Power system stability evaluation method, device, equipment, medium and program product

Abstract

The invention relates to a power system stability evaluation method, device and equipment, a medium and a program product. The method comprises the following steps: determining an output differential passivity index of to-be-evaluated equipment according to the equipment type and the equipment parameter by acquiring the equipment type and the equipment parameter of the to-be-evaluated equipment in the power system, and determining the output differential passivity index of the to-be-evaluated equipment according to a power flow model of a transmission network in the power system. And determining a transfer function matrix of a transmission network for representing a relationship between the to-be-evaluated equipment input and the to-be-evaluated equipment output, and determining a stability evaluation result of the power system based on the output differential passivity index and the transfer function matrix, the stability of the power system is evaluated in a distributed manner based on the output differential passivity index of the to-be-evaluated device, that is, the stability of the power system can be evaluated only by providing the passivity index of each distributed device, so that the stability of the novel power system can be better evaluated.

Description

Technical Field

[0001] The present application relates to the technical field of novel power systems, and in particular to a method, apparatus, device, medium, and program product for evaluating the stability of a power system. Background Art

[0002] Power system stability refers to the ability of a power system operating under normal operating conditions to return to a state of operational equilibrium after a disturbance. A disruption in power system stability could lead to widespread power outages and even the collapse of the entire power system, with potentially serious consequences. Therefore, assessing power system stability is crucial for its safe and reliable operation.

[0003] In traditional power systems dominated by synchronous units, since the equipment in the power system has strong dynamic isomorphism, that is, the equipment in the power system is in a synchronous operation state, a centralized analysis method can be used to evaluate the stability of the power system.

[0004] However, with the transformation of new power systems, the proportion of new energy in the power grid has gradually increased, more and more power electronic equipment has been incorporated into the power grid, and the dynamic heterogeneity of equipment in the power grid has become increasingly obvious. Therefore, the centralized analysis method is no longer suitable for evaluating the stability of new power systems. Summary of the Invention

[0005] Based on this, it is necessary to provide a power system stability assessment method, device, equipment, medium and program product that can be used to evaluate new power systems in response to the above technical problems.

[0006] In a first aspect, the present application provides a method for evaluating the stability of a power system. The method comprises:

[0007] Obtain the device type and device parameters of the device to be evaluated in the power system;

[0008] Determining an output differential passivity index of the device to be evaluated according to the device type and the device parameters; the output differential passivity index is a diagonal matrix;

[0009] Determining a transfer function matrix of the transmission network according to a power flow model of the transmission network in the power system; the transfer function matrix is a matrix used to represent the relationship between the input and output of the transmission network;

[0010] A stability assessment result of the power system is determined based on the output differential passivity index and the transfer function matrix.

[0011] In one embodiment, determining a stability assessment result of the power system based on the output differential passivity index and the transfer function matrix includes:

[0012] determining an intermediate matrix according to the output differential passivity index and the transfer function matrix;

[0013] A stability assessment result of the power system is determined according to the intermediate matrix.

[0014] In one embodiment, determining an intermediate matrix according to the output differential passivity indicator and the transfer function matrix includes:

[0015] determining an input differential passivity index of the transmission network according to a negative matrix of the output differential passivity index;

[0016] The intermediate matrix is determined as a result of subtracting the transfer function matrix from the input differential passivity index.

[0017] In one embodiment, determining the stability assessment result of the power system according to the intermediate matrix includes:

[0018] If the intermediate matrix is a semi-positive definite matrix, the stability of the power system is taken as the stability evaluation result;

[0019] If the intermediate matrix is a non-positive semi-definite matrix, the power system is considered unstable as the stability evaluation result.

[0020] In one embodiment, the transfer function matrix of the transmission network is determined according to the power flow model of the transmission network in the power system:

[0021] According to the power flow model, a first transfer function matrix, a second transfer function matrix, and a third transfer function matrix of the transmission network are determined; the first transfer function matrix is a transfer function matrix for characterizing the relationship between the phase angle change of the device to be evaluated and the change in active power injected at the node; the second transfer function matrix is a transfer function matrix for characterizing the relationship between the voltage change of the device to be evaluated and the change in the first ratio; the third transfer function matrix is a transfer function matrix for characterizing the relationship between the phase angle change of the device to be evaluated and the change in the first ratio, and the relationship between the voltage change of the device to be evaluated and the change in active power injected at the node; the first ratio is the ratio of the reactive power injected at the node to the voltage of the device to be evaluated;

[0022] A transfer function matrix of the transmission network is determined according to the first transfer function matrix, the second transfer function matrix, and the third transfer function matrix.

[0023] In one embodiment, determining the output differential passivity index of the device to be evaluated based on the device type and the device parameters includes:

[0024] Determine the dynamic model of the device to be evaluated according to the device type;

[0025] An output differential passivity index of the device to be evaluated is determined according to the dynamic model and the device parameters.

[0026] In a second aspect, the present application also provides a power system stability assessment device. The device includes:

[0027] An acquisition module, used to acquire the device type and device parameters of the device to be evaluated in the power system;

[0028] A first determination module is configured to determine an output differential passivity index of the device to be evaluated according to the device type and the device parameters; the output differential passivity index is a diagonal matrix;

[0029] A second determining module is configured to determine a transfer function matrix of the transmission network according to a power flow model of the transmission network in the power system; the transfer function matrix is a matrix used to represent the relationship between the transmission network input and the transmission network output;

[0030] The third determination module is configured to determine a stability assessment result of the power system based on the output differential passivity index and the transfer function matrix.

[0031] In a third aspect, the present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of any of the above methods when executing the computer program.

[0032] In a fourth aspect, the present application also provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of any of the above methods when executed by a processor.

[0033] In a fifth aspect, the present application also provides a computer program product, comprising a computer program, which implements the steps of any of the above methods when executed by a processor.

[0034] The above-mentioned power system stability assessment method, device, equipment, medium and program product obtains the device type and equipment parameters of the equipment to be evaluated in the power system, determines the output differential passivity index of the equipment to be evaluated based on the equipment type and equipment parameters, determines the transfer function matrix of the transmission network used to characterize the relationship between the input of the equipment to be evaluated and the output of the equipment to be evaluated based on the power flow model of the transmission network in the power system, and determines the stability assessment result of the power system based on the output differential passivity index and the transfer function matrix, thereby realizing distributed assessment of power system stability based on the output differential passivity index of the equipment to be evaluated, that is, each distributed device only needs to provide its own passivity index to perform power system stability, thereby better assessing the stability of the new power system, and distributed assessment of power system stability can also improve computing efficiency and the privacy of power system data. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a diagram of the internal structure of a computer device provided in an embodiment of the present application;

[0036] Figure 2 This is a flow chart of a method for evaluating power system stability provided by an embodiment of the present application;

[0037] Figure 3 1 is a flow chart of a method for determining stability evaluation results provided in an embodiment of the present application;

[0038] Figure 4 This is a block diagram of differential passivity of a power system dynamic device output provided by an embodiment of the present application;

[0039] Figure 5 This is a block diagram of a power system transmission network input differential passivity provided by an embodiment of the present application;

[0040] Figure 6 This is a block diagram of a power system negative feedback interconnection model provided by an embodiment of the present application;

[0041] Figure 7 1 is a flow chart of a method for determining an intermediate matrix provided in an embodiment of the present application;

[0042] Figure 8 1 is a flow chart of another method for determining stability evaluation results provided in an embodiment of the present application;

[0043] Figure 9 1 is a flow chart of a method for determining a transfer function matrix provided in an embodiment of the present application;

[0044] Figure 10 1 is a flow chart of a method for determining an output differential passivity index provided in an embodiment of the present application;

[0045] Figure 11 This is a flow chart of a novel power system stability assessment method based on differential passivity index provided in an embodiment of the present application;

[0046] Figure 12 This is a structural block diagram of a power system stability assessment device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0048] Power system stability refers to the ability of a power system operating under normal operating conditions to return to a state of operational equilibrium after a disturbance. A disruption in power system stability could lead to widespread power outages and even the collapse of the entire power system, with potentially serious consequences. Therefore, assessing power system stability is crucial for its safe and reliable operation.

[0049] In traditional power systems dominated by synchronous units, since the equipment in the power system has strong dynamic isomorphism, that is, the equipment in the power system is in a synchronous operation state, a centralized analysis method can be used to evaluate the stability of the power system.

[0050] However, with the transformation of new power systems, the proportion of new energy in the power grid has gradually increased, more and more power electronic equipment has been incorporated into the power grid, and the dynamic heterogeneity of equipment in the power grid has become increasingly obvious. Therefore, the centralized analysis method is no longer suitable for evaluating the stability of new power systems.

[0051] In one embodiment, when evaluating the stability of a power system, a power system model needs to be established. Typically, the power system is considered as a coupled model in which the device dynamics are interconnected through a network, where the device dynamics have the general form shown in the following formula (1):

[0052] (1)

[0053] In formula (1), the subscript Representative devices, The device status, which usually includes the phase angle of the device and voltage ; For the dynamic input of the device, in the embodiment of the present application, the input can be taken as the ratio of the node injected power and reactive power to the voltage, that is, ; is the output of the device dynamics. In the embodiment of the present application, the phase angle of the device dynamics can be selected as and voltage ,Right now .

[0054] For the power network model, the line dynamics are usually ignored and the power flow model shown in the following formula (3) is adopted:

[0055] (2)

[0056] In formula (2), and is the network admittance matrix The elements in Represents the nodes in the network The set of adjacent nodes, On this basis, ignoring network loss, we can get:

[0057] (3)

[0058] The set of all node input vectors is denoted as , the output vector set is recorded as , then the network model can be recorded as , then the power system model can be expressed as the following formula (4):

[0059] (4)

[0060] The power system stability assessment method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Figure 1 This is an internal structure diagram of a computer device provided in an embodiment of the present application. The computer device may be a server, and its internal structure diagram may be as follows: Figure 1 As shown. The computer device includes a processor, memory, and a network interface connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, it implements a power system stability assessment method.

[0061] Those skilled in the art will understand that Figure 1 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0062] In one embodiment, Figure 2 As shown, Figure 2 This is a flow chart of a method for evaluating the stability of a power system provided by an embodiment of the present application. This method can be applied to Figure 1 In a computer device, the method comprises the following steps:

[0063] S201: Obtain device type and device parameters of a device to be evaluated in a power system.

[0064] Optionally, the device type of the device to be evaluated may include, for example, at least one of a synchronous generator (SG), a conventional droop inverter (CD), and a secondary droop inverter.

[0065] For example, if the device type of the device to be evaluated includes a synchronous generator (SG), the device parameters include the integral control parameter , negative feedback control parameters , d-axis reactance and d-axis transient reactance If the device type to be evaluated includes a conventional droop inverter (CD), the device parameters include droop gain and , steady-state voltage value , steady-state value of node injected reactive power If the device type of the device to be evaluated includes a secondary droop inverter, the device parameters include droop gain and .

[0066] It should be noted that the power system consists of a transmission network and several nodes connected to it. Different devices may be connected to the nodes. The devices to be evaluated may include all devices in the power system or any one or more devices in the power system.

[0067] S202: Determine the output differential passivity index of the device to be evaluated according to the device type and device parameters.

[0068] Among them, the output differential passivity index is a diagonal matrix.

[0069] In the embodiment of the present application, the input and output of the device can be selected as two-dimensional vectors, and the output differential passivity index of the device is a second-order diagonal matrix, that is, The two diagonal elements are the passivity index of the active-frequency path and the passivity index of the reactive-voltage path, respectively. This allows the focus to be placed on the internal paths of the equipment during power system stability analysis, reducing control costs. Furthermore, thanks to the splitting of the passive paths, the embodiments of this application no longer require that every device in the power system possess sufficient passivity and stability. Instead, the interconnection of the transmission network allows for the mutual compensation of excess and insufficient passivity across different paths within the equipment and between devices, reducing the conservatism of stability determinations.

[0070] It should be noted that, since the device to be evaluated includes any one or more devices in the power system, the output differential passivity index of the device to be evaluated is a collection of the output differential passivity indicators of each device.

[0071] For example, the output differential passivity index of the device is , then the output differential passivity index of the device to be evaluated can be expressed as the following formula (5):

[0072] (5)

[0073] Optionally, the dynamic model of the device to be evaluated may be determined according to the device type of the device to be evaluated, and thus the output differential passivity index of the device to be evaluated may be determined according to the dynamic model and device parameters of the device to be evaluated.

[0074] In one embodiment, for the power system shown in the following formula (6), , , if there is a and a continuously differentiable locally positive definite function Make , then the power system is output differential passive, and further if there exists a positive definite function satisfy Make , then the power system is strictly output differential passive; if , then the power system is input differential passive:

[0075] (6)

[0076] S203 , determining a transfer function matrix of the transmission network according to a power flow model of the transmission network in the power system.

[0077] The transfer function matrix is a matrix used to represent the relationship between the transmission network input and the transmission network output.

[0078] In the embodiment of the present application, for the power flow model of the transmission network in the power system as shown in formula (3), the output of the device to be evaluated is Input to the transmission network , the negative input of the device to be evaluated Output of the transmission network , the transmission network from arrive The transfer function matrix is recorded as , can be calculated by linearizing the power flow model of the transmission network Elements in .

[0079] For example, it can be determined based on the linearized power flow model. arrive The first transfer function matrix ,from arrive The second transfer function matrix ,from arrive and from arrive The third transfer function matrix , then according to the first transfer function matrix , the second transfer function matrix and the third transfer function matrix , determine the transfer function matrix of the transmission network :

[0080] (7)

[0081] S204 , determining a stability assessment result of the power system based on the output differential passivity index and the transfer function matrix.

[0082] Optionally, the sum of the transfer function matrix and the output differential passivity index can be determined , and then according to the summation result , determine the stability assessment results of the power system.

[0083] For example, if the summation result is a semi-positive definite matrix, then the stability assessment result of the power system is that the power system is stable; if the summation result If it is a non-semi-positive definite matrix, the stability assessment result of the power system is that the power system is unstable.

[0084] In one embodiment, when the stability assessment result of the power system is that the power system is unstable, the equipment parameters can be adjusted through equipment adjustment or control design, so that the passivity between different paths within the equipment to be assessed or between different equipment to be assessed is redistributed to achieve compatibility and complementarity, and then the power system stability assessment can be re-performed.

[0085] In an embodiment of the present application, by obtaining the device type and device parameters of the device to be evaluated in the power system, determining the output differential passivity index of the device to be evaluated based on the device type and device parameters, determining the transfer function matrix of the transmission network used to characterize the relationship between the input of the device to be evaluated and the output of the device to be evaluated based on the power flow model of the transmission network in the power system, and determining the stability evaluation result of the power system based on the output differential passivity index of the device to be evaluated, a distributed evaluation of the stability of the power system based on the output differential passivity index of the device to be evaluated is realized, that is, each distributed device only needs to provide its own passivity index to perform the stability of the power system, thereby better evaluating the stability of the new power system, and the distributed evaluation of the stability of the power system can also improve the computing efficiency and the privacy of the power system data.

[0086] Reference Figure 3 , Figure 3This is a flow chart of a method for determining stability assessment results provided by an embodiment of the present application. This embodiment involves a possible implementation method for determining the stability assessment result of a power system based on the output differential passivity index and the transfer function matrix. Based on the above embodiment, the above S204 includes the following steps:

[0087] S301 : determining an intermediate matrix according to an output differential passivity index and a transfer function matrix.

[0088] Optionally, the transfer function matrix can be summed with the output differential passivity index Determine the intermediate matrix.

[0089] Alternatively, the input differential passivity of the transmission network can be determined based on the output differential passivity , then the result of subtracting the transfer function matrix from the input differential passivity index is Determine the intermediate matrix.

[0090] S302: Determine a stability assessment result of the power system according to the intermediate matrix.

[0091] Optionally, if the intermediate matrix is a semi-positive definite matrix, the stability assessment result of the power system is that the power system is stable; if the intermediate matrix is a non-semi-positive definite matrix, the stability assessment result of the power system is that the power system is unstable.

[0092] Reference Figure 4-6 , Figure 4 This is a block diagram of a power system dynamic device output differential passivity provided by an embodiment of the present application. Figure 5 This is a block diagram of a power system transmission network input differential passivity provided by an embodiment of the present application. Figure 6 This is a block diagram of a negative feedback interconnection model of a power system provided in an embodiment of the present application. For example, the output differential passivity of the device to be evaluated can be defined as the following formula (8):

[0093] (8)

[0094] Formula (8) is equivalent to ,make , ,but , so from arrive The output differential passivity is equivalent to arrive The output differential passivity of a dynamic device can be expressed as Figure 4 shown.

[0095] Optionally, the input differential passivity of the transmission network is indicated by , the input differential passivity of the transmission network can be defined as the following formula (9):

[0096] (9)

[0097] Formula (9) is equivalent to ,make , ,but , so from arrive The output differential passivity is equivalent to arrive The input differential passivity of the power system transmission network can be expressed as Figure 5 As shown. arrive The transfer function is , according to the passivity theory, when Semi-positive timing, system Passive, so the network input differential is passive, and the corresponding input differential passivity index is .

[0098] Based on the above port definitions, the transmission network can be regarded as the negative feedback of the equipment, and the entire power system model can be as follows: Figure 6 shown. Figure 6 The devices and networks shown are modeled and interconnected in the form of differential passivity. In order to maintain the equivalence with the original modeling, a negative feedback channel needs to be added, namely Since the system composed of negative feedback connections between passive systems is still passive, and the equipment and network are passive respectively, if is also passive, then the entire system is passive, and thus the stability of the system equilibrium point can be obtained.

[0099] According to the above passivity theory, when Semi-positive definite time, transfer function Passive, but The selection of and the transfer function matrix after network linearization Relevant, need to ensure Semi-positive definite satisfies the input differential passivity condition of the network, so when verifying the stability of the power system, it is only necessary to Select as ,verify The positive semidefinite property of .

[0100] In an embodiment of the present application, an intermediate matrix is determined based on the output differential passivity index and the transfer function matrix, and the stability evaluation result of the power system is determined based on the intermediate matrix, thereby realizing a distributed evaluation of the stability of the power system based on the output differential passivity index of the device to be evaluated, that is, each distributed device only needs to provide its own passivity index to perform the stability of the power system, thereby better evaluating the stability of the new power system, and the distributed evaluation of the stability of the power system can also improve the computing efficiency and the privacy of the power system data.

[0101] Reference Figure 7 , Figure 7 : This is a flow chart of a method for determining an intermediate matrix provided by an embodiment of the present application. This embodiment relates to a possible implementation method for determining an intermediate matrix based on an output differential passivity index and a transfer function matrix. Based on the above embodiment, the above S301 includes the following steps:

[0102] S701 : Determine an input differential passivity index of a transmission network according to a negative matrix of the output differential passivity index.

[0103] In one embodiment, the negative matrix of the output differential passivity index can be Determined as the input differential passivity index of the transmission network .

[0104] S702 : Determine the result of subtracting the transfer function matrix from the input differential passivity index as an intermediate matrix.

[0105] Optionally, the transfer function matrix can be summed with the output differential passivity index Alternatively, the result of subtracting the transfer function matrix from the input differential passivity index can be Determined as the intermediate matrix, since the input differential passivity index is the negative matrix of the output differential passivity index, .

[0106] In an embodiment of the present application, the input differential passivity index of the transmission network is determined based on the negative matrix of the output differential passivity index, the result of subtracting the transfer function matrix from the input differential passivity index is determined as an intermediate matrix, and then the stability evaluation result of the power system is determined based on the intermediate matrix, thereby realizing a distributed evaluation of the stability of the power system based on the output differential passivity index of the device to be evaluated, that is, each distributed device only needs to provide its own passivity index to perform the stability of the power system, thereby better evaluating the stability of the new power system, and the distributed evaluation of the stability of the power system can also improve the computing efficiency and the privacy of the power system data.

[0107] Reference Figure 8 , Figure 8 This is a flow chart of another method for determining stability assessment results provided by an embodiment of the present application. This embodiment involves a possible implementation method of how to determine the stability assessment result of the power system based on the intermediate matrix. Based on the above embodiment, the above S302 includes the following steps:

[0108] S801: If the intermediate matrix is a semi-positive definite matrix, the stability of the power system is used as the stability assessment result.

[0109] In one embodiment, since the intermediate matrix is a real symmetric matrix, the eigenvalues of the intermediate matrix can be calculated. If the eigenvalues of the intermediate matrix are not less than zero, the intermediate matrix is a semi-positive definite matrix, and the stability of the power system is used as the stability evaluation result.

[0110] S802: If the intermediate matrix is not a positive semi-definite matrix, the instability of the power system is regarded as a stability assessment result.

[0111] Optionally, if there is an eigenvalue less than zero among the eigenvalues of the intermediate matrix, the intermediate matrix is a non-positive semi-definite matrix, and instability of the power system is taken as the stability assessment result.

[0112] In an embodiment of the present application, if the intermediate matrix is a semi-positive definite matrix, the stability of the power system is taken as the stability evaluation result; if the intermediate matrix is a non-semi-positive definite matrix, the instability of the power system is taken as the stability evaluation result, thereby realizing a distributed evaluation of the stability of the power system based on the output differential passivity index of the device to be evaluated, that is, each distributed device only needs to provide its own passivity index to perform the stability of the power system, thereby better evaluating the stability of the new power system, and the distributed evaluation of the stability of the power system can also improve the computing efficiency and the privacy of the power system data.

[0113] Reference Figure 9 , Figure 9 This is a flow chart of a method for determining a transfer function matrix provided in an embodiment of the present application. This embodiment relates to a possible implementation method for determining a transfer function matrix of a transmission network based on a power flow model of the transmission network in a power system. Based on the above embodiment, the above S203 includes the following steps:

[0114] S901 : Determine a first transfer function matrix, a second transfer function matrix, and a third transfer function matrix of a transmission network according to a power flow model.

[0115] Among them, the first transfer function matrix is a transfer function matrix used to characterize the relationship between the phase angle change of the device to be evaluated and the change in active power injected by the node, the second transfer function matrix is a transfer function matrix used to characterize the relationship between the voltage change of the device to be evaluated and the change in the first ratio, and the third transfer function matrix is a transfer function matrix used to characterize the relationship between the phase angle change of the device to be evaluated and the change in the first ratio, as well as the relationship between the voltage change of the device to be evaluated and the change in active power injected by the node; the first ratio is the ratio of the node injected reactive power to the voltage of the device to be evaluated.

[0116] In the embodiment of the present application, for the power flow model of the transmission network in the power system as shown in formula (3), the output of the device to be evaluated is Input to the transmission network , the negative input of the device to be evaluated Output of the transmission network , the transmission network from arrive The transfer function matrix is recorded as , can be calculated by linearizing the power flow model of the transmission network Elements in .

[0117] Alternatively, the linearized power flow model can be used to determine the arrive The first transfer function matrix ,from arrive The second transfer function matrix ,from arrive and from arrive The third transfer function matrix .

[0118] For example, from arrive The first transfer function matrix It can be expressed as the following formula (10):

[0119] (10)

[0120] For example, from arrive The second transfer function matrix It can be expressed as the following formula (11):

[0121] (11)

[0122] For example, from arrive and from arrive The third transfer function matrix It can be expressed as the following formula (12):

[0123] (12)

[0124] S902 : Determine a transfer function matrix of a transmission network according to the first transfer function matrix, the second transfer function matrix, and the third transfer function matrix.

[0125] For example, the first transfer function matrix , the second transfer function matrix and the third transfer function matrix , determine the transfer function matrix of the transmission network :

[0126] (7)

[0127] In an embodiment of the present application, the first transfer function matrix, the second transfer function matrix and the third transfer function matrix of the transmission network are determined according to the power flow model, and the transfer function matrix of the transmission network is determined according to the first transfer function matrix, the second transfer function matrix and the third transfer function matrix. Then, the stability of the power system can be evaluated according to the transfer function matrix, thereby realizing a distributed evaluation of the stability of the power system based on the output differential passivity index of the device to be evaluated, that is, each distributed device only needs to provide its own passivity index to perform the stability of the power system, thereby better evaluating the stability of the new power system, and the distributed evaluation of the stability of the power system can also improve the computing efficiency and the privacy of the power system data.

[0128] Reference Figure 10 , Figure 10 This is a flow chart of a method for determining an output differential passivity index provided in an embodiment of the present application. This embodiment involves a possible implementation method for determining the output differential passivity index of a device to be evaluated based on the device type and device parameters. Based on the above embodiment, the above S202 includes the following steps:

[0129] S1001: Determine a dynamic model of a device to be evaluated according to the device type.

[0130] Alternatively, if the device type of the device to be evaluated includes a synchronous generator (SG), the dynamic model of the device to be evaluated may include a dynamic model of the synchronous generator as shown in the following formula (13):

[0131] (13)

[0132] In formula (13), the subscript Indicates that the synchronous generator is the first equipment, is the generator voltage phase angle, is the rotor angular frequency, is the potential amplitude in the generator's q-axis, is the inertia constant, is the damping coefficient, is the q-axis open-loop transient time constant, for Shaft reactance, for Shaft transient reactance, is the line reactance, Simplify the total circuit reactance for the system, and are the mechanical power and excitation voltage of the synchronous generator respectively. In order to enhance the stability of the system, Using PI control, Using negative feedback control:

[0133] (14)

[0134] In formula (14), and is the control set value, is the integral control parameter, is the proportional control parameter, is the negative feedback control parameter.

[0135] Alternatively, if the device type of the device to be evaluated includes a conventional droop inverter (CD), the dynamic model of the device to be evaluated may include a dynamic model of the conventional droop inverter (CD) as shown in the following formula (15):

[0136] (15)

[0137] In formula (15), the superscript represents the steady-state value of the corresponding variable, and is the time constant, and is the droop gain.

[0138] Optionally, if the device type of the device to be evaluated includes a quadratic droop inverter, the dynamic model of the device to be evaluated may include a dynamic model of the quadratic droop inverter as shown in the following formula (16):

[0139] (16)

[0140] In formula (16), is a steady-state constant that satisfies the following formula (17):

[0141] (17)

[0142] S1002: Determine the output differential passivity index of the device to be evaluated based on the dynamic model and device parameters.

[0143] In one embodiment, if the device type of the device to be evaluated includes a synchronous generator (SG), the output differential passivity index of the device to be evaluated may include the output differential passivity index of the synchronous generator. The output differential passivity index of the path is , The output differential passivity index of the path is , so the output differential passivity index of the synchronous generator can be expressed as the following formula (18):

[0144] (18)

[0145] Optionally, if the device type of the device to be evaluated includes a conventional droop inverter (CD), the output differential passivity index of the device to be evaluated may include the output differential passivity index of the conventional droop inverter. The output differential passivity index of the path is , The output differential passivity index of the path is , so the output differential passivity index of the traditional droop inverter can be expressed as the following formula (19):

[0146] (19)

[0147] In one embodiment, if the device type of the device to be evaluated includes a quadratic droop inverter, the output differential passivity index of the device to be evaluated may include the output differential passivity index of the quadratic droop inverter. The output differential passivity index of the path is , The output differential passivity index of the path is , so the output differential passivity index of the quadratic droop inverter can be expressed as the following formula (20):

[0148] (20)

[0149] In an embodiment of the present application, a dynamic model of the device to be evaluated is determined according to the device type, and the output differential passivity index of the device to be evaluated is determined according to the dynamic model and the device parameters. Then, the stability of the power system can be evaluated based on the output differential passivity index, thereby realizing a distributed evaluation of the stability of the power system based on the output differential passivity index of the device to be evaluated. That is, each distributed device only needs to provide its own passivity index to perform the stability of the power system, thereby better evaluating the stability of the new power system, and the distributed evaluation of the stability of the power system can also improve the computing efficiency and the privacy of the power system data.

[0150] Reference Figure 11 , Figure 11 : This is a flow chart of a novel power system stability assessment method based on differential passivity index provided in an embodiment of the present application. The method comprises the following steps:

[0151] S1101: Obtain device type and device parameters of a device to be evaluated in a power system.

[0152] S1102 : Determine a dynamic model of the device to be evaluated according to the device type, and determine an output differential passivity index of the device to be evaluated according to the dynamic model and device parameters.

[0153] S1103, calculating the transfer function matrix of the transmission network.

[0154] S1104 , determining the input differential passivity index of the transmission network according to the negative matrix of the output differential passivity index, and determining the result of subtracting the transfer function matrix from the input differential passivity index as an intermediate matrix.

[0155] S1105: If the intermediate matrix is a semi-positive definite matrix, the stability of the power system is used as the stability assessment result.

[0156] S1106: If the intermediate matrix is not a positive semi-definite matrix, the power system is considered unstable as a stability assessment result.

[0157] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0158] Based on the same inventive concept, embodiments of the present application also provide a power system stability assessment device for implementing the power system stability assessment method described above. The solution provided by this device is similar to the solution described in the method described above. Therefore, the specific limitations in one or more power system stability assessment device embodiments provided below can be found in the limitations of the power system stability assessment method described above and will not be repeated here.

[0159] In one embodiment, Figure 12 As shown, Figure 12 1 is a block diagram of a power system stability assessment device provided in an embodiment of the present application. The device 1200 includes:

[0160] The acquisition module 1201 is used to acquire the device type and device parameters of the device to be evaluated in the power system.

[0161] The first determining module 1202 is configured to determine an output differential passivity index of the device to be evaluated according to the device type and device parameters; the output differential passivity index is a diagonal matrix.

[0162] The second determining module 1203 is used to determine the transfer function matrix of the transmission network according to the power flow model of the transmission network in the power system; the transfer function matrix is a matrix used to represent the relationship between the transmission network input and the transmission network output.

[0163] The third determining module 1204 is configured to determine a stability assessment result of the power system based on the output differential passivity index and the transfer function matrix.

[0164] In one embodiment, the third determining module 1204 includes:

[0165] The first determining unit is configured to determine an intermediate matrix according to the output differential passivity index and the transfer function matrix.

[0166] The second determining unit is used to determine the stability assessment result of the power system according to the intermediate matrix.

[0167] In one embodiment, the first determining unit includes:

[0168] The first determining subunit is configured to determine the input differential passivity index of the transmission network according to the negative matrix of the output differential passivity index.

[0169] The second determining subunit is configured to determine a result of subtracting a transfer function matrix from an input differential passivity index as an intermediate matrix.

[0170] In one embodiment, the second determining unit includes:

[0171] The third determining subunit is configured to take the stability of the power system as a stability evaluation result if the intermediate matrix is a positive semi-definite matrix.

[0172] The fourth determining subunit is configured to take the instability of the power system as a stability assessment result if the intermediate matrix is a non-positive semi-definite matrix.

[0173] In one embodiment, the second determining module 1203 includes:

[0174] The fourth determination module is used to determine the first transfer function matrix, the second transfer function matrix and the third transfer function matrix of the transmission network according to the power flow model; the first transfer function matrix is used to represent the relationship between the phase angle change of the device to be evaluated and the change in the active power injected by the node, the second transfer function matrix is used to represent the relationship between the voltage change of the device to be evaluated and the change in the first ratio; the third transfer function matrix is used to represent the relationship between the phase angle change of the device to be evaluated and the change in the first ratio, and the relationship between the voltage change of the device to be evaluated and the change in the active power injected by the node; the first ratio is the ratio of the reactive power injected by the node to the voltage of the device to be evaluated.

[0175] The fifth determining module is configured to determine a transfer function matrix of the transmission network according to the first transfer function matrix, the second transfer function matrix, and the third transfer function matrix.

[0176] In one embodiment, the first determining module 1202 includes:

[0177] The sixth determining module is used to determine the dynamic model of the device to be evaluated according to the device type.

[0178] The seventh determination module is used to determine the output differential passivity index of the device to be evaluated based on the dynamic model and device parameters.

[0179] Each module in the above-mentioned power system stability assessment device can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a memory in the computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0180] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0181] Obtain the device type and device parameters of the device to be evaluated in the power system;

[0182] Determine the output differential passivity index of the device to be evaluated based on the device type and device parameters; the output differential passivity index is a diagonal matrix;

[0183] According to the power flow model of the transmission network in the power system, the transfer function matrix of the transmission network is determined; the transfer function matrix is a matrix used to represent the relationship between the input and output of the transmission network;

[0184] Based on the output differential passivity index and the transfer function matrix, the stability assessment results of the power system are determined.

[0185] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0186] Determine the intermediate matrix according to the output differential passivity index and the transfer function matrix;

[0187] The stability assessment result of the power system is determined based on the intermediate matrix.

[0188] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0189] Determine the input differential passivity index of the transmission network according to the negative matrix of the output differential passivity index;

[0190] The intermediate matrix is determined by subtracting the transfer function matrix from the input differential passivity index.

[0191] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0192] If the intermediate matrix is a semi-positive definite matrix, the power system stability is taken as the stability assessment result;

[0193] If the intermediate matrix is not positive semidefinite, the power system is considered unstable as the stability assessment result.

[0194] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0195] According to the power flow model, a first transfer function matrix, a second transfer function matrix, and a third transfer function matrix of the transmission network are determined; the first transfer function matrix is a transfer function matrix used to characterize the relationship between the phase angle change of the device to be evaluated and the change in active power injected at the node, the second transfer function matrix is a transfer function matrix used to characterize the relationship between the voltage change of the device to be evaluated and the change in the first ratio, and the third transfer function matrix is a transfer function matrix used to characterize the relationship between the phase angle change of the device to be evaluated and the change in the first ratio, as well as the relationship between the voltage change of the device to be evaluated and the change in active power injected at the node; the first ratio is the ratio of the reactive power injected at the node to the voltage of the device to be evaluated;

[0196] A transfer function matrix of the transmission network is determined according to the first transfer function matrix, the second transfer function matrix, and the third transfer function matrix.

[0197] In one embodiment, when the processor executes the computer program, the processor further implements the following steps:

[0198] Determine the dynamic model of the equipment to be evaluated based on the equipment type;

[0199] Determine the output differential passivity index of the device to be evaluated based on the dynamic model and device parameters.

[0200] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0201] Obtain the device type and device parameters of the device to be evaluated in the power system;

[0202] Determine the output differential passivity index of the device to be evaluated based on the device type and device parameters; the output differential passivity index is a diagonal matrix;

[0203] According to the power flow model of the transmission network in the power system, the transfer function matrix of the transmission network is determined; the transfer function matrix is a matrix used to represent the relationship between the input and output of the transmission network;

[0204] Based on the output differential passivity index and the transfer function matrix, the stability assessment results of the power system are determined.

[0205] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0206] Determine the intermediate matrix according to the output differential passivity index and the transfer function matrix;

[0207] The stability assessment result of the power system is determined based on the intermediate matrix.

[0208] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0209] Determine the input differential passivity index of the transmission network according to the negative matrix of the output differential passivity index;

[0210] The intermediate matrix is determined by subtracting the transfer function matrix from the input differential passivity index.

[0211] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0212] If the intermediate matrix is a semi-positive definite matrix, the power system stability is taken as the stability assessment result;

[0213] If the intermediate matrix is not positive semidefinite, the power system is considered unstable as the stability assessment result.

[0214] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0215] According to the power flow model, a first transfer function matrix, a second transfer function matrix, and a third transfer function matrix of the transmission network are determined; the first transfer function matrix is a transfer function matrix used to characterize the relationship between the phase angle change of the device to be evaluated and the change in active power injected at the node, the second transfer function matrix is a transfer function matrix used to characterize the relationship between the voltage change of the device to be evaluated and the change in the first ratio, and the third transfer function matrix is a transfer function matrix used to characterize the relationship between the phase angle change of the device to be evaluated and the change in the first ratio, as well as the relationship between the voltage change of the device to be evaluated and the change in active power injected at the node; the first ratio is the ratio of the reactive power injected at the node to the voltage of the device to be evaluated;

[0216] A transfer function matrix of the transmission network is determined according to the first transfer function matrix, the second transfer function matrix, and the third transfer function matrix.

[0217] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0218] Determine the dynamic model of the equipment to be evaluated based on the equipment type;

[0219] Determine the output differential passivity index of the device to be evaluated based on the dynamic model and device parameters.

[0220] In one embodiment, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the following steps:

[0221] Obtain the device type and device parameters of the device to be evaluated in the power system;

[0222] Determine the output differential passivity index of the device to be evaluated based on the device type and device parameters; the output differential passivity index is a diagonal matrix;

[0223] According to the power flow model of the transmission network in the power system, the transfer function matrix of the transmission network is determined; the transfer function matrix is a matrix used to represent the relationship between the input and output of the transmission network;

[0224] Based on the output differential passivity index and the transfer function matrix, the stability assessment results of the power system are determined.

[0225] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0226] Determine the intermediate matrix according to the output differential passivity index and the transfer function matrix;

[0227] The stability assessment result of the power system is determined based on the intermediate matrix.

[0228] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0229] Determine the input differential passivity index of the transmission network according to the negative matrix of the output differential passivity index;

[0230] The intermediate matrix is determined by subtracting the transfer function matrix from the input differential passivity index.

[0231] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0232] If the intermediate matrix is a semi-positive definite matrix, the power system stability is taken as the stability assessment result;

[0233] If the intermediate matrix is not positive semidefinite, the power system is considered unstable as the stability assessment result.

[0234] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0235] According to the power flow model, a first transfer function matrix, a second transfer function matrix, and a third transfer function matrix of the transmission network are determined; the first transfer function matrix is a transfer function matrix used to characterize the relationship between the phase angle change of the device to be evaluated and the change in active power injected at the node, the second transfer function matrix is a transfer function matrix used to characterize the relationship between the voltage change of the device to be evaluated and the change in the first ratio, and the third transfer function matrix is a transfer function matrix used to characterize the relationship between the phase angle change of the device to be evaluated and the change in the first ratio, as well as the relationship between the voltage change of the device to be evaluated and the change in active power injected at the node; the first ratio is the ratio of the reactive power injected at the node to the voltage of the device to be evaluated;

[0236] A transfer function matrix of the transmission network is determined according to the first transfer function matrix, the second transfer function matrix, and the third transfer function matrix.

[0237] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0238] Determine the dynamic model of the equipment to be evaluated based on the equipment type;

[0239] Determine the output differential passivity index of the device to be evaluated based on the dynamic model and device parameters.

[0240] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like.

[0241] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0242] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for evaluating power system stability, characterized in that: The method comprises: Obtain the device type and device parameters of the device to be evaluated in the power system; Determining an output differential passivity index of the device to be evaluated according to the device type and the device parameters; the output differential passivity index is a diagonal matrix; Determining a transfer function matrix of the transmission network according to a power flow model of the transmission network in the power system; the transfer function matrix is a matrix used to represent the relationship between the input and output of the transmission network; A stability assessment result of the power system is determined based on the output differential passivity index and the transfer function matrix.

2. The method according to claim 1, characterized in that Determining a stability assessment result of the power system based on the output differential passivity index and the transfer function matrix includes: determining an intermediate matrix according to the output differential passivity index and the transfer function matrix; A stability assessment result of the power system is determined according to the intermediate matrix.

3. The method according to claim 2, characterized in that The determining of the intermediate matrix according to the output differential passivity index and the transfer function matrix comprises: determining an input differential passivity index of the transmission network according to a negative matrix of the output differential passivity index; The intermediate matrix is determined as a result of subtracting the transfer function matrix from the input differential passivity index.

4. The method according to claim 2, characterized in that Determining the stability assessment result of the power system according to the intermediate matrix includes: If the intermediate matrix is a semi-positive definite matrix, taking the stability of the power system as the stability evaluation result; If the intermediate matrix is a non-positive semi-definite matrix, the power system is considered unstable as the stability evaluation result.

5. The method according to claim 1, wherein Determining the transfer function matrix of the transmission network according to the power flow model of the transmission network in the power system includes: According to the power flow model, a first transfer function matrix, a second transfer function matrix, and a third transfer function matrix of the transmission network are determined; the first transfer function matrix is a transfer function matrix for characterizing the relationship between the phase angle change of the device to be evaluated and the change in the active power injected at the node; the second transfer function matrix is a transfer function matrix for characterizing the relationship between the voltage change of the device to be evaluated and the change in the first ratio; the third transfer function matrix is a transfer function matrix for characterizing the relationship between the phase angle change of the device to be evaluated and the change in the first ratio, and the relationship between the voltage change of the device to be evaluated and the change in the active power injected at the node; the first ratio is the ratio of the reactive power injected at the node to the voltage of the device to be evaluated; A transfer function matrix of the transmission network is determined according to the first transfer function matrix, the second transfer function matrix, and the third transfer function matrix.

6. The method according to any one of claims 1 to 5, characterized in that Determining the output differential passivity index of the device to be evaluated according to the device type and the device parameters includes: Determining a dynamic model of the device to be evaluated according to the device type; An output differential passivity index of the device to be evaluated is determined according to the dynamic model and the device parameters.

7. A power system stability assessment device, characterized in that: The device comprises: An acquisition module, used to acquire the device type and device parameters of the device to be evaluated in the power system; A first determining module is configured to determine an output differential passivity index of the device to be evaluated according to the device type and the device parameters; the output differential passivity index is a diagonal matrix; A second determining module is configured to determine a transfer function matrix of the transmission network according to a power flow model of the transmission network in the power system; the transfer function matrix is a matrix used to represent the relationship between the input and output of the transmission network; A third determination module is configured to determine a stability assessment result of the power system based on the output differential passivity index and the transfer function matrix.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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