A combination method of multiple power quality regulation resources based on capability vector projection and clustering

Abstract

The present invention provides a method for combining multiple power quality regulation resources based on capability vector projection and clustering, which belongs to the field of energy, and includes: calculating the power quality regulation resource vector projection regulation capability; calculating the distance index between the power quality regulation resource and the power quality problem point; calculating the power quality regulation resource governance capability density function according to the power quality regulation resource vector projection regulation capability and the distance index; clustering and combining the power quality regulation resources according to the specific numerical value of the power quality regulation resource governance capability density function. The present invention provides an available resource set for regulation resource optimization and multi-level collaborative operation.

Description

Technical Field

[0001] The present invention belongs to the field of energy, and in particular relates to a method for combining multiple power quality regulation resources based on capability vector projection and clustering. Background Art

[0002] In the process of rapid urbanization and industrial transformation, a large proportion of renewable energy, flexible loads, etc. are connected to the power grid. The access of a large number of renewable energy sources has led to frequent power quality problems in the power grid. Renewable energy connected to the grid using power electronic equipment can also participate in the power quality problem management of the system as a power quality regulation resource while generating power quality problems. However, due to the complexity of the types of power quality problems, the generation mechanism is different from the characteristics of the required regulation resources, and the line topology between the regulation resources and the location where the power quality problems occur is complex. In order to better play the characteristics of different power quality regulation resources and use power quality regulation resources in a targeted and efficient manner, it is necessary to evaluate the specific governance capabilities of different power quality regulation resources for different types of power quality problems in different locations. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for combining multiple power quality regulation resources based on capability vector projection and clustering. Aiming at the characteristics of multiple stakeholders, wide distribution of multiple types of regulation resources, and different endowment characteristics such as renewable energy, flexible multi-feeder control equipment, new flexible loads, and energy storage, the regulation capabilities of different resources are vector-projected and decomposed into different parameters such as active / reactive power, which is convenient for direct evaluation and calculation of the capabilities; and the governance capability density function is converted and obtained in combination with the electrical distance between each resource and the power quality problem point; further, through cluster analysis, multiple types of regulation resources with governance capability density values ​​within a certain range are quickly combined to provide an available resource set for regulation resource optimization and multi-level collaborative operation.

[0004] In order to achieve the above object, the present invention adopts the following technical solution:

[0005] The method for combining multiple power quality regulation resources based on capability vector projection and clustering includes the following steps:

[0006] Step 1: Calculate the projection regulation capability of the power quality regulation resource vector;

[0007] Step 2: Calculate the distance index between the power quality regulation resource and the power quality problem point;

[0008] Step 3: Calculate the power quality regulation resource governance capacity density function according to the power quality regulation resource vector projection regulation capacity of step 1 and the distance index of step 2;

[0009] Step 4: Cluster and combine power quality regulation resources according to the specific numerical value of the energy quality regulation resource management capacity density function in step 3.

[0010] Beneficial effects:

[0011] When the present invention is used, when a power quality problem occurs at a node in the line, a comprehensive evaluation is performed based on the node location and the electrical distance between the node and the surrounding power quality regulation resource monomers and the vector projection regulation capacity of each power quality regulation resource, and the power quality regulation resource governance capacity density function is obtained by combining the distance index between the power quality regulation resource and the power quality problem point. Further transformation can obtain the membership function and normalized index, providing a fast resource combination method for regulation resource optimization and multi-level collaborative operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a flow chart of the method for combining multiple power quality regulation resources based on capability vector projection and clustering of the present invention;

[0013] Figure 2 Schematic diagram of power quality regulation resource vector projection regulation capability. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0015] like Figure 1 As shown, the power quality multi-regulation resource combination method based on capability vector projection and clustering of the present invention includes the following steps:

[0016] Step 1: Calculate the projection regulation capability of the power quality regulation resource vector, including:

[0017] The rated capacity of the power quality regulation resource is S, the real-time active power is P0, the real-time reactive power is Q0, and the maximum active power is P max , the maximum reactive power is Q max , the rated power factor angle is .

[0018] like Figure 2 As shown, the rated capacity of the power quality regulation resource is S, the real-time active power is P0, the real-time reactive power is Q0, and the maximum active power is P max , the maximum reactive power is Q max, the rated power factor angle is ,u P Active power vector projection regulation capability of power quality regulation resources, u Q is the reactive power vector projection regulation capacity of the power quality regulation resource, and the shadow range is the joint surplus capacity u of the active power and reactive power vector projection of the power quality regulation resource P,Q , the specific calculation formula is as follows:

[0019] (1)

[0020] Among them, x represents the unknown variable and is used for integration operation.

[0021] Active power vector projection regulation capability u of power quality regulation resources P for:

[0022] (2)

[0023] Reactive vector projection regulation capability of power quality regulation resources Q for:

[0024] (3)

[0025] In summary, the power quality regulation resource vector projection regulation capability u1 can be obtained as:

[0026] (4)

[0027] Among them, max means to find the maximum value, and min means to find the minimum value.

[0028] Step 2: Calculate the distance index between the power quality regulation resource and the power quality problem point, including:

[0029] According to the different electrical connection paths, the electrical distances between the power quality problem points and the power quality regulation resources are n is the number of electrical connection paths between the power quality regulation resource and the power quality problem point.

[0030] According to the different electrical connection paths, the line impedance between the power quality problem point and the power quality regulation resource is . resistance of different connection paths for power quality regulation resources; Inductance of different connection paths for power quality regulation resources; Capacitors for different connection paths of power quality regulation resources; is an imaginary unit; is the angular frequency of the system.

[0031] The distance index is u2, and the specific calculation formula is as follows:

[0032] (5)

[0033] in, They are the fitting ratio of electrical distance and the fitting ratio of line impedance respectively. The electrical distance between the power quality problem point and the power quality regulation resource; resistance of different connection paths for power quality regulation resources; Inductance of different connection paths for power quality regulation resources; Capacitors for different connection paths of power quality regulation resources; is an imaginary unit; is the angular frequency of the system.

[0034] Step 3: Calculate the power quality regulation resource management capacity density function, including:

[0035] The power quality regulation resource management capacity density function is u0, and the specific calculation formula is as follows:

[0036] (6)

[0037] The power quality regulation resource management capability density function can evaluate the regulation capability of a certain power quality regulation resource for power quality problems occurring at a specific location. The larger the value, the greater the regulation capability of this power quality regulation resource for power quality problems occurring at this specific location.

[0038] Step 4: Clustering and combining power quality regulation resources according to the specific numerical value of the power quality regulation resource governance capacity density function in step 3, including:

[0039] After calculating the specific governance capacity density value according to the power quality regulation resource governance capacity density function u0, clustering can be further performed according to the size of the specific governance capacity density value, and the membership function segmentation values ​​n1 and n2 are set to perform membership function transformation on the governance capacity density values ​​of multiple power quality regulation resources. The specific formula is as follows:

[0040] (7)

[0041] The above membership function is used to normalize the power quality regulation resource governance capacity density value and convert it into a value within the range of Normalized evaluation index between .

[0042] Setting the clustering decision threshold of the governance capacity density value of power quality regulation resources When the normalized evaluation index When it is 0, the power quality regulation resource has poor regulation capability for the power quality problem occurring at this specific location; exist When the normalized evaluation index is Greater than When , this power quality regulation resource has a better regulation capability for the power quality problem occurring at this specific location. Through cluster analysis, the normalized evaluation index of the governance capacity density value is Greater than It can quickly combine multiple types of regulation resources to provide an available resource set for regulation resource optimization and multi-level collaborative operation.

Claims

1. A power quality multi-regulation resource combination method based on capability vector projection and clustering, characterized in that: The steps include: Step 1: Calculate the projection regulation capability of the power quality regulation resource vector, including: The joint surplus capacity u of the active power and reactive power vector projection of the power quality regulation resources P,Q The calculation formula is as follows: （1） Among them, x represents the unknown variable, which is used for integration operation; S is the rated capacity of the power quality regulation resource, P0 is the real-time active power, Q0 is the real-time reactive power, P max is the maximum active power, Q max is the maximum reactive power, is the rated power factor angle; Step 2: Calculate the distance index between the power quality regulation resource and the power quality problem point, including: According to the different electrical connection paths, the electrical distances between the power quality problem points and the power quality regulation resources are , n is the number of electrical connection paths between the power quality regulation resource and the power quality problem point; According to the different electrical connection paths, the line impedance between the power quality problem point and the power quality regulation resource is ; in, resistance of different connection paths for power quality regulation resources; Inductance of different connection paths for power quality regulation resources; Capacitors for different connection paths of power quality regulation resources; is an imaginary unit; is the angular frequency of the system; The distance index u2 is calculated as follows: （5） in, They are the fitting ratio of electrical distance and the fitting ratio of line impedance respectively; The electrical distance between the power quality problem point and the power quality regulation resource; Step 3: Calculate the power quality regulation resource governance capacity density function based on the power quality regulation resource vector projection regulation capacity of step 1 and the distance index of step 2. The power quality regulation resource governance capacity density function is u0. The specific calculation formula is as follows: （6）； Step 4: Cluster and combine power quality regulation resources according to the specific numerical value of the energy quality regulation resource management capacity density function in step 3.

2. The method for combining multiple power quality regulation resources based on capability vector projection and clustering according to claim 1 is characterized in that: The step 1 also includes: The joint surplus capacity u of active power and reactive power vector projection of power quality regulation resources P,Q and the active vector projection regulation capability u of power quality regulation resources P , reactive power vector projection regulation capability of power quality regulation resources u Q Calculate the power quality regulation resource vector projection regulation capability u1, the formula is: （4） Among them, the active vector projection regulation capability u of the power quality regulation resource P for: （2） Reactive vector projection regulation capability of power quality regulation resources Q for: （3） Among them, max means to find the maximum value, and min means to find the minimum value.

3. The method for combining multiple power quality regulation resources based on capability vector projection and clustering according to claim 1, characterized in that: The step 4 comprises: After calculating the specific governance capacity density value according to the power quality regulation resource governance capacity density function u0, further clustering is performed according to the size of the specific governance capacity density value, and the membership function segment values ​​n1 and n2 are set to perform membership function transformation on the governance capacity density values ​​of multiple power quality regulation resources.

4. The method for combining multiple power quality regulation resources based on capability vector projection and clustering according to claim 3 is characterized in that: The specific formula for transforming the membership function of the governance capacity density values ​​of multiple power quality regulation resources is as follows: （7） The above membership function normalizes the power quality regulation resource governance capacity density value and transforms it into a value in the range Normalized evaluation index between .

5. The method for combining multiple power quality regulation resources based on capability vector projection and clustering according to claim 4 is characterized in that: Setting the clustering decision threshold of the governance capacity density value of power quality regulation resources ; When the normalized evaluation index Greater than When , this power quality regulation resource has the best regulation capability for the power quality problem occurring at this specific location; through cluster analysis, the normalized evaluation index of the governance capacity density value is Greater than It can quickly combine multiple types of regulation resources to provide an available resource set for regulation resource optimization and multi-level collaborative operation.

Images