Three-phase balance adjusting method and system for low-voltage transformer area

Abstract

The invention relates to a three-phase balance adjusting method for a low-voltage transformer area. The method comprises the following steps: collecting three-phase current data and voltage data of the low-voltage transformer area; calculating a three-phase current unbalance degree and a three-phase power unbalance degree of the low-voltage transformer area according to the three-phase current data and the voltage data; using the three-phase current unbalance degree and the three-phase power unbalance degree to initialize an agent algorithm Agent; phase adjustment is carried out through an agent algorithm Agent, and three-phase balance of the low-voltage transformer area is achieved. According to the method, the three-phase current unbalance degree and the three-phase power unbalance degree are accurately calculated, and the intelligent agent algorithm Agent is used for phase adjustment, so that more accurate three-phase balance can be realized, and electrical equipment loss and potential safety hazards caused by three-phase unbalance can be reduced.

Description

Technical Field

[0001] The present invention relates to a three-phase balance adjustment method and system for a low-voltage power distribution area, belonging to the technical field of power regulation and control. Background Art

[0002] Currently, due to the large number of users, different household establishment times, and daily electricity peak differences in the low-voltage power distribution area, the three-phase imbalance of the line is likely to occur. The three-phase imbalance will cause the three-phase voltage asymmetry, resulting in the displacement of the neutral point potential, the increase of the highest phase current of the load, and the temperature rise of the electrical equipment (including transformers, circuit breakers, etc.), lines, and electrical connectors on the power distribution area side, seriously affecting the service life of the electrical equipment.

[0003] Currently, in the treatment of the three-phase imbalance problem in the power distribution area, mainly two methods are adopted: one is the manual phase change method, which requires regularly collecting and statistically analyzing the electricity consumption data and manually adjusting it. This process is both cumbersome and time-consuming, and this method will be gradually reduced; the other is the load compensation method, which can solve the three-phase balance problem, but the equipment cost is relatively high and the stability is not good, so there are certain difficulties in the actual application in the power distribution area.

[0004] The patent document with the patent number "CN105870945A" discloses an automatic adjustment algorithm for three-phase current imbalance in a low-voltage distribution network. The problems existing in this method are as follows: the data window set by the phase changer calculates the average current every 1 minute, which may lead to the failure to timely identify and adjust the three-phase imbalance problem in the case of rapid load changes, and there are certain real-time limitations. It mainly relies on the phase changer for phase adjustment. When the three-phase imbalance problem is serious, it may not be completely solved only by phase change, and more flexible and diverse adjustment strategies are needed. The three-phase imbalance is detected by accumulating the average current per minute and comparing the average current within half an hour, but this method requires continuous accumulation and calculation, increasing the computational complexity of the system. Summary of the Invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a three-phase balance adjustment method and system for a low-voltage power distribution area.

[0006] The technical solution of the present invention is as follows:

[0007] On the one hand, the present invention provides a three-phase balance adjustment method for a low-voltage power distribution area, including the following steps:

[0008] Collect the three-phase current data and voltage data of the low-voltage power distribution area;

[0009] Calculate the three-phase current imbalance degree and three-phase power imbalance degree of the low-voltage power distribution area according to the three-phase current data and voltage data;

[0010] Initialize the intelligent agent algorithm Agent using the three-phase current unbalance degree and the three-phase power unbalance degree;

[0011] Perform phase adjustment through the intelligent agent algorithm Agent to achieve three-phase balance in the low-voltage power distribution area.

[0012] As a preferred embodiment, the calculation method of the three-phase current unbalance degree is:

[0013] Obtain the instantaneous current values IA, IB, and IC of phase A, phase B, and phase C according to the three-phase current data A 、I B 、I C ;

[0014] Obtain the instantaneous power values PA, PB, and PC of phase A, phase B, and phase C through the voltage data and the instantaneous current values A 、P B 、P C ;

[0015] The calculation method of the three-phase current unbalance degree ∈ is:

[0016]

[0017] where max represents the maximum value function, and I ave represents the average instantaneous current of phase A, phase B, and phase C;

[0018] The calculation method of the three-phase power unbalance degree g k is:

[0019]

[0020] k = A, B, C;

[0021]

[0022] where k represents phase A, phase B, or phase C in sequence, P k represents the instantaneous power value of phase k, and P ave represents the average instantaneous power of phase A, phase B, and phase C.

[0023] As a preferred embodiment, the initialization process of the intelligent agent algorithm Agent is:

[0024] Let the objective function F be expressed as:

[0025] F = min{γ1·∈ + γ2·g k};

[0026] where min represents the minimum value function, and γ1, γ2 represent preset weights;

[0027] Let the state vector s be expressed as:

[0028] s = [∈, g A , g B , g C ;

[0029] Among them, g A represents the power imbalance degree of phase A, g B represents the power imbalance degree of phase B, g C represents the power imbalance degree of phase C;

[0030] Let the behavior function be expressed as:

[0031] a = f(s);

[0032] Among them, a represents the adjustment strategy, and f() represents the decision function of the intelligent agent algorithm Agent.

[0033] As a preferred implementation method, the process of the phase adjustment is as follows:

[0034] S1. Obtain the three-phase current imbalance degree and three-phase power imbalance degree of the current low-voltage power grid area;

[0035] S2. Calculate the expected return Q(s, a) of the current state vector s and several adjustment strategies a:

[0036]

[0037] Among them, θ represents the observed return value, β represents the preset weight, represents the new state vector, à represents the adjustment strategy of, represents the expected return of, max à represents the maximum value function;

[0038] S3. Calculate the probability distribution π(a|s) according to the expected return Q(s, a):

[0039]

[0040] Among them, Q(s, à) represents the expected return of s and à;

[0041] S4. Select the corresponding à for adjustment according to the probability distribution π(a|s), and update the expected return Q(s, a):

[0042]

[0043] Among them, σ represents the learning rate, and r represents the immediate return of the adjustment strategy a under the state vector s;

[0044] S5. Repeat the execution of S2 until the objective function F is less than the preset value.

[0045] As a preferred embodiment, the adjustment strategy includes adjusting the wiring mode of the transformer;

[0046] Load reallocation includes adjusting the connection mode or power factor of the load;

[0047] Install a phase conversion switch.

[0048] On the other hand, the present invention also provides a three-phase balance adjustment system for a low-voltage power distribution area, including:

[0049] Data acquisition module: Collect three-phase current data and voltage data of the low-voltage power distribution area;

[0050] Imbalance calculation module: Calculate the three-phase current imbalance and three-phase power imbalance of the low-voltage power distribution area according to the three-phase current data and voltage data;

[0051] Algorithm design module: Initialize the intelligent agent algorithm Agent using the three-phase current imbalance and three-phase power imbalance;

[0052] Implementation module: Perform phase adjustment through the intelligent agent algorithm Agent to achieve three-phase balance in the low-voltage power distribution area.

[0053] The present invention has the following beneficial effects:

[0054] The present invention realizes the automatic adjustment of three-phase balance through the intelligent agent algorithm Agent. Compared with the traditional manual phase conversion method, it greatly reduces the cumbersome data collection and manual adjustment processes, improving efficiency and accuracy. By accurately calculating the three-phase current imbalance and three-phase power imbalance and using the intelligent agent algorithm Agent for phase adjustment, more precise three-phase balance can be achieved, which helps to reduce electrical equipment losses and safety hazards caused by three-phase imbalance. Description of the Drawings

[0055] Figure 1 It is a flowchart of the method implementation of the present invention. Detailed Embodiments

[0056] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] It should be understood that the step numbers used in the text are only for convenience of description and do not limit the order of execution of the steps.

[0058] It should be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0059] The terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0060] The term " / and" refers to any combination and all possible combinations of one or more of the associated listed items and includes these combinations.

[0061] Embodiment 1:

[0062] See Figure 1 , the present invention provides a three-phase balance adjustment method for a low-voltage power distribution area, including the following steps:

[0063] Collect three-phase current data and voltage data of the low-voltage power distribution area;

[0064] Calculate the three-phase current unbalance degree and the three-phase power unbalance degree of the low-voltage power distribution area according to the three-phase current data and the voltage data;

[0065] Initialize the intelligent agent algorithm Agent with the three-phase current unbalance degree and the three-phase power unbalance degree;

[0066] Perform phase adjustment through the intelligent agent algorithm Agent to achieve three-phase balance in the low-voltage power distribution area;

[0067] The present invention reduces manual intervention through an automated intelligent agent algorithm Agent, improves the efficiency of three-phase balance adjustment, and reduces the cost and time consumption of manual operation.

[0068] As a preferred embodiment, the calculation method of the three-phase current unbalance degree is:

[0069] Obtain the instantaneous current values I A , I B , I C of phase A, phase B, and phase C according to the three-phase current data;

[0070] Obtain the instantaneous power values P A , P B , PC ;

[0071] The calculation method of the three - phase current unbalance degree ∈ is as follows:

[0072]

[0073] Among them, max represents the maximum value function, and I ave represents the average instantaneous current of phase A, phase B, and phase C;

[0074] The three - phase power unbalance degree g k The calculation method is as follows:

[0075]

[0076] k = A, B, C;

[0077]

[0078] Among them, k represents phase A, phase B, or phase C in sequence, and P k represents the instantaneous power value of phase k, and P ave represents the average instantaneous power of phase A, phase B, and phase C.

[0079] As a preferred embodiment, the initialization process of the intelligent agent algorithm Agent is as follows:

[0080] Let the objective function F be expressed as:

[0081] F = min{γ1·∈ + γ2·g k};

[0082] Among them, min represents the minimum value function, and γ1, γ2 represent preset weights;

[0083] Let the state vector s be expressed as:

[0084] s = [∈, g A , g B , g C ;

[0085] Among them, g A represents the power unbalance degree of phase A, g B represents the power unbalance degree of phase B, g C represents the power unbalance degree of phase C;

[0086] Let the behavior function be expressed as:

[0087] a = f(s);

[0088] Among them, a represents the adjustment strategy, and f() represents the decision - making function of the intelligent agent algorithm Agent.

[0089] As a preferred embodiment, the process of phase adjustment is as follows:

[0090] S1. Obtain the three-phase current unbalance degree and three-phase power unbalance degree of the current low-voltage power distribution area;

[0091] S2. Calculate the expected return Q(s, a) of the current state vector s and several adjustment strategies a:

[0092]

[0093] where θ represents the observed return value, β represents the preset weight, represents the new state vector, à represents the adjustment strategy of, represents the expected return of, max à represents the maximum value function;

[0094] S3. Calculate the probability distribution π(a|s) according to the expected return Q(s, a):

[0095]

[0096] where Q(s, à) represents the expected return of s and à;

[0097] S4. Select the corresponding à for adjustment according to the probability distribution π(a|s), and update the expected return Q(s, a):

[0098]

[0099] where σ represents the learning rate, and r represents the immediate return of the adjustment strategy a under the state vector s;

[0100] S5. Repeat S2 until the objective function F is less than the preset value.

[0101] As a preferred embodiment, the adjustment strategy includes adjusting the wiring mode of the transformer;

[0102] Load reallocation, including adjusting the connection mode or power factor of the load;

[0103] Install a phase-changing switch.

[0104] On the other hand, the present invention also provides a three-phase balance adjustment system for a low-voltage power distribution area, including:

[0105] Data acquisition module: Collect three-phase current data and voltage data of the low-voltage power distribution area;

[0106] Unbalance degree calculation module: Calculate the three-phase current unbalance degree and three-phase power unbalance degree of the low-voltage power distribution area according to the three-phase current data and voltage data;

[0107] Algorithm design module: Initialize the intelligent agent algorithm Agent using the three-phase current unbalance degree and the three-phase power unbalance degree;

[0108] Implementation module: Perform phase adjustment through the intelligent agent algorithm Agent to achieve three-phase balance in the low-voltage power distribution area.

[0109] In the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent the cases of A existing alone, A and B existing simultaneously, and B existing alone. Where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one of the following" and its similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0110] Those of ordinary skill in the art can realize that the units and algorithm steps described in the embodiments disclosed herein can be implemented by a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0111] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be repeated herein.

[0112] In several embodiments provided in the present application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks, or optical discs.

[0113] The above are only the embodiments of the present invention, and thus do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A three-phase balance adjustment method for a low-voltage area, characterized in that: The following steps are involved: Collect three-phase current and voltage data of low-voltage substations; Calculate the three-phase current imbalance and three-phase power imbalance in the low-voltage area based on the three-phase current data and voltage data; Initialize the intelligent agent algorithm Agent using the three-phase current imbalance and the three-phase power imbalance; Phase adjustment is performed through the agent algorithm to achieve three-phase balance in the low-voltage area.

2. The low voltage area three-phase balance adjustment method according to claim 1 is characterized in that: The calculation method of the three-phase current unbalance degree is: According to the three-phase current data, the instantaneous current values ​​I of phase A, phase B, and phase C are obtained. A ,I B ,I C ; The instantaneous power values ​​P of phase A, phase B, and phase C are obtained through voltage data and instantaneous current values. A , P B , P C ; The calculation method of three-phase current unbalance ∈ is: Among them, max represents the maximum value function, I ave Indicates the instantaneous current average value of phase A, phase B, and phase C; Three-phase power imbalance g k The calculation method is: k = A, B, C; Where, k represents phase A, phase B or phase C, P k Indicates the instantaneous power value of phase k, P ave Indicates the instantaneous average power of phase A, phase B, and phase C.

3. The low voltage area three-phase balance adjustment method according to claim 2 is characterized in that: The initialization process of the agent algorithm Agent is: Let the objective function F be expressed as: F=min{γ1·∈+γ2·g k }; Among them, min represents the minimum function, γ1 and γ2 represent the preset weights; Let the state vector s be expressed as: s=[∈,g A ,g B ,g C ]; Among them, g A Indicates the power imbalance of phase A, g B Indicates the power imbalance of phase B, g C Indicates the power imbalance of phase C; Let the behavior function be expressed as: a=f(s); Among them, a represents the adjustment strategy, and f() represents the agent algorithm decision function.

4. The low voltage area three-phase balance adjustment method according to claim 3 is characterized in that: The phase adjustment process is as follows: S1. Obtain the three-phase current imbalance and three-phase power imbalance of the current low-voltage area; S2. Calculate the expected return Q(s,a) of the current state vector s and several adjustment strategies a: in, represents the observed return value, β represents the preset weight, represents the new state vector, express adjustment strategy, express The expected return, represents the maximum value function; S3. Calculate the probability distribution π(a|s) based on the expected return Q(s,a): in, Indicates s and expected return; S4. Select the corresponding Make adjustments and update the expected return Q(s,a): Among them, σ represents the learning rate, r represents the immediate return of adjusting strategy a under the state vector s; S5. Repeat S2 until the objective function F is less than a preset value.

5. The low voltage area three-phase balance adjustment method according to claim 4 is characterized in that: The adjustment strategy includes adjusting the wiring mode of the transformer; Load redistribution, including adjustment of load connection method or power factor; Install the phase change switch.

6. A three-phase balance regulation system for low-voltage substations, characterized in that: include: Data acquisition module: collects three-phase current data and voltage data of low-voltage substations; Unbalance calculation module: calculates the three-phase current imbalance and three-phase power imbalance of the low-voltage area according to the three-phase current data and voltage data; Algorithm design module: using the three-phase current imbalance and the three-phase power imbalance to initialize the intelligent agent algorithm Agent; Implementation module: Phase adjustment is performed through the agent algorithm to achieve three-phase balance in the low-voltage area.

7. The low voltage area three-phase balance regulation system according to claim 6 is characterized in that: The imbalance calculation module calculates the three-phase current imbalance as follows: According to the three-phase current data, the instantaneous current values ​​i of phase A, phase B, and phase C are obtained. A 、i B ,I C ; The instantaneous power values ​​P of phase A, phase B, and phase C are obtained through voltage data and instantaneous current values. A , P B , P C ; The calculation method of three-phase current unbalance ∈ is: Among them, max represents the maximum value function, I ave Indicates the instantaneous current average value of phase A, phase B, and phase C; Three-phase power imbalance g k The calculation method is: k=A,B,C; Among them, k represents phase A, phase B or phase C, P k Indicates the instantaneous power value of phase k, P ave Indicates the instantaneous average power of phase A, phase B, and phase C.

8. The low voltage area three-phase balance regulation system according to claim 7 is characterized in that: The algorithm design module, the initialization process of the agent algorithm Agent is: Let the objective function F be expressed as: F=min{γ1·∈+γ2·g k }; Among them, min represents the minimum function, γ1 and γ2 represent the preset weights; Let the state vector s be expressed as: s=[∈,g A ,g B ,g C ]; Among them, g A Indicates the power imbalance of phase A, g B Indicates the power imbalance of phase B, g C Indicates the power imbalance of phase C; Let the behavior function be expressed as: a=f(s); Among them, a represents the adjustment strategy, and f() represents the agent algorithm decision function.

9. The low voltage area three-phase balance regulation system according to claim 8, characterized in that: The implementation module, the phase adjustment process is: S1. Obtain the three-phase current imbalance and three-phase power imbalance of the current low-voltage area; S2. Calculate the expected return Q(s,a) of the current state vector s and several adjustment strategies a: Among them, θ represents the observed return value, β represents the preset weight, represents the new state vector, express adjustment strategy, express The expected return, represents the maximum value function; S3. Calculate the probability distribution π(a|s) based on the expected return Q(s,a): in, Indicates s and expected return; S4. Select the corresponding Make adjustments and update the expected return Q(s,a): Among them, σ represents the learning rate, r represents the immediate return of adjusting strategy a under the state vector s; S5. Repeat S2 until the objective function F is less than a preset value.

10. The low voltage area three-phase balance regulation system according to claim 9, characterized in that: It also includes an adjustment strategy module, including adjusting the wiring method of the transformer; Load redistribution, including adjustment of load connection method or power factor; Install the phase change switch.

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