Transient power angle stability influence degree calculation method and system based on active balance division point, storage medium and equipment

Abstract

The invention discloses a transient power angle stability influence degree calculation method and system based on active balance points, a storage medium and equipment. The method specifically comprises the steps that the power grid active balance points corresponding to all simulation time points after disturbance are determined; dividing network nodes into two node sets by taking an active balance division point as a boundary, and determining node set attributes according to a rotor inertia center angle of a synchronous generator in the node sets; according to a relative rotor inertia center angle between the synchronous generators in the node set after disturbance, determining a time period of transient power angle stability influence degree calculation; and calculating the influence degree of the element on the transient power angle stability of the power grid after disturbance in the preset power grid operation state according to the active power and node set attributes of the power grid injected by the element at each simulation time point through each connected node and the steady-state active power of the element injected into the power grid through each connected node in the influence degree calculation time period. According to the method, the influence degree of the disturbed element on the transient power angle stability of the power system can be calculated efficiently and accurately, and an optimization direction is provided for a transient power angle stability control decision.

Description

Technical Field

[0001] The present invention relates to power system stability analysis, and in particular to a method, system, storage medium and device for calculating transient power angle stability influence based on active power balance points. Background Art

[0002] Calculating the impact of power system components on transient power angle stability is the basis for optimizing transient power angle stability control decisions. Existing technologies for impact calculation include two types: one uses a parameter perturbation method to determine the impact of parameters on transient power angle stability based on the difference in the time-domain simulation curves of the synchronous generator power angle before and after the parameter change. The other method uses the equivalent power angle curve corresponding to the dominant grouping mode of the synchronous generator identified by the extended equal area method to determine the impact calculation time. The proportional relationship between the kinetic energy of the synchronous generators at that moment determines the impact of the synchronous generator on transient power angle stability. The impact of the non-synchronous active components on transient power angle stability is determined based on the increment of energy injected into the grid by each grid-connected point of the non-synchronous active components before that moment in the transient process, combined with oscillation center identification.

[0003] After a power system disturbance, the active power injected into the grid by each grid-connected component changes under the constraints of the electrical network equations. The power angle of the synchronous generator also changes due to the imbalance between the electromagnetic and mechanical power injected into the grid. Transient power angle stability is closely related to the active power injected into the grid by each component during the transient process. Therefore, determining the relationship between the active power injected by each component and the active power of the synchronous generator at each point in the transient process is key to determining the component's impact on transient power angle stability. The first type of technique requires two time-domain simulations with a preset disturbance to determine the impact of a single component on transient power angle stability, resulting in low computational efficiency. Furthermore, the technique fails to determine the impact of a component on transient power angle stability from the perspective of active power changes during the transient process, resulting in insufficient accuracy. The second type of technique, while proposing a method that can determine the impact of a component on transient power angle stability with only a single simulation, fails to distinguish between the differences in the relationship between the active power injected by the component and the active power of the synchronous generator at each simulation point during the transient process. This makes it difficult to accurately assess the impact of a component on transient power angle stability, thus affecting the accuracy of the optimization decision.

[0004] Therefore, a technology is needed that can efficiently calculate the impact of components on transient power angle stability based on the active power injected by the components at each time point in the transient process, so as to improve the accuracy of transient power angle stability emergency control optimization decisions in the event of power system disturbances and transient power angle stability preventive control decisions for preset disturbances. Summary of the Invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a method, system, storage medium and device for calculating the influence of transient power angle stability based on active power balance points, which can calculate the influence of components after disturbance on transient power angle stability with high efficiency and high accuracy.

[0006] Technical solution: To achieve the above-mentioned purpose, the method for calculating the transient power angle stability influence based on the active power balance point of the present invention includes the following steps:

[0007] Step 1: Perform a time domain simulation of a preset disturbance for a preset grid operation state, and determine the specific location of the grid active power balance points corresponding to each simulation time point after the preset disturbance;

[0008] Step 2: At each simulation time point, the nodes in the power grid network equation are divided into two node sets with the power grid active balance point as the boundary, and the two node sets corresponding to each simulation time point are obtained;

[0009] Step 3: For each simulation time point, by calculating the central angle of inertia of the synchronous generator rotor in the two node sets, the node set with the larger central angle of inertia of the rotor is defined as the leading node set, and the node set with the smaller central angle of inertia of the rotor is defined as the lagging node set, and the properties of the two node sets corresponding to each simulation time point are obtained;

[0010] Step 4: Determine the time period for calculating the transient power angle stability impact based on the relative rotor inertia center angle between the synchronous generators in the leading node set and the lagging node set corresponding to each simulation time point;

[0011] Step 5: Based on the active power and node set attributes injected by the component into the grid through each connected node at each simulation time point during the period of transient power angle stability impact calculation, and the steady-state active power injected by the component into the grid through each connected node under the preset grid operation state, calculate the impact of the component on the transient power angle stability of the grid after the preset disturbance under the preset grid operation state.

[0012] Among them, the time domain simulation of the preset disturbance is performed for the preset power grid operation state in step 1, and the specific position of the power grid active balance point corresponding to each simulation time point after the preset disturbance is determined. The specific process is as follows:

[0013] For each simulation time point, the following processing is performed respectively:

[0014] According to the network equation and the potential phase angle of the synchronous generator at the corresponding simulation time point, the dominant index of each active power point of the power grid at the simulation time point is calculated, and the active power point corresponding to the maximum value of the dominant index is defined as the dominant active power point at the simulation time point. The two synchronous generator groups corresponding to the dominant index of the dominant active power point are regarded as the two dominant groups of synchronous generators at the simulation time point.

[0015] For the power grid at the simulation time point, a Y-Δ network equivalent transformation is performed on the network adjacent to the dominant active power distribution point. After the transformation, the power grid consists of two subnets connected by a T-type network consisting of three equivalent nodes, two equivalent branches, and one equivalent load branch. The two dominant groups of synchronous generators at the simulation time point are located in different subnets, the active power flowing from the two equivalent branches into the equivalent load branch is equal, and the electrical distance between the node connected to the equivalent load branch and the dominant active power distribution point is minimized.

[0016] The equivalent nodes connected to the equivalent load branches are used as active power balance points.

[0017] Among them, the dominant index of each active point of the power grid at the simulation time point is calculated based on the network equation corresponding to the simulation time point and the potential phase angle of the synchronous generator. The specific formula is:

[0018]

[0019] Where, L i is the complete set of active points at the ith simulation time point, γ l.i is the i-th simulation time point L i The dominant indicator of the active point l, G i is the set of synchronous generators at the ith simulation time point, G1 and G2 are the two synchronous generator groups corresponding to the dominant index of active power distribution point l at the ith simulation time point, are the sensitivities of the active power of synchronous generator g1 and synchronous generator g2 to the active power flowing out of active distribution point l at the i-th simulation time point, are the internal potential phase angles of synchronous generator g1 and synchronous generator g2 at the i-th simulation time point respectively.

[0020] In step 2, for each simulation time point, the nodes in the power grid network equation are divided into two node sets with the power grid active balance point as the boundary, and the two node sets corresponding to each simulation time point are obtained, specifically:

[0021] According to the Y-Δ network equivalent transformation process backtracking, the specific positions of the active balance points on the components in the network before the transformation are determined. The specific positions of the active balance points on the components are connected as the dividing line of the power grid. The nodes in the power grid network equation are divided into two node sets with the dividing line as the boundary, and the two node sets corresponding to each simulation time point are obtained.

[0022] The specific calculation formula for the central angle of inertia of the synchronous generator rotor in the two nodes in step 3 is:

[0023]

[0024]

[0025] Where Ai 、B i are the two node sets corresponding to the i-th simulation time point, A i 、B i The rotor inertia center angle of the synchronous generator at the i-th simulation time point, M i.a , δ i.a A i The moment of inertia and internal potential phase angle of synchronous generator a at the i-th simulation time point, M i.b , δ i.b B i The moment of inertia and internal potential phase angle of synchronous generator b at the i-th simulation time point;

[0026] The node set attribute is referred to as "leading" or "lagging".

[0027] Among them, the step 4 determines the time period for calculating the transient power angle stability influence according to the relative rotor inertia center angle between the synchronous generators in the leading node set and the lagging node set corresponding to each simulation time point. The specific process is as follows:

[0028] If the A corresponding to the i-th simulation time point i If the leading node set is the set of nodes, then the relative rotor inertia center angle δ between the synchronous generators in the leading node set and the lagging node set corresponding to the i-th simulation time point is i Set to Otherwise, the relative rotor inertia center angle δ between the synchronous generators in the leading node set and the lagging node set corresponding to the i-th simulation time point is i Set to in A i 、B i The central angle of rotor inertia of the synchronous generator at the i-th simulation time point;

[0029] Starting from the second simulation time point, the transient power angle stability impact calculation period is determined in the manner of increasing the simulation time points in sequence. Specifically, if δ i <δ s And δ i-1 <δ i , δ i >δ i+1 , then the period between the first simulation time point and the i-th simulation time point is used as the period for calculating the transient power angle stability influence. If δ i ≥δ s , then the period between the first simulation time point and the i-th simulation time point is used as the period for calculating the transient power angle stability influence, where δ s To set parameters;

[0030] In the process of determining the transient power angle stability influence calculation period, if the transient power angle stability influence calculation period has been determined, the determination of the transient power angle stability influence calculation period is terminated.

[0031] The specific formula for calculating the influence of the device on the transient power angle stability of the power grid after the preset disturbance under the preset power grid operating state in step 5 is:

[0032] d tas =E d / max(|E d |,d∈D),

[0033]

[0034] Where D is the grid component set, C d The set of nodes injected into the grid for element d, d tas is the influence of the component d on the transient power angle stability of the grid after the preset disturbance under the preset grid operation state; s i.j Is positive or negative, if the ith simulation time point C d If the middle node j belongs to the preceding node set, the negative sign is taken, otherwise, s i.j Take the positive sign; I is the last simulation time point corresponding to the transient power angle stability influence calculation period, P i.j is the i-th simulation time point C d The active power injected into the grid at node j, P 0.j C d The steady-state active power injected into the grid at node j, t i is the transient process moment corresponding to the i-th simulation time point;

[0035] The components mentioned above refer to primary equipment components in the power grid except synchronous generators.

[0036] In step 5, for the situation where the power grid after the preset disturbance in the preset power grid operation state is composed of two or more asynchronous operation sub-grids, each asynchronous operation sub-grid is processed independently.

[0037] The transient power angle stability influence calculation system based on active power balance points includes:

[0038] Active power balance point determination module: performs time domain simulation of preset disturbances based on preset grid operation states, and determines the specific locations of active power balance points corresponding to each simulation time point after the preset disturbances;

[0039] Node set generation module: For each simulation time point, the nodes in the power grid network equation are divided into two node sets with the power grid active balance point as the boundary, and the two node sets corresponding to each simulation time point are obtained;

[0040] Node set attribute determination module: For each simulation time point, by calculating the central angle of inertia of the synchronous generator rotor in two node sets, the node set with the larger central angle of inertia is defined as the leading node set, and the node set with the smaller central angle of inertia is defined as the lagging node set, and the attributes of the two node sets corresponding to each simulation time point are obtained;

[0041] Impact calculation period determination module: determines the period for transient power angle stability impact calculation based on the relative rotor inertia center angle between the synchronous generators in the leading node set and the lagging node set corresponding to each simulation time point;

[0042] Equipment impact calculation module: Based on the active power and node set attributes of the components injected into the grid through the connected nodes at each simulation time point during the period of transient power angle stability impact calculation, as well as the steady-state active power injected into the grid by the components through the connected nodes under the preset grid operation state, calculate the impact of the components on the transient power angle stability of the grid after the preset disturbance under the preset grid operation state.

[0043] A computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the above-mentioned methods for calculating the transient power angle stability influence based on the active power balance point.

[0044] The computing device comprises:

[0045] One or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for executing any of the above-mentioned methods for calculating the transient power angle stability influence based on the active power balance point.

[0046] Beneficial effects: The present invention has the following advantages: 1. The present invention only needs to determine the specific location of the active power balance points of the power grid corresponding to each simulation time point after the preset disturbance through a single time-domain simulation, and then calculate the influence of all primary components in the power grid except the synchronous generator on the transient power angle stability, thereby improving the calculation efficiency of the influence of the components on the transient power angle stability;

[0047] 2. The present invention determines the position of the active balance point in the power system by calculating the dominant index of the active power distribution point at each time point in the transient process, and dynamically groups the active self-balancing node set of each node in the power system to determine the relationship between the active power injected by the component and the active power of the synchronous generator at different simulation time points in the transient process, accurately reflecting the impact of the component on the active power of the synchronous generator at each time point, and improving the accuracy of calculating the impact of the component on the transient power angle stability

[0048] 3. The influence calculation method proposed in the present invention can not only be used to guide the optimization decision of transient power angle stability emergency control after the actual disturbance occurs, but also can be used to guide the optimization decision of transient power angle stability preventive control for preset disturbances. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of the process of the present invention;

[0050] Figure 2 Schematic diagram of the Y-Δ network equivalent transformation process for the network adjacent to the dominant active distribution point. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is described in detail below with reference to the embodiments and drawings.

[0052] An active power balance point is a point where the injected active power on both sides is equal. If the power system is divided into two subsystems with the active power balance point as the boundary, and the ground branch of the active power balance point is evenly divided into the two subsystems, then the two subsystems each constitute a set of components with self-balancing active power. The change in active power of a component within a subsystem is only related to the active power of other components within that subsystem and is unrelated to the active power of components in the other subsystem. Therefore, based on the active power balance point, it is possible to distinguish the nature of the impact of the active power of non-synchronous generator components on the electromagnetic power of synchronous generator groups in different subsystems. Based on the change in the active power of non-synchronous generator components, the degree of their influence on transient power angle stability (the relative motion between two synchronous generator groups) can be assessed.

[0053] like Figure 1 As shown, the calculation method of the transient power angle stability influence degree based on the active power balance point includes the following steps:

[0054] Step 1: Perform a time domain simulation of a preset disturbance for a preset power grid operation state, and determine the specific positions of the power grid active power balance points corresponding to each simulation time point after the preset disturbance.

[0055] For each simulation time point, the specific process is as follows:

[0056] 1-1) Calculating the dominant index of each active power distribution point in the power grid at the simulation time point based on the network equation and the internal potential phase angle of the synchronous generator at the simulation time point, defining the active power distribution point corresponding to the maximum value of the dominant index as the dominant active power distribution point at the simulation time point, and defining the two synchronous generator groups corresponding to the dominant index of the dominant active distribution point as the two dominant synchronous generator groups at the simulation time point;

[0057] 1-2) For the power grid at the simulation time point, a Y-Δ network equivalent transformation is performed on the network adjacent to the dominant active power distribution point, so that the transformed power grid consists of two subnets connected by a T-type network consisting of three equivalent nodes, two equivalent branches and one equivalent load branch. In addition, the two dominant groups of synchronous generators at the simulation time point are respectively in different subnets, the active power flowing from the two equivalent branches into the equivalent load branch is equal, and the electrical distance between the node connected to the equivalent load branch and the dominant active power distribution point is the shortest, as shown in the following example. Figure 2 shown.

[0058] 1-3) The nodes connected to the equivalent load branches are used as active power balance points.

[0059] Among them, the dominant index of each active point in the power grid at the time of simulation is calculated. The specific formula is:

[0060]

[0061] Where, L i is the complete set of active points at the ith simulation time point, γ l.i is the i-th simulation time point L i The dominant indicator of the active point l, G i is the complete set of synchronous generators at the ith simulation time point, G1 and G2 are the two synchronous generator groups corresponding to the dominant index of active power distribution point l at the ith simulation time point, are the sensitivities of the active power of synchronous generator g1 and synchronous generator g2 to the active power flowing out of active distribution point l at the i-th simulation time point, are the internal potential phase angles of synchronous generator g1 and synchronous generator g2 at the i-th simulation time point respectively.

[0062] Step 2: For each simulation time point, the nodes in the power grid network equation are divided into two node sets with the power grid active balance point as the boundary, and two node sets corresponding to each simulation time point are obtained.

[0063] The specific process is:

[0064] 2-1) Based on the Y-Δ network equivalent transformation process, the specific location of the active power balance point on the network components before the transformation is determined;

[0065] 2-2) Connect the active power balance points at specific locations on the components as the dividing lines of the power grid;

[0066] 2-3) Divide the nodes in the power grid network equation into two node sets using the dividing line as the boundary, and obtain two node sets corresponding to each simulation time point.

[0067] Step 3: For each simulation time point, by calculating the central angle of inertia of the synchronous generator rotor in the two node sets, the node set with the larger central angle of inertia of the rotor is defined as the leading node set, and the node set with the smaller central angle of inertia of the rotor is defined as the lagging node set, and the properties of the two node sets corresponding to each simulation time point are obtained.

[0068] The specific calculation formula for the central angle of the rotor inertia of the synchronous generator with two nodes is:

[0069]

[0070]

[0071] Where A i 、B i are the two node sets corresponding to the i-th simulation time point, A i 、B i The rotor inertia center angle of the synchronous generator at the i-th simulation time point, M i.a , δ i.a A i The moment of inertia and internal potential phase angle of synchronous generator a at the i-th simulation time point, M i.b , δ i.b B i The moment of inertia and internal potential phase angle of synchronous generator b at the i-th simulation time point;

[0072] The node set attribute is referred to as "leading" or "lagging".

[0073] Step 4: Determine the time period for calculating the transient power angle stability influence according to the relative rotor inertia center angle between the synchronous generators in the leading node set and the lagging node set corresponding to each simulation time point.

[0074] The specific process is:

[0075] 4-1) If the A corresponding to the i-th simulation time point i If the leading node set is the set of nodes, then the relative rotor inertia center angle δ between the synchronous generators in the leading node set and the lagging node set corresponding to the i-th simulation time point is i Set to Otherwise, the relative rotor inertia center angle δ between the synchronous generators in the leading node set and the lagging node set corresponding to the i-th simulation time point is i Set to

[0076] 4-2) Starting from the second simulation time point, the transient power angle stability impact calculation period is determined in the manner of increasing the simulation time points. Specifically: if δ i <δ s And δi-1 <δ i , δ i >δ i+1 , then the period between the first simulation time point and the i-th simulation time point is used as the period for calculating the transient power angle stability influence. If δ i ≥δ s , then the period between the first simulation time point and the i-th simulation time point is used as the period for calculating the transient power angle stability influence, where δ s To set the parameters, it is usually set to 180°;

[0077] In the process of determining the transient power angle stability influence calculation period, if the transient power angle stability influence calculation period has been determined, the determination of the transient power angle stability influence calculation period is terminated.

[0078] Step 5: Calculate the influence of the component on the transient power angle stability of the grid after the preset disturbance under the preset grid operation state based on the active power injected by the component through each connected node and the node set attributes at each simulation time point during the period of transient power angle stability influence calculation, as well as the steady-state active power injected by the component through each connected node under the preset grid operation state.

[0079] The specific formula is;

[0080] d tas =E d / max(|E d |,d∈D),

[0081]

[0082] Where D is the grid component set, C d The set of nodes injected into the grid for element d, d tas is the influence of component d on the transient power angle stability of the grid after the preset disturbance under the preset grid operation state, s i.j Is positive or negative, if the ith simulation time point C d If the middle node j belongs to the preceding node set, the negative sign is taken, otherwise, s i.j Take the positive sign, I is the last simulation time point corresponding to the transient power angle stability influence calculation period, P i.j is the i-th simulation time point C d The active power injected into the grid at node j, P 0.j C d The steady-state active power injected into the grid at node j, t i is the transient process moment corresponding to the i-th simulation time point;

[0083] The components mentioned above refer to primary equipment components in the power grid except synchronous generators.

[0084] In view of the situation that the power grid after the preset disturbance in the preset power grid operation state is composed of two or more asynchronous operation sub-grids, each asynchronous operation sub-grid is processed independently.

[0085] If a component is injected into multiple asynchronous operation sub-grids, the impact of the component on the transient power angle stability includes its impact on the transient power angle stability of each asynchronous operation sub-grid.

[0086] Through the above method, if the influence of the device on the transient power angle stability of the power grid is greater than 0, it means that the component is beneficial to the transient power angle stability, and the larger the value, the more beneficial it is. If the influence of the component on the transient power angle stability of the power grid is less than 0, it means that the component is not conducive to the transient power angle stability, and the smaller the value, the more unfavorable it is. If the influence of the component on the transient power angle stability of the power grid is equal to 0, it means that the component has no influence on the transient power angle stability of the power grid.

[0087] The above method realizes a quantitative evaluation of the impact of all primary equipment in the power grid except synchronous generators on transient power angle stability based on a time-domain simulation calculation, which provides a decision-making basis for the coordinated participation of large-scale multi-type components including new energy power generation units (stations), loads, energy storage power stations, DC systems, and even AC lines and transformers in transient power angle stability optimization control, thereby improving the efficiency of optimization decision-making.

[0088] The transient power angle stability impact calculation system based on active power balance points includes:

[0089] Active power balance point determination module: performs time domain simulation of preset disturbances based on preset grid operation states, and determines the specific locations of active power balance points corresponding to each simulation time point after the preset disturbances;

[0090] Node set generation module: For each simulation time point, the nodes in the power grid network equation are divided into two node sets with the power grid active balance point as the boundary, and the two node sets corresponding to each simulation time point are obtained;

[0091] Node set attribute determination module: For each simulation time point, by calculating the central angle of inertia of the synchronous generator rotor in two node sets, the node set with the larger central angle of inertia is defined as the leading node set, and the node set with the smaller central angle of inertia is defined as the lagging node set, and the attributes of the two node sets corresponding to each simulation time point are obtained;

[0092] Impact calculation period determination module: determines the period for transient power angle stability impact calculation based on the relative rotor inertia center angle between the synchronous generators in the leading node set and the lagging node set corresponding to each simulation time point;

[0093] Component influence calculation module: Based on the active power injected by the component through each connected node and the node set attributes at each simulation time point during the period of transient power angle stability influence calculation, as well as the steady-state active power injected by the component through each connected node under the preset grid operation state, the influence of the component on the transient power angle stability of the grid after the preset disturbance under the preset grid operation state is calculated.

[0094] A computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions, which, when executed by a computing device, enable the computing device to perform a method for calculating transient power angle stability influence based on active power balance points.

[0095] A computing device includes one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing a method for calculating the transient power angle stability influence based on an active power balance point.

Claims

1. A method for calculating the transient power angle stability impact based on active power balance points, characterized in that: The following steps are involved: Step 1: Perform a time domain simulation of a preset disturbance for a preset grid operation state, and determine the specific location of the grid active power balance points corresponding to each simulation time point after the preset disturbance; Step 2: At each simulation time point, the nodes in the power grid network equation are divided into two node sets with the power grid active balance point as the boundary, and the two node sets corresponding to each simulation time point are obtained; Step 3: For each simulation time point, by calculating the central angle of inertia of the synchronous generator rotor in the two node sets, the node set with the larger central angle of inertia of the rotor is defined as the leading node set, and the node set with the smaller central angle of inertia of the rotor is defined as the lagging node set, and the properties of the two node sets corresponding to each simulation time point are obtained; Step 4: Determine the time period for calculating the transient power angle stability impact based on the relative rotor inertia center angle between the synchronous generators in the leading node set and the lagging node set corresponding to each simulation time point; Step 5: Based on the active power and node set attributes injected by the component into the grid through each connected node at each simulation time point during the period of transient power angle stability impact calculation, and the steady-state active power injected by the component into the grid through each connected node under the preset grid operation state, calculate the impact of the component on the transient power angle stability of the grid after the preset disturbance under the preset grid operation state.

2. The method for calculating the transient power angle stability influence based on the active power balance point according to claim 1 is characterized in that: Step 1 is to perform a time domain simulation of a preset disturbance for a preset power grid operating state, and determine the specific location of the power grid active balance points corresponding to each simulation time point after the preset disturbance. The specific process is as follows: For each simulation time point, the following processing is performed respectively: According to the network equation and the potential phase angle of the synchronous generator at the corresponding simulation time point, the dominant index of each active power point of the power grid at the simulation time point is calculated, and the active power point corresponding to the maximum value of the dominant index is defined as the dominant active power point at the simulation time point. The two synchronous generator groups corresponding to the dominant index of the dominant active power point are regarded as the two dominant groups of synchronous generators at the simulation time point. For the power grid at the simulation time point, a Y-Δ network equivalent transformation is performed on the network adjacent to the dominant active power distribution point. After the transformation, the power grid consists of two subnets connected by a T-type network consisting of three equivalent nodes, two equivalent branches, and one equivalent load branch. The two dominant groups of synchronous generators at the simulation time point are located in different subnets, the active power flowing from the two equivalent branches into the equivalent load branch is equal, and the electrical distance between the node connected to the equivalent load branch and the dominant active power distribution point is minimized. The equivalent nodes connected to the equivalent load branches are used as active power balance points.

3. The method for calculating the transient power angle stability influence based on the active power balance point according to claim 2 is characterized in that: The dominant index of each active point in the power grid at the simulation time point is calculated based on the network equation corresponding to the simulation time point and the potential phase angle of the synchronous generator. The specific formula is: Where, L i is the complete set of active points at the ith simulation time point, γ l.i is the i-th simulation time point L i The dominant indicator of the active point l, G i is the complete set of synchronous generators at the ith simulation time point, G1 and G2 are the two synchronous generator groups corresponding to the dominant index of active power distribution point l at the ith simulation time point, are the sensitivities of the active power of synchronous generator g1 and synchronous generator g2 to the active power flowing out of active distribution point l at the i-th simulation time point, are the internal potential phase angles of synchronous generator g1 and synchronous generator g2 at the i-th simulation time point respectively.

4. The method for calculating the transient power angle stability influence based on active power balance points according to claim 1 or 2, characterized in that: In step 2, for each simulation time point, the nodes in the power grid network equation are divided into two node sets with the power grid active balance point as the boundary, and the two node sets corresponding to each simulation time point are obtained, specifically: According to the Y-Δ network equivalent transformation process backtracking, the specific positions of the active balance points on the components in the network before the transformation are determined. The specific positions of the active balance points on the components are connected as the dividing line of the power grid. The nodes in the power grid network equation are divided into two node sets with the dividing line as the boundary, and the two node sets corresponding to each simulation time point are obtained.

5. The method for calculating the transient power angle stability influence based on active power balance points according to claim 1 is characterized in that: The specific calculation formula for the central angle of inertia of the synchronous generator rotor in the two nodes in step 3 is: Where A i 、B i are the two node sets corresponding to the i-th simulation time point, A i 、B i The rotor inertia center angle of the synchronous generator at the i-th simulation time point, M i.a , δ i.a A i The moment of inertia and internal potential phase angle of synchronous generator a at the i-th simulation time point, M i.b , δ i.b B i The moment of inertia and internal potential phase angle of synchronous generator b at the i-th simulation time point; The node set attribute is referred to as "leading" or "lagging".

6. The method for calculating the transient power angle stability influence based on active power balance points according to claim 1, characterized in that: In step 4, the time period for calculating the transient power angle stability influence is determined based on the relative rotor inertia center angle between the synchronous generators in the leading node set and the lagging node set corresponding to each simulation time point. The specific process is as follows: If the A corresponding to the i-th simulation time point i If the leading node set is the set of nodes, then the relative rotor inertia center angle δ between the synchronous generators in the leading node set and the lagging node set corresponding to the i-th simulation time point is i Set to Otherwise, the relative rotor inertia center angle δ between the synchronous generators in the leading node set and the lagging node set corresponding to the i-th simulation time point is i Set to in A i 、B i The central angle of rotor inertia of the synchronous generator at the i-th simulation time point; Starting from the second simulation time point, the transient power angle stability impact calculation period is determined in the manner of increasing the simulation time points in sequence. Specifically, if δ i <δ s And δ i-1 <δ i , δ i >δ i+1 , then the period between the first simulation time point and the i-th simulation time point is used as the period for calculating the transient power angle stability influence. If δ i ≥δ s , then the period between the first simulation time point and the i-th simulation time point is used as the period for calculating the transient power angle stability influence, where δ s To set parameters; In the process of determining the transient power angle stability influence calculation period, if the transient power angle stability influence calculation period has been determined, the determination of the transient power angle stability influence calculation period is terminated.

7. The method for calculating the transient power angle stability influence based on active power balance points according to claim 1, characterized in that: The specific formula for calculating the influence of the device on the transient power angle stability of the power grid after the preset disturbance in the preset power grid operating state in step 5 is: d tas =E d / max(|E d |,d∈D), Where D is the grid component set, C d The set of nodes injected into the grid for element d, d tas is the influence of the component d on the transient power angle stability of the power grid after the preset disturbance under the preset power grid operation state; s i.j Is positive or negative, if the ith simulation time point C d If the node j belongs to the preceding node set, the negative sign is taken, otherwise, s i.j Take the positive sign; I is the last simulation time point corresponding to the transient power angle stability influence calculation period, P i.j is the i-th simulation time point C d The active power injected into the grid at node j, P 0.j C d The steady-state active power injected into the grid at node j, t i is the transient process moment corresponding to the i-th simulation time point; The components mentioned above refer to primary equipment components in the power grid except synchronous generators.

8. The method for calculating the transient power angle stability influence based on active power balance points according to claim 1 is characterized in that: In step 5, for the situation where the power grid after the preset disturbance in the preset power grid operation state is composed of two or more asynchronous operation sub-grids, each asynchronous operation sub-grid is processed independently.

9. The transient power angle stability impact calculation system based on active power balance points is characterized by: include, Active power balance point determination module: performs time domain simulation of preset disturbances based on preset grid operation states, and determines the specific locations of active power balance points corresponding to each simulation time point after the preset disturbances; Node set generation module: For each simulation time point, the nodes in the power grid network equation are divided into two node sets with the power grid active balance point as the boundary, and the two node sets corresponding to each simulation time point are obtained; Node set attribute determination module: For each simulation time point, by calculating the central angle of inertia of the synchronous generator rotor in two node sets, the node set with the larger central angle of inertia is defined as the leading node set, and the node set with the smaller central angle of inertia is defined as the lagging node set, and the attributes of the two node sets corresponding to each simulation time point are obtained; Impact calculation period determination module: determines the period for transient power angle stability impact calculation based on the relative rotor inertia center angle between the synchronous generators in the leading node set and the lagging node set corresponding to each simulation time point; Equipment impact calculation module: Based on the active power and node set attributes of the components injected into the grid through the connected nodes at each simulation time point during the period of transient power angle stability impact calculation, as well as the steady-state active power injected into the grid by the components through the connected nodes under the preset grid operation state, calculate the impact of the components on the transient power angle stability of the grid after the preset disturbance under the preset grid operation state.

10. A computer-readable storage medium storing one or more programs, characterized in that: The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any one of the methods according to claims 1 to 8.

11. A computing device, characterized in that: The method comprises one or more processors, one or more memories, and one or more programs, wherein the one or more programs are stored in the one or more memories and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing any one of the methods according to claims 1 to 8.

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