, due to the complexity of the distribution network structure and load, the use of tie switches to directly close the loop during the flow transfer process will cause problems such as uncertain flow direction and large short-circuit current.

[0003] Flexible loop closing device can solve the above problems well and plays an important role in the power system. It realizes seamless switching of loop closing by utilizing the flexible and controllable advantages of the output compensation voltage, effectively reduces the current fluctuation and impact caused by loop closing, and avoids the instability of the power grid and equipment damage caused by loop closing operation, thereby ensuring the stability and reliability of the power system. However, due to factors such as the drastic load fluctuation caused by the increase in users, the uncertainty introduced by temporary and seasonal power consumption, the unbalanced phase distribution of users' three-phase power equipment, and the lack of effective management of the three-phase load distribution on the distribution network side, the voltage of a certain phase fluctuates, and the voltage deviation occurs compared with other phases, resulting in frequent three-phase imbalance problems in the distribution network. Summary of the invention

[0004] In order to overcome the above-mentioned defects, the present invention proposes a tidal current transfer method and device based on a flexible loop closing device.

[0005] In a first aspect, a power flow transfer method based on a flexible loop closing device is provided, and the power flow transfer method based on the flexible loop closing device comprises:

[0006] Sending a control signal for controlling the compensation voltage corresponding to the output power flow transfer instruction to the actuator in the flexible loop closing device; the power flow transfer instruction is used to realize the power flow transfer process of the distribution network where the flexible loop closing device is located;

[0007] When there is a three-phase imbalance at the incoming line of the flexible loop closing device, the compensation voltage corresponding to the power flow transfer instruction is updated based on the voltage deviation at the incoming line of the flexible loop closing device.

[0008] Preferably, the power flow transfer instruction is as follows:

[0009] P ref =P ref '+P

[0010] In the above formula, P ref is the power transfer instruction, P ref' is the change in the flow transfer, and P is the current flow transfer.

[0011] Furthermore, when the difference in load rate between the substations on both sides of the flexible loop closing device is greater than 5%, the change in the power flow transfer is as follows:

[0012]

[0013] In the above formula, P tr1 and P tr2 are the real-time active power of the substation on one side of the flexible loop closing device and the substation on the other side, P etr1 and P etr2 They are the rated powers of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

[0014] Furthermore, the difference in load rate between the substations on both sides of the flexible loop closing device is as follows:

[0015] F err_str =F tr1 -F tr2

[0016] In the above formula, F err_str is the difference in load rate between the substations on both sides of the flexible loop closing device, F tr1 is the load factor of the substation on one side of the flexible loop closing device, F tr2 is the load rate of the substation on the other side of the flexible loop closing device, wherein the load rate of the substation on one side of the flexible loop closing device and the load rate of the substation on the other side of the flexible loop closing device are as follows:

[0017]

[0018] In the above formula, S tr1 and S tr2 are the apparent power of the substation on one side of the flexible loop closing device and the substation on the other side, S etr1 and S etr2 They are the rated capacities of the substation on one side of the flexible loop closing device and the substation on the other side respectively.

[0019] Furthermore, the apparent power of the substation on one side and the substation on the other side of the flexible loop closing device is as follows:

[0020]

[0021] In the above formula, Qtr1 and Qtr2 They are the real-time reactive power of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

[0022] Furthermore, when the difference in load rate between the interconnected lines on both sides of the flexible loop closing device is greater than 10%, the change in the power flow transfer is as follows:

[0023]

[0024] In the above formula, P L1 and P L2 are the real-time active power of the interconnected line busbar side on one side of the flexible ring closing device and the interconnected line busbar side on the other side, P eL1 and P eL2 They are the rated powers of the interconnected line busbar side on one side of the flexible loop closing device and the interconnected line busbar side on the other side respectively.

[0025] Furthermore, the difference in load rate between the interconnected lines on both sides of the flexible loop closing device is as follows:

[0026] F err_L =F L1 -F L2

[0027] In the above formula, F err_L is the difference in load rate between interconnected lines on both sides of the flexible loop closing device, F L1 is the interconnection line load rate on one side of the flexible loop closing device, F L2 is the load rate of the interconnection line on the other side of the flexible loop closing device, wherein the load rate of the interconnection line on one side of the flexible loop closing device and the load rate of the interconnection line on the other side of the flexible loop closing device are as follows:

[0028]

[0029] In the above formula, S L1 and S L2 are the apparent powers of the interconnected lines on one side of the flexible loop closing device and the interconnected lines on the other side of the flexible loop closing device, S eL1 and S eL2 They are respectively the rated capacities of the interconnection lines on one side of the flexible loop closing device and the interconnection lines on the other side of the flexible loop closing device.

[0030] Furthermore, the apparent power of the interconnection line on one side of the flexible loop closing device and the interconnection line on the other side of the flexible loop closing device is as follows:

[0031]

[0032] In the above formula, QL1 and QL2 They are the real-time reactive power on the interconnected line bus side on one side of the flexible loop closing device and on the interconnected line bus side on the other side.

[0033] Furthermore, the compensation voltage corresponding to the power flow transfer instruction is as follows:

[0034] U T =3U ph ZP ref

[0035] In the above formula, U T is the compensation voltage corresponding to the power transfer instruction, U ph is the phase voltage at the input end of the flexible loop closing device, and Z is the sum of the line impedance between the substations on both sides of the flexible loop closing device and the equivalent impedance of the flexible loop closing device.

[0036] Preferably, when the voltage deviation of phase x at the incoming line of the flexible loop closing device exceeds 2% Un, there is three-phase imbalance at phase x at the incoming line of the flexible loop closing device, Un is the rated voltage, and x is a, b and / or c.

[0037] Furthermore, when there is a three-phase imbalance in the x-phase at the inlet of the flexible loop closing device, the x-phase compensation voltage corresponding to the power flow transfer instruction is updated according to the following formula:

[0038] U Tx ′=U Tx +U x

[0039] In the above formula, U Tx ′ is the x-phase compensation voltage corresponding to the updated power transfer instruction, U Tx is the original value of the x-phase compensation voltage corresponding to the power transfer instruction, U x It is the compensation voltage corresponding to the x-phase voltage deviation at the incoming line of the flexible closing device.

[0040] Preferably, the flexible loop closing device comprises: a first incoming line connection port, a second incoming line connection port, a parallel transformer, an actuator and a series transformer;

[0041] The first incoming line connection port and the second incoming line connection port are respectively connected to outgoing lines of substations on both sides of the flexible loop closing device;

[0042] The first incoming line connection port is connected to the head end of the primary side of the parallel transformer, and the three phases of the tail end of the primary side of the parallel transformer constitute a neutral point. Each phase of the secondary side of the parallel transformer includes multiple secondary windings, and each secondary winding includes three taps. Each tap is connected to the secondary side of the series transformer through an actuator. The two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer.

[0043] Furthermore, the first incoming line connection port and the second incoming line connection port are respectively connected to a first voltage acquisition device and a second voltage acquisition device for measuring the first incoming line connection port voltage and the second incoming line connection port voltage; the first incoming line connection port and the second incoming line connection port are respectively connected to a first current acquisition device and a second current acquisition device for measuring the first incoming line connection port current and the second incoming line connection port current.

[0044] Furthermore, a first switch is connected between the first incoming line connection port and the head end of the primary side of the parallel transformer, and a second switch is connected to the connection line between the second incoming line connection port and the primary side of the series transformer.

[0045] Furthermore, the actuator includes a power valve corresponding to each secondary winding on the secondary side of the parallel transformer, and the three AC ports of the power valve are respectively connected to the three taps of the corresponding secondary winding. The power valves corresponding to one secondary winding per phase on the secondary side of the parallel transformer are connected in series head to tail to form a power valve group, and the head end of the power valve group is connected to the head end of the secondary side of the series transformer, and the tail end of the power valve group is connected to the tail end of the secondary side of the series transformer.

[0046] Furthermore, the power valve includes three pairs of thyristors connected in positive and negative parallel.

[0047] Furthermore, each phase of the secondary side of the parallel transformer includes three secondary windings.

[0048] Furthermore, the control signal of the compensation voltage corresponding to the power flow transfer instruction is obtained by querying a preset table, and the preset table consists of the compensation voltage corresponding to the power flow transfer instruction and its corresponding actuator control signal.

[0049] In a second aspect, a tidal current transfer device based on a flexible loop closing device is provided, wherein the tidal current transfer device based on the flexible loop closing device comprises:

[0050] A control module, used for sending a control signal for controlling the output of a compensation voltage corresponding to a power flow transfer instruction to an actuator in the flexible loop closing device; the power flow transfer instruction is used for realizing a power flow transfer process of a distribution network where the flexible loop closing device is located;

[0051] The updating module is used to update the compensation voltage corresponding to the power flow transfer instruction based on the voltage deviation at the incoming line of the flexible loop closing device when there is a three-phase imbalance at the incoming line of the flexible loop closing device.

[0052] Preferably, the power flow transfer instruction is as follows:

[0053] P ref =P ref '+P

[0054] In the above formula, P ref is the power transfer instruction, P ref ' is the change in the flow transfer, and P is the current flow transfer.

[0055] Furthermore, when the difference in load rate between the substations on both sides of the flexible loop closing device is greater than 5%, the change in the power flow transfer is as follows:

[0056]

[0057] In the above formula, P tr1 and P tr2 are the real-time active power of the substation on one side of the flexible loop closing device and the substation on the other side, P etr1 and P etr2 They are the rated powers of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

[0058] Furthermore, the difference in load rate between the substations on both sides of the flexible loop closing device is as follows:

[0059] F err_str =F tr1 -F tr2

[0060] In the above formula, F err_str is the difference in load rate between the substations on both sides of the flexible loop closing device, F tr1 is the load factor of the substation on one side of the flexible loop closing device, F tr2 is the load rate of the substation on the other side of the flexible loop closing device, wherein the load rate of the substation on one side of the flexible loop closing device and the load rate of the substation on the other side of the flexible loop closing device are as follows:

[0061]

[0062] In the above formula, S tr1 and S tr2 are the apparent power of the substation on one side of the flexible loop closing device and the substation on the other side, S etr1 and S etr2 They are the rated capacities of the substation on one side of the flexible loop closing device and the substation on the other side respectively.

[0063] Furthermore, the apparent power of the substation on one side and the substation on the other side of the flexible loop closing device is as follows:

[0064]

[0065] In the above formula, Qtr1 and Qtr2 They are the real-time reactive power of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

[0066] Furthermore, when the difference in load rate between the interconnected lines on both sides of the flexible loop closing device is greater than 10%, the change in the power flow transfer is as follows:

[0067]

[0068] In the above formula, P L1 and P L2 are the real-time active power of the interconnected line busbar side on one side of the flexible ring closing device and the interconnected line busbar side on the other side, PeL1 and P eL2 They are the rated powers of the interconnected line busbar side on one side of the flexible loop closing device and the interconnected line busbar side on the other side respectively.

[0069] Furthermore, the difference in load rate between the interconnected lines on both sides of the flexible loop closing device is as follows:

[0070] F err_L =F L1 -F L2

[0071] In the above formula, F err_L is the difference in load rate between interconnected lines on both sides of the flexible loop closing device, F L1 is the interconnection line load rate on one side of the flexible loop closing device, F L2 is the load rate of the interconnection line on the other side of the flexible loop closing device, wherein the load rate of the interconnection line on one side of the flexible loop closing device and the load rate of the interconnection line on the other side of the flexible loop closing device are as follows:

[0072]

[0073] In the above formula, S L1 and S L2 are the apparent powers of the interconnected lines on one side of the flexible loop closing device and the interconnected lines on the other side of the flexible loop closing device, S eL1 and S eL2 They are respectively the rated capacities of the interconnection lines on one side of the flexible loop closing device and the interconnection lines on the other side of the flexible loop closing device.

[0074] Furthermore, the apparent power of the interconnection line on one side of the flexible loop closing device and the interconnection line on the other side of the flexible loop closing device is as follows:

[0075]

[0076] In the above formula, QL1 and QL2 They are the real-time reactive power on the interconnected line bus side on one side of the flexible loop closing device and on the interconnected line bus side on the other side.

[0077] Furthermore, the compensation voltage corresponding to the power flow transfer instruction is as follows:

[0078] U T =3U ph ZP ref

[0079] In the above formula, U T is the compensation voltage corresponding to the power transfer instruction, U ph is the phase voltage at the input end of the flexible loop closing device, and Z is the sum of the line impedance between the substations on both sides of the flexible loop closing device and the equivalent impedance of the flexible loop closing device.

[0080] Preferably, when the voltage deviation of phase x at the incoming line of the flexible loop closing device exceeds 2% Un, there is three-phase imbalance at phase x at the incoming line of the flexible loop closing device, Un is the rated voltage, and x is a, b and / or c.

[0081] Furthermore, when there is a three-phase imbalance in the x-phase at the inlet of the flexible loop closing device, the x-phase compensation voltage corresponding to the power flow transfer instruction is updated according to the following formula:

[0082] U Tx ′=U Tx +U x

[0083] In the above formula, U Tx ′ is the x-phase compensation voltage corresponding to the updated power transfer instruction, U Tx is the original value of the x-phase compensation voltage corresponding to the power transfer instruction, U x It is the compensation voltage corresponding to the x-phase voltage deviation at the incoming line of the flexible closing device.

[0084] Further, the flexible loop closing device includes: a first incoming line connection port, a second incoming line connection port, a parallel transformer, an actuator and a series transformer;

[0085] The first incoming line connection port and the second incoming line connection port are respectively connected to outgoing lines of substations on both sides of the flexible loop closing device;

[0086] The first incoming line connection port is connected to the head end of the primary side of the parallel transformer, and the three phases of the tail end of the primary side of the parallel transformer constitute a neutral point. Each phase of the secondary side of the parallel transformer includes multiple secondary windings, and each secondary winding includes three taps. Each tap is connected to the secondary side of the series transformer through an actuator. The two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer.

[0087] Furthermore, the first incoming line connection port and the second incoming line connection port are respectively connected to a first voltage acquisition device and a second voltage acquisition device for measuring the first incoming line connection port voltage and the second incoming line connection port voltage; the first incoming line connection port and the second incoming line connection port are respectively connected to a first current acquisition device and a second current acquisition device for measuring the first incoming line connection port current and the second incoming line connection port current.

[0088] Furthermore, a first switch is connected between the first incoming line connection port and the head end of the primary side of the parallel transformer, and a second switch is connected to the connection line between the second incoming line connection port and the primary side of the series transformer.

[0089] Furthermore, the actuator includes a power valve corresponding to each secondary winding on the secondary side of the parallel transformer, and the three AC ports of the power valve are respectively connected to the three taps of the corresponding secondary winding. The power valves corresponding to one secondary winding per phase on the secondary side of the parallel transformer are connected in series head to tail to form a power valve group, and the head end of the power valve group is connected to the head end of the secondary side of the series transformer, and the tail end of the power valve group is connected to the tail end of the secondary side of the series transformer.

[0090] Furthermore, the power valve includes three pairs of thyristors connected in positive and negative parallel.

[0091] Furthermore, each phase of the secondary side of the parallel transformer includes three secondary windings.

[0092] Furthermore, the control signal of the compensation voltage corresponding to the power flow transfer instruction is obtained by querying a preset table, and the preset table consists of the compensation voltage corresponding to the power flow transfer instruction and its corresponding actuator control signal.

[0093] In a third aspect, a computer device is provided, comprising: one or more processors;

[0094] The processor is configured to execute one or more programs;

[0095] When the one or more programs are executed by the one or more processors, the power flow transfer method based on the flexible loop closing device is implemented.

[0096] In a fourth aspect, a computer-readable storage device is provided, on which a computer program is stored, and when the computer program is executed, the flow transfer method based on the flexible loop closing device is implemented.

[0097] The above one or more technical solutions of the present invention have at least one or more of the following beneficial effects:

[0098] The present invention provides a method and device for power flow transfer based on a flexible loop closing device, including: sending a control signal for controlling the compensation voltage corresponding to the output power flow transfer instruction to the actuator in the flexible loop closing device; the power flow transfer instruction is used to realize the power flow transfer process of the distribution network where the flexible loop closing device is located; when there is a three-phase imbalance at the incoming line of the flexible loop closing device, the compensation voltage corresponding to the power flow transfer instruction is updated based on the voltage deviation at the incoming line of the flexible loop closing device. The technical solution provided by the present invention avoids various complex transformations and PI closed-loop control in terms of three-phase imbalance control, can effectively control the three-phase imbalance problem, has a small amount of calculation, and is not prone to problems such as overvoltage and overcurrent caused by regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0099] Figure 11 is a schematic flow chart of the main steps of a power flow transfer method based on a flexible loop closing device according to an embodiment of the present invention;

[0100] Figure 2 is a structural diagram of a flexible ring closing device according to an embodiment of the present invention;

[0101] Figure 3 4 is a vector point principle diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0102] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0103] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0104] As disclosed in the background technology, in recent years, various problems of radial grids have gradually emerged in the open-loop operation mode of traditional distribution networks, and the distribution network closing technology has become a hot topic for scientific researchers. However, due to the complexity of the distribution network structure and load, using tie switches to directly close the loop during the flow transfer process will cause problems such as uncertain flow direction and large short-circuit current.

[0105] Flexible loop closing device can solve the above problems well and plays an important role in the power system. It realizes seamless switching of loop closing by utilizing the flexible and controllable advantages of the output compensation voltage, effectively reduces the current fluctuation and impact caused by loop closing, and avoids the instability of the power grid and equipment damage caused by loop closing operation, thereby ensuring the stability and reliability of the power system. However, due to factors such as drastic load fluctuations caused by the increase in users, uncertainty introduced by temporary and seasonal power consumption, as well as unbalanced phase distribution of users' three-phase power equipment and lack of effective management of three-phase load distribution on the distribution network side, the voltage of a certain phase fluctuates, and voltage deviations occur compared with other phases, resulting in frequent three-phase imbalance problems in the distribution network.

[0106] In order to improve the above problems, the present invention provides a method and device for power flow transfer based on a flexible loop closing device, including: sending a control signal for controlling the compensation voltage corresponding to the output power flow transfer instruction to the actuator in the flexible loop closing device; the power flow transfer instruction is used to realize the power flow transfer process of the distribution network where the flexible loop closing device is located; when there is a three-phase imbalance at the incoming line of the flexible loop closing device, the compensation voltage corresponding to the power flow transfer instruction is updated based on the voltage deviation at the incoming line of the flexible loop closing device. The technical solution provided by the present invention avoids various complex transformations and PI closed-loop control in terms of three-phase imbalance control, can effectively control the three-phase imbalance problem, has a small amount of calculation, and is not prone to problems such as overvoltage and overcurrent caused by regulation.

[0107] The above scheme is described in detail below.

[0108] Example 1

[0109] See attached Figure 1 , Figure 1 FIG. 1 is a flow chart showing the main steps of a method for power flow transfer based on a flexible loop closing device according to an embodiment of the present invention. Figure 1 As shown, the power flow transfer method based on the flexible loop closing device in the embodiment of the present invention mainly includes the following steps:

[0110] Step S101: sending a control signal for controlling the compensation voltage corresponding to the output power flow transfer instruction to the actuator in the flexible loop closing device; the power flow transfer instruction is used to implement the power flow transfer process of the distribution network where the flexible loop closing device is located;

[0111] Step S102: when there is a three-phase imbalance at the inlet of the flexible loop closing device, the compensation voltage corresponding to the power flow transfer instruction is updated based on the voltage deviation at the inlet of the flexible loop closing device.

[0112] In this embodiment, the power flow transfer instruction is as follows:

[0113] P ref =P ref '+P

[0114] In the above formula, P ref is the power transfer instruction, P ref ' is the change in the flow transfer, and P is the current flow transfer.

[0115] In one embodiment, when the difference in load rate between the substations on both sides of the flexible loop closing device is greater than 5%, the change in the power flow transfer is as follows:

[0116]

[0117] In the above formula, P tr1and P tr2 are the real-time active power of the substation on one side of the flexible loop closing device and the substation on the other side, P etr1 and P etr2 They are the rated powers of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

[0118] In one embodiment, the difference in load rate between the substations on both sides of the flexible loop closing device is as follows:

[0119] F err_str =F tr1 -F tr2

[0120] In the above formula, F err_str is the difference in load rate between the substations on both sides of the flexible loop closing device, F tr1 is the load factor of the substation on one side of the flexible loop closing device, F tr2 is the load rate of the substation on the other side of the flexible loop closing device, wherein the load rate of the substation on one side of the flexible loop closing device and the load rate of the substation on the other side of the flexible loop closing device are as follows:

[0121]

[0122] In the above formula, S tr1 and S tr2 are the apparent power of the substation on one side of the flexible loop closing device and the substation on the other side, S etr1 and S etr2 They are the rated capacities of the substation on one side of the flexible loop closing device and the substation on the other side respectively.

[0123] In one embodiment, the apparent power of the substation on one side and the substation on the other side of the flexible loop closing device is as follows:

[0124]

[0125] In the above formula, Q tr1 and Q tr2 They are the real-time reactive power of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

[0126] In one embodiment, when the difference in load rate between interconnected lines on both sides of the flexible loop closing device is greater than 10%, the change in the power flow transfer is as follows:

[0127]

[0128] In the above formula, P L1 and P L2 are the real-time active power of the interconnected line busbar side on one side of the flexible ring closing device and the interconnected line busbar side on the other side, P eL1 and P eL2They are the rated powers of the interconnected line busbar side on one side of the flexible loop closing device and the interconnected line busbar side on the other side respectively.

[0129] In one embodiment, the difference in load rate between interconnected lines on both sides of the flexible loop closing device is as follows:

[0130] F err_L =F L1 -F L2

[0131] In the above formula, F err_L is the difference in load rate between interconnected lines on both sides of the flexible loop closing device, F L1 is the interconnection line load rate on one side of the flexible loop closing device, F L2 is the load rate of the interconnection line on the other side of the flexible loop closing device, wherein the load rate of the interconnection line on one side of the flexible loop closing device and the load rate of the interconnection line on the other side of the flexible loop closing device are as follows:

[0132]

[0133] In the above formula, S L1 and S L2 are the apparent powers of the interconnected lines on one side of the flexible loop closing device and the interconnected lines on the other side of the flexible loop closing device, S eL1 and S eL2 They are respectively the rated capacities of the interconnection lines on one side of the flexible loop closing device and the interconnection lines on the other side of the flexible loop closing device.

[0134] In one embodiment, the apparent power of the interconnection line on one side of the flexible loop closing device and the interconnection line on the other side of the flexible loop closing device is as follows:

[0135]

[0136] In the above formula, QL1 and QL2 They are the real-time reactive power on the interconnected line bus side on one side of the flexible loop closing device and on the interconnected line bus side on the other side.

[0137] In one embodiment, the compensation voltage corresponding to the power flow transfer instruction is as follows:

[0138] U T =3U ph ZP ref

[0139] In the above formula, U T is the compensation voltage corresponding to the power transfer instruction, U ph is the phase voltage at the input end of the flexible loop closing device, and Z is the sum of the line impedance between the substations on both sides of the flexible loop closing device and the equivalent impedance of the flexible loop closing device.

[0140] In this embodiment, when the voltage deviation of phase x at the inlet of the flexible loop closing device exceeds 2% Un, there is three-phase imbalance at the inlet of the flexible loop closing device, where Un is the rated voltage and x is a, b and / or c.

[0141] In one embodiment, when there is a three-phase imbalance in the x-phase at the inlet of the flexible loop closing device, the x-phase compensation voltage corresponding to the power flow transfer instruction is updated according to the following formula:

[0142] U Tx ′=U Tx +U x

[0143] In the above formula, U Tx ′ is the x-phase compensation voltage corresponding to the updated power transfer instruction, U Tx is the original value of the x-phase compensation voltage corresponding to the power transfer instruction, U x It is the compensation voltage corresponding to the x-phase voltage deviation at the incoming line of the flexible closing device.

[0144] In this embodiment, the ring closing device is as follows: Figure 2 As shown, it includes: a first incoming line connection port, a second incoming line connection port, a parallel transformer, an actuator and a series transformer;

[0145] The first incoming line connection port and the second incoming line connection port are respectively connected to outgoing lines of substations on both sides of the flexible loop closing device;

[0146] The first incoming line connection port is connected to the head end of the primary side of the parallel transformer, and the three phases of the tail end of the primary side of the parallel transformer constitute a neutral point. Each phase of the secondary side of the parallel transformer includes multiple secondary windings, and each secondary winding includes three taps. Each tap is connected to the secondary side of the series transformer through an actuator. The two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer.

[0147] In one embodiment, the first incoming line connection port and the second incoming line connection port are respectively connected to a first voltage acquisition device and a second voltage acquisition device for measuring the first incoming line connection port voltage and the second incoming line connection port voltage; the first incoming line connection port and the second incoming line connection port are respectively connected to a first current acquisition device and a second current acquisition device for measuring the first incoming line connection port current and the second incoming line connection port current.

[0148] In one embodiment, a first switch QF01 is connected between the first incoming line connection port and the first current collection device, and a second switch QF02 is connected between the second incoming line connection port and the first current collection device.

[0149] In one embodiment, the actuator includes a power valve corresponding to each secondary winding on the secondary side of the parallel transformer, and the three AC ports of the power valve are respectively connected to the three taps of the corresponding secondary winding. The power valves corresponding to one secondary winding per phase on the secondary side of the parallel transformer are connected in series head to tail to form a power valve group, and the head end of the power valve group is connected to the head end of the secondary side of the series transformer, and the tail end of the power valve group is connected to the tail end of the secondary side of the series transformer.

[0150] In one embodiment, the power valve includes three pairs of thyristors connected in parallel.

[0151] In one embodiment, each phase of the secondary side of the parallel transformer includes three secondary windings.

[0152] In one embodiment, the control signal of the compensation voltage corresponding to the power flow transfer instruction is obtained by querying a preset table, wherein the preset table is composed of the compensation voltage corresponding to the power flow transfer instruction and the corresponding actuator control signal.

[0153] The parallel part of the closing device is the excitation link, which is a multi-winding multi-tap transformer, with one primary winding and three secondary windings for each phase, and a total of 9 secondary windings for the three phases; the actuator is the compensation voltage generation link, with a total of 9 units, corresponding to the 9 secondary windings respectively, and is responsible for selecting the appropriate gear according to the gear command issued by the control and protection system, and reorganizing the secondary windings of the parallel transformer to obtain the final compensation voltage. The series part is the voltage compensation link, which is responsible for connecting the voltage synthesized by the actuator into the line through the series transformer. For example, an A-phase secondary winding, a B-phase secondary winding, and a C-phase secondary winding are taken out from the parallel transformer, and the three secondary windings are connected in series to obtain the system A-phase compensation voltage vector, which is connected in series to the A-phase secondary winding of the series transformer, and the other two phases are similar. The voltage vector that can be synthesized by the actuator is a regular hexagon, as shown in the attached figure. Figure 3 In the middle blue area, there are 127 vectors in total, as shown in the attached figure. Figure 3 Black vector points in the medium blue area.

[0154] In a specific embodiment, the present invention provides a device-level algorithm for a loop closing device, which is as follows:

[0155] In the first step, the loop closing device receives the power flow transfer instruction Pref issued by the distribution automation system.

[0156] In the second step, the loop closing device calculates the difference between the three-phase voltage and the rated voltage, Ua, based on the voltage collected on both sides of the device. 差 =Ua-Un,Ub 差 =Ub-Un,Uc 差 =Uc-Un.

[0157] The third step is to determine whether the system is three-phase balanced and calculate Ua respectively. 差 ,Ub 差 ,Uc 差 Is it greater than or equal to 2%? If any one of them is greater than or equal to 2%, the system is considered to be unbalanced in three phases; otherwise, the system is considered to be balanced in three phases.

[0158] The fourth step is that if the three phases are unbalanced, the three-phase unbalance algorithm is executed to find the phases whose deviation from the system rated voltage is greater than or equal to 2%, and then the deviated phases are individually controlled. For example, if phase A has a deviation, the additional compensation voltage vector required for the deviation is calculated based on the deviation between the phase and the rated voltage, and the corresponding additional compensation voltage vector is found in the vector table.

[0159] Step 5, mapping the additional compensation voltage vector to the device output voltage vector diagram, and determining the gear offset required to correct the deviation;

[0160] Step 6: If the three phases are balanced, the closing device calculates the compensation voltage vector Ua that the corresponding device needs to synthesize according to the Pref given by the distribution automation system, and finds the corresponding vector in the table.

[0161] Step 7: Map the compensation voltage vector to the device output voltage vector diagram to determine the basic gear position.

[0162] In the eighth step, the basic gear determined by the calculated compensation voltage vector and the gear offset determined by the additional compensation voltage vector are superimposed to obtain the final gear, and the final gear is sent to the actuator.

[0163] Step 9: The actuator is adjusted to the final gear position. The device-level control algorithm process ends.

[0164] Example 2

[0165] Based on the same inventive concept, the present invention also provides a tidal current transfer device based on a flexible loop-closing device, the tidal current transfer device based on a flexible loop-closing device comprises:

[0166] A control module, used for sending a control signal for controlling the output of a compensation voltage corresponding to a power flow transfer instruction to an actuator in the flexible loop closing device; the power flow transfer instruction is used for realizing a power flow transfer process of a distribution network where the flexible loop closing device is located;

[0167] The updating module is used to update the compensation voltage corresponding to the power flow transfer instruction based on the voltage deviation at the incoming line of the flexible loop closing device when there is a three-phase imbalance at the incoming line of the flexible loop closing device.

[0168] Preferably, the power flow transfer instruction is as follows:

[0169] P ref =Pref '+P

[0170] In the above formula, P ref is the power transfer instruction, P ref ' is the change in the flow transfer, and P is the current flow transfer.

[0171] Furthermore, when the difference in load rate between the substations on both sides of the flexible loop closing device is greater than 5%, the change in the power flow transfer is as follows:

[0172]

[0173] In the above formula, P tr1 and P tr2 are the real-time active power of the substation on one side of the flexible loop closing device and the substation on the other side, P etr1 and P etr2 They are the rated powers of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

[0174] Furthermore, the difference in load rate between the substations on both sides of the flexible loop closing device is as follows:

[0175] F err_str =F tr1 -F tr2

[0176] In the above formula, F err_str is the difference in load rate between the substations on both sides of the flexible loop closing device, F tr1 is the load factor of the substation on one side of the flexible loop closing device, F tr2 is the load rate of the substation on the other side of the flexible loop closing device, wherein the load rate of the substation on one side of the flexible loop closing device and the load rate of the substation on the other side of the flexible loop closing device are as follows:

[0177]

[0178] In the above formula, S tr1 and S tr2 are the apparent power of the substation on one side of the flexible loop closing device and the substation on the other side, S etr1 and S etr2 They are the rated capacities of the substation on one side of the flexible loop closing device and the substation on the other side respectively.

[0179] Furthermore, the apparent power of the substation on one side and the substation on the other side of the flexible loop closing device is as follows:

[0180]

[0181] In the above formula, Qtr1 and Qtr2 They are the real-time reactive power of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

[0182] Furthermore, when the difference in load rate between the interconnected lines on both sides of the flexible loop closing device is greater than 10%, the change in the power flow transfer is as follows:

[0183]

[0184] In the above formula, P L1 and P L2 are the real-time active power of the interconnected line busbar side on one side of the flexible ring closing device and the interconnected line busbar side on the other side, P eL1 and P eL2 They are the rated powers of the interconnected line busbar side on one side of the flexible loop closing device and the interconnected line busbar side on the other side respectively.

[0185] Furthermore, the difference in load rate between the interconnected lines on both sides of the flexible loop closing device is as follows:

[0186] F err_L =F L1 -F L2

[0187] In the above formula, F err_L is the difference in load rate between interconnected lines on both sides of the flexible loop closing device, F L1 is the interconnection line load rate on one side of the flexible loop closing device, F L2 is the load rate of the interconnection line on the other side of the flexible loop closing device, wherein the load rate of the interconnection line on one side of the flexible loop closing device and the load rate of the interconnection line on the other side of the flexible loop closing device are as follows:

[0188]

[0189] In the above formula, S L1 and S L2 are the apparent powers of the interconnected lines on one side of the flexible loop closing device and the interconnected lines on the other side of the flexible loop closing device, S eL1 and S eL2 They are respectively the rated capacities of the interconnection lines on one side of the flexible loop closing device and the interconnection lines on the other side of the flexible loop closing device.

[0190] Furthermore, the apparent power of the interconnection line on one side of the flexible loop closing device and the interconnection line on the other side of the flexible loop closing device is as follows:

[0191]

[0192] In the above formula, QL1 and QL2 They are the real-time reactive power on the interconnected line bus side on one side of the flexible loop closing device and on the interconnected line bus side on the other side.

[0193] Furthermore, the compensation voltage corresponding to the power flow transfer instruction is as follows:

[0194] U T =3U ph ZP ref

[0195] In the above formula, U T is the compensation voltage corresponding to the power transfer instruction, U ph is the phase voltage at the input end of the flexible loop closing device, and Z is the sum of the line impedance between the substations on both sides of the flexible loop closing device and the equivalent impedance of the flexible loop closing device.

[0196] Preferably, when the voltage deviation of phase x at the incoming line of the flexible loop closing device exceeds 2% Un, there is three-phase imbalance at phase x at the incoming line of the flexible loop closing device, Un is the rated voltage, and x is a, b and / or c.

[0197] Furthermore, when there is a three-phase imbalance in the x-phase at the inlet of the flexible loop closing device, the x-phase compensation voltage corresponding to the power flow transfer instruction is updated according to the following formula:

[0198] U Tx ′=U Tx +U x

[0199] In the above formula, U Tx ′ is the x-phase compensation voltage corresponding to the updated power transfer instruction, U Tx is the original value of the x-phase compensation voltage corresponding to the power transfer instruction, U x It is the compensation voltage corresponding to the x-phase voltage deviation at the incoming line of the flexible closing device.

[0200] Further, the flexible loop closing device includes: a first incoming line connection port, a second incoming line connection port, a parallel transformer, an actuator and a series transformer;

[0201] The first incoming line connection port and the second incoming line connection port are respectively connected to outgoing lines of substations on both sides of the flexible loop closing device;

[0202] The first incoming line connection port is connected to the head end of the primary side of the parallel transformer, and the three phases of the tail end of the primary side of the parallel transformer constitute a neutral point. Each phase of the secondary side of the parallel transformer includes multiple secondary windings, and each secondary winding includes three taps. Each tap is connected to the secondary side of the series transformer through an actuator. The two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer.

[0203] Furthermore, the first incoming line connection port and the second incoming line connection port are respectively connected to a first voltage acquisition device and a second voltage acquisition device for measuring the first incoming line connection port voltage and the second incoming line connection port voltage; the first incoming line connection port and the second incoming line connection port are respectively connected to a first current acquisition device and a second current acquisition device for measuring the first incoming line connection port current and the second incoming line connection port current.

[0204] Furthermore, a first switch is connected between the first incoming line connection port and the head end of the primary side of the parallel transformer, and a second switch is connected to the connection line between the second incoming line connection port and the primary side of the series transformer.

[0205] Furthermore, the actuator includes a power valve corresponding to each secondary winding on the secondary side of the parallel transformer, and the three AC ports of the power valve are respectively connected to the three taps of the corresponding secondary winding. The power valves corresponding to one secondary winding per phase on the secondary side of the parallel transformer are connected in series head to tail to form a power valve group, and the head end of the power valve group is connected to the head end of the secondary side of the series transformer, and the tail end of the power valve group is connected to the tail end of the secondary side of the series transformer.

[0206] Furthermore, the power valve includes three pairs of thyristors connected in positive and negative parallel.

[0207] Furthermore, each phase of the secondary side of the parallel transformer includes three secondary windings.

[0208] Furthermore, the control signal of the compensation voltage corresponding to the power flow transfer instruction is obtained by querying a preset table, and the preset table consists of the compensation voltage corresponding to the power flow transfer instruction and its corresponding actuator control signal.

[0209] Example 3

[0210] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, wherein the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of a power flow transfer method based on a flexible loop device in the above embodiment.

[0211] Example 4

[0212] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage device (Memory), which is a memory device in a computer device for storing programs and data. It can be understood that the computer-readable storage device here can include both the built-in storage medium in the computer device and the extended storage medium supported by the computer device. The computer-readable storage device provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage device here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage device to implement the steps of a power flow transfer method based on a flexible loop device in the above embodiment.

[0213] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0214] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks 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 produce 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.

[0215] 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 comprising 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.

[0216] 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 The steps for the functions specified in one or more boxes.

[0217] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A power flow transfer method based on a flexible loop closing device, characterized in that: The method comprises: Sending a control signal for controlling the output of a compensation voltage corresponding to a power flow transfer instruction to an actuator in the flexible loop closing device; the power flow transfer instruction is used to implement a power flow transfer process of the distribution network where the flexible loop closing device is located; When there is a three-phase imbalance at the incoming line of the flexible loop closing device, the compensation voltage corresponding to the power flow transfer instruction is updated through the control signal based on the voltage deviation at the incoming line of the flexible loop closing device.

2. The method according to claim 1, characterized in that The power flow transfer instructions are as follows: P ref =P ref ’+P In the above formula, P ref is the power transfer instruction, P ref ' is the change in the flow transfer, and P is the current flow transfer.

3. The method according to claim 2, characterized in that When the difference in load rate between the substations on both sides of the flexible loop closing device is greater than 5%, the change in the power flow transfer is as follows: In the above formula, P tr1 and P tr2 are the real-time active power of the substation on one side of the flexible loop closing device and the substation on the other side, P etr1 and P etr2 They are the rated powers of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

4. The method according to claim 3, characterized in that The difference in load rate between the substations on both sides of the flexible loop closing device is as follows: F err_str =F tr1 -F tr2 In the above formula, F err_str is the difference in load rate between the substations on both sides of the flexible loop closing device, F tr1 is the load factor of the substation on one side of the flexible loop closing device, F tr2 is the load rate of the substation on the other side of the flexible loop closing device, wherein the load rate of the substation on one side of the flexible loop closing device and the load rate of the substation on the other side of the flexible loop closing device are as follows: In the above formula, S tr1 and S tr2 are the apparent power of the substation on one side of the flexible loop closing device and the substation on the other side, S etr1 and S etr2 They are the rated capacities of the substation on one side of the flexible loop closing device and the substation on the other side respectively.

5. The method according to claim 4, characterized in that The apparent power of the substation on one side and the substation on the other side of the flexible loop closing device is as follows: In the above formula, Qtr1 and Qtr2 They are the real-time reactive power of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

6. The method according to claim 2, characterized in that When the load rate difference between the interconnected lines on both sides of the flexible loop closing device is greater than 10%, the change in the power flow transfer is as follows: In the above formula, P L1 and P L2 are the real-time active power of the interconnected line busbar side on one side of the flexible ring closing device and the interconnected line busbar side on the other side, P eL1 and P eL2 They are the rated powers of the interconnected line busbar side on one side of the flexible loop closing device and the interconnected line busbar side on the other side respectively.

7. The method according to claim 6, characterized in that The difference in load rate of interconnected lines on both sides of the flexible loop closing device is as follows: F err_L =F L1 -F L2 In the above formula, F err_L is the difference in load rate between interconnected lines on both sides of the flexible loop closing device, F L1 is the interconnection line load rate on one side of the flexible loop closing device, F L2 is the load rate of the interconnection line on the other side of the flexible loop closing device, wherein the load rate of the interconnection line on one side of the flexible loop closing device and the load rate of the interconnection line on the other side of the flexible loop closing device are as follows: In the above formula, S L1 and S L2 are the apparent powers of the interconnected lines on one side of the flexible loop closing device and the interconnected lines on the other side of the flexible loop closing device, S eL1 and S eL2 They are respectively the rated capacities of the interconnection lines on one side of the flexible loop closing device and the interconnection lines on the other side of the flexible loop closing device.

8. The method according to claim 7, characterized in that The apparent power of the interconnection line on one side of the flexible loop closing device and the interconnection line on the other side of the flexible loop closing device is as follows: In the above formula, QL1 and QL2 They are the real-time reactive power on the interconnected line bus side on one side of the flexible loop closing device and on the interconnected line bus side on the other side.

9. The method according to claim 2, characterized in that The compensation voltage corresponding to the power flow transfer instruction is as follows: AT T =3U ph ZP ref In the above formula, U T is the compensation voltage corresponding to the power flow transfer instruction, U ph is the phase voltage at the input end of the flexible loop closing device, and Z is the sum of the line impedance between the substations on both sides of the flexible loop closing device and the equivalent impedance of the flexible loop closing device.

10. The method according to claim 1, characterized in that When the voltage deviation of phase x at the incoming line of the flexible loop closing device exceeds 2%Un, there is three-phase imbalance at phase x at the incoming line of the flexible loop closing device, where Un is the rated voltage and x is a, b and / or c.

11. The method according to claim 10, characterized in that When there is three-phase imbalance in the x-phase at the inlet of the flexible loop closing device, the x-phase compensation voltage corresponding to the power flow transfer instruction is updated as follows: IN Tx ′=U Tx +U x In the above formula, U Tx ′ is the x-phase compensation voltage corresponding to the updated power transfer instruction, U Tx is the original value of the x-phase compensation voltage corresponding to the power transfer instruction, U x It is the compensation voltage corresponding to the x-phase voltage deviation at the incoming line of the flexible closing device.

12. The method according to claim 1, characterized in that The flexible loop closing device comprises: a first incoming line connection port, a second incoming line connection port, a parallel transformer, an actuator and a series transformer; The first incoming line connection port and the second incoming line connection port are respectively connected to outgoing lines of substations on both sides of the flexible loop closing device; The first incoming line connection port is connected to the head end of the primary side of the parallel transformer, and the three phases of the tail end of the primary side of the parallel transformer are connected to form a neutral point. Each phase of the secondary side of the parallel transformer includes multiple secondary windings, and each secondary winding includes three taps. Each tap is connected to the secondary side of the series transformer through an actuator. The two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer.

13. The method according to claim 12, characterized in that A first switch is connected between the first incoming line connection port and the head end of the primary side of the parallel transformer, and a second switch is connected to the connection line between the second incoming line connection port and the primary side of the series transformer.

14. The method according to claim 12, characterized in that The actuator includes a power valve corresponding to the secondary winding on the secondary side of the parallel transformer, the three AC ports of the power valve are respectively connected to the three taps of the corresponding secondary winding, and the power valve corresponding to each secondary winding of each phase of the secondary side of the parallel transformer is connected in series to form a power valve group. The head end of the power valve group is connected to the head end of the secondary side of the series transformer, and the tail end of the power valve group is connected to the tail end of the secondary side of the series transformer.

15. The method according to claim 14, characterized in that The power valve comprises three pairs of thyristors connected in parallel.

16. The method according to claim 12, characterized in that Each phase of the secondary side of the parallel transformer includes three secondary windings.

17. The method according to claim 1, wherein: The control signal of the compensation voltage corresponding to the power flow transfer instruction is obtained by querying a preset table, and the preset table is composed of the compensation voltage corresponding to the power flow transfer instruction and the corresponding actuator control signal.

18. A tidal current transfer device based on a flexible loop closing device, characterized in that: The device comprises: A control module, used for sending a control signal for controlling the output of a compensation voltage corresponding to a power flow transfer instruction to an actuator in the flexible loop closing device; the power flow transfer instruction is used for realizing a power flow transfer process of a distribution network where the flexible loop closing device is located; The updating module is used to update the compensation voltage corresponding to the power flow transfer instruction based on the voltage deviation at the incoming line of the flexible loop closing device when there is a three-phase imbalance at the incoming line of the flexible loop closing device.

19. The device according to claim 18, characterized in that The power flow transfer instructions are as follows: P ref =P ref ’+P In the above formula, P ref is the power transfer instruction, P ref ' is the change in the flow transfer, and P is the current flow transfer.

20. The device according to claim 19, characterized in that When the difference in load rate between the substations on both sides of the flexible loop closing device is greater than 5%, the change in the power flow transfer is as follows: In the above formula, P tr1 and P tr2 are the real-time active power of the substation on one side of the flexible loop closing device and the substation on the other side, P etr1 and P etr2 They are the rated powers of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

21. The device according to claim 20, characterized in that The difference in load rate between the substations on both sides of the flexible loop closing device is as follows: F err_str =F tr1 -F tr2 In the above formula, F err_str is the difference in load rate between the substations on both sides of the flexible loop closing device, F tr1 is the load factor of the substation on one side of the flexible loop closing device, F tr2 is the load rate of the substation on the other side of the flexible loop closing device, wherein the load rate of the substation on one side of the flexible loop closing device and the load rate of the substation on the other side of the flexible loop closing device are as follows: In the above formula, S tr1 and S tr2 are the apparent power of the substation on one side of the flexible loop closing device and the substation on the other side, S etr1 and S etr2 They are the rated capacities of the substation on one side of the flexible loop closing device and the substation on the other side respectively.

22. The device according to claim 21, characterized in that The apparent power of the substation on one side and the substation on the other side of the flexible loop closing device is as follows: In the above formula, Q tr1 and Q tr2 They are the real-time reactive power of the substation on one side and the substation on the other side of the flexible loop closing device respectively.

23. The device according to claim 19, characterized in that When the load rate difference between the interconnected lines on both sides of the flexible loop closing device is greater than 10%, the change in the power flow transfer is as follows: In the above formula, P L1 and P L2 are the real-time active power of the interconnected line busbar side on one side of the flexible ring closing device and the interconnected line busbar side on the other side, P eL1 and P eL2 They are the rated powers of the interconnected line busbar side on one side of the flexible loop closing device and the interconnected line busbar side on the other side respectively.

24. The device according to claim 23, characterized in that The difference in load rate of interconnected lines on both sides of the flexible loop closing device is as follows: F err_L =F L1 -F L2 In the above formula, F err_L is the difference in load rate between interconnected lines on both sides of the flexible loop closing device, F L1 is the interconnection line load rate on one side of the flexible loop closing device, F L2 is the load rate of the interconnection line on the other side of the flexible loop closing device, wherein the load rate of the interconnection line on one side of the flexible loop closing device and the load rate of the interconnection line on the other side of the flexible loop closing device are as follows: In the above formula, S L1 and S L2 are the apparent powers of the interconnected lines on one side of the flexible loop closing device and the interconnected lines on the other side of the flexible loop closing device, S eL1 and S eL2 They are respectively the rated capacities of the interconnection lines on one side of the flexible loop closing device and the interconnection lines on the other side of the flexible loop closing device.

25. The device according to claim 24, characterized in that The apparent power of the interconnection line on one side of the flexible loop closing device and the interconnection line on the other side of the flexible loop closing device is as follows: In the above formula, QL1 and QL2 They are the real-time reactive power on the interconnected line bus side on one side of the flexible loop closing device and on the interconnected line bus side on the other side.

26. The device according to claim 19, characterized in that The compensation voltage corresponding to the power flow transfer instruction is as follows: AT T =3U ph ZP ref In the above formula, U T is the compensation voltage corresponding to the power flow transfer instruction, U ph is the phase voltage at the input end of the flexible loop closing device, and Z is the sum of the line impedance between the substations on both sides of the flexible loop closing device and the equivalent impedance of the flexible loop closing device.

27. The device according to claim 18, characterized in that When the voltage deviation of phase x at the incoming line of the flexible loop closing device exceeds 2%Un, there is three-phase imbalance at phase x at the incoming line of the flexible loop closing device, where Un is the rated voltage and x is a, b and / or c.

28. The device according to claim 27, characterized in that When there is three-phase imbalance in the x-phase at the inlet of the flexible loop closing device, the x-phase compensation voltage corresponding to the power flow transfer instruction is updated as follows: IN Tx ′=U Tx +U x In the above formula, U Tx ′ is the x-phase compensation voltage corresponding to the updated power transfer instruction, U Tx is the original value of the x-phase compensation voltage corresponding to the power transfer instruction, U x It is the compensation voltage corresponding to the x-phase voltage deviation at the incoming line of the flexible closing device.

29. The device according to claim 18, characterized in that The flexible loop closing device comprises: a first incoming line connection port, a second incoming line connection port, a parallel transformer, an actuator and a series transformer; The first incoming line connection port and the second incoming line connection port are respectively connected to outgoing lines of substations on both sides of the flexible loop closing device; The first incoming line connection port is connected to the head end of the primary side of the parallel transformer, and the three phases of the tail end of the primary side of the parallel transformer constitute a neutral point. Each phase of the secondary side of the parallel transformer includes multiple secondary windings, and each secondary winding includes three taps. Each tap is connected to the secondary side of the series transformer through an actuator. The two ends of the primary side of the series transformer are respectively connected to the second incoming line connection port and the head end of the primary side of the parallel transformer.

30. The device according to claim 29, characterized in that A first switch is connected between the first incoming line connection port and the head end of the primary side of the parallel transformer, and a second switch is connected to the connection line between the second incoming line connection port and the primary side of the series transformer.

31. The device according to claim 29, characterized in that The actuator includes a power valve corresponding to each secondary winding on the secondary side of the parallel transformer, and the three AC ports of the power valve are respectively connected to the three taps of the corresponding secondary winding. The power valves corresponding to one secondary winding per phase on the secondary side of the parallel transformer are connected in series head to tail to form a power valve group, and the head end of the power valve group is connected to the head end of the secondary side of the series transformer, and the tail end of the power valve group is connected to the tail end of the secondary side of the series transformer.

32. The device according to claim 31, characterized in that The power valve comprises three pairs of thyristors connected in parallel.

33. The device according to claim 29, characterized in that Each phase of the secondary side of the parallel transformer includes three secondary windings.

34. The device according to claim 18, characterized in that The control signal of the compensation voltage corresponding to the power flow transfer instruction is obtained by querying a preset table, and the preset table is composed of the compensation voltage corresponding to the power flow transfer instruction and the corresponding actuator control signal.

35. A computer device, characterized in that: include: one or more processors; The processor is configured to execute one or more programs; When the one or more programs are executed by the one or more processors, the power flow transfer method based on the flexible loop closing device as described in any one of claims 1 to 17 is implemented.

36. A computer readable storage device, characterized in that: A computer program is stored thereon, and when the computer program is executed, the method for power flow transfer based on a flexible loop closing device as described in any one of claims 1 to 17 is implemented.

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