A phase-changing method and device based on phase-changing switch

Abstract

The embodiment of the present application discloses a phase-changing method and device based on a phase-changing switch. When the three-phase load is unbalanced, the phases to which each phase-changing switch is currently connected are obtained; all phase-changing schemes are determined according to the number and combination of the phase-changing switches; the three-phase imbalance corresponding to each phase-changing scheme is determined according to the current change of the phase-changing switches in each phase-changing scheme; the phases to which the phase-changing switches in each phase-changing scheme are connected are compared with the phases to which each current phase-changing switch is respectively connected to determine the number of phase-changing switches switched in each phase-changing scheme; each phase-changing scheme is grouped according to the number of phase-changing switches switched; according to the three-phase imbalance, the phase-changing scheme to be selected is determined in each group, and the phase-changing operation is performed based on the phase-changing scheme to be selected to reduce the three-phase imbalance. Through the above method, the number of times the phase-changing switch is operated is reduced, and the service life of the phase-changing switch is extended.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a phase-changing method and device based on a phase-changing switch. Background Art

[0002] Most of the distribution terminal users use single-phase electricity. Due to the unbalanced load and different electricity consumption times, the three-phase load imbalance in the distribution area is relatively serious. At this time, it will have an adverse impact on the power supply safety, power supply quality and economic operation of the distribution network.

[0003] The existing technology usually uses a phase-changing switch to solve the problem of three-phase imbalance caused by different power loads on the three phases. The phase-changing switch is connected to the low-voltage side of the transformer at the top and the user terminal at the bottom. When the power load of a phase is too high, a phase-changing switch connected to this phase can be switched to a phase with a lower load to balance the load of the three phases.

[0004] In the prior art, in order to find a commutation scheme to reduce the three-phase imbalance during commutation, the listed schemes are verified one by one. During the process, the phase of the commutation switch is frequently changed, which greatly affects the service life of the commutation switch. Summary of the invention

[0005] The embodiments of the present application provide a phase-changing method and device based on a phase-changing switch, which are used to solve the following technical problems: In order to find a phase-changing scheme to reduce the three-phase imbalance, the prior art verifies the listed schemes one by one, during which the phase of the phase-changing switch is frequently changed, which greatly affects the service life of the phase-changing switch.

[0006] The embodiment of the present application provides a phase-changing method based on a phase-changing switch. The method includes: when the three-phase load is unbalanced, obtaining the phases to which each current phase-changing switch is connected; determining all phase-changing schemes according to the number and combination of the phase-changing switches; determining the three-phase imbalance corresponding to each phase-changing scheme according to the current change of the phase-changing switches in each phase-changing scheme; comparing the phases to which the phase-changing switches in each phase-changing scheme are connected with the phases to which the current phase-changing switches are connected, so as to determine the number of phase-changing switches switched in each phase-changing scheme; grouping each phase-changing scheme according to the number of phase-changing switches switched; determining the phase-changing schemes to be selected in each group according to the three-phase imbalance, and performing phase-changing operations based on the phase-changing schemes to be selected to reduce the three-phase imbalance.

[0007] The embodiment of the present application groups all the commutation schemes by determining all the commutation schemes and according to the number of commutation switches that are switched. The commutation schemes with the same number of commutation switches that are switched can be grouped as the same group, and the commutation scheme with the lowest three-phase imbalance in each group can be selected to obtain the commutation scheme to be selected, thereby reducing the number of commutation schemes. In addition, the embodiment of the present application also selects a scheme that meets the current needs based on the commutation scheme to be selected, thereby solving the problem of frequently replacing the commutation switch to verify multiple commutation schemes and extending the service life of the commutation switch.

[0008] In one implementation of the present application, based on the three-phase imbalance, a commutation scheme to be selected is determined in each group, specifically including: determining the commutation scheme with the smallest three-phase imbalance in each group, and using the commutation scheme with the smallest three-phase imbalance as the commutation scheme to be selected.

[0009] In one implementation of the present application, a commutation operation is performed based on a commutation scheme to be selected to reduce the three-phase imbalance, specifically including: determining a weight value of the corresponding number of commutation switches according to the current commutation demand; obtaining a scheme score corresponding to the commutation scheme to be selected according to the weight value of the number of commutation switches, the three-phase imbalance corresponding to the commutation scheme to be selected, and the number of commutation switches that are switched; determining the commutation scheme to be selected corresponding to the minimum scheme score, and performing an operation based on the commutation scheme to be selected to reduce the three-phase imbalance.

[0010] The embodiment of the present application selects a corresponding weight value according to the current commutation demand, and selects a commutation scheme that meets the current demand from the commutation schemes to be selected according to the weight value. A compromise solution can be obtained between reducing the three-phase imbalance and reducing the number of commutation switches, so that the selected solution can not only meet the demand for reducing the three-phase imbalance, but also reduce the number of commutation as much as possible.

[0011] In one implementation of the present application, the scheme score corresponding to the commutation scheme to be selected is obtained according to the weight value of the number of commutation switches, the three-phase imbalance corresponding to the commutation scheme to be selected, and the number of commutation switches to be switched, specifically including: according to the preset formula

[0012] R=W×n+U

[0013] The scheme score corresponding to the commutation scheme to be selected is obtained; wherein R is the scheme score; W is the weight value of the number of commutation switches; n is the number of commutation switches; and U is the three-phase imbalance.

[0014] In one implementation of the present application, the weight value of the corresponding number of phase-changing switches is determined according to the current phase-changing demand, specifically including: if the phase-changing demand is to reduce the number of phase-changing times, then the weight value of the number of phase-changing switches is increased; if the phase-changing demand is to reduce the three-phase imbalance, then the weight value of the number of phase-changing switches is reduced.

[0015] In one implementation of the present application, multiple switching schemes are determined based on the number and combination of phase-changing switches, specifically including: determining a corresponding cardinality based on the number of phase-changing switches; wherein the cardinality is a set array related to the number of phase-changing switches; decomposing each number in the cardinality to obtain permutation and combination data corresponding to the cardinality; wherein each permutation and combination data corresponds to a switching scheme; determining the phase difference corresponding to the cardinality; and obtaining all switching schemes based on the permutation and combination data corresponding to the cardinality and the phase difference corresponding to the cardinality.

[0016] In one implementation of the present application, the three-phase imbalance corresponding to each commutation scheme is determined according to the current change of the commutation switch in each commutation scheme, specifically including: determining the current of each phase before commutation, and the current currently corresponding to each commutation switch; obtaining the current after commutation according to the commutation scheme, the current of each phase before commutation, and the current currently corresponding to the commutation switch; determining the three-phase imbalance corresponding to the current after commutation in the preset current data information, and using the three-phase imbalance as the three-phase imbalance corresponding to the commutation scheme; wherein the preset current data information includes multiple currents after commutation, and the three-phase imbalances corresponding to the multiple currents after commutation.

[0017] After calculating the three-phase current after phase switching, the embodiment of the present application first searches the current data information to see whether there is a three-phase imbalance corresponding to the current. If so, the corresponding three-phase imbalance can be directly obtained, thereby reducing the amount of calculation and improving calculation efficiency.

[0018] In one implementation of the present application, after obtaining the current after commutation, the method also includes: in the case where the current after commutation does not exist in the preset current data information, obtaining the average current after commutation based on the current after commutation; obtaining the imbalance corresponding to each phase based on the current corresponding to each phase and the average current; and taking the imbalance with the largest value as the three-phase imbalance corresponding to the current after commutation.

[0019] In an implementation of the present application, each commutation scheme is grouped according to the number of switching of the commutation switches, specifically including: determining one or more commutation schemes with the same number of switching of the commutation switches, and dividing the one or more commutation schemes into the same group.

[0020] The embodiment of the present application provides a phase-changing device based on a phase-changing switch, comprising: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can: when the three-phase load is unbalanced, obtain the phases to which each phase-changing switch is currently connected; determine all phase-changing schemes according to the number and combination of the phase-changing switches; determine the three-phase imbalance corresponding to each phase-changing scheme according to the current change of the phase-changing switches in each phase-changing scheme; compare the phases to which the phase-changing switches in each phase-changing scheme are connected with the phases to which the current phase-changing switches are connected, so as to determine the number of phase-changing switches switched in each phase-changing scheme; group each phase-changing scheme according to the number of phase-changing switches switched; determine a phase-changing scheme to be selected in each group according to the three-phase imbalance, and perform a phase-changing operation based on the phase-changing scheme to be selected to reduce the three-phase imbalance.

[0021] At least one of the above technical solutions adopted in the embodiment of the present application can achieve the following beneficial effects: the embodiment of the present application groups all the commutation schemes by determining all the commutation schemes and according to the number of commutation switches that are switched. The commutation schemes with the same number of commutation switches that are switched can be grouped as the same group, and the commutation scheme with the lowest three-phase imbalance in each group can be selected to obtain the commutation scheme to be selected, thereby reducing the number of commutation schemes. In addition, the embodiment of the present application also selects a scheme that meets the current needs based on the commutation scheme to be selected, thereby solving the problem of frequently replacing the commutation switch to verify multiple commutation schemes and extending the service life of the commutation switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. In the drawings:

[0023] Figure 1 A flow chart of a phase-changing method based on a phase-changing switch provided in an embodiment of the present application;

[0024] Figure 2 A schematic structural diagram of a phase-changing device based on a phase-changing switch provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The embodiments of the present application provide a phase-changing method and device based on a phase-changing switch.

[0026] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0027] Most of the distribution terminal users use single-phase electricity. Due to the unbalanced load and different electricity consumption times, the three-phase load imbalance in the distribution area is relatively serious. At this time, it will have an adverse impact on the power supply safety, power supply quality and economic operation of the distribution network.

[0028] Different loads on the three phases lead to imbalance in the three phases, which is usually solved by using a phase-changing switch. The phase-changing switch is connected to the low-voltage side of the transformer and to the end user. When the load of a certain item is too high, a phase-changing switch connected to this phase can be switched to a phase with a lower load to balance the load of the three phases.

[0029] In the prior art, in order to find a commutation scheme that reduces the three-phase imbalance during commutation, an exhaustive method is generally used to obtain the commutation scheme with the lowest three-phase imbalance. This method has a large amount of calculation, and in order to minimize the three-phase imbalance, it may be necessary to frequently switch the commutation switch, which affects the service life of the commutation switch. Another method of introducing an optimization algorithm, such as a particle swarm algorithm, involves matrix operations and optimization algorithms, and has high requirements for algorithm implementation.

[0030] In order to solve the above problems, the embodiments of the present application provide a phase-changing method, device and medium based on phase-changing switches. All phase-changing schemes are grouped by determining all phase-changing schemes and according to the number of phase-changing switches that are switched. Phase-changing schemes with the same number of phase-changing switches that are switched can be grouped as the same group, and the phase-changing scheme with the lowest three-phase imbalance in each group can be selected to obtain the phase-changing scheme to be selected, thereby reducing the number of phase-changing schemes. In addition, the embodiments of the present application also select a scheme that meets the current needs based on the phase-changing scheme to be selected, thereby solving the problem of frequently replacing the phase-changing switch to verify multiple phase-changing schemes and extending the service life of the phase-changing switch.

[0031] The technical solution proposed in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0032] Figure 1 A flow chart of a phase-changing method based on a phase-changing switch provided in an embodiment of the present application. Figure 1 As shown, the commutation method includes the following steps:

[0033] S101. When the three-phase load is unbalanced, a phase-changing device based on a phase-changing switch obtains the phase to which each phase-changing switch is currently connected.

[0034] In one embodiment of the present application, when the three-phase load is unbalanced, it is necessary to determine a corresponding phase switching scheme based on the phases currently connected to each three-phase switch to balance the three-phase load.

[0035] Specifically, most of the distribution terminal users use single-phase electricity. The phase-changing switch is connected to the low-voltage side of the transformer and the terminal user. Different power loads on the three phases can easily lead to three-phase imbalance. If one or more power loads are too high, it means that the current three-phase load is unbalanced. At this time, it is necessary to obtain the phase that the current phase-changing switch is connected to, and select the corresponding phase-changing scheme based on the current access mode of the three-phase switch to balance the three-phase load.

[0036] S102: Determine all commutation schemes according to the number and combination of commutation switches.

[0037] In one embodiment of the present application, a corresponding cardinality is determined according to the number of phase-changing switches, wherein the cardinality is a set array related to the number of phase-changing switches. The cardinality is decomposed to obtain permutation and combination data corresponding to a plurality of cardinality. Each permutation and combination data corresponds to a phase-changing scheme. The phase difference corresponding to the cardinality is determined. All phase-changing schemes are obtained according to the permutation and combination data of the cardinality and the phase difference corresponding to the cardinality.

[0038] Specifically, each phase-changing switch can be connected to any of the three phases. Therefore, for one phase-changing switch, there are 3 access methods, which can be connected to phase A, phase B, and phase C. For two phase-changing switches, there are 9 access methods, which can be connected to phase A, phase A, phase B, phase A, phase C, phase B, phase B, phase B, phase C, phase C, phase A, phase C, phase B, and phase C. Therefore, for N phase-changing switches, there are 3 n Combination methods, for each 0 to 3 n (Including 0, excluding 3 n ) can determine the phases to which each commutation switch is connected, that is, determine the commutation scheme corresponding to the integer.

[0039] Taking two phase-changing switches as an example, there are a total of 9 possible phase-changing schemes that can be connected. For details, please refer to the phase-changing scheme list corresponding to the two phase-changing switches shown in Table 1.

[0040] Combination Cardinality Cardinality Decomposition Access phase 0 0 0 AA 1 0 1 AB 2 0 2 AC 3 1 0 BA 4 1 1 BB 5 1 2 BC 6 2 0 CA 7 2 1 CB 8 2 2 CC

[0041] Table 1

[0042] As shown in Table 1, there are 9 possible combinations of two phase-changing switches corresponding to the combination radix. The embodiment of the present application draws on the idea of ​​adding 1 every 2 in the binary system and adding 1 every 8 in the octal system, and implements adding 1 every 3 to obtain the data corresponding to the radix decomposition. Among them, the data corresponding to the radix decomposition is the data after the radix is ​​decomposed. Among them, 0 corresponds to the connection to phase A, 1 corresponds to the connection to phase B, and 2 corresponds to the connection to phase C. The rightmost character in the column of the connected phase is the phase connected to the first phase-changing switch, the next right is the phase connected to the second phase-changing switch, and so on. For example, AC means that the first phase-changing switch is connected to phase C, and the second phase-changing switch is connected to phase A.

[0043] S103: Determine the three-phase imbalance corresponding to each commutation scheme according to the current change of the commutation switch in each commutation scheme.

[0044] In one embodiment of the present application, the current of each phase before commutation and the current currently corresponding to the commutation switch are determined. According to the commutation scheme, the current of each phase before commutation and the current currently corresponding to the commutation switch, the current after commutation is obtained. In the preset current data information, the three-phase imbalance corresponding to the current after commutation is determined, and the three-phase imbalance is used as the three-phase imbalance after commutation corresponding to the commutation scheme. Among them, the preset current data information includes multiple currents after commutation and the three-phase imbalances corresponding to the multiple currents after commutation.

[0045] Specifically, after obtaining the current after commutation, the embodiment of the present application first searches the cache, that is, in the preset current data information, to see whether the imbalance corresponding to the same current value is cached. If it is cached, the three-phase imbalance corresponding to the current value in the cache is obtained, and it is used as the three-phase imbalance after commutation corresponding to the commutation scheme. If the preset current data information does not cache the current data, the three-phase imbalance corresponding to the current is calculated, and the calculation result is placed in the cache to reduce the amount of calculation. For details, see Table 2, a comparison table of currents before and after commutation.

[0046] Phase change switch name Before switching, connect the phase After phase switching, the phase Commutation switch current Phase change switch 1 A A 10A Phase change switch 2 B C 20A

[0047] Table 2

[0048] Hypothesis I A ,I B ,I C They are the currents of the three phases before commutation, I A' ,I B' ,I C' are the currents of the three phases after phase switching. As shown in Table 2, the load connected to phase A has not changed, so I A' =I A The phase-changing switch 2 is connected from phase B to phase C, so the load of phase B is reduced by 20A and the load of phase C is increased by 20A. Therefore, I B'=I B -20,I C '=I C After determining the three-phase current after phase switching, it is possible to search whether the current information is stored in the preset current data information. If so, the three-phase unbalance degree corresponding to the current is obtained.

[0049] In one embodiment of the present application, when there is no current after commutation in the preset current data information, the average current after commutation is obtained according to the current after commutation. The unbalance degree corresponding to each phase is obtained according to the current corresponding to each phase and the average current. The unbalance degree with the largest value is used as the three-phase unbalance degree corresponding to the current after commutation.

[0050] Specifically, assuming that the current of phase A is I A , the current of phase B is I B , the current of phase C is IC. At this time, the average current of the three phases is I avg =(I A +I B +I C ) / 3. The unbalance degree of phase A is I UA , according to the formula

[0051] The unbalance degree of phase A can be obtained. Similarly, replace I in the formula A , replaced by I B with I C , we can get the unbalance degree of phase B and phase C. By comparison, the unbalance degree with the largest value is taken as the three-phase unbalance degree corresponding to the current after commutation.

[0052] S104: Compare the phases to which the commutation switches in each commutation scheme are connected with the phases to which each current commutation switch is connected, so as to determine the number of switchings of the commutation switches in each commutation scheme.

[0053] In one embodiment of the present application, multiple commutation schemes are compared with the phases to which the commutation switches are connected before commutation, and the number of commutation switches that commutate in each commutation scheme can be obtained. For example, there may be one commutation switch switched to other phases, or there may be two or more commutation switches switched to other phases.

[0054] S105 , grouping each commutation scheme according to the number of switchings of the commutation switches.

[0055] In one embodiment of the present application, all obtained commutation schemes are grouped according to the determined number of commutation switches to be switched.

[0056] Specifically, one or more commutation schemes with the same number of commutation switches are determined, and the one or more commutation schemes are divided into the same group. For example, commutation schemes with 1 commutation switch being switched are divided into the same group, and commutation schemes with 2 commutation switches being switched are divided into the same group. Thus, commutation schemes with the same number of commutation switches being switched can be divided into the same group.

[0057] For details, please refer to Table 3, which shows a three-phase imbalance table after phase switching.

[0058] Solution Name Number of commutation switches that switch Unbalance after commutation Plan A 1 10 Plan B 2 9 Plan C 3 12 Plan D 1 5 Plan E 4 0

[0059] Table 3

[0060] As shown in Table 3, the number of phase-changing switches that are switched in Scheme A and Scheme D is the same, which is 1. In this case, Scheme A and Scheme D can be divided into the same group.

[0061] S106. Determine a commutation scheme to be selected in each group according to the three-phase imbalance, and perform commutation operation based on the commutation scheme to be selected to reduce the three-phase imbalance.

[0062] In one embodiment of the present application, a commutation scheme with the smallest three-phase imbalance in each group is determined, and the commutation scheme with the smallest three-phase imbalance is used as a candidate commutation scheme. For example, as shown in Table 3, taking only one commutation switch as an example, only one commutation switch in Scheme A and Scheme D has a commutation. After executing Scheme A, the imbalance is 10, and after executing Scheme D, the imbalance is 5, so Scheme D has a better governance effect than Scheme A. At this time, Scheme D is used as the candidate commutation scheme for the group. For details, please refer to a table of candidate commutation schemes shown in Table 4.

[0063] Number of commutation switches that switch Solution Name Unbalance after commutation 1 Plan D 5 2 Plan B 9 3 Plan C 12 4 Plan E 0

[0064] Table 4

[0065] As shown in Table 4, the commutation schemes to be selected for each group are counted according to the number of commutation switches that are switched. For example, when only one commutation switch is switched, the imbalance degree after commutation corresponding to scheme D is the lowest, so scheme D is selected as the commutation scheme to be selected for the group.

[0066] It should be noted that when the number of phase-changing switches gradually increases, the corresponding imbalance after phase-changing may not necessarily decrease. For example, taking phase A as an example, the current on phase A is 100A before phase-changing, and phase-changing switch 1 is connected to phase A, and the current of phase-changing switch 1 is 10A. At this time, the current of phase A is 100A and phase-changing switch 1 is 10A; the current of phase B is 110A, and the corresponding phase-changing switch 2 is 5A, and the phase-changing switch 4 is 6A; the current of phase C is 105A, and the corresponding phase-changing switch 3 is 8A. After phase-changing, the current of phase A becomes 105A, and at this time, both phase-changing switch 1 and phase-changing switch 2 are connected to phase A; the current of phase B becomes 105A, and the corresponding current of phase-changing switch 4 is 6A; the current of phase C is 105A, and the corresponding current of phase-changing switch 3 is 8A. At this time, the phase-changing switch 2 switches from phase B to phase A. At this time, the three phases are completely balanced, and the number of phase changes corresponding to this scheme is small, and the three-phase imbalance after phase change is 0, so this scheme is the best scheme. When the number of phase changes is more than other times, it cannot be less than the number of this scheme or the three-phase imbalance after phase change is lower. Therefore, at this time, as the number of phase changes increases, the three-phase imbalance will be greater than zero.

[0067] In one embodiment of the present application, a corresponding weight value is determined according to the current commutation demand. A scheme score corresponding to the commutation scheme to be selected is obtained according to the weight value, the three-phase imbalance corresponding to the commutation scheme to be selected, and the number of commutation switches to be switched. The commutation scheme to be selected corresponding to the minimum scheme score is determined, so as to operate based on the commutation scheme to be selected to reduce the three-phase imbalance.

[0068] Specifically, according to the preset formula

[0069] R=W×n+U

[0070] The scheme score corresponding to the selected commutation scheme is obtained. Among them, R is the scheme score; W is the weight value of the number of commutation switches; n is the number of commutation switches; and U is the three-phase imbalance.

[0071] In one embodiment of the present application, if the commutation requirement is to reduce the number of commutations, the weight value is increased. If the commutation requirement is to reduce the three-phase imbalance, the weight value is reduced. For details, see Table 5 showing the score table of each scheme when the weight is 1, and Table 6 showing the score table of each scheme when the weight is 2.

[0072] Switch quantity Solution Name Unbalance after commutation Final score 1 Plan D 5 6 2 Plan B 9 11 3 Plan C 12 15 4 Plan E 0 4

[0073] Table 5

[0074] Switch quantity Solution Name Unbalance after commutation Final score 1 Plan D 5 7 2 Plan B 9 13 3 Plan C 12 18 4 Plan E 0 8

[0075] Table 6

[0076] As shown in Table 5, when the weight is 1, the best solution is E, and 4 phase-changing switches execute the phase-changing instructions. As shown in Table 6, when the weight is 2, solution D is the best solution, and only one phase-changing switch executes the phase-changing instruction. Therefore, to reduce the number of phase-changing switches, the weight value can be increased. To reduce the three-phase imbalance as much as possible and accept the phase-changing switch to execute the phase-changing instruction multiple times, the weight value can be reduced.

[0077] In order to balance the reduction of three-phase imbalance and the number of commutation times of the commutation switch, the embodiment of the present application determines the commutation scheme that meets the current needs from the commutation schemes to be selected by weight, thereby solving the problem that sending commutation instructions to the commutation switch too frequently will affect the service life of the commutation switch.

[0078] Figure 2 The following is a schematic diagram of the structure of a phase-changing device based on a phase-changing switch provided in an embodiment of the present application. Figure 2 As shown, a phase-changing device based on a phase-changing switch comprises:

[0079] at least one processor; and,

[0080] a memory communicatively connected to the at least one processor; wherein,

[0081] The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

[0082] When the three-phase load is unbalanced, obtain the phases to which each phase-changing switch is currently connected;

[0083] Determine all commutation schemes according to the number and combination of the commutation switches;

[0084] Determine the three-phase imbalance corresponding to each commutation scheme according to the current change of the commutation switch in each commutation scheme;

[0085] Compare the phases connected to the commutation switches in each commutation scheme with the phases connected to each current commutation switch to determine the number of commutation switches switched in each commutation scheme;

[0086] Grouping each commutation scheme according to the number of switchings of the commutation switches;

[0087] According to the three-phase imbalance, a commutation scheme to be selected is determined in each group, and a commutation operation is performed based on the commutation scheme to be selected to reduce the three-phase imbalance.

[0088] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device, equipment, and non-volatile computer storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0089] The above describes specific embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0090] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the embodiments of the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present application should be included in the scope of the claims of the present application.

Claims

1. A commutation method based on a commutation switch, characterized in that: The method comprises: When the three-phase load is unbalanced, obtain the phases to which each phase-changing switch is currently connected; Determine all commutation schemes according to the number and combination of the commutation switches; Determining the three-phase imbalance corresponding to each commutation scheme according to the current change of the commutation switch in each commutation scheme, including determining the three-phase imbalance corresponding to the current after commutation in the preset current data information; Compare the phases connected to the commutation switches in each commutation scheme with the phases connected to each current commutation switch to determine the number of commutation switches switched in each commutation scheme; Grouping each commutation scheme according to the number of switchings of the commutation switches; According to the three-phase imbalance, a commutation scheme to be selected is determined in each group, and a commutation operation is performed based on the commutation scheme to be selected to reduce the three-phase imbalance, specifically including: determining the commutation scheme with the smallest three-phase imbalance in each group, and using the commutation scheme with the smallest three-phase imbalance as the commutation scheme to be selected; determining the weight value of the corresponding number of commutation switches according to the current commutation demand; obtaining the scheme score corresponding to the commutation scheme to be selected according to the weight value of the number of commutation switches, the three-phase imbalance corresponding to the commutation scheme to be selected, and the number of commutation switches that are switched; determining the commutation scheme to be selected corresponding to the minimum scheme score, and performing operations based on the commutation scheme to be selected to reduce the three-phase imbalance.

2. A commutation method based on a commutation switch according to claim 1, characterized in that: The scheme score corresponding to the commutation scheme to be selected is obtained according to the weight value of the number of commutation switches, the three-phase imbalance corresponding to the commutation scheme to be selected, and the number of commutation switches to be switched, specifically including: According to the preset formula R=W×n+U The scheme score corresponding to the commutation scheme to be selected is obtained; wherein R is the scheme score; W is the weight value of the number of commutation switches; n is the number of commutation switches; and U is the three-phase imbalance.

3. A commutation method based on a commutation switch according to claim 1, characterized in that: Determining the weight value of the corresponding number of commutation switches according to the current commutation demand specifically includes: If the commutation requirement is to reduce the number of commutation times, then increase the weight value of the number of commutation switches; If the commutation requirement is to reduce the three-phase imbalance, the weight value of the number of commutation switches is reduced.

4. A commutation method based on a commutation switch according to claim 1, characterized in that: Determining all commutation schemes according to the number and combination of the commutation switches specifically includes: According to the number of the phase-changing switches, a corresponding cardinality is determined; wherein the cardinality is a set array related to the number of the phase-changing switches; Decomposing each number in the base to obtain permutation and combination data corresponding to the base; wherein each permutation and combination data corresponds to a commutation scheme; Determining the phase difference corresponding to the cardinality; According to the permutation and combination data corresponding to the cardinality and the phase difference corresponding to the cardinality, the entire commutation scheme is obtained.

5. A commutation method based on a commutation switch according to claim 1, characterized in that: Determining the three-phase imbalance corresponding to each commutation scheme according to the current change of the commutation switch in each commutation scheme specifically includes: Determine the current of each phase before commutation and the current corresponding to each commutation switch; Obtaining the current after commutation according to the commutation scheme, the current of each phase before commutation, and the current currently corresponding to the commutation switch; In the preset current data information, the three-phase imbalance is used as the three-phase imbalance corresponding to the commutation scheme; wherein the preset current data information includes multiple commutated currents and the three-phase imbalances corresponding to the multiple commutated currents respectively.

6. A commutation method based on a commutation switch according to claim 5, characterized in that: After obtaining the current after commutation, the method further includes: When the current after phase switching does not exist in the preset current data information, obtaining the average current after phase switching according to the current after phase switching; Obtaining the unbalance degree corresponding to each phase according to the current corresponding to each phase and the average current; The imbalance degree with the largest value is used as the three-phase imbalance degree corresponding to the current after the phase switching.

7. A commutation method based on a commutation switch according to claim 1, characterized in that: The grouping of each commutation scheme according to the number of switchings of the commutation switches specifically includes: One or more commutation schemes in which the number of switchings of the commutation switches is the same are determined, and the one or more commutation schemes are divided into the same group.

8. A phase-changing device based on a phase-changing switch, comprising: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 7.

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