Energy storage locating and sizing method and system considering area management demand degree

Abstract

The invention discloses an energy storage locating and sizing method and system considering the management demand degree of a transformer area. The method comprises the following steps: delimiting a distributed energy storage planning area; acquiring basic data of all to-be-governed transformer areas in the planning range; defining a governance demand degree index based on the basic data, and calculating a comprehensive index according to the governance demand degree index; the treatment demand degree comprehensive index values of all the to-be-treated transformer areas in the distributed energy storage planning area are calculated, and the to-be-treated transformer areas with the large treatment demand degree comprehensive index values are preferentially selected for treatment; setting multiple types of operation scenes in the selected transformer area, and setting different distributed energy storage access positions, powers and capacities according to different operation scenes; according to the method, the indexes of the treatment demand degree of the transformer area are defined, the problem severity degree of the transformer area is measured through the indexes, and the energy storage access priorities can be sorted by comparing the values of the index values of the treatment demand degree of the transformer area.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a method and system for selecting a site and determining the capacity of energy storage that takes into account the degree of governance requirements of a substation. Background Art

[0002] With the rapid growth and access of new loads such as distributed power sources and electric vehicles, the power structure and operating environment of the distribution network have undergone profound changes. The volatility and randomness of the distribution network load have become increasingly significant, making the planning and operation management of the distribution network more difficult. After a large number of distributed resources are connected, how to ensure the safety and high-quality power supply of the distribution network is a core issue. Secondly, since the construction of the distribution network lags behind the growth of electricity demand, the distribution capacity in some areas is insufficient, and the problems of short-term heavy overload and low voltage for users are prominent. If only the structural upgrade and transformation of the distribution network is implemented to solve the problem, the cost is high, and the contradiction between the rapid growth of user load and the realization of efficient and accurate investment is becoming increasingly prominent. While distributed photovoltaics have entered a stage of prosperous development, the power grid's absorption capacity is facing increasing pressure. Due to the rapid development of new energy such as photovoltaics, the transformation of the power grid has failed to keep up with its pace, resulting in a huge increase in both transformer capacity and power grid absorption pressure. In some areas, problems such as insufficient transmission and transformation capacity and difficulty in peak load absorption during holidays have emerged. Therefore, for power grid companies, how to solve this challenge and promote the absorption of new energy is an important task currently faced, and it is urgent to take multiple measures to resolve the problem of new energy absorption.

[0003] In this context, energy storage technology and equipment are developing rapidly. It can achieve efficient and friendly use of green energy, improve the randomness and volatility of distributed renewable energy, and reduce energy costs through energy storage, such as peak shaving and valley filling, demand response, and grid peak and frequency regulation. However, in terms of site selection and capacity determination of distributed energy storage considering distribution network management, the current distributed energy storage optimization configuration in the substation is usually optimized for access to the distribution network high-voltage line, and the optimization target does not take into account the various substation operation scenarios and the deployment priority of multiple substations. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method and system for energy storage site selection and sizing that takes into account the demand for substation management. Its purpose is to effectively measure the urgency of distributed energy storage management in the substation, and to efficiently and reliably solve various operating problems such as short-term heavy overload of the distribution network, high / low voltage of users, and power reverse transmission.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a method for selecting and sizing energy storage sites taking into account the demand for substation management, comprising the following steps: Step S1: Delineate the distributed energy storage planning area for the distribution lines that have governance requirements, and determine the number of areas to be governed within the planning scope; Step S2: Collect basic data of all the areas to be managed in the distributed energy storage planning area in step S1; Step S3: defining the governance demand index of the substation in the distributed energy storage planning area based on the basic data of the substation to be governed, and calculating the comprehensive index according to the governance demand index; Step S4: Calculate the comprehensive index values ​​of governance requirements of all the to-be-governed substations in the distributed energy storage planning area, and sort them from large to small, giving priority to the to-be-governed substations with large comprehensive index values ​​of governance requirements for governance; Step S5: setting multiple operating scenarios in the selected substation, and setting different locations, powers and capacities of distributed energy storage access according to different operating scenarios; Among them, the governance demand index includes the heavy overload assessment index of the substation area , Substation reverse power transmission evaluation indicators , Low voltage assessment indicators for users in the substation area High voltage assessment indicators for users in the area ; Among them, the lines in the selected area include the following: node, node, node, Node and node; Setting multiple operating scenarios includes: The first type of operation scenario: there is a short-term heavy overload in the substation, that is, the load rate is greater than the preset ratio and the voltage on the user side is normal; The second operating scenario: the substation has no heavy overload and the node To Node The voltage is normal, the node To Node The user has a short-term low voltage. Representation Node To Node A node in between; The third type of operation scenario: at the same time, nodes To Node The voltage is normal and the node To Node Short-term low voltage occurs to users; The fourth type of operation scenario: There is no heavy overload in the substation, but there is short-term reverse transmission and node To Node The user has high voltage, that is, the voltage value is greater than the preset value; Representation Node To Node A node in between.

[0006] Furthermore, the heavy overload assessment index of the substation , expressed as: (1); In the formula, represents the exponential function; represents the base of natural logarithms; Indicates the maximum forward load rate of the station area; Indicates the transformer capacity of the substation; Substation reverse power transmission evaluation index , expressed as: (2); In the formula, Indicates the maximum reverse load rate of the area; Low voltage assessment indicators for users in the substation area , expressed as: (3); In the formula, Indicates the rated voltage of users in the substation area; Indicates the lowest voltage for users in the area; High voltage assessment indicators for users in the substation area , expressed as: (4); In the formula, Indicates the highest voltage of users in the substation area.

[0007] Furthermore, the comprehensive index of the demand for district governance It is expressed as: (5).

[0008] Furthermore, when running the scenario for the first category, Energy storage is deployed at the node, and the energy storage power and capacity are configured according to equations (6) and (7); (6); (7); In the formula, Indicates the maximum charging and discharging power of energy storage; Indicates the capacity of the energy storage battery.

[0009] Furthermore, when running the scenario for the second type, at the node Deploy energy storage and configure the energy storage power and capacity according to equations (8), (9), (10) and (11); (8); (9); (10); (11).

[0010] Furthermore, when running the scenario for the third category, at the node Deploy energy storage and configure the energy storage power and capacity through equations (12) and (13); (12); (13).

[0011] Furthermore, when running the scenario for the fourth category, at the node Deploy energy storage and configure the energy storage power and capacity through equations (14), (15), (16) and (17); (14); (15); (16); (17).

[0012] Furthermore, when the maximum reverse load rate of the area is less than 0, the current value is taken, and when the maximum reverse load rate of the area is greater than 0, the value is taken as 0.

[0013] A system for selecting and sizing energy storage sites considering the demand for power station management, comprising: The division module is used to define the distributed energy storage planning area for the substations under the line where there is a need for management in the distribution network, and determine the number of substations to be managed within the planning scope;

[0014] The acquisition module is used to collect basic data of all the substations to be managed in the distributed energy storage planning area; An indicator definition calculation module is used to define the governance demand index of the substation in the distributed energy storage planning area based on the basic data of the substation to be governed, and calculate the comprehensive index according to the governance demand index; The selection module is used to calculate the comprehensive index values ​​of governance demand of all the to-be-governed substations in the distributed energy storage planning area, and sort them from large to small, giving priority to the to-be-governed substations with large comprehensive index values ​​of governance demand for governance; The site selection and capacity determination module is used to set multiple operating scenarios in the selected substation area, and set different locations, powers and capacities of distributed energy storage access according to different operating scenarios.

[0015] Compared with the existing technology, the present invention has the following beneficial effects: the present invention defines the index of the need for substation governance for various operating scenarios such as short-term heavy overload, high / low voltage for users, and power reverse transmission in the operation of the distribution network, measures the severity of substation problems through the index, and sorts the energy storage access priority by comparing the values ​​of the index of the need for substation governance; by measuring the data of each node, for various operating scenarios such as short-term heavy overload, high / low voltage for users, and power reverse transmission in the operation of the distribution network, user-level distributed energy storage site selection and sizing can be achieved within the substation, effectively improving the accuracy of the substation energy storage deployment location, improving the utilization rate of distributed energy storage, improving the economic efficiency of energy storage investment, and ensuring the stability of the operation of the distribution station substation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a flow chart of the method of the present invention.

[0017] Figure 2 A schematic diagram of the area topology selected for the present invention. DETAILED DESCRIPTION

[0018] like Figure 1 As shown, the present invention provides a technical solution: a method for selecting a location and determining the capacity of energy storage considering the demand for substation management, comprising the following steps:

[0019] Step S1: For the substations under the control of the lines that have management needs in the distribution network, the power supply enterprise or energy storage planning unit shall delineate the distributed energy storage planning area and determine the number of substations to be managed within the planning scope.

[0020] Step S2: Collect the basic data (voltage, capacity, load rate and user-side voltage, etc.) of all the substations to be managed in the distributed energy storage planning area in step S1.

[0021] Step S3: Based on the basic data of the substation to be governed, define the governance demand index of the substation in the distributed energy storage planning area, and calculate the comprehensive index based on the governance demand index.

[0022] Step S4: Calculate the comprehensive index values ​​of governance requirements of all the to-be-governed substations in the distributed energy storage planning area, and sort them from large to small, giving priority to selecting the to-be-governed substations with large comprehensive index values ​​of governance requirements for governance.

[0023] Step S5: Set multiple operating scenarios in the selected substation, and set different locations, powers and capacities of distributed energy storage access according to different operating scenarios.

[0024] Among them, the governance demand indicators of the Taiwan area include:

[0025] Heavy overload assessment index of the substation , expressed as: (1); In the formula, represents the exponential function; represents the base of natural logarithms; Indicates the maximum forward load rate of the station area; Indicates the transformer capacity in the substation.

[0026] Substation reverse power transmission evaluation index , expressed as: (2); In the formula, Indicates the maximum reverse load rate of the area (if the maximum reverse load rate of the area is less than 0, the current value is used; if the maximum reverse load rate of the area is greater than 0, the value is 0).

[0027] Low voltage assessment indicators for users in the substation area , expressed as: (3); In the formula, Indicates the rated voltage of users in the substation area; Indicates the lowest voltage for users in the area.

[0028] High voltage assessment indicators for users in the substation area , expressed as: (4); In the formula, Indicates the highest voltage of users in the substation area.

[0029] Comprehensive index of the need for governance in the Taiwan area It is expressed as: (5).

[0030] like Figure 2 As shown, the selected lines in the area include node, node, node, Node and node.

[0031] The first type of operation scenario: There is a short-term heavy overload in the substation (load rate greater than 80%) and the voltage on the user side is normal.

[0032] The first type of operation scenario only includes the problem of heavy overload in the substation area. Energy storage is deployed at the node, and the energy storage power and capacity are configured according to equations (6) and (7); (6); (7); In the formula, Indicates the maximum charging and discharging power of energy storage; represents the capacity of the energy storage battery; formulas (6) and (7) indicate that when the fully charged energy storage is discharged at the maximum charge and discharge power, all the electricity can be discharged in 2 hours.

[0033] The second operating scenario: the substation has no heavy overload and the node To Node The voltage is normal, the node To Node The user has a short-term low voltage; Representation Node To Node A node in between.

[0034] The second type of operation scenario is generally when the line is too long and there are low-voltage users at the end (voltage value is less than 0.9U), so it is only necessary to Deploy energy storage and configure the energy storage power and capacity according to equations (8), (9), (10) and (11); (8); (9); (10); (11); Equations (8), (9), (10) and (11) indicate that when the fully charged energy storage is discharged at the maximum charge and discharge power, all the electricity can be discharged in 2 hours.

[0035] The third type of operation scenario: at the same time, nodes To Node The voltage is normal and the node To Node Short-term low voltage occurs to users.

[0036] The third type of operation scenario includes both heavy overload in the substation area and low voltage for users in the substation area. Therefore, it is necessary to adjust the access point. Deploy energy storage and use the discharge of energy storage to reduce the maximum load rate of the substation and reduce the line power. Combining the deployment modes of the first and second operating scenarios, select the minimum power that meets the substation load rate and low voltage management as the energy storage power, and charge and discharge at a rate of 0.5C; configure the energy storage power and capacity through equations (12) and (13); (12); (13); The fourth type of operation scenario: There is no heavy overload in the substation, but there is short-term reverse transmission and node To Node The user has high voltage (voltage value greater than 1.07U), at the node Deploy energy storage, Representation Node To Node A node between the two is selected, and the multi-scenario deployment mode is integrated to select the minimum power that meets the reverse load rate and high voltage management of the substation as the energy storage power, and charge and discharge at a rate of 0.5C; the energy storage power and capacity are configured through equations (14), (15), (16) and (17); (14); (15); (16); (17).

[0037] A system for selecting and sizing energy storage sites considering the demand for power station management, comprising:

[0038] The division module is used to define the distributed energy storage planning area for the lines that have management needs in the distribution network, and determine the number of substations to be managed within the planning scope by the power supply company or energy storage planning unit.

[0039] The acquisition module is used to collect basic data (voltage, capacity, load rate and user-side voltage, etc.) of all the substations to be managed in the distributed energy storage planning area.

[0040] The indicator definition calculation module is used to define the governance demand index of the substation in the distributed energy storage planning area based on the basic data of the substation to be governed, and calculate the comprehensive index based on the governance demand index.

[0041] The selection module is used to calculate the comprehensive index values ​​of governance demand of all the to-be-governed substations in the distributed energy storage planning area, and sort them from large to small, giving priority to the to-be-governed substations with large comprehensive index values ​​of governance demand for governance.

[0042] The site selection and capacity determination module is used to set multiple operating scenarios in the selected substation area, and set different locations, powers and capacities of distributed energy storage access according to different operating scenarios.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for selecting and sizing energy storage sites considering the demand for regional management, characterized in that: The steps include: Step S1: Delineate the distributed energy storage planning area for the distribution lines that have governance requirements, and determine the number of distribution areas to be governed within the planning scope; Step S2: Collect basic data of all the areas to be managed in the distributed energy storage planning area in step S1; Step S3: defining the governance demand index of the substation in the distributed energy storage planning area based on the basic data of the substation to be governed, and calculating the comprehensive index according to the governance demand index; Step S4: Calculate the comprehensive index values ​​of governance requirements of all the to-be-governed substations in the distributed energy storage planning area, and sort them from large to small, giving priority to the to-be-governed substations with large comprehensive index values ​​of governance requirements for governance; Step S5: setting multiple operating scenarios in the selected substation, and setting different locations, powers and capacities of distributed energy storage access according to different operating scenarios; Among them, the governance demand index includes the heavy overload assessment index of the substation area , Substation reverse power transmission evaluation indicators , Low voltage assessment indicators for users in the substation area High voltage assessment indicators for users in the area ; Among them, the lines in the selected area include the following: node, node, node, Node and node; Setting multiple operating scenarios includes: The first type of operation scenario: there is a short-term heavy overload in the substation, that is, the load rate is greater than the preset ratio and the voltage on the user side is normal; The second operating scenario: the substation has no heavy overload and the node To Node The voltage is normal, the node To Node The user has a short-term low voltage. Representation Node To Node A node in between; The third type of operation scenario: at the same time, nodes To Node The voltage is normal and the node To Node Short-term low voltage occurs to users; The fourth type of operation scenario: There is no heavy overload in the substation, but there is short-term reverse transmission and node To Node The user has high voltage, that is, the voltage value is greater than the preset value; Representation Node To Node A node in between.

2. The method for selecting a location and determining the capacity of energy storage considering the demand for substation management according to claim 1 is characterized in that: Heavy overload assessment index of the substation , expressed as: （1）； In the formula, represents the exponential function; represents the base of natural logarithms; Indicates the maximum forward load rate of the station area; Indicates the transformer capacity of the substation; Evaluation index of reverse power transmission in the substation area , expressed as: （2）； In the formula, Indicates the maximum reverse load rate of the area; Low voltage assessment indicators for users in the substation area , expressed as: （3）； In the formula, Indicates the rated voltage of users in the substation area; Indicates the lowest voltage for users in the area; High voltage assessment indicators for users in the substation area , expressed as: （4）； In the formula, Indicates the highest voltage of users in the substation area.

3. The method for selecting a location and determining the capacity of energy storage considering the demand for substation management according to claim 2 is characterized in that: Comprehensive index of the need for governance in the Taiwan area It is expressed as: （5）。 4. The method for selecting a location and determining the capacity of energy storage considering the demand for substation management according to claim 3 is characterized by: When running the scenario for the first category, Energy storage is deployed at the node, and the energy storage power and capacity are configured according to equations (6) and (7); （6）； （7）； In the formula, Indicates the maximum charging and discharging power of energy storage; Indicates the capacity of the energy storage battery.

5. The method for selecting a location and determining the capacity of energy storage considering the demand for substation management according to claim 4 is characterized in that: When running the scenario for the second category, at the node Deploy energy storage and configure the energy storage power and capacity according to equations (8), (9), (10) and (11); （8）； （9）； （10）； （11）。 6. The method for selecting a location and determining the capacity of energy storage considering the demand for substation management according to claim 5 is characterized by: When running the scenario for the third category, at the node Deploy energy storage and configure the energy storage power and capacity through equations (12) and (13); （12）； （13）。 7. The method for selecting a location and determining the capacity of energy storage considering the demand for substation management according to claim 6 is characterized by: When running the scenario for the fourth category, at the node Deploy energy storage and configure the energy storage power and capacity through equations (14), (15), (16) and (17); （14）； （15）； （16）； （17）。 8. The method for selecting a location and determining the capacity of energy storage considering the demand for substation management according to claim 2 is characterized by: When the maximum reverse load rate of the area is less than 0, the current value is taken; when the maximum reverse load rate of the area is greater than 0, the value is 0.

9. A system for selecting and determining the location and capacity of energy storage considering the demand for substation management, characterized in that: include: The division module is used to define the distributed energy storage planning area for the substations under the line where there is a need for management in the distribution network, and determine the number of substations to be managed within the planning scope; The acquisition module is used to collect basic data of all the substations to be managed in the distributed energy storage planning area; An indicator definition calculation module is used to define the governance demand index of the substation in the distributed energy storage planning area based on the basic data of the substation to be governed, and calculate the comprehensive index according to the governance demand index; The selection module is used to calculate the comprehensive index values ​​of governance demand of all the to-be-governed substations in the distributed energy storage planning area, and sort them from large to small, giving priority to the to-be-governed substations with large comprehensive index values ​​of governance demand for governance; The site selection and capacity determination module is used to set multiple operating scenarios in the selected substation area, and set different locations, powers and capacities of distributed energy storage access according to different operating scenarios.

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