A programmable power array for power distribution network and control method thereof

Abstract

The present invention proposes a programmable power array for a power distribution network and a control method thereof, comprising: a programmable power array controller; the programmable power array controller comprises an AC / DC port demand analysis unit; the AC / DC port demand analysis unit detects the functional requirements of the AC side port, and for the flexible port on the AC side, its power set is LH, and the power value represented by the set is PLH; the AC / DC port demand analysis unit detects the functional requirements of the DC side port, and for the DC side of the DC side according to the energy storage port, its power set is CN, and the power value represented by the set is PCN; if PLH does not exceed the flexible port power limit, the ports in the LH set are proportionally allocated power PLH according to the rated capacity of the distribution network connected thereto; if PLH exceeds the flexible port power limit, the ports in the LH set are operated according to the maximum capacity of the power that can be flexibly adjusted in the distribution network connected thereto, and the ports in the CN set are allocated power according to the rated capacity of the energy storage system connected thereto.

Description

Technical Field

[0001] The present invention belongs to the technical field of converters, and in particular relates to a programmable power array for a power distribution network and a control method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, a large number of distributed photovoltaics have been connected to the distribution network. Due to the limited capacity of the transmission channels such as the distribution network, the photovoltaic consumption faces challenges. The traditional solution is to limit photovoltaic installation or photovoltaic power generation, resulting in a waste of light resources. In recent years, academia and industry have proposed the use of flexible interconnection devices to connect adjacent distribution networks and share transmission channels. However, the photovoltaic penetration rates of adjacent distribution networks are highly similar, and their photovoltaic power generation peak times are similar. Therefore, the power complementarity between adjacent distribution networks is poor, and the operation effect of traditional flexible interconnection devices is average. In addition, when designing flexible interconnection devices, they are often based on the maximum capacity of power transmission between distribution networks, and the power path is fixed, without programmable features, which makes it unable to adapt to the diverse working conditions of the actual distribution network, which easily leads to capacity waste.

[0004] On the other hand, rural areas and other regions are rich in photovoltaic resources, and it is difficult to solve the consumption problem by simply sending them out. Local consumption is the fundamental way to solve the problem. If electric vehicles can be quickly charged using rural distribution networks, local consumption can be achieved. Therefore, it is necessary to vigorously develop the construction of fast charging facilities for rural distribution networks. However, the existing rural distribution network capacity is small and it is impossible to build high-power charging facilities.

[0005] In summary, the existing distribution network architecture cannot be flexibly configured and cannot meet the needs of large-scale new energy consumption and high-power charging. Summary of the invention

[0006] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a programmable power array for a power distribution network, which can meet the charging needs of electric vehicles and can also meet the charging and discharging needs of energy storage systems during idle time periods.

[0007] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0008] In a first aspect, a programmable power array for a power distribution network is disclosed, comprising:

[0009] Programmable power array controller; the programmable power array controller includes an AC / DC port demand analysis unit;

[0010] The AC / DC port demand analysis unit detects the functional requirements of the AC side port. For the flexible port on the AC side, its power set is LH, and the power value represented by the set is PLH;

[0011] The AC / DC port demand analysis unit detects the functional requirements of the DC side port, and for the DC side of the DC side according to the energy storage port, its power set is CN, and the power value represented by the set is PCN;

[0012] If the PLH does not exceed the flexible port power limit, the ports in the LH set are allocated power PLH in proportion to the rated capacity of the distribution network to which they are connected;

[0013] If the PLH exceeds the flexible port power limit, the ports in the LH set operate according to the maximum capacity of the flexibly adjustable power in the distribution network to which they are connected, and the ports in the CN set allocate power according to the rated capacity of the energy storage system to which they are connected.

[0014] As a further technical solution, a programmable power array power circuit is also included, and the programmable power array power circuit includes an AC side programmable port, a DC side programmable port and an AC / DC power array.

[0015] As a further technical solution, the AC side programmable port is defined as AC 1 To AC N , the AC side port of the AC / DC converter in the AC / DC power array is defined as A 1 To A M , A.C. 1 To AC N and A 1 To A M The link relationship between them can be represented by a matrix.

[0016] As a further technical solution, the numbers of the AC-side programmable ports and the AC-side ports of the AC / DC converters in the AC / DC power array are equal or unequal, and are represented by different matrices.

[0017] As a further technical solution, the DC side programmable port is defined as DC 1 To DC Y , the AC side port of the DC / DC converter in the AC / DC power array is defined as D 1 To D X , D.C. 1 To DC Y and D 1 To D X The link relationship between them can be represented by a matrix.

[0018] As a further technical solution, the numbers of the DC-side programmable ports and the AC-side ports of the DC / DC converters in the AC / DC power array are equal or unequal, and are represented by different matrices.

[0019] As a further technical solution, the programmable power array controller also includes a programmable power array resource configuration unit, which configures array resources according to the power of the AC and DC port demand analysis unit. When configuring the array resources, the conditions satisfied by the AC side and the conditions satisfied by the DC side must be met.

[0020] As a further technical solution, the programmable power array controller also includes an AC side programmable port control unit and a DC side programmable port control unit, which respectively execute the link relationship matrix solved from the conditions satisfied by the AC side and the link relationship matrix solved from the conditions satisfied by the DC side.

[0021] As a further technical solution, the programmable power array controller also includes an AC / DC power array control unit for controlling the AC / DC converters in the AC / DC power array to execute P AC , control the DC / DC converter in the AC / DC power array to perform P DC .

[0022] In a second aspect, a power distribution method for a programmable power array of a power distribution network is disclosed, comprising:

[0023] Detect the functional requirements of the AC side port. For the flexible port on the AC side, its power set is LH, and the power value represented by the set is PLH;

[0024] Detect the functional requirements of the DC side port. For the DC side of the DC side, according to the energy storage port, its power set is CN, and the power value represented by the set is PCN;

[0025] If the PLH does not exceed the flexible port power limit, the ports in the LH set are allocated power PLH in proportion to the rated capacity of the distribution network to which they are connected;

[0026] If the PLH exceeds the flexible port power limit, the ports in the LH set operate according to the maximum capacity of the flexibly adjustable power in the distribution network to which they are connected, and the ports in the CN set allocate power according to the rated capacity of the energy storage system to which they are connected.

[0027] One or more of the above technical solutions have the following beneficial effects:

[0028] The technical solution of the present invention can flexibly configure the power between multiple AC distribution network ports on the AC side, realize power mutual assistance between multiple distribution networks, and at the same time distribute the fast charging power of electric vehicles in multiple distribution networks to ensure that each distribution network can operate within a reasonable capacity range. On the DC side, the power of multiple DC ports can be flexibly configured to meet the charging needs of electric vehicles and the charging and discharging needs of energy storage systems during idle time periods. By utilizing the AC programmable port and the DC programmable port, the internal AC / DC and DC / DC power units can be maximized, improving the economic benefits of the entire system.

[0029] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0031] Figure 1 This is an overall system diagram of a programmable power array according to an embodiment of the present invention;

[0032] Figure 2 A power circuit diagram of a programmable power array according to an embodiment of the present invention;

[0033] Figure 3 This is an application example of the AC port of an embodiment of the present invention;

[0034] Figure 4 This is an application example of the DC port of an embodiment of the present invention. DETAILED DESCRIPTION

[0035] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0036] It should be noted that the terms used herein are for describing specific embodiments only and are not intended to be limiting of exemplary embodiments according to the present invention.

[0037] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0038] Embodiment 1

[0039] like Figure 1 As shown, this embodiment discloses a programmable power array for a power distribution network, including a programmable power array power circuit and a programmable power array controller;

[0040] The programmable power array power circuit includes an AC-side programmable port (ACIO), a DC-side programmable port (DCIO), and an AC-DC power array (ACDCM).

[0041] The programmable power array controller includes an AC-DC port demand analysis unit (RU), a programmable power array resource configuration unit (AU), an AC-side programmable port control unit (ACPU), an AC-DC power array control unit (PMCU), and a DC-side programmable port control unit (DCPU).

[0042] The AC-side programmable port (ACIO) is as Figure 2 shown. Figure 2 Taking 4 AC distribution network ports and 4 AC / DC converters as an example, the method of this embodiment is applicable to any number of AC distribution network ports and any number of AC / DC converters. The AC distribution network ports are defined as AC 1 to AC N , and the AC-side ports of the AC / DC converters are defined as A 1 to A M . The connection relationship between AC 1 to AC N and A 1 to A M can be represented by the matrix S_A. If the number of AC distribution network ports is equal to the number of AC / DC converters, i.e., N = M, then S_A is represented as:

[0043]

[0044] If the number of AC distribution network ports is greater than the number of AC / DC converters, i.e., N > M, then the upper M×M matrix in S_A is the same as the formula (1) and is represented as:

[0045]

[0046] If the number of AC distribution network ports is less than the number of AC / DC converters, i.e., N < M, then the left N×N matrix in S_A is the same as the formula (1) and is represented as:

[0047]

[0048] The elements in S_A represent the connection relationship between nodes. For the diagonal elements, taking S_A ii as an example, if S_A ii is 1, it means that the AC distribution port AC i is connected to the AC-side programmable port (ACIO), and if it is 0, it means that the AC distribution port AC iThere is no access to the AC-side programmable port (ACIO). For non-diagonal elements, taking S_A ij as an example, S_A ij being 1 means that the AC / DC converter port A i is connected to A j .

[0049] The DC-side programmable port (DCIO) is as Figure 2 shown Figure 2 Taking 4 AC distribution network ports and 4 DC / DC converters as an example, this standard method can be applied to any number of AC distribution network ports and any number of DC / DC converters. The DC ports are defined as DC 1 to DC Y , and the AC-side ports of the DC / DC converters are defined as D 1 to D X . The connection relationship between DC 1 to DC Y and D 1 to D X can be represented by the matrix S_D. If the number of DC ports is equal to the number of DC / DC converters, i.e., N = M, then S_D is represented as:

[0050]

[0051] If the number of DC ports is greater than the number of DC / DC converters, i.e., Y > X, then the upper part X×X matrix in S_D is the same as formula (4) and is represented as:

[0052]

[0053] If the number of AC distribution network ports is less than the number of DC / DC converters, i.e., Y < X, then the upper part Y×Y matrix in S_D is the same as formula (4) and is represented as:

[0054]

[0055] The elements in S_D represent the connection relationship between nodes. For diagonal elements, taking S_D ii as an example, S_D ii being 1 means that the AC distribution port DC i is connected to the AC-side programmable port (DCIO), and being 0 means that the AC distribution port DC i has no access to the AC-side programmable port (DCIO). For non-diagonal elements, taking S_D ij as an example, S_D ij being 1 means that the DC / DC converter port D i is connected to D j .

[0056] AC / DC power matrix (ACDCM) Figure 2 As shown, it is composed of several AC / DC converters and DC / DC converters. The specific connection method is common knowledge and will not be introduced here.

[0057] Embodiment 2

[0058] The purpose of this embodiment is to provide a control method for a programmable power array for a power distribution network, comprising the following parts:

[0059] The AC / DC port demand analysis unit (RU) detects the functional requirements of the AC side port. The AC port power value is defined as PA 1 To PA N , the direction pointing to the distribution network is the positive direction. The AC side is divided into three categories according to off-grid ports, ports requiring mutual assistance, and flexible ports, and their power sets are represented as DW, HJ, and LH respectively. The power values ​​represented by the sets are PDW, PHJ, and PLH, respectively. The calculation method is the sum of the power values ​​of the ports in the set, which provides data support for the subsequent analysis of DC port demand, where PDW and PHJ are known quantities.

[0060] The AC / DC port demand analysis unit (RU) detects the functional requirements of the DC side port. The AC port power value is defined as PD 1 To PD Y , the output direction is positive. The DC side is divided into three categories according to the energy storage port and the charging port, and their power sets are represented as CN and CD respectively. The power values ​​represented by the sets are PCN and PCD respectively, and the calculation method is the sum of the power values ​​of the ports in the set. Among them, PCD is a known quantity.

[0061] The following relationship is satisfied between PLH, PCN and PDW, PHJ, PCD:

[0062] If PLH does not exceed the flexible port power limit PLH max ,but:

[0063] PCN=0; PLH=-PDW-PHJ-PCD (7)

[0064] The ports in the LH set are allocated power PLH in proportion to the rated capacity of the distribution network to which they are connected, which can ensure that the power of the distribution network in the LH set does not exceed the limit.

[0065] If PLH exceeds the flexible port power limit PLH max ,but:

[0066] PCN=PLH max -PDW-PHJ-PCD (8)

[0067] Among them, the ports in the LH set operate according to the maximum capacity of the power distribution network to which they are connected and can flexibly adjust the power. The ports in the CN set allocate power according to the rated capacity of the energy storage system to which they are connected, and the PCN can be evenly distributed to several energy storage systems, which can ensure that the power of the energy storage system in the CN set does not exceed the limit.

[0068] The programmable power array resource configuration unit (AU) configures array resources according to the power distribution of the AC and DC port demand analysis unit (RU). The AC side satisfies the following formula:

[0069]

[0070] -P AC,rated <P AC1 ,...,P AM <P AC,rated

[0071] Among them, P AC,rated is the rated capacity of the AC / DC converter.

[0072] The DC side satisfies the following formula:

[0073]

[0074] -P DC,rated <P DC1 ,...,P DX <P DC,rated

[0075] DC port power requirement for PD 1 To PD Y .

[0076] Among them, P DC,rated is the rated capacity of the DC / DC converter. Formulas (9) and (10) can be solved using existing intelligent optimization algorithms.

[0077] The AC side programmable port control unit (ACPU) executes the link relationship matrix S_A solved in formula (9). The DC side programmable port control unit (DCPU) executes the link relationship matrix S_D solved in formula (10). The AC / DC power array control unit (PMCU) controls the AC / DC converter to execute P AC , control the DC / DC converter to execute P DC , P AC , P DC They represent the power sets of the AC / DC converter and the DC / DC converter respectively, which can be calculated by formulas (9) and (10). The specific calculation process is common knowledge.

[0078] like Figure 3As shown, the programmable port on the AC side can be flexibly switched according to demand. Figure 3 In (a), distribution networks 1, 2, 3, and 4 are all connected to the AC / DC converter and transmit power to each other. Figure 3 In (b), distribution network 1 and distribution network 2 are directly interconnected to achieve hard loop, and distribution network 3 and distribution network 4 are connected through AC / DC conversion to achieve flexible interconnection. Figure 3 In (c), distribution network 3 and distribution network 4 are respectively connected to two AC / DC converters to achieve high-power flexible interconnection.

[0079] like Figure 4 As shown, the DC side programmable port can be flexibly switched according to demand. Figure 4 (a) indicates that ports 1 and 2 are connected to the energy storage battery, and ports 3 and 4 are connected to the electric vehicle. Figure 4 (b) in the middle indicates that ports 1 and 2 are respectively connected to energy storage batteries to achieve high-power charging and discharging.

[0080] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A programmable power array for a power distribution network, Its characteristics are: include: The programmable power array includes a programmable power array power circuit and a programmable power array controller; The programmable power array controller includes an AC / DC port demand analysis unit; The AC / DC port demand analysis unit detects the functional requirements of the AC side port. For the flexible port on the AC side, its power set is LH, and the power value represented by the set is PLH; The AC / DC port demand analysis unit detects the functional requirements of the DC side port, and the power set of the DC side is CN according to the energy storage port; If the PLH does not exceed the flexible port power limit, the ports in the LH set are allocated power PLH in proportion to the rated capacity of the distribution network to which they are connected; If the PLH exceeds the flexible port power limit, the ports in the LH set will operate according to the maximum capacity of the power distribution network to which they are connected and the ports in the CN set will be allocated power according to the rated capacity of the energy storage system to which they are connected; It also includes a programmable power array power circuit, which includes an AC side programmable port, a DC side programmable port and an AC / DC power array; The AC side ports are divided into three categories: off-grid ports, ports requiring mutual assistance, and flexible ports; The DC side ports are divided into two categories: energy storage ports and charging ports.

2. A programmable power array for a power distribution network as claimed in claim 1, Its characteristics are: The AC side programmable port is defined as AC 1 To AC N , the AC side port of the AC / DC converter in the AC / DC power array is defined as A 1 To A M , A.C. 1 To AC N and A 1 To A M The link relationship between them can be represented by a matrix.

3. A programmable power array for a power distribution network as claimed in claim 1, Its characteristics are: The numbers of the AC-side programmable ports and the AC-side ports of the AC / DC converters in the AC / DC power array are equal or unequal, and are represented by different matrices.

4. A programmable power array for a power distribution network as claimed in claim 1, Its characteristics are: The DC side programmable port is defined as DC 1 To DC Y , the AC side port of the DC / DC converter in the AC / DC power array is defined as D 1 To D X , D.C. 1 To DC Y and D 1 To D X The link relationship between them can be represented by a matrix.

5. A programmable power array for a power distribution network as claimed in claim 1, Its characteristics are: The numbers of the DC-side programmable ports and the AC-side ports of the DC / DC converters in the AC / DC power array are equal or unequal, and are represented by different matrices.

6. A programmable power array for a power distribution network as claimed in claim 1, Its characteristics are: The programmable power array controller also includes a programmable power array resource configuration unit, which configures array resources according to the power of the AC and DC port demand analysis unit. When configuring the array resources, the conditions satisfied by the AC side and the conditions satisfied by the DC side need to be met.

7. A programmable power array for a power distribution network as claimed in claim 6, Its characteristics are: The programmable power array controller also includes an AC side programmable port control unit and a DC side programmable port control unit, which respectively execute the link relationship matrix solved from the conditions satisfied by the AC side and the link relationship matrix solved from the conditions satisfied by the DC side.

8. A programmable power array for a power distribution network as claimed in claim 1, Its characteristics are: The programmable power array controller also includes an AC / DC power array control unit for controlling the AC / DC converters in the AC / DC power array to execute P AC , control the DC / DC converter in the AC / DC power array to perform P DC .

9. A power distribution method for a programmable power array for a power distribution network, based on the programmable power array for a power distribution network as claimed in any one of claims 1 to 8, Its characteristics are: include: Detect the functional requirements of the AC side port. For the flexible port on the AC side, its power set is LH, and the power value represented by the set is PLH; Detect the functional requirements of the DC side port. For the DC side of the DC side, according to the energy storage port, its power set is CN, and the power value represented by the set is PCN; If the PLH does not exceed the flexible port power limit, the ports in the LH set are allocated power PLH in proportion to the rated capacity of the distribution network to which they are connected; If the PLH exceeds the flexible port power limit, the ports in the LH set operate according to the maximum capacity of the flexibly adjustable power in the distribution network to which they are connected, and the ports in the CN set allocate power according to the rated capacity of the energy storage system to which they are connected.

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