Full-stop and full-transfer method and system for transformer substation

Abstract

The invention provides a full-stop and full-rotation method and system for a transformer substation, and solves the problem that in the prior art, main and distribution linkage is insufficient in the fault recovery process, so that equipment is overloaded or the loss load is too large when a high-voltage-class bus breaks down, and the method comprises the steps that a full-stop and full-rotation model is established; acquiring main network real-time data and distribution network real-time data; monitoring whether the serial power supply network has a fault or not, and if yes, positioning fault equipment; generating a full-stop full-rotation switch action sequence; and executing the full-stop full-rotation switch action sequence. The system comprises a modeling module, a data acquisition module, a fault monitoring and positioning module, a switch action sequence generation module and a switch action sequence execution module. According to the method, the cooperative transfer capacity of the main network and the distribution network is comprehensively considered, the power supply of the power-off transformer substation is recovered to the maximum extent under the condition that the safety and overload of the main network and the distribution network equipment are ensured, the power-off range is reduced, and the power supply reliability and the user satisfaction are improved.

Description

Technical Field

[0001] The present invention relates to the field of power system fault recovery, and in particular to a method and system for full shutdown and full rotation of a transformer substation. Background Art

[0002] With the development of social economy, the scale of urban and rural power grids is constantly expanding, and the power grid structure is becoming increasingly complex, which puts forward higher and higher requirements for ensuring the reliability of power supply from substations. There are many factors that affect the reliability of power supply, such as the geographical location and climate environment of the substation, the reliability of the primary and secondary equipment in the station, the operation and management of the substation, the reasonable power grid structure, and the perfect backup power supply automatic investment plan. Among them, the backup power supply automatic investment (abbreviated as backup automatic investment) is an effective means to improve the reliability of power supply.

[0003] Traditional backup automatic switching devices only use the information of the local station to formulate corresponding action strategies, with fixed action logic, and can only adapt to specific operating modes. The regional backup automatic switching deployed in the control center expands the backup automatic switching function, mainly used to solve the problem of power restoration when a single power supply serial power supply fails. Although the current regional backup automatic switching considers overload joint cutting after action, it does not fully utilize the load transfer capacity of the distribution network to reduce the scope of power outage when the equipment is overloaded or a higher voltage level bus fails, and the main distribution network is not linked enough when handling faults. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the problem that the prior art has insufficient main and distribution linkage during fault recovery, resulting in equipment overload or excessive load loss when a higher voltage level bus fails, and to provide a full stop and full turn method and system for a substation with main and distribution coordination.

[0005] A first aspect of the present invention provides a substation full stop and full rotation method, comprising the following steps:

[0006] Establish a full-stop full-speed model including a serial power supply network;

[0007] Corresponding to the full stop and full start model, obtain the real-time data of the main network and the distribution network;

[0008] Monitor whether the serial power supply network has any faults based on the real-time data of the main network and the distribution network, and locate the faulty device if there is any fault;

[0009] Based on the position of the faulty equipment in the full stop and full rotation model, the full stop and full rotation switch action sequence is generated and executed with the strategy of gradually restoring the lost power bus to the power outage area and transferring power to the distribution network side without exceeding the limit.

[0010] Preferably, the establishing of a full-stop full-run model including a serial power supply network comprises:

[0011] Setting the power substations at both ends of the serial power supply network and several load substations in the middle included in the full stop and full rotation model;

[0012] Set up higher voltage level busbars in each substation and lines connecting the substations;

[0013] Setting a protection action signal associated with a higher voltage level busbar in the substation and a protection action signal associated with the line;

[0014] According to the topological relationship, the line switches on both sides corresponding to the line, the low-voltage side bus of the substation, and all feeders connected to the low-voltage side bus are automatically searched to complete the construction of the full stop and full rotation model of the substation.

[0015] Preferably, the main network real-time data obtained includes:

[0016] The line switch position, the three-phase voltage of the higher voltage bus, the three-phase voltage of the low voltage side bus, the bus protection action signal associated with the higher voltage bus, the line protection action signal associated with the line, the line flow and the low voltage side outgoing line flow of the substation;

[0017] The obtained real-time data of the distribution network includes:

[0018] Section switch position, tie switch position and section switch flow.

[0019] Preferably, the fault location criterion is: the equipment has a protection action and the associated switch is opened; the equipment is a line in the serial power supply network or a higher voltage level bus in the substation.

[0020] Preferably, the generated and executed full stop and full turn switch action sequence includes:

[0021] Restore the power supply of the busbar with a higher voltage level, starting from the open-loop point, and gradually restore the power-lost busbar to the power outage area, forming the first switch action sequence;

[0022] Calculate the expected power flow distribution after the execution of the first switch action sequence to check whether it causes equipment overload; if the equipment is overloaded, perform over-limit power transfer analysis on the substation associated with the overloaded equipment to form a second switch action sequence that can eliminate the over-limit; if the equipment is not overloaded, set the second switch action sequence to empty;

[0023] If the faulty device is a line, the third switch action sequence is set to empty; if the faulty device is a higher voltage level bus in the substation, causing the low-voltage side bus of the same substation to lose voltage and stop completely, first separate the low-voltage side switch of the main transformer of the substation, and perform a full stop and transfer analysis on the distribution network side of the substation to form the third switch action sequence;

[0024] The first, second and third switching action sequences form a full stop and full turn switching action sequence to be executed.

[0025] Preferably, the over-limit transfer analysis includes:

[0026] Search all feeders of the substation associated with the overload device to form a feeder set A;

[0027] Take out feeders from the feeder set A in sequence according to a set order, and transfer all or part of the load to the opposite feeder taking into account the capacity margin of the opposite feeder;

[0028] If the over-limit is eliminated after a certain feeder is taken out and its load is transferred out, the over-limit transfer analysis ends;

[0029] If the over-limit situation is not eliminated after all the feeders of the opposite side in the feeder set A are transferred, the principle of minimum load removal is followed, and part or all of the load carried by the untransferred feeders in the feeder set A is removed in a set order until the over-limit situation is eliminated.

[0030] Preferably, the substation distribution network side full stop power supply analysis step:

[0031] Among all the feeders connected to the substation, if there is an opposite-side feeder, transfer all the load to the opposite-side feeder, check the capacity margin of the opposite-side feeder, and if the capacity margin of the opposite-side feeder is insufficient, transfer part of the load to the opposite-side feeder;

[0032] If there is still a load outage after all the feeders connected to the substation with opposite-side feeders are transferred, the opposite-side feeder with the largest remaining capacity margin after receiving the transferred load is selected, that is, the reverse power supply support feeder, and the feeder outlet switch on the substation side corresponding to the reverse power supply support feeder is closed to reverse power supply from the low-voltage side bus of the substation to the untransferred load;

[0033] Check the remaining capacity margin of the reverse power supply support feeder. If the capacity margin is insufficient, the load removal amount is minimized in principle, and part of the untransferred load is removed in a set order.

[0034] Preferably, the execution of the full stop and full turn switch action sequence includes:

[0035] The second switch action sequence is executed first, and then the first switch action sequence is executed, and the third switch action sequence is executed in parallel with the second switch action sequence and the first switch action sequence;

[0036] During the execution of the first switch action sequence, before closing the switch to restore power supply to the corresponding bus, it must be confirmed that the bus to which the switch is to restore power is without pressure and the bus on the backup power supply side has pressure. Otherwise, the execution process of the first switch action sequence will be paused and wait until the conditions are met or the execution process times out.

[0037] Preferably, the second switching action sequence and the third switching action sequence are executed in parallel by feeder grouping.

[0038] Preferably, when executing the last step of the first switch action sequence to close the line switch, if the line switch trips again, it is determined that the actual faulty device is the busbar, and an additional analysis of the full shutdown of the substation distribution network side is performed to form a third switch action sequence and execute it additionally.

[0039] A second aspect of the present invention provides a substation full stop and full turn system, comprising:

[0040] Modeling module, establishing full-stop full-run model corresponding to each serial power supply network;

[0041] A data acquisition module, periodically acquiring real-time data of each of the full-stop and full-speed models;

[0042] A fault monitoring and locating module monitors faults in each of the full-stop and full-run models and locates faulty equipment;

[0043] A switch action sequence generation module generates a switch action sequence for restoring power supply according to the located faulty device;

[0044] The switch action sequence execution module sends a remote control command to execute the generated switch action sequence.

[0045] The present invention proposes a method and system for full shutdown and full transfer of a substation. Compared with the prior art, the method and system comprehensively consider the coordinated transfer capacity of the main network and the distribution network, and maximize the restoration of power supply to the outage substation while ensuring the safety of the main network and the distribution network equipment without overload, thereby reducing the scope of power outage and improving power supply reliability and user satisfaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a schematic diagram of the connection relationship between the main and distribution networks of a serial power supply network used in an exemplary embodiment of the present invention;

[0047] Figure 2 It is a flow chart of the method for full stop and full rotation of a substation of the present invention. DETAILED DESCRIPTION

[0048] like Figure 1 , 2 As shown, embodiment 1 of the present invention provides a method for full stop and full rotation of a substation, comprising the following steps:

[0049] Step 1: Build a full-stop full-speed model including a series power supply network.

[0050] Preferably but not limiting, step 1 specifically comprises:

[0051] Step 1.1: Set the power substations at both ends of the serial power supply network and several load substations in the middle, which are included in the full stop and full rotation model.

[0052] Step 1.2: Setting a higher voltage level busbar in the substation and a line connecting the substation. It is to be understood that in the subsequent description of the present invention, "line" refers to the connecting line between substations.

[0053] Step 1.3: Setting the protection action signal associated with the higher voltage level busbar in the substation and the protection action signal associated with the line.

[0054] Step 1.4: After completing the settings of step 1.3, automatically search for the line switches on both sides of the line corresponding to the line, the low-voltage side bus of the substation, and all feeders connected to the low-voltage side bus according to the topological relationship to complete the construction of the full stop and full rotation model of the substation.

[0055] It can be understood that all feeders connected to the low-voltage side bus are identified by the name of the outgoing line switch, and according to the topological structure, they may include the outgoing line switch, section switch, connecting switch and the opposite side feeder also identified by the name of the outgoing line switch, etc.

[0056] Step 2: Corresponding to the full stop and full start model, obtain the real-time data of the main network and the distribution network.

[0057] Preferably but not limiting, step 2 specifically comprises:

[0058] The real-time data of the main grid obtained include: the position of the line switch, the three-phase voltage of the higher voltage level bus, the three-phase voltage of the low-voltage side bus, the bus protection action signal associated with the higher voltage level bus, the line protection action signal associated with the line, the line flow and the low-voltage side outgoing line flow of the substation.

[0059] The obtained real-time data of the distribution network include: section switch position, tie switch position, and section switch power flow.

[0060] Step 3: Monitor the serial power supply network for faults based on the real-time data of the main network and the distribution network, and locate the faulty device if a fault occurs.

[0061] Preferably but not restrictively, the fault location criterion in step 3 is: the equipment has protection action and the associated switch is open; the equipment is a line in the serial power supply network or a higher voltage level bus in the substation.

[0062] Step 4: Based on the position of the faulty equipment in the full stop and full rotation model, the full stop and full rotation switch action sequence is generated with the strategy of gradually restoring the de-energized busbar to the power outage area and analyzing the power transfer on the distribution network side without exceeding the limit.

[0063] Preferably but not limiting, step 4 specifically comprises:

[0064] Step 4.1: Restore the power supply of the higher voltage level busbar, starting from the open-loop point, and gradually restore the power-lost busbar to the power outage area, forming the first switch action sequence.

[0065] It can be understood that no matter the faulty device is located as a line or a bus, in order to restore power to as many substations as possible, step 4.1 adopts a strategy of gradually restoring the lost busbar to the power outage area.

[0066] Step 4.2: Calculate the expected power flow distribution after the execution of the first switch action sequence to check whether it causes equipment overload; if equipment overload occurs, execute step 4.3; if equipment overload does not occur, set the second switch action sequence to empty, and continue to execute step 4.4 for bus faults and step 4.5 for line faults.

[0067] Step 4.3: Perform over-limit power transfer analysis on the substation associated with the overloaded equipment to form a second switch action sequence that can eliminate the over-limit; continue with step 4.4 for busbar faults and continue with step 4.5 for line faults.

[0068] Further preferably but not limitingly, the over-limit transfer analysis in step 4.3 comprises the steps of:

[0069] Step 4.3.1: Search all feeders of the substation associated with the overload device to form a feeder set A;

[0070] Step 4.3.2: Take out feeders from the feeder set A in sequence according to a set order, and transfer all or part of the load to the opposite feeder under the premise of considering the capacity margin of the opposite feeder;

[0071] Step 4.3.3: If the over-limit is eliminated after a feeder is taken out and its load is transferred out, the over-limit transfer analysis is completed;

[0072] Step 4.3.4: If the over-limit situation is not eliminated after all the feeders of the opposite side feeders in the feeder set A are transferred, the load removal amount shall be minimized and part or all of the load carried by the untransferred feeders in the feeder set A shall be removed in a set order until the over-limit situation is eliminated.

[0073] Faults in the lines within the serial power supply network or in the higher voltage busbars within the substation require over-limit transfer analysis. In both fault situations, transferring the load to the backup power supply side may cause overload.

[0074] Step 4.4: If the faulty equipment is a busbar with a higher voltage level, causing the low-voltage side busbar of the same substation to lose voltage and stop completely, first separate the low-voltage side switch of the substation main transformer, and perform a full stop and transfer analysis on the distribution network side of the substation to form a third switch action sequence, and use the first, second and third switch action sequences to form a full stop and full transfer switch action sequence to be executed.

[0075] Further preferably but not restrictively, the substation distribution network side full stop power transfer analysis in step 4.4 comprises the steps of:

[0076] Step 4.4.1: Among all the feeders connected to the substation, if there is an opposite-side feeder, transfer all loads to the opposite-side feeder, check the capacity margin of the opposite-side feeder, and if the capacity margin of the opposite-side feeder is insufficient, transfer part of the load to the opposite-side feeder;

[0077] Step 4.4.2: If there is still a load outage after all the feeders connected to the substation with opposite-side feeders are transferred, the opposite-side feeder with the largest remaining capacity margin after receiving the transferred load is selected, that is, the reverse power supply support feeder, and the feeder outlet switch on the substation side corresponding to the reverse power supply support feeder is closed to reverse power supply from the low-voltage side bus of the substation to the untransferred load;

[0078] Step 4.4.3: Check the remaining capacity margin of the reverse power supply support feeder. If the capacity margin is insufficient, the load shedding amount is minimized and part of the untransferred load is shedded in the set order.

[0079] Step 4.5: If the faulty device is a line, the third switch action sequence is set to be empty, and the first, second and third switch action sequences form a full stop and full turn switch action sequence to be executed.

[0080] Step 5: Execute the full stop and full turn switch action sequence.

[0081] Preferably but not restrictively, step 5 first executes the second switch action sequence, and then executes the first switch action sequence, and the third switch action sequence is executed in parallel with the second switch action sequence and the first switch action sequence; during the execution of the switch action sequence 1, before closing the switch to restore the corresponding bus power supply, it must be confirmed that the bus to which the switch is to restore power is without pressure, and the bus on the backup power supply side is with pressure, otherwise the execution process of the switch action sequence 1 is paused and waited until the condition is met or the execution process times out; the second switch action sequence and the third switch action sequence are executed in parallel by feeder grouping.

[0082] It is worth noting that, as one of the outstanding essential features of the present invention, considering that busbar protection or line longitudinal protection may not be configured at the actual site, when the busbar fails, the line protection associated with the line will be activated and the line switch will be opened, that is, step 3 will mistakenly locate the faulty equipment as the line.

[0083] In the above situation, it is impossible to distinguish between line fault and bus fault, and the situation of closing the fault may occur. In order to restore power to as many substations as possible, the step 4.1 first adopts the strategy of gradually restoring the de-energized bus to the power outage area according to the line fault, and first generates an action sequence according to the line fault. In the execution stage, when the line switch is closed in the last step of the first switch action sequence in step 5, the faulty bus will be closed, causing the line switch to trip again. At this time, the bus fault can be confirmed. In this case, after the execution of the switch action sequence in step 5 is completed, the analysis of the full shutdown of the substation distribution network side is performed in step 4.4 to form a third switch action sequence and execute it additionally.

[0084] Embodiment 2 of the present invention provides a substation full stop and full turn system, which runs the substation full stop and full turn method as described in Embodiment 1, including:

[0085] Modeling module, establishing full-stop full-run model corresponding to each serial power supply network;

[0086] A data acquisition module, periodically acquiring real-time data of each of the full-stop and full-speed models;

[0087] A fault monitoring and locating module monitors faults in each of the full-stop and full-run models and locates faulty equipment;

[0088] A switch action sequence generation module generates a switch action sequence for restoring power supply according to the located faulty device;

[0089] The switch action sequence execution module sends a remote control command to execute the generated switch action sequence.

[0090] In order to more clearly introduce the outstanding essential features of the present invention and the significant progress it brings to the prior art, an application example of implementing the present invention is introduced below.

[0091] The exemplary embodiment of the present invention uses Figure 1 The serial power supply network shown includes four substations, namely 220kV substation A, 110kV substation B, 110kV substation C, and 220kV substation D. In the exemplary embodiment of the present invention, the higher voltage level is 110kV, 1M, 2M, 3M, 4M are 110kV busbars, L1, L2, L3 are 110kV lines; the low voltage side is 10kV voltage level, 5M, 6M, 7M, 8M are 10kV busbars. Figure 1The dotted box contains the equipment in substation B, including 110kV bus 2M, 10kV bus 5M, transformer T1, and switches 2DL, 3DL, 7DL, 8DL, 9DL, 10DL, 11DL, and 12DL. The feeders connected to substation B include 9DL, 10DL, 11DL, and 12DL (identified by the names of outgoing line switches, the same below). The opposite feeder of feeder 9DL is 13DL, and the connecting switch is KG1; the opposite feeder of feeder 10DL is 14DL, and the connecting switch is KG2; feeder 11DL has no opposite feeder; the opposite feeder of feeder 12DL is 15DL, and the connecting switch is KG6. Switches KG3, KG4, and KG5 are section switches for feeder 12DL.

[0092] According to an exemplary embodiment of the present invention, the outgoing line switch flow of feeder 9DL, i.e., the load carried is 60A, and the capacity margin of opposite feeder 13DL is 100A; the load carried by feeder 10DL is 50A, and the capacity margin of opposite feeder 14DL is 110A; the load carried by feeder 11DL is 35A, and there is no opposite feeder; the load carried by feeder 12DL is 120A, and the capacity margin of opposite feeder 15DL is 90A. The flow of section switch KG3 of feeder 12DL is 100A; the flow of section switch KG4 is 85A; the flow of section switch KG5 is 65A.

[0093] According to an exemplary embodiment of the present invention, the substation full stop and full rotation method includes:

[0094] S1. Establish a full stop and full turn model.

[0095] The power substations at both ends of the serial power supply network included in the full stop and full rotation model are set to be 220kV substation A and 220kV substation D, and the two load substations in the middle are set to be 110kV substation B and 110kV substation C. The lines connecting the substations are set to be 110kV lines L1, L2, and L3. The protection action signals associated with the higher voltage level busbars 1M, 2M, 3M, and 4M in the substation and the protection action signals associated with the lines L1, L2, and L3 are set.

[0096] After the setting, step S1 automatically searches for the line switches on both sides of the line according to the topological relationship. The line switches on both sides of line L1 are 1DL and 2DL; the line switches on both sides of line L2 are 3DL and 4DL; the line switches on both sides of line L3 are 5DL and 6DL. Automatically set the low-voltage side busbar of the substation and all feeders connected to the low-voltage side busbar. Taking 110kV substation B as an example, the low-voltage side busbar is 5M, and the feeders connected to the low-voltage side busbar 5M include 9DL, 10DL, 11DL, and 12DL.

[0097] S2. Obtain real-time data of the main network and distribution network.

[0098] The real-time data of the main network obtained include: the switch positions of the line switches 1DL, 2DL, 3DL, 4DL, 5DL, and 6DL; the three-phase voltages of the higher voltage level busbars 1M, 2M, 3M, and 4M; the three-phase voltage of the low-voltage side busbar, taking 110kV substation B as an example, is the three-phase voltage of the low-voltage side busbar 5M; the busbar protection action signals associated with the higher voltage level busbars 1M, 2M, 3M, and 4M; the line protection action signals associated with the lines L1, L2, and L3; the line flow of the lines L1, L2, and L3; the outgoing line flow on the low-voltage side of the substation, taking 110kV substation B as an example, is the switch flow of the outgoing line switches 9DL, 10DL, 11DL, and 12DL.

[0099] The real-time distribution network data obtained include: the position of the section switch, taking the 110kV substation B feeder 12DL as an example, it is the switch position of the section switches KG3, KG4, and KG5; the interconnecting switch position, taking the feeder connected to the 110kV substation B as an example, it is the switch position of the interconnecting switches KG1, KG2, and KG6; the section switch flow, taking the 110kV substation B feeder 12DL as an example, it is the switch flow of the section switches KG3, KG4, and KG5.

[0100] S3. Monitor the serial power supply network for faults and locate the faulty device if any.

[0101] Assume that a fault K1 occurs on line L1, and the fault location criterion is: the line protection associated with line L1 is actuated, and the line switch 1DL is opened.

[0102] Assuming that a fault K2 occurs on bus 2M, the fault location criterion is: the bus protection associated with bus 2M is actuated, and switches 2DL, 3DL, and 7DL are opened.

[0103] Take fault K1 as an example.

[0104] S4. Generate a full stop and full turn switch action sequence. The step S4 includes:

[0105] S41. Restore power supply of higher voltage level busbars, start from the open loop point, and gradually restore the power-off busbars to the power outage area, forming a switch action sequence 1. The switch action sequence 1 includes: open 4DL, close 5DL, open 2DL, close 4DL.

[0106] Considering that the actual site may not be equipped with busbar protection or line longitudinal protection, for example, in the exemplary embodiment of the present invention, if busbar 2M is not equipped with busbar protection, when the busbar fails, the line protection associated with line L1 is activated, and the line switch 1DL is opened, that is, the faulty device will be mistakenly located as line L1. In the above situation, it is impossible to distinguish between line fault and busbar fault, and the situation of closing the fault may occur. In order to restore power to as many substations as possible, the step S41 adopts the strategy of gradually restoring the de-energized busbar to the power outage area.

[0107] S42. Calculate the expected power flow distribution after the execution of the switch action sequence 1, and check whether it causes equipment overload.

[0108] According to an exemplary embodiment of the present invention, it is envisioned that after the switch action sequence 1 is executed, substation B and substation C are powered by substation D, and at this time, line L3 is overloaded, with the over-limit being 120A.

[0109] S43. If the equipment is overloaded, the overload transfer analysis is performed on the associated substation to form a switch action sequence 2. The step S43 overload transfer analysis includes the following steps:

[0110] S431. Search all feeders of the substation associated with the overload device to form a feeder set A.

[0111] According to an exemplary embodiment of the present invention, the substations associated with the overload device L3 are substation B and substation C. Feeder set A includes all feeders connected to substation B and substation C, wherein the feeders connected to substation B include 9DL, 10DL, 11DL, and 12DL.

[0112] S432. Take out feeders from the feeder set A in sequence according to a set order, and transfer all or part of the load to the opposite feeder while considering the capacity margin of the opposite feeder.

[0113] According to an exemplary embodiment of the present invention, among the feeders connected to substation B, 9DL carries a load of 60A, and the capacity margin of the opposite feeder is 100A, so all of its load can be transferred out; 10DL carries a load of 50A, and the capacity margin of the opposite feeder is 110A, so all of its load can be transferred out; 11DL carries a load of 35A, and there is no opposite feeder, so the load cannot be transferred out; 12DL carries a load of 120A, and the capacity margin of the opposite feeder is 90A, so the load downstream of the section switch KG4 can be transferred out at most 85A, and the load downstream of the section switch KG5 can be transferred out secondarily 65A. According to an exemplary embodiment of the present invention, the set extraction order is 9DL, 12DL, and 10DL.

[0114] S433. If the over-limit is eliminated after a feeder is taken out and its load is transferred out, the over-limit transfer analysis ends;

[0115] According to an exemplary embodiment of the present invention, according to the set extraction order, 9DL is first extracted to transfer its entire load of 60A, and the over-limit of line L3 is reduced from 120A to 60A; then 12DL is extracted, and according to the principle of smaller load transfer (less load impact), the downstream load of its section switch KG5 is transferred out by 65A, which is greater than the remaining over-limit of line L3 by 60A, and the over-limit is eliminated, and the over-limit transfer analysis is completed. At this time, the switch action sequence 2 includes: opening 9DL, closing KG1, opening KG5, and closing KG6.

[0116] S434. If the over-limit situation is not eliminated after all the feeders of the opposite side in the feeder set A are transferred, the principle of minimum load removal is followed, and part or all of the load carried by the untransferred feeders in the feeder set A is removed in a set order until the over-limit situation is eliminated.

[0117] According to an exemplary embodiment of the present invention, it is assumed that after all the feeders in the feeder set A are switched, line L3 still exceeds the limit by 15A. According to an exemplary embodiment of the present invention, at this time, the load carried by feeder 9DL is 0A; the load carried by feeder 10DL is 0A; the load carried by feeder 11DL is 35A; the load carried by feeder 12DL is 55A, the downstream load of section switch KG3 is 35A, and the downstream load of section switch KG4 is 20A. According to an exemplary embodiment of the present invention, the order of load removal is set to 12DL and 11DL, and according to the principle of minimum load removal, the downstream load of section switch KG4 is removed by 20A, which is greater than the remaining over-limit amount of line L3 of 15A, and the over-limit is eliminated. At this time, the switch action sequence two includes: open 9DL, close KG1, open 10DL, close KG2, open KG5, close KG6, and open KG4.

[0118] S44. If the faulty equipment is a busbar of a higher voltage level, causing the busbar on the low voltage side of the same substation to lose voltage and stop completely, then a full shutdown and power transfer analysis will be performed on the distribution network side of the substation to form the switch action sequence three.

[0119] According to an exemplary embodiment of the present invention, the fault K1 occurs in the line L1 and is not in the higher voltage level busbar, so the switch action sequence three is empty.

[0120] S5. Execute the full stop and full turn switch action sequence. According to an exemplary embodiment of the present invention, the switch action sequence 2 is first executed: open 9DL, close KG1, open KG5, close KG6; then the switch action sequence 1 is executed: open 4DL, close 5DL, open 2DL, close 4DL. The switch action sequence 2 is internally executed in parallel by feeder grouping, switch action sequence 2 group A: open 9DL, close KG1; switch action sequence 2 group B: open KG5, close KG6.

[0121] The switch action sequence 2 is executed in parallel by feeder grouping, which can shorten the overall execution time and speed up the fault handling and fault recovery process. The switch action sequence 2 is executed first to perform the over-limit power transfer, which can ensure that the subsequent execution of the switch action sequence 1 will not cause equipment overload.

[0122] According to an exemplary embodiment of the present invention, during the execution of the switch action sequence 1, before closing 5DL, it is necessary to confirm that the bus 3M to be restored to power is without pressure and the bus 4M on the backup power supply side is with pressure; before closing 4DL, it is necessary to confirm that the bus 2M to be restored to power is without pressure and the bus 3M on the backup power supply side is with pressure. If the no-pressure and pressure conditions are not met, the execution process of the switch action sequence 1 is suspended and waits until the conditions are met or the execution process times out.

[0123] Before closing the switch to restore power supply to the corresponding bus, first confirm that the bus to which the switch is to restore power is without pressure to prevent the formation of a ring network, which would affect the safe and stable operation of the power grid; confirm that the bus on the backup power supply side has pressure to ensure that the depressurized bus can resume power supply after closing the switch.

[0124] Take fault K2 as an example.

[0125] S4. Generate a full stop and full turn switch action sequence. The step S4 includes:

[0126] S41. Restore power supply of higher voltage level busbars, start from the open loop point, and gradually restore the power-off busbars to the power outage area, forming a switch action sequence 1. The switch action sequence 1 includes: opening 4DL and closing 5DL.

[0127] S42. Calculate the expected power flow distribution after the execution of the switch action sequence 1, and check whether it causes equipment overload.

[0128] According to an exemplary embodiment of the present invention, it is envisioned that after the switch action sequence 1 is executed, substation B is powered off, and substation C is powered by substation D, and no equipment is overloaded at this time.

[0129] S43. If the device is overloaded, an over-limit power transfer analysis is performed on its associated substation to form a switch action sequence 2. According to an exemplary embodiment of the present invention, since no device is overloaded, the switch action sequence 2 is empty.

[0130] S44. If the faulty equipment is a busbar with a higher voltage level, causing the busbar on the low-voltage side of the same substation to lose voltage and stop completely, first separate the low-voltage side switch of the main transformer of the substation, and perform a full shutdown and power transfer analysis on the distribution network side of the substation to form the switch action sequence three.

[0131] According to an exemplary embodiment of the present invention, the fault K2 occurs on the higher voltage level bus 2M, causing the low voltage side bus 5M of the substation B to lose voltage and stop completely. Therefore, the low voltage side switch 8DL of the main transformer T1 of the substation B is firstly switched off, and then the distribution network side of the substation B is fully stopped and transferred for analysis, including the steps of:

[0132] S441. Among all the feeders connected to the substation, if there is an opposite-side feeder, transfer all the load to the opposite-side feeder, check the capacity margin of the opposite-side feeder, and if the capacity margin of the opposite-side feeder is insufficient, transfer part of the load to the opposite-side feeder.

[0133] According to an exemplary embodiment of the present invention, among the feeders connected to substation B, 9DL carries a load of 60A, and the capacity margin of the opposite feeder is 100A, so all its loads can be transferred out; 10DL carries a load of 50A, and the capacity margin of the opposite feeder is 110A, so all its loads can be transferred out; 11DL carries a load of 35A, and there is no opposite feeder, so the load cannot be transferred out; 12DL carries a load of 120A, and the capacity margin of the opposite feeder is 90A, so 85A of the downstream load of the section switch KG4 can be transferred out. The switch action sequence three adds switch actions: 9DL is opened, KG1 is closed, 10DL is opened, KG2 is closed, KG4 is opened, and KG6 is closed.

[0134] S442. If there is still a load outage after all the feeders connected to the opposite side feeder of the substation are transferred, the opposite side feeder with the largest remaining capacity margin after receiving the transferred load is selected, that is, the reverse power supply support feeder, and the feeder outgoing switch on the substation side corresponding to the reverse power supply support feeder is closed to reverse power supply from the low-voltage side bus of the substation to the untransferred load.

[0135] According to an exemplary embodiment of the present invention, after all the feeders connected to the opposite side feeder of substation B are transferred, 11DL has no opposite side feeder and a 35A load is out of power; 12DL has transferred part of the load, and a 35A load is still out of power. After 9DL transfers a load of 60A, its opposite side feeder 13DL has a remaining capacity margin of 40A; after 10DL transfers a load of 50A, its opposite side feeder 14DL has a remaining capacity margin of 60A. Therefore, according to an exemplary embodiment of the present invention, the reverse power supply support feeder is selected as 14DL, and the corresponding feeder outgoing line switch 10DL on the local side of the substation can be closed to reverse power from the bus 5M to the untransferred load. The switch action sequence three adds a switch action: close 10DL.

[0136] S443. Check the remaining capacity margin of the reverse power supply support feeder. If the capacity margin is insufficient, cut off part of the untransferred load in a set order.

[0137] According to an exemplary embodiment of the present invention, the remaining capacity margin of the reverse power supply support feeder 14DL is 60A, and the power outage load is 70A, so it is necessary to cut off part of the untransferred load. According to an exemplary embodiment of the present invention, the order of load removal is set to 12DL and 11DL, and according to the principle of minimum load removal, the untransferred load 15A downstream of the sectional switch KG3 is cut off, and the remaining power outage load 55A is less than the remaining capacity margin of 60A of the reverse power supply support feeder 14DL, and reverse power supply can be provided by the reverse power supply support feeder 14DL. The switch action sequence three adds a switch action: divide KG3.

[0138] According to an exemplary embodiment of the present invention, in step S44, switch 10DL is first opened and then closed. To reduce the number of switch actions, 10DL may not be operated; at the same time, closing KG2 is moved to the end of the switch action sequence three, that is, the reverse power supply is performed last. In summary, the switch action sequence three includes: opening 8DL, opening 9DL, closing KG1, opening KG4, closing KG6, opening KG3, and closing KG2.

[0139] S5. Execute the full stop and full turn switch action sequence. According to an exemplary embodiment of the present invention, the switch action sequence one and the switch action sequence three are executed in parallel, the switch action sequence one includes: open 4DL, close 5DL; the switch action sequence three includes: open 8DL, open 9DL, close KG1, open KG4, close KG6, open KG3, close KG2. The switch action sequence three is internally executed in parallel by feeder grouping, switch action sequence three group A: open 9DL, close KG1; switch action sequence three group B: open KG4, close KG6, open KG3.

[0140] Parallel execution can shorten the overall execution time of the full-stop and full-turn switch action sequence and speed up the fault handling and fault recovery process.

[0141] According to an exemplary embodiment of the present invention, during the execution of the switch action sequence 1, before closing 5DL, it is necessary to confirm that the bus 3M to be restored has no pressure and the backup power supply side bus 4M has pressure. If the no-pressure and pressure conditions are not met, the execution process of the switch action sequence 1 is suspended and waits until the conditions are met or the execution process times out.

[0142] According to an exemplary embodiment of the present invention, the substation full stop and full turn system is deployed in the power control center, including a modeling module, a data acquisition module, a fault monitoring and positioning module, a switch action sequence generation module and a switch action sequence execution module. The modeling module establishes a full stop and full turn model corresponding to each serial power supply network; the data acquisition module periodically acquires the real-time data of each of the full stop and full turn models; the fault monitoring and positioning module monitors the faults in each of the full stop and full turn models and locates the faulty equipment; the switch action sequence generation module generates a switch action sequence for restoring power supply according to the located faulty equipment; the switch action sequence execution module sends a remote control command to execute the generated switch action sequence.

[0143] 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, and any modifications or equivalent replacements that do 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 method for full stop and full rotation of a substation, characterized in that: The following steps are involved: Establish a full-stop full-speed model including a serial power supply network; Corresponding to the full stop and full start model, obtain the real-time data of the main network and the distribution network; Monitor whether the serial power supply network has any faults based on the real-time data of the main network and the distribution network, and locate the faulty device if there is any fault; Based on the position of the faulty equipment in the full stop and full rotation model, the full stop and full rotation switch action sequence is generated and executed with the strategy of gradually restoring the lost power bus to the blackout area and transferring power to the distribution network side without exceeding the limit.

2. A method for full stop and full rotation of a substation according to claim 1, characterized in that: The establishment of a full stop full rotation model including a serial power supply network includes: Setting the power substations at both ends of the serial power supply network and several load substations in the middle included in the full stop and full rotation model; Set up higher voltage level busbars in each substation and lines connecting the substations; Setting a protection action signal associated with a higher voltage level busbar in the substation and a protection action signal associated with the line; According to the topological relationship, the line switches on both sides corresponding to the line, the low-voltage side bus of the substation, and all feeders connected to the low-voltage side bus are automatically searched to complete the construction of the full stop and full rotation model of the substation.

3. A method for full stop and full rotation of a substation according to claim 1 or 2, characterized in that: The main network real-time data obtained includes: The line switch position, the three-phase voltage of the higher voltage bus, the three-phase voltage of the low voltage side bus, the bus protection action signal associated with the higher voltage bus, the line protection action signal associated with the line, the line flow and the low voltage side outgoing line flow of the substation; The obtained real-time data of the distribution network includes: Section switch position, tie switch position and section switch flow.

4. A method for full stop and full rotation of a substation according to claim 1 or 2, characterized in that: The fault location criterion is: the equipment has protection action and the associated switch is open; the equipment is a line in the serial power supply network or a higher voltage level bus in the substation.

5. A method for full stop and full rotation of a substation according to claim 1, characterized in that: The generated and executed full stop full turn switch action sequence includes: Restore the power supply of the busbar with a higher voltage level, starting from the open-loop point, and gradually restore the power-lost busbar to the power outage area, forming the first switch action sequence; Calculate the expected power flow distribution after the execution of the first switch action sequence to check whether it causes equipment overload; if the equipment is overloaded, perform over-limit power transfer analysis on the substation associated with the overloaded equipment to form a second switch action sequence that can eliminate the over-limit; if the equipment is not overloaded, set the second switch action sequence to empty; If the faulty device is a line, the third switch action sequence is set to empty; if the faulty device is a higher voltage level bus in the substation, causing the low-voltage side bus of the same substation to lose voltage and stop completely, first separate the low-voltage side switch of the main transformer of the substation, and perform a full stop and transfer analysis on the distribution network side of the substation to form the third switch action sequence; The first, second and third switching action sequences form a full stop and full turn switching action sequence to be executed.

6. A method for full stop and full rotation of a substation according to claim 5, characterized in that: The over-limit transfer analysis includes: Search all feeders of the substation associated with the overload device to form a feeder set A; Take out feeders from the feeder set A in sequence according to a set order, and transfer all or part of the load to the opposite feeder taking into account the capacity margin of the opposite feeder; If the over-limit is eliminated after a certain feeder is taken out and its load is transferred out, the over-limit transfer analysis ends; If the over-limit situation is not eliminated after all the feeders of the opposite side in the feeder set A are transferred, the principle of minimum load removal is followed, and part or all of the load carried by the untransferred feeders in the feeder set A is removed in a set order until the over-limit situation is eliminated.

7. A method for full stop and full rotation of a substation according to claim 5, characterized in that: The analysis steps of the full shutdown of the substation distribution network side: Among all the feeders connected to the substation, if there is an opposite-side feeder, transfer all the load to the opposite-side feeder, check the capacity margin of the opposite-side feeder, and if the capacity margin of the opposite-side feeder is insufficient, transfer part of the load to the opposite-side feeder; If there is still a load outage after all the feeders connected to the substation with opposite-side feeders are transferred, the opposite-side feeder with the largest remaining capacity margin after receiving the transferred load is selected, that is, the reverse power supply support feeder, and the feeder outlet switch on the substation side corresponding to the reverse power supply support feeder is closed to reverse power supply from the low-voltage side bus of the substation to the untransferred load; Check the remaining capacity margin of the reverse power supply support feeder. If the capacity margin is insufficient, the load removal amount is minimized in principle, and part of the untransferred load is removed in a set order.

8. A method for full stop and full rotation of a substation according to claim 5, characterized in that: The execution of the full stop and full turn switch action sequence includes: The second switch action sequence is executed first, and then the first switch action sequence is executed, and the third switch action sequence is executed in parallel with the second switch action sequence and the first switch action sequence; During the execution of the first switch action sequence, before closing the switch to restore power supply to the corresponding bus, it must be confirmed that the bus to which the switch is to restore power is without pressure and the bus on the backup power supply side has pressure. Otherwise, the execution process of the first switch action sequence will be paused and wait until the conditions are met or the execution process times out.

9. A method for full stop and full rotation of a substation according to claim 8, characterized in that: The second switching action sequence and the third switching action sequence are internally executed in parallel by feeder grouping.

10. A method for full stop and full rotation of a substation according to any one of claims 5 to 9, characterized in that: When executing the last step of the first switch action sequence to close the line switch, if the line switch trips again, it is determined that the actual faulty equipment is the busbar, and an additional analysis of the complete shutdown of the substation distribution network side is performed to form the third switch action sequence and execute it additionally.

11. A full stop and full rotation system for a substation, characterized in that: include: Modeling module, establishing full-stop full-run model corresponding to each serial power supply network; A data acquisition module, periodically acquiring real-time data of each of the full-stop and full-speed models; A fault monitoring and locating module monitors faults in each of the full-stop and full-run models and locates faulty equipment; A switch action sequence generation module generates a switch action sequence for restoring power supply according to the located faulty device; The switch action sequence execution module sends a remote control command to execute the generated switch action sequence.

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