A large-scale power grid full electromagnetic transient and SIMULINK co-simulation method and system

Abstract

The present invention provides a method and system for joint simulation of full electromagnetic transients and SIMULINK in a large-scale power grid. The present invention combines the full electromagnetic transient simulation of a large-scale power grid with SIMULINK simulation. Norton equivalent circuits at both ends of the Bergeron transmission line model are respectively built in the full electromagnetic transient simulation program of the large-scale power grid and SIMULINK. Physical quantities of the two-side simulation programs are respectively transmitted to the opposite side through a shared memory communication mechanism, thereby realizing an efficient joint simulation between the full electromagnetic transient simulation platform of the large-scale power grid and the SIMULINK electromagnetic simulation program, expanding the scale of full electromagnetic transient simulation, avoiding repeated modeling, and avoiding harmonic losses caused by electromechanical-electromagnetic hybrid interface simulation. The joint simulation effect is exactly the same as that of simulation completely in the same full electromagnetic platform, providing strong support for the full electromagnetic transient simulation of a new power system.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic transient simulation of power systems, and in particular to a method and system for joint simulation of full electromagnetic transient and SIMULINK in a large-scale power grid. Background Technique

[0002] With the rapid development of the power grid, the scale of new energy and DC transmission is getting larger and larger, forming the current new power system. The double-high problems of the new power system exceed the scope of people's cognition. Improving the full electromagnetic transient simulation ability and achieving accurate cognition of the grid characteristics have become new planning requirements. Full electromagnetic transient simulation requires the establishment of accurate simulation models. Currently, a large number of simulation models used by users are modeled with SIMULINK. However, the SIMULINK simulation scale is small and the efficiency is low, and it cannot effectively perform full electromagnetic transient simulation of large-scale power grids. To make full use of the existing SIMULINK model assets of users, it is necessary to conduct joint simulation with a new generation of large-scale power grid full electromagnetic transient simulation program and establish a joint simulation interface between the two electromagnetic transient simulation programs.

[0003] Due to the existence of propagation delay, only the historical voltage and current before the propagation delay at the other end are required at one end of the Bergeron transmission line model. Therefore, as long as the voltage and current at the other end are transmitted through communication before being used, the Bergeron model can be accurately realized, and this is also the principle of the interface between electromagnetic transient programs. Currently, the interfaces for joint simulation with electromagnetic transient simulation programs are mainly electromechanical-electromagnetic hybrid simulation interfaces. Since the electromechanical transient simulation program uses phasor description, while the electromagnetic transient program is based on time-domain instantaneous values, there may be high-frequency waveform losses when performing interface hybrid simulation, and it cannot fully reflect harmonic characteristics when performing simulations involving power electronics such as new energy and DC. Currently, there are few studies on joint simulation between heterogeneous full electromagnetic transient simulation platforms. In order to facilitate the expansion of the simulation scale, avoid duplicate modeling, and avoid harmonic losses caused by electromechanical-electromagnetic hybrid interface simulation, a joint simulation interface between different electromagnetic transient simulation platforms is urgently needed. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and system for joint simulation of full electromagnetic transient and SIMULINK in a large-scale power grid, aiming to solve the problem of waveform loss in joint simulation with electromagnetic transient simulation programs in the prior art, and to achieve the expansion of the full electromagnetic transient simulation scale, avoid duplicate modeling, and avoid harmonic losses caused by electromechanical-electromagnetic hybrid interface simulation.

[0005] To achieve the above technical purpose, the present invention provides a method for joint simulation of full electromagnetic transient and SIMULINK in a large-scale power grid, and the method includes the following operations:

[0006] Select a transmission line with an appropriate length according to the line parameters, and the propagation delay of the line needs to be greater than one simulation step;

[0007] Decouple the transmission line simulation model into a two-terminal circuit represented by Norton equivalent resistors;

[0008] Build the Norton equivalent circuits at both ends of the Bergeron transmission line in the large-scale power grid full electromagnetic transient simulation program and SIMULINK respectively;

[0009] Establish a shared memory communication mechanism between the large-scale full electromagnetic transient simulation program and SIMULINK based on Sfunction;

[0010] In each calculation step, transfer the physical quantities of the simulation programs on both sides to the opposite side through the shared memory communication mechanism.

[0011] Preferably, the propagation delay is calculated according to the line parameters of the line connected to the bus ready to interface with SIMULINK in the large power grid. When the line length cannot meet the propagation delay requirement, reduce the simulation step.

[0012] Preferably, the equivalent resistance matrix is calculated according to the Bergeron transmission line model equation and the line parameters.

[0013] Preferably, building the Norton equivalent circuit in SIMULINK includes an equivalent resistance matrix and a historical current source, and the calculation of the historical current is placed in the large-scale power grid full electromagnetic transient calculation program.

[0014] Preferably, the three-phase voltages and the three-phase line currents measured on the SIMULINK side are transferred to the large-scale full electromagnetic transient simulation program through the shared memory, and the large-scale power grid full electromagnetic transient simulation program only needs to transfer the historical current value to the controlled current source in SIMULINK through the shared memory.

[0015] The present invention also provides a large-scale power grid full electromagnetic transient and SIMULINK co-simulation system, and the system includes:

[0016] A transmission line setting module, configured to select a transmission line with an appropriate length according to the line parameters, and the propagation delay of the line needs to be greater than one simulation step;

[0017] A transmission line model decoupling module, configured to decouple the transmission line simulation model into a two-terminal circuit represented by Norton equivalent resistors;

[0018] An equivalent circuit building module, configured to build the Norton equivalent circuits at both ends of the Bergeron transmission line in the large-scale power grid full electromagnetic transient simulation program and SIMULINK respectively;

[0019] A communication module for establishing a shared memory communication mechanism between a large-scale full electromagnetic transient simulation program and SIMULINK based on Sfunction;

[0020] A physical quantity transmission module for transmitting the physical quantities of the two-side simulation programs to the opposite side respectively through the shared memory communication mechanism at each calculation step.

[0021] Preferably, the propagation delay is calculated according to the line parameters of the bus connected to the SIMULINK interface in the large power grid. When the line length cannot meet the propagation delay requirement, the simulation step size is reduced.

[0022] Preferably, the equivalent resistance matrix is calculated according to the Bergeron transmission line model equation and the line parameters.

[0023] Preferably, the Norton equivalent circuit built in SIMULINK includes an equivalent resistance matrix and a historical current source, and the calculation of the historical current is placed in the large-scale power grid full electromagnetic transient calculation program.

[0024] Preferably, the three-phase voltages measured on the SIMULINK side and the three-phase line currents are transmitted to the large-scale full electromagnetic transient simulation program through the shared memory, and the large-scale power grid full electromagnetic transient simulation program only needs to transmit the historical current value to the controlled current source in SIMULINK through the shared memory.

[0025] The effects provided in the invention content are only the effects of the embodiments, rather than all the effects of the invention. One of the above technical solutions has the following advantages or beneficial effects:

[0026] Compared with the prior art, the present invention combines the large-scale power grid full electromagnetic transient simulation and the SIMULINK simulation, builds the Norton equivalent circuits at both ends of the Bergeron transmission line model in the large-scale power grid full electromagnetic transient simulation program and SIMULINK respectively, and transmits the physical quantities of the two-side simulation programs to the opposite side through the shared memory communication mechanism, thereby realizing the efficient co-simulation between the large-scale power grid full electromagnetic transient simulation platform and the SIMULINK electromagnetic simulation program, expanding the scale of the full electromagnetic transient simulation, avoiding repeated modeling, and avoiding the harmonic loss caused by the electromechanical-electromagnetic hybrid interface simulation. The co-simulation effect is exactly the same as that of the simulation in the same full electromagnetic platform, providing strong support for the full electromagnetic transient simulation of the new power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a logic flowchart of a method for co-simulating a large-scale power grid full electromagnetic transient and SIMULINK provided in an embodiment of the present invention;

[0028] Figure 2Schematic diagram of a large-scale power grid full electromagnetic transient and SIMULINK co-simulation provided in the embodiments of the present invention;

[0029] Figure 3 Comparison diagram of DC waveforms inside the fan models in the simulation in SIMULINK and the co-simulation provided in the embodiments of the present invention;

[0030] Figure 4 System block diagram of a large-scale power grid full electromagnetic transient and SIMULINK co-simulation provided in the embodiments of the present invention. Specific implementation manners

[0031] To clearly illustrate the technical features of the present solution, the present invention will be elaborated in detail below through specific implementation manners and in combination with its accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. In addition, the present invention may repeat reference numerals and / or letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. It should be noted that the components illustrated in the accompanying drawings are not necessarily drawn to scale. The present invention omits the description of well-known components and processing technologies and processes to avoid unnecessarily limiting the present invention.

[0032] The following will detail a large-scale power grid full electromagnetic transient and SIMULINK co-simulation method and system provided in the embodiments of the present invention in combination with the accompanying drawings.

[0033] As Figure 1 shown, the embodiments of the present invention disclose a large-scale power grid full electromagnetic transient and SIMULINK co-simulation method, and the method includes the following operations:

[0034] Calculate and select a transmission line with an appropriate length according to the line parameters, and the propagation delay of the line needs to be greater than one simulation step;

[0035] Decouple the transmission line simulation model into two-terminal circuits both using Norton equivalent resistances;

[0036] Build Norton equivalent circuits at both ends of the Bergeron transmission line in the large-scale power grid full electromagnetic transient simulation program and SIMULINK respectively;

[0037] Establish a shared memory communication mechanism between the large-scale electromagnetic transient simulation program and SIMULINK based on Sfunction;

[0038] In each calculation step, transfer the physical quantities of the two-side simulation programs to the opposite side respectively through the shared memory communication mechanism.

[0039] In the embodiment of the present invention, based on the Bergeron transmission line model, two simulation programs, namely the full electromagnetic transient simulation of a large-scale power grid and the SIMULINK simulation, are combined.

[0040] According to the line parameters, a transmission line with an appropriate length is calculated and selected. The propagation delay of the line needs to be greater than one simulation step. According to the line parameters of the lines connected to the bus ready for the SIMULINK interface in the large power grid, the propagation delay of each line is calculated. If the line length cannot meet the requirements, the simulation step needs to be reduced.

[0041] According to the decoupling characteristics of the Bergeron transmission line, the transmission line simulation model is decoupled into two-terminal circuits both represented by Norton equivalents. Among them, the resistance of the Norton equivalent can be calculated from the transmission line parameters. The equivalent resistance matrix is calculated according to the Bergeron transmission line model equation and the line parameters.

[0042] The Norton equivalent circuits at both ends of the Bergeron transmission line are respectively built in the full electromagnetic transient simulation program of the large-scale power grid and SIMULINK. Among them, building the Norton equivalent circuit in SIMULINK includes the equivalent resistance matrix and the historical current source, and the injected current is represented by a controlled current source; the Norton equivalent circuit is also built in the large-scale electromagnetic transient simulation program. To reduce the calculation amount on the SIMULINK side, the calculation of the historical current is placed in the full electromagnetic simulation platform of the large-scale power grid.

[0043] Based on the Sfunction, the communication and synchronization mechanisms between the large-scale electromagnetic transient simulation program and SIMULINK are established. Since SIMULINK provides a C language custom programming method for Sfunction, in order to improve the communication efficiency between the calculation programs, shared memory is used to exchange data.

[0044] In each calculation step, the physical quantities of the two-side simulation programs are respectively transmitted to the opposite side through the shared memory communication mechanism. The three-phase voltage measured on the SIMULINK side and the three-phase line current are transmitted to the full electromagnetic transient simulation platform of the large-scale power grid through the shared memory. And the large-scale electromagnetic transient simulation program only needs to transmit the historical current value to the controlled current source in SIMULINK through the shared memory. This implementation method reduces the amount of data transmission and improves the efficiency.

[0045] As Figure 2 shown, an AC network circuit and the Norton equivalent circuit of the interface line are built on the side of the full electromagnetic transient simulation program of the large-scale power grid, where Zk is the equivalent resistance and Ikhis is the historical current. A DFIG doubly-fed wind turbine model and an interface line model are built on the SIMULINK side, where Zm is the equivalent resistance and Imhis is the historical current.

[0046] Figure 3The figure shows the comparison chart of the DC waveforms inside the fan model in the simulation and co-simulation in SIMULINK. Through comparison, all waveforms in the two cases are almost completely coincident, indicating the accuracy of the co-simulation.

[0047] In the embodiment of the present invention, the full electromagnetic transient simulation of the large-scale power grid is combined with the SIMULINK simulation. The Norton equivalent circuits at both ends of the Bergeron transmission line model are respectively built in the full electromagnetic transient simulation program of the large-scale power grid and in SIMULINK. The physical quantities of the two-side simulation programs are respectively transmitted to the opposite side through the shared memory communication mechanism, thereby realizing the efficient co-simulation between the full electromagnetic transient simulation platform of the large-scale power grid and the SIMULINK electromagnetic simulation program, expanding the scale of the full electromagnetic transient simulation, avoiding repeated modeling, and avoiding the harmonic loss caused by the electromechanical and electromagnetic hybrid interface simulation. The co-simulation effect is exactly the same as that of the simulation completely in the same full electromagnetic platform, providing strong support for the full electromagnetic transient simulation of the new power system.

[0048] As Figure 4 shown, the embodiment of the present invention also discloses a large-scale power grid full electromagnetic transient and SIMULINK co-simulation system, and the system includes:

[0049] A transmission line setting module, configured to calculate and select a transmission line with an appropriate length according to the line parameters, and the propagation delay of the line needs to be greater than one simulation step;

[0050] A transmission line model decoupling module, configured to decouple the transmission line simulation model into two-end circuits both represented by Norton equivalent resistors;

[0051] An equivalent circuit building module, configured to build the Norton equivalent circuits at both ends of the Bergeron transmission line in the full electromagnetic transient simulation program of the large-scale power grid and in SIMULINK respectively;

[0052] A communication module, configured to establish a shared memory communication mechanism between the full electromagnetic transient simulation program of the large-scale power grid and SIMULINK based on Sfunction;

[0053] A physical quantity transmission module, configured to transmit the physical quantities of the two-side simulation programs to the opposite side respectively through the shared memory communication mechanism in each calculation step.

[0054] Calculate and select a transmission line with an appropriate length according to the line parameters, and the propagation delay of the line needs to be greater than one simulation step. Calculate the propagation delay of each line according to the line parameters of the line connected to the bus to be interfaced with SIMULINK in the large power grid. If the line length does not meet the requirements, the simulation step needs to be reduced.

[0055] According to the decoupling characteristics of the Bergeron transmission line, the transmission line simulation model is decoupled into two-terminal circuits both represented by Norton equivalents, where the resistance of the Norton equivalent can be calculated from the transmission line parameters. The equivalent resistance matrix is calculated based on the Bergeron transmission line model equations and the line parameters.

[0056] Build the Norton equivalent circuits at both ends of the Bergeron transmission line in the large-scale power grid full electromagnetic transient simulation program and SIMULINK respectively. Among them, building the Norton equivalent circuit in SIMULINK includes the equivalent resistance matrix and the historical current source, and the injected current is represented by a controlled current source; build the Norton equivalent circuit in the large-scale electromagnetic transient simulation program as well. To reduce the computational load on the SIMULINK side, the calculation of the historical current is placed in the large-scale power grid full electromagnetic simulation platform.

[0057] Establish the communication and synchronization mechanism between the large-scale electromagnetic transient simulation program and SIMULINK based on Sfunction. Since SIMULINK provides a C-language custom programming method for Sfunction, in order to improve the communication efficiency between the calculation programs, shared memory is used to exchange data.

[0058] In each calculation step, the physical quantities of the two-side simulation programs are transmitted to the opposite side through the shared memory communication mechanism respectively. The three-phase voltages measured on the SIMULINK side and the three-phase line currents are transmitted to the large-scale power grid full electromagnetic transient simulation platform through the shared memory, while the large-scale electromagnetic transient simulation program only needs to transmit the historical current value to the controlled current source in SIMULINK through the shared memory. This implementation method reduces the amount of data transmission and improves the efficiency.

[0059] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A full electromagnetic transient and SIMULINK co-simulation method for large-scale power grids, characterized in that, The method includes the following operations: Calculate and select a transmission line with an appropriate length according to the line parameters, and the propagation delay of the line needs to be greater than one simulation step; Decouple the transmission line simulation model into two-terminal circuits both represented by Norton equivalent resistances; Build Norton equivalent circuits at both ends of the Bergeron transmission line in the large-scale power grid full electromagnetic transient simulation program and SIMULINK respectively; Establish a shared memory communication mechanism between the large-scale full electromagnetic transient simulation program and SIMULINK based on Sfunction; In each calculation step, transfer the physical quantities of the two-side simulation programs to the opposite side respectively through the shared memory communication mechanism; The three-phase voltages measured on the SIMULINK side and the three-phase line currents are transferred to the large-scale full electromagnetic transient simulation program through the shared memory, and the large-scale power grid full electromagnetic transient simulation program only needs to transfer the historical current values to the controlled current source in SIMULINK through the shared memory.

2. A full electromagnetic transient and SIMULINK co-simulation method for large-scale power grids according to claim 1, characterized in that The propagation delay is calculated according to the line parameters of the bus connected to the SIMULINK interface in the large power grid. When the line length cannot meet the propagation delay requirement, reduce the simulation step; 3. A full electromagnetic transient and SIMULINK co-simulation method for large-scale power grids according to claim 1, characterized in that The equivalent resistance matrix is calculated according to the Bergeron transmission line model equation and the line parameters; 4. A full electromagnetic transient and SIMULINK co-simulation method for large-scale power grids according to claim 1, characterized in that Building the Norton equivalent circuit in the SIMULINK includes an equivalent resistance matrix and a historical current source, and the calculation of the historical current is placed in the large-scale power grid full electromagnetic transient calculation program; 5. A large-scale power grid full electromagnetic transient and SIMULINK joint simulation system, characterized by: The system includes: A transmission line setting module, which is used to calculate and select a transmission line with an appropriate length according to the line parameters, and the propagation delay of the line needs to be greater than one simulation step; A transmission line model decoupling module, which is used to decouple the transmission line simulation model into two-terminal circuits both represented by Norton equivalent resistances; An equivalent circuit building module, which is used to build Norton equivalent circuits at both ends of the Bergeron transmission line in the large-scale power grid full electromagnetic transient simulation program and SIMULINK respectively; A communication module, which is used to establish a shared memory communication mechanism between the large-scale full electromagnetic transient simulation program and SIMULINK based on Sfunction; A physical quantity transfer module, which is used to transfer the physical quantities of the two-side simulation programs to the opposite side respectively through the shared memory communication mechanism in each calculation step; 6. A large-scale power grid full electromagnetic transient and SIMULINK co-simulation system according to claim 5, characterized in that, The propagation delay is calculated according to the line parameters of the bus connected to the SIMULINK interface in the large power grid. When the line length cannot meet the propagation delay requirement, reduce the simulation step; 7. A large-scale power grid full electromagnetic transient and SIMULINK co-simulation system according to claim 5, characterized in that, The equivalent resistance matrix is calculated according to the Bergeron transmission line model equation and the line parameters;

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