Parallel computing method for security domain of commercial load cluster of power distribution network

Abstract

The invention discloses a parallel computing method for a safety domain of a commercial load cluster of a power distribution network. The parallel computing method comprises the following steps: computing an operation domain of power flowing into each low-voltage power distribution network from a medium-voltage bus when only the constraint of the low-voltage power distribution network is considered in each low-voltage power distribution network; in each possible topology of the medium-voltage power distribution network, the operation domain of the power of each medium-voltage bus flowing into the connected low-voltage power distribution network is calculated in parallel; calculating the safety domain of the power of each medium-voltage bus flowing into the connected low-voltage distribution network; and refining the security domain of the power of each medium-voltage bus flowing into the connected low-voltage power distribution network into the security domain of the commercial load cluster of the power distribution network. Based on the analysis of the topological structure of the power distribution network, the calculation of the security domain of the commercial load cluster of the power distribution network is decomposed into a plurality of steps, and each step is decomposed into a plurality of subtasks which can be executed in parallel, so that the rapid definition of the security domain of the commercial load cluster of the power distribution network is realized, and the commercial load cluster of the power distribution network is supported to participate in demand side response.

Description

Technical Field

[0001] The present invention belongs to the technical field of distribution network security domain analysis and calculation, and in particular relates to a parallel calculation method for the security domain of a commercial load cluster in a distribution network. Background Art

[0002] With the rapid growth of renewable energy penetration in power systems, the demand for real-time balance in power systems is also increasing. In recent years, as an important resource for maintaining the real-time balance of power generation and consumption in power grids, the demand-side response capability of commercial loads has received increasing attention. Commercial loads include some flexible loads, and adjusting their power within a certain range will not cause significant impact. Therefore, commercial loads can respond to load increase and decrease instructions from the power grid dispatching center to help maintain the real-time balance of power generation and consumption. Considering the thermal stability constraints of distribution network lines, it is necessary to define the safety domain of commercial load clusters in the state space composed of the adjustable power range of all commercial loads, and limit the adjustment range of each commercial load power within the safety domain to ensure that the distribution network after participating in demand-side response still meets the N-1 safety operation criterion. The N-1 safety operation criterion means that after any accident in the expected accident concentration occurs and the supply is transferred, the power of each feeder section of the distribution network does not exceed the limit.

[0003] According to the granularity from coarse to fine, the safety domain of the distribution network can be divided into the substation perspective, the main transformer perspective, the feeder perspective and the load perspective. The existing distribution network safety domain calculation method adopts the boundary point simulation method to determine the boundary of the safety domain by simulating the flow of each working point. Considering the amount of calculation, the existing method can only calculate the safety domain from the first three perspectives. Refining the safety domain to the load perspective will lead to an exponential increase in the amount of calculation, which will lead to a long time to calculate the safety domain, affecting real-time performance. However, the safety domain granularity under the first three perspectives is too coarse, and cannot effectively constrain the adjustment range of each commercial load power, and cannot be applied to the demand-side response scenario of commercial load clusters. . Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention constructs a parallel calculation method for the safety domain of commercial load clusters in a distribution network, which solves the problem that the calculation of the safety domain of the distribution network cannot take into account both granularity and speed.

[0005] The present invention discloses a parallel computing method for a commercial load cluster security domain of a distribution network, the method comprising the following steps:

[0006] S1: Calculation is performed in parallel in each low-voltage distribution network. In each low-voltage distribution network, according to the adjustable range of each commercial load power and the maximum current carrying capacity of each feeder segment, the operating domain of each low-voltage feeder segment power is calculated in order from downstream to upstream, and then the operating domain of the power flowing from the medium-voltage bus into the low-voltage distribution network when only the constraints of the low-voltage distribution network are considered is obtained;

[0007] S2: performing calculations in parallel in each possible topology of the medium-voltage distribution network. In each possible topology of the medium-voltage distribution network, according to the operating domain of the power flowing from each medium-voltage bus into the connected low-voltage distribution network and the maximum current carrying capacity of each feeder segment, the operating domain of the power of each medium-voltage feeder segment in the topology is calculated in order from downstream to upstream;

[0008] S3: performing calculations in parallel in each possible topology of the medium-voltage distribution network, and determining the operating domain of the power flowing into the connected low-voltage distribution network from each medium-voltage bus in the topology in accordance with the operating domain of the power of each medium-voltage feeder segment in order from upstream to downstream in each possible topology of the medium-voltage distribution network;

[0009] S4: Take the overlapping part of the operation domain of the power flowing from each medium-voltage bus to the connected low-voltage distribution network in all possible topologies of the medium-voltage distribution network as the safety domain of the power flowing from each medium-voltage bus to the connected low-voltage distribution network;

[0010] S5: Replace the power variable of each medium-voltage bus flowing into the connected low-voltage distribution network in the security domain obtained in step S4 with the sum of the power variables of all commercial loads in the low-voltage distribution network connected to the medium-voltage bus, and refine the security domain of the power of each medium-voltage bus flowing into the connected low-voltage distribution network into the security domain of the distribution network commercial load cluster.

[0011] Step S1 further comprises:

[0012] S1.1: point the pointer to the most downstream feeder segment in the low-voltage distribution network;

[0013] S1.2: If the feeder segment pointed to by the pointer is the most downstream feeder segment, its power operating domain is calculated based on its maximum current carrying capacity and the adjustable range of its downstream adjacent commercial load power; if the feeder segment pointed to by the pointer is not the most downstream feeder segment, its power operating domain is calculated based on its maximum current carrying capacity, the adjustable range of its downstream adjacent commercial load power and the operating domain of its downstream adjacent feeder segment power;

[0014] S1.3: Determine whether the feeder segment pointed to by the pointer is the most upstream feeder segment in the low-voltage distribution network. If so, mark the task status as completed and proceed to step S1.4. Otherwise, move the pointer one feeder segment upstream and return to step S1.2.

[0015] S1.4: The operating domain of the power of the most upstream feeder section of the low-voltage distribution network is taken as the operating domain of the power flowing from the medium-voltage bus into the low-voltage distribution network when only the constraints of the low-voltage distribution network are considered.

[0016] Preferably, in step S1.2, if the feeder segment pointed to by the pointer is the most downstream feeder segment, the feeder segment power S Line(LV) The operating domain is:

[0017]

[0018] In the formula, Indicates the adjustable range of the power of the downstream adjacent commercial load of the feeder segment pointed by the pointer. and Respectively represent the adjustable range S D,Load The upper and lower limits of Indicates the maximum current carrying capacity of the feeder segment pointed to by the pointer; min(a,b) indicates the minimum value of a and b;

[0019] If the feeder segment pointed to by the pointer is not the most downstream feeder segment, the operating domain S of the feeder segment power pointed to by the pointer Line(LV) for:

[0020]

[0021] in, Indicates the operating domain of the power of the downstream adjacent feeder segment of the feeder segment pointed to by the pointer, and Respectively represent the operation domain S D,Line(LV) upper and lower limits.

[0022] Preferably, each possible topology of the medium voltage distribution network refers to a distribution network topology formed by reconstruction after any fault in the expected fault set occurs in the medium voltage distribution network.

[0023] Step S2 further comprises:

[0024] S2.1: point the pointer to the most downstream medium voltage feeder segment in the current topology;

[0025] S2.2: If the feeder segment pointed to by the pointer is the most downstream feeder segment, its power operating domain is calculated based on its maximum current carrying capacity and the operating domain of the power of the connected low-voltage distribution network flowing from its downstream adjacent medium-voltage busbar; if the feeder segment pointed to by the pointer is not the most downstream feeder segment, its power operating domain is calculated based on its maximum current carrying capacity, the operating domain of the power of the connected low-voltage distribution network flowing from its downstream adjacent medium-voltage busbar and the operating domain of the power of its downstream adjacent feeder segment;

[0026] S2.3: If the feeder segment pointed to by the pointer is the most upstream feeder segment in the current topology, the task status is marked as completed and the process ends; otherwise, the pointer is moved one feeder segment upstream in the current topology and the process goes to step S2.2.

[0027] Preferably, in step S2.2, if the feeder segment pointed to by the pointer is the most downstream feeder segment, the operating domain S of the power of the feeder segment pointed to by the pointer is Line(MV) for:

[0028]

[0029] In the formula, Indicates the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus of the feeder segment pointed to by the pointer. and Respectively represent the operation domain S D,Bus The upper and lower limits of Indicates the maximum current carrying capacity of the feeder segment pointed by the pointer;

[0030] If the feeder segment pointed to by the pointer is not the most downstream feeder segment, the operating domain S of the feeder segment power pointed to by the pointer Line(MV) for:

[0031]

[0032] in, Indicates the operating domain of the power of the downstream adjacent feeder segment of the feeder segment pointed to by the pointer, and Respectively represent the operation domain S D,Line(MV) upper and lower limits.

[0033] Step S3 further comprises:

[0034] S3.1: point the pointer to the most upstream medium voltage feeder segment in the current topology;

[0035] S3.2: If the feeder segment pointed to by the pointer is the most downstream feeder segment, then the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus is determined based on its power operating domain; if the feeder segment pointed to by the pointer is not the most downstream feeder segment, then the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus and the power of the downstream adjacent feeder segment is determined based on its power operating domain;

[0036] S3.3: Determine whether the feeder segment pointed to by the pointer is the most downstream feeder segment in the current topology. If so, mark the task status as completed and end the process; otherwise, move the pointer one feeder segment downstream in the current topology and return to step S3.2.

[0037] Preferably, in step S3.2, if the feeder segment pointed to by the pointer is the most downstream feeder segment, the operating domain of the power flowing from the downstream adjacent medium-voltage bus to the connected low-voltage distribution network is:

[0038]

[0039] In the formula, S U,Bus The vector representing the power of each medium-voltage bus upstream of the feeder segment pointed to by the pointer flowing into the connected low-voltage distribution network; S Line(MV) Indicates the power of the feeder section pointed by the pointer; Indicates the operating domain of the feeder segment power pointed to by the pointer, i indicates the topological number, f i (S Line(MV) ,S U,Bus ) indicates that S Line(MV) and S U,Bus is a function of a variable, and S D,Bus Indicates the power flowing into the connected low-voltage distribution network from the adjacent medium-voltage busbar downstream of the feeder segment pointed to by the pointer;

[0040] If the feeder segment pointed to by the pointer is not the most downstream feeder segment, the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus and the power of the downstream adjacent feeder segment is:

[0041]

[0042] In the formula, S D,Line(MV) Indicates the power of the adjacent feeder section downstream of the feeder section pointed by the pointer, f i (S D,Line(MV) +S D,Bus ,S U,Bus ) means f i (S Line(MV) ,S U,Bus ) Line(MV) Replace all with S D,Line(MV) +S D,Bus The function formed afterwards.

[0043] Step S4 further comprises:

[0044] Combine the operating domains of the power flowing into the connected low-voltage distribution network from each medium-voltage bus in all topologies:

[0045]

[0046] Where i represents the topology number, n represents the number of all possible topologies of the medium voltage distribution network, S Bus It represents the power variable of each medium voltage bus flowing into the connected low voltage distribution network. represents the operating domain of the power flowing into the connected low-voltage distribution network from each medium-voltage bus in topology i, g i (S Bus ) indicates S Bus The linear combination of the variables in and Respectively represent g i (S Bus )’s upper and lower limits;

[0047] The simplex method is used to eliminate the redundant constraints and obtain the safety domain of the power flowing into the connected low-voltage distribution network of each medium-voltage bus:

[0048] h min ≤h(S Bus )≤h max

[0049] Among them, h(S Bus ) is S Bus The linear combination of the variables in h max and h min h(S Bus )’s upper and lower limits.

[0050] Further, in step S5, each medium voltage bus flows into the safety domain h of the low voltage distribution network power connected to it. min ≤h(S Bus )≤h max In the Bus =[S 1 ,S 2 ,…,S m ] is replaced by:

[0051]

[0052] Get the security domain of the commercial load cluster of the distribution network:

[0053] h min ≤h(S load )≤h max ;

[0054] Among them, S j is the power variable flowing from medium voltage bus j to the connected low voltage distribution network, m is the number of medium voltage buses, S j,k is the power variable of the kth commercial load in the low-voltage distribution network connected to the medium-voltage bus j, l j is the number of commercial loads in the low-voltage distribution network connected to the medium-voltage bus j.

[0055] The beneficial effects of the present invention are:

[0056] In view of the problem that the current distribution network security domain calculation method based on point-by-point simulation is difficult to take into account both the security domain granularity and the calculation speed, the present invention proposes a parallel distribution network security domain calculation method, which can quickly complete the fine-grained distribution network security domain calculation from the load perspective, realize the definition of the security domain of the distribution network commercial load cluster, and support the distribution network commercial load cluster to participate in the demand-side response. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a flow chart of a method for parallel calculation of a safety domain of a commercial load cluster in a distribution network according to an embodiment of the present invention;

[0058] Figure 2is a schematic diagram of a distribution network sample for illustrating a parallel calculation method of a distribution network commercial load cluster safety domain according to an embodiment of the present invention;

[0059] Figure 3 Schematic diagram of all possible topologies of a medium voltage distribution network according to an embodiment of the present invention. DETAILED DESCRIPTION

[0060] The following examples will enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0061] like Figure 1 As shown, a parallel computing method for a distribution network commercial load cluster security domain of the present invention comprises the following steps:

[0062] S1: Calculation is performed in parallel in each low-voltage distribution network. In each low-voltage distribution network, according to the adjustable range of each commercial load power and the maximum current carrying capacity of each feeder segment, the operating domain of each low-voltage feeder segment power is calculated in order from downstream to upstream, and then the operating domain of the power flowing from the medium-voltage bus into the low-voltage distribution network when only the constraints of the low-voltage distribution network are considered is obtained;

[0063] S2: performing calculations in parallel in each possible topology of the medium-voltage distribution network. In each possible topology of the medium-voltage distribution network, according to the operating domain of the power flowing from each medium-voltage bus into the connected low-voltage distribution network and the maximum current carrying capacity of each feeder segment, the operating domain of the power of each medium-voltage feeder segment in the topology is calculated in order from downstream to upstream;

[0064] S3: performing calculations in parallel in each possible topology of the medium-voltage distribution network, and determining the operating domain of the power flowing into the connected low-voltage distribution network from each medium-voltage bus in the topology in accordance with the operating domain of the power of each medium-voltage feeder segment in order from upstream to downstream in each possible topology of the medium-voltage distribution network;

[0065] S4: Take the overlapping part of the operation domain of the power flowing from each medium-voltage bus to the connected low-voltage distribution network in all possible topologies of the medium-voltage distribution network as the safety domain of the power flowing from each medium-voltage bus to the connected low-voltage distribution network;

[0066] S5: Replace the power variable of each medium-voltage bus flowing into the connected low-voltage distribution network in the safety domain obtained in step S4 with the sum of the power variables of all commercial loads in the low-voltage distribution network connected to the medium-voltage bus, thereby refining the safety domain of the power of each medium-voltage bus flowing into the connected low-voltage distribution network into the safety domain of the distribution network commercial load cluster.

[0067] In step S1, in each low-voltage distribution network, the operating domain of each low-voltage feeder segment power is calculated in order from downstream to upstream, and then the operating domain of the power flowing from the medium-voltage bus into the low-voltage distribution network when only the constraints of the low-voltage distribution network are considered is obtained, which specifically includes:

[0068] S1.1 points the pointer to the most downstream feeder segment in the low-voltage distribution network;

[0069] S1.2 If the feeder segment pointed to by the pointer is the most downstream feeder segment, its power operating domain shall be calculated based on its maximum current carrying capacity and the adjustable range of power of its downstream adjacent commercial load; if the feeder segment pointed to by the pointer is not the most downstream feeder segment, its power operating domain shall be calculated based on its maximum current carrying capacity, the adjustable range of power of its downstream adjacent commercial load and the power operating domain of its downstream adjacent feeder segment;

[0070] S1.3 If the feeder segment pointed by the pointer is the most upstream feeder segment in the low-voltage distribution network, mark the "task status" as "completed", otherwise move the pointer one feeder segment upstream;

[0071] S1.4 Repeat S1.2 and S1.3 until the “Task Status” is “Completed”;

[0072] S1.5 takes the operating domain of the power of the most upstream feeder section of the low-voltage distribution network as the operating domain of the power flowing from the medium-voltage bus into the low-voltage distribution network when only the constraints of the low-voltage distribution network are considered.

[0073] The step S1.2 specifically includes:

[0074] If the feeder segment pointed by the pointer is the most downstream feeder segment, the adjustable range of the power of the downstream adjacent commercial load of the feeder segment pointed by the pointer is The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S Line(LV) The operating domain is

[0075]

[0076] If the feeder segment pointed by the pointer is not the most downstream feeder segment, the adjustable range of the power of the downstream adjacent commercial load of the feeder segment pointed by the pointer is The operating domain of the power of the downstream adjacent feeder segment of the feeder segment pointed by the pointer is The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S Line(LV) The operating domain is

[0077]

[0078] in, and YesS D,Load The upper and lower limits of the adjustable range, and YesS D,Line(LV)The upper and lower limits of the operating domain, min(a,b) represents the minimum value of a and b.

[0079] In the steps S2 and S3, each possible topology of the medium voltage distribution network refers to a distribution network topology formed by reconstruction after any fault in the expected fault set occurs in the medium voltage distribution network.

[0080] In step S2, in each possible topology of the medium voltage distribution network, the operating domain of the power of each medium voltage feeder segment in the topology is calculated in order from downstream to upstream, specifically including:

[0081] S2.1 points the pointer to the most downstream medium voltage feeder segment in the current topology;

[0082] S2.2 If the feeder segment pointed by the pointer is the most downstream feeder segment, then the operating domain of the power flowing into the connected low-voltage distribution network from the adjacent medium-voltage bus downstream is determined based on its power operating domain; if the feeder segment pointed by the pointer is not the most downstream feeder segment, then the operating domain of the power flowing into the connected low-voltage distribution network from the adjacent medium-voltage bus downstream and the power of the adjacent feeder segment downstream is determined based on its power operating domain;

[0083] S2.3 If the feeder segment pointed to by the pointer is the most upstream feeder segment in the current topology, the "task status" is marked as "completed", otherwise the pointer is moved one feeder segment upstream in the current topology;

[0084] S2.4 Repeat S2.2 and S2.3 until the “task status” is “completed”.

[0085] The step S2.2 specifically includes:

[0086] Assume that the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus of the feeder segment pointed by the pointer is The operating range of the power of the downstream adjacent feeder segment (if any) of the feeder segment pointed to by the pointer is The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S Line(MV) The operating domain is

[0087]

[0088] If the feeder segment pointed by the pointer is the most downstream feeder segment, let the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus of the feeder segment pointed by the pointer be The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S Line(MV) The operating domain is

[0089]

[0090] If the feeder segment pointed by the pointer is not the most downstream feeder segment, the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus of the feeder segment pointed by the pointer is The operating domain of the power of the downstream adjacent feeder segment of the feeder segment pointed by the pointer is The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S Line(MV) The operating domain is

[0091]

[0092] in, and For S D,Bus The upper and lower limits of the operating domain, and For S D,Line(MV) The upper and lower limits of the operating domain.

[0093] In step S3, in each possible topology of the medium voltage distribution network, the operation domain of the power flowing into the connected low voltage distribution network from each medium voltage bus in the topology is determined in order from upstream to downstream, specifically including:

[0094] S3.1 points the pointer to the most upstream medium voltage feeder segment in the current topology;

[0095] S3.2 If the feeder segment pointed by the pointer is the most downstream feeder segment, then the operating domain of the power flowing into the connected low-voltage distribution network from the adjacent medium-voltage busbar downstream shall be determined according to its power operating domain; if the feeder segment pointed by the pointer is not the most downstream feeder segment, then the operating domain of the power flowing into the connected low-voltage distribution network from the adjacent medium-voltage busbar downstream and the power of the adjacent feeder segment downstream shall be determined according to its power operating domain;

[0096] S3.3 If the feeder segment pointed to by the pointer is the most downstream feeder segment in the current topology, the “task status” is marked as “completed”; otherwise, the pointer is moved one feeder segment downstream in the current topology;

[0097] S3.4 Repeat S3.2 and S3.3 until the “task status” is “completed”.

[0098] The step S3.2 specifically includes:

[0099] Suppose the vector of power flowing into the connected low-voltage distribution network from each medium-voltage bus upstream of the feeder segment pointed by the pointer is S U,Bus , the power of the feeder segment pointed by the pointer is S Line(MV) , the operating domain of the feeder section power pointed by the pointer is Then the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus and the power of the downstream adjacent feeder section (if any) is

[0100]

[0101] Among them, i is the serial number of the current topology, f i (S Line(MV) ,S U,Bus ) is S Line(MV) and S U,Bus is a function of a variable, and As its upper and lower limits, S D,Bus S is the power flowing from the medium-voltage busbar downstream of the feeder segment pointed to by the pointer into the connected low-voltage distribution network. D,Line(MV) is the power of the adjacent feeder section downstream of the feeder section pointed by the pointer, f i (S D,Line(MV) +S D,Bus ,S U,Bus ) is to convert f i (S Line(MV) ,S U,Bus ) Line(MV) Replace all with S D,Line(MV) +S D,Bus The function formed afterwards.

[0102] In step S4, the overlapping part of the operation domain of the power flowing into the connected low-voltage distribution network of each medium-voltage bus in all possible topologies of the medium-voltage distribution network is taken as the safety domain of the power flowing into the connected low-voltage distribution network, which specifically includes:

[0103] Combine the operating domains of the power flowing into the connected low-voltage distribution network from each medium-voltage bus in all topologies:

[0104]

[0105] Where i is the topology number, n is the number of all possible topologies of the medium voltage distribution network, S Bus is the power variable of each medium voltage bus flowing into the connected low voltage distribution network, is the operating domain of the power flowing into the connected low-voltage distribution network of each medium-voltage bus in topology i calculated in step S3, g i (S Bus ) is S Bus The linear combination of the variables in and g i (S Bus )’s upper and lower limits.

[0106] The simplex method is used to eliminate the redundant constraints and obtain the safety domain of the power flowing into the connected low-voltage distribution network of each medium-voltage bus:

[0107] h min ≤h(SBus )≤h max

[0108] Among them, h(S Bus ) is S Bus The linear combination of the variables in h max and h min h(S Bus )’s upper and lower limits.

[0109] In the step S5, the power variable of each medium-voltage bus in the safety domain obtained in step S4 flowing into the connected low-voltage distribution network is replaced by the sum of the power variables of all commercial loads in the low-voltage distribution network connected to the medium-voltage bus, specifically including:

[0110] In h min ≤h(S Bus )≤h max In

[0111] S Bus =[S 1 ,S 2 ,…,S m ]

[0112] Replace with

[0113]

[0114] Get the security domain of the commercial load cluster of the distribution network

[0115] h min ≤h(S load )≤h max

[0116] Among them, S j is the power variable flowing from medium voltage bus j to the connected low voltage distribution network, m is the number of medium voltage buses, S j,k is the power variable of the kth commercial load in the low-voltage distribution network connected to the medium-voltage bus j, l j is the number of commercial loads in the low-voltage distribution network connected to the medium-voltage bus j. Specific embodiments

[0118] A parallel computing method for a commercial load cluster security domain of a distribution network of the present invention comprises:

[0119] In the first step, calculations are performed in parallel in each low-voltage distribution network. In each low-voltage distribution network, the operating domain of the power of each low-voltage feeder segment is calculated in order from downstream to upstream according to the adjustable range of each commercial load power and the maximum current carrying capacity of each feeder segment. Then, the operating domain of the power flowing from the medium-voltage bus into the low-voltage distribution network is obtained when only the constraints of the low-voltage distribution network are considered.

[0120] Figure 2 The distribution network shown contains three low-voltage distribution networks, and calculations are performed in these low-voltage distribution networks. Taking low-voltage distribution network 1 as an example, point the pointer to the most downstream feeder segment "commercial load 1_2-commercial load 1_3", and calculate its power operation domain based on the adjustable power range and maximum current carrying capacity of the downstream adjacent commercial load 1_3. Assume that the adjustable power range of commercial load 1_3 is The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S (1,2),(1,3) The operating domain is

[0121]

[0122] Among them, min(a,b) represents the minimum value of a and b.

[0123] Point the pointer to the feeder segment "commercial load 1_1-commercial load 1_2", and calculate its power operating domain based on the adjustable range of the power of its downstream adjacent commercial load 1_2, the power operating domain of its downstream adjacent feeder segment "commercial load 1_2-commercial load 1_3" and its maximum current carrying capacity. Assume that the adjustable range of the power of commercial load 1_2 is The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S (1,1),(1,2) The operating domain is

[0124]

[0125] Point the pointer to the feeder section "Medium Voltage Bus 1-Commercial Load 1_1", and calculate its power operating domain according to the adjustable range of the power of its downstream adjacent commercial load 1_1, the power operating domain of its downstream adjacent feeder section "Commercial Load 1_1-Commercial Load 1_2" and its maximum current carrying capacity. Assume that the adjustable range of the power of commercial load 1_1 is The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S (1,0),(1,1) The operating domain is

[0126]

[0127] At this point, the pointer has pointed to the most upstream feeder segment, and the calculation task in the low-voltage distribution network 1 is completed. (1,0),(1,1) The operating domain is the operating domain of the power flowing from the medium-voltage bus 1 into the low-voltage distribution network 1 when only the low-voltage distribution network constraints are considered. During the above calculation process, similar calculations are also performed in the low-voltage distribution networks 2 and 3 to obtain the operating domain of the power flowing from the medium-voltage bus 2 into the low-voltage distribution network 2 and the operating domain of the power flowing from the medium-voltage bus 3 into the low-voltage distribution network 3 when only the low-voltage distribution network constraints are considered.

[0128] The second step is to perform calculations in parallel in each possible topology of the medium-voltage distribution network. In each possible topology of the medium-voltage distribution network, the operating domain of the power of each medium-voltage feeder segment is calculated in order from downstream to upstream based on the operating domain of the power flowing from each medium-voltage bus into the connected low-voltage distribution network and the maximum current carrying capacity of each feeder segment.

[0129] exist Figure 2 In the distribution network shown in Figure 2, there are four possible topologies for the medium voltage distribution network, such as Figure 3 As shown. Calculations are performed in these four topologies at the same time. Taking topology 1 as an example, the pointer is pointed to the most downstream feeder segment "medium voltage bus 1-medium voltage bus 2". According to the operating domain of the power of the medium voltage bus 1 connected to the downstream of the feeder segment pointed to by the pointer and the maximum current carrying capacity of the feeder segment pointed to by the pointer, the operating domain of the power of the feeder segment pointed to by the pointer is calculated. Assume that the operating domain of the power of the medium voltage bus 1 flowing into the connected low voltage distribution network is The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S 1,2(MV) The operating domain is

[0130]

[0131] Point the pointer to the feeder section "Medium Voltage Bus 2-Medium Voltage Bus 3", and calculate the operating domain of the power of the feeder section pointed by the pointer according to the operating domain of the power of the medium voltage bus 2 flowing into the connected low voltage distribution network, the operating domain of the power of the downstream adjacent feeder section "Medium Voltage Bus 1-Medium Voltage Bus 2", and the maximum current carrying capacity of the feeder section pointed by the pointer. Assume that the operating domain of the power of the medium voltage bus 2 flowing into the connected low voltage distribution network is The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S 2,3(MV) The operating domain is

[0132]

[0133] Point the pointer to the feeder segment "Medium-voltage bus 3-substation", and calculate the operating domain of the power of the feeder segment pointed by the pointer based on the operating domain of the power of the medium-voltage bus 3 flowing into the connected low-voltage distribution network, the operating domain of the power of the downstream adjacent feeder segment "Medium-voltage bus 2-Medium-voltage bus 3", and the maximum current carrying capacity of the feeder segment pointed by the pointer. Assume that the operating domain of the power of the medium-voltage bus 3 flowing into the connected low-voltage distribution network is The maximum current carrying capacity of the feeder segment pointed by the pointer is Then the power of the feeder section pointed by the pointer is S 3,4(MV) The operating domain is

[0134]

[0135] At this point, the pointer has pointed to the most upstream feeder segment, and the calculation task in topology 1 is completed. During the above calculation process, similar calculations are also performed in topologies 2, 3, and 4.

[0136] The third step is to perform calculations in parallel in each possible topology of the medium-voltage distribution network. In each possible topology of the medium-voltage distribution network, according to the operating domain of the power of each medium-voltage feeder segment, the operating domain of the power flowing into the connected low-voltage distribution network of each medium-voltage bus is determined in order from upstream to downstream.

[0137] Taking topology 1 as an example, point the pointer to the upstream feeder segment "medium voltage bus 3-substation", and determine the operating domain of the power of the downstream adjacent medium voltage bus 3 flowing into the connected low voltage distribution network and the power of the downstream adjacent feeder segment "medium voltage bus 2-medium voltage bus 3" according to the operating domain of the feeder segment power pointed to by the pointer. Suppose the operating domain of the feeder segment "medium voltage bus 3-substation" is Then the operating domain of the power flowing into the connected low-voltage distribution network of medium-voltage bus 3 and the power of the feeder section "medium-voltage bus 2-medium-voltage bus 3" is

[0138]

[0139] Point the pointer to the feeder section "Medium Voltage Bus 2-Medium Voltage Bus 3". According to the operating domain of the power of the feeder section pointed by the pointer, determine the operating domain of the power of the downstream adjacent medium voltage bus 2 flowing into the connected low voltage distribution network and the power of the downstream adjacent feeder section "Medium Voltage Bus 1-Medium Voltage Bus 2" as follows:

[0140]

[0141] Point the pointer to the feeder section "Medium voltage bus 1-Medium voltage bus 2". According to the operating domain of the power of the feeder section pointed by the pointer, determine the operating domain of the power of the downstream adjacent medium voltage bus 1 flowing into the connected low voltage distribution network as

[0142]

[0143] At this time, the pointer has pointed to the most downstream feeder segment, and the calculation task in topology 1 is completed. During the above calculation process, similar calculations are also performed in topologies 2, 3, and 4.

[0144] The fourth step is to take the overlapping part of the operating domain of the power flowing from each medium-voltage bus into the connected low-voltage distribution network in all possible topologies of the medium-voltage distribution network as the safety domain of the power flowing from each medium-voltage bus into the connected low-voltage distribution network.

[0145] Will be from Figure 3 The operating domains of the power flowing into the connected low-voltage distribution network from each medium-voltage bus obtained in the four topologies shown are combined:

[0146]

[0147] The simplex method is used to eliminate the redundant constraints and obtain the safety domain of the power flowing into the connected low-voltage distribution network of each medium-voltage bus:

[0148] h min ≤h(S 1 ,S 2 ,S 3 )≤h max

[0149] In the fifth step, the power variable of each medium-voltage bus flowing into the connected low-voltage distribution network in the obtained security domain is replaced by the sum of the power variables of all commercial loads in the connected low-voltage distribution network, thereby refining the security domain of the power of each medium-voltage bus flowing into the connected low-voltage distribution network into the security domain of the distribution network commercial load cluster.

[0150] In h min ≤h(S 1 ,S 2 ,S 3 )≤h max In the 1 Replace with S 1,1 +S 1,2 +S 1,3 , S 2 Replace with S 2,1 +S 2,2 +S 2,3 , S 3 Replace with S 3,1 +S 3,2 +S 3,3 , and obtain the security domain of the commercial load cluster of the distribution network

[0151] h min ≤h(S 1,1 +S 1,2 +S 1,3 ,S 2,1 +S 2,2 +S 2,3 ,S 3,1 +S 3,2 +S 3,3 )≤h max .

[0152] Based on the analysis of the topological structure of the distribution network, the present invention decomposes the calculation of the safety domain of the commercial load cluster of the distribution network into multiple steps, and then decomposes each step into multiple subtasks that can be executed in parallel, thereby realizing the rapid definition of the safety domain of the commercial load cluster of the distribution network and supporting the commercial load cluster of the distribution network to participate in the demand-side response.

[0153] The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A parallel computing method for the safety domain of a commercial load cluster in a distribution network, characterized in that: The method comprises the following steps: S1: Calculation is performed in parallel in each low-voltage distribution network. In each low-voltage distribution network, according to the adjustable range of each commercial load power and the maximum current carrying capacity of each feeder segment, the operating domain of each low-voltage feeder segment power is calculated in order from downstream to upstream, and then the operating domain of the power flowing from the medium-voltage bus into the low-voltage distribution network when only the constraints of the low-voltage distribution network are considered is obtained; S2: performing calculations in parallel in each possible topology of the medium-voltage distribution network. In each possible topology of the medium-voltage distribution network, according to the operating domain of the power flowing from each medium-voltage bus into the connected low-voltage distribution network and the maximum current carrying capacity of each feeder segment, the operating domain of the power of each medium-voltage feeder segment in the topology is calculated in order from downstream to upstream; S3: performing calculations in parallel in each possible topology of the medium-voltage distribution network, and determining the operating domain of the power flowing into the connected low-voltage distribution network from each medium-voltage bus in the topology in accordance with the operating domain of the power of each medium-voltage feeder segment in order from upstream to downstream in each possible topology of the medium-voltage distribution network; S4: Take the overlapping part of the operation domain of the power flowing from each medium-voltage bus to the connected low-voltage distribution network in all possible topologies of the medium-voltage distribution network as the safety domain of the power flowing from each medium-voltage bus to the connected low-voltage distribution network; S5: Replace the power variable of each medium-voltage bus flowing into the connected low-voltage distribution network in the security domain obtained in step S4 with the sum of the power variables of all commercial loads in the low-voltage distribution network connected to the medium-voltage bus, and refine the security domain of the power of each medium-voltage bus flowing into the connected low-voltage distribution network into the security domain of the distribution network commercial load cluster.

2. The parallel computing method for the commercial load cluster security domain of the distribution network according to claim 1 is characterized in that: Step S1 further comprises: S1.1: point the pointer to the most downstream feeder segment in the low-voltage distribution network; S1.2: If the feeder segment pointed to by the pointer is the most downstream feeder segment, its power operating domain is calculated based on its maximum current carrying capacity and the adjustable range of its downstream adjacent commercial load power; if the feeder segment pointed to by the pointer is not the most downstream feeder segment, its power operating domain is calculated based on its maximum current carrying capacity, the adjustable range of its downstream adjacent commercial load power and the operating domain of its downstream adjacent feeder segment power; S1.3: Determine whether the feeder segment pointed to by the pointer is the most upstream feeder segment in the low-voltage distribution network. If so, mark the task status as completed and proceed to step S1.

4. Otherwise, move the pointer one feeder segment upstream and return to step S1.

2. S1.4: The operating domain of the power of the most upstream feeder section of the low-voltage distribution network is taken as the operating domain of the power flowing from the medium-voltage bus into the low-voltage distribution network when only the constraints of the low-voltage distribution network are considered.

3. The parallel computing method for the safety domain of commercial load clusters in a distribution network according to claim 2, characterized in that: In step S1.2, if the feeder segment pointed to by the pointer is the most downstream feeder segment, the power S of the feeder segment pointed to by the pointer is Line(LV) The operating domain is: In the formula, Indicates the adjustable range of the power of the downstream adjacent commercial load of the feeder segment pointed by the pointer. and Respectively represent the adjustable range S D,Load The upper and lower limits of Indicates the maximum current carrying capacity of the feeder segment pointed by the pointer; min(a,b) means the minimum value of a and b; If the feeder segment pointed to by the pointer is not the most downstream feeder segment, the operating domain S of the feeder segment power pointed to by the pointer Line(LV) for: in, Indicates the operating domain of the power of the downstream adjacent feeder segment of the feeder segment pointed to by the pointer, and Respectively represent the operation domain S D,Line(LV) upper and lower limits.

4. The parallel computing method for the commercial load cluster security domain of the distribution network according to claim 1, characterized in that: Each possible topology of the medium voltage distribution network refers to a distribution network topology formed by reconstruction after any fault in the expected fault set occurs in the medium voltage distribution network.

5. The parallel computing method for the commercial load cluster security domain of the distribution network according to claim 1, characterized in that: Step S2 further comprises: S2.1: point the pointer to the most downstream medium voltage feeder segment in the current topology; S2.2: If the feeder segment pointed to by the pointer is the most downstream feeder segment, its power operating domain is calculated based on its maximum current carrying capacity and the operating domain of the power of the connected low-voltage distribution network flowing from its downstream adjacent medium-voltage busbar; if the feeder segment pointed to by the pointer is not the most downstream feeder segment, its power operating domain is calculated based on its maximum current carrying capacity, the operating domain of the power of the connected low-voltage distribution network flowing from its downstream adjacent medium-voltage busbar and the operating domain of the power of its downstream adjacent feeder segment; S2.3: If the feeder segment pointed to by the pointer is the most upstream feeder segment in the current topology, the task status is marked as completed and the process ends; otherwise, the pointer is moved one feeder segment upstream in the current topology and the process goes to step S2.

2.

6. The parallel computing method for the commercial load cluster security domain of the distribution network according to claim 5, characterized in that: In step S2.2, if the feeder segment pointed to by the pointer is the most downstream feeder segment, the operating domain S of the power of the feeder segment pointed to by the pointer is Line(MV) for: In the formula, Indicates the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus of the feeder segment pointed to by the pointer. and Respectively represent the operation domain S D,Bus The upper and lower limits of Indicates the maximum current carrying capacity of the feeder segment pointed by the pointer; If the feeder segment pointed to by the pointer is not the most downstream feeder segment, the operating domain S of the feeder segment power pointed to by the pointer Line(MV) for: in, Indicates the operating domain of the power of the downstream adjacent feeder segment of the feeder segment pointed to by the pointer, and Respectively represent the operation domain S D,Line(MV) upper and lower limits.

7. The parallel computing method for the commercial load cluster security domain of the distribution network according to claim 1, characterized in that: Step S3 further comprises: S3.1: point the pointer to the most upstream medium voltage feeder segment in the current topology; S3.2: If the feeder segment pointed to by the pointer is the most downstream feeder segment, then the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus is determined based on its power operating domain; if the feeder segment pointed to by the pointer is not the most downstream feeder segment, then the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus and the power of the downstream adjacent feeder segment is determined based on its power operating domain; S3.3: Determine whether the feeder segment pointed to by the pointer is the most downstream feeder segment in the current topology. If so, mark the task status as completed and end the process; otherwise, move the pointer one feeder segment downstream in the current topology and return to step S3.

2.

8. The parallel computing method for the commercial load cluster security domain of the distribution network according to claim 7, characterized in that: In step S3.2, if the feeder segment pointed to by the pointer is the most downstream feeder segment, the operating domain of the power flowing from the downstream adjacent medium-voltage bus into the connected low-voltage distribution network is: f i min ≤f i (S D,Bus ,S U,Bus )≤f i max ; In the formula, S U,Bus The vector representing the power of each medium-voltage bus upstream of the feeder segment pointed to by the pointer flowing into the connected low-voltage distribution network; S Line(MV) Indicates the power of the feeder section pointed by the pointer; f i min ≤f i (S Line(MV) ,S U,Bus )≤f i max Indicates the operating domain of the feeder segment power pointed to by the pointer, i indicates the topological number, f i (S Line(MV) ,S U,Bus ) indicates that S Line(MV) and S U,Bus is a function of a variable, f i max and f i min S D,Bus Indicates the power flowing into the connected low-voltage distribution network from the adjacent medium-voltage busbar downstream of the feeder segment pointed to by the pointer; If the feeder segment pointed to by the pointer is not the most downstream feeder segment, the operating domain of the power flowing into the connected low-voltage distribution network from the downstream adjacent medium-voltage bus and the power of the downstream adjacent feeder segment is: f i min ≤f i (S D,Line(MV) +S D,Bus ,S U,Bus )≤f i max ; In the formula, S D,Line(MV) Indicates the power of the adjacent feeder section downstream of the feeder section pointed by the pointer, f i (S D,Line(MV) +S D,Bus ,S U,Bus ) means f i (S Line(MV) ,S U,Bus ) Line(MV) Replace all with S D,Line(MV) +S D,Bus The function formed afterwards.

9. The parallel computing method for the commercial load cluster security domain of the distribution network according to claim 1, characterized in that: Step S4 further comprises: Combine the operating domains of the power flowing into the connected low-voltage distribution network from each medium-voltage bus in all topologies: Where i represents the topology number, n represents the number of all possible topologies of the medium voltage distribution network, S Bus It represents the power variable of each medium voltage bus flowing into the connected low voltage distribution network. represents the operating domain of the power flowing into the connected low-voltage distribution network from each medium-voltage bus in topology i, g i (S Bus ) indicates S Bus The linear combination of the variables in and Respectively represent g i (S Bus )’s upper and lower limits; The simplex method is used to eliminate the redundant constraints and obtain the safety domain of the power flowing into the connected low-voltage distribution network of each medium-voltage bus: h min ≤h(S Bus )≤h max Among them, h(S Bus ) is S Bus The linear combination of the variables in h max and h min h(S Bus )’s upper and lower limits.

10. The parallel computing method for the commercial load cluster security domain of the distribution network according to claim 1, characterized in that: In step S5, each medium voltage bus flows into the safety domain h of the low voltage distribution network connected to it. min ≤h(S Bus )≤h max In the Bus =[S1,S2,…,S m ] is replaced by: Get the security domain of the commercial load cluster of the distribution network: h min ≤h(S load )≤h max ; Among them, S j is the power variable flowing from medium voltage bus j to the connected low voltage distribution network, m is the number of medium voltage buses, S j,k is the power variable of the kth commercial load in the low-voltage distribution network connected to the medium-voltage bus j, l j is the number of commercial loads in the low-voltage distribution network connected to the medium-voltage bus j.

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