Full-automatic debugging and modeling method for electromagnetic transient simulation of alternating-current and direct-current power grid

Abstract

The invention provides an alternating current and direct current power grid electromagnetic transient simulation full-automatic debugging modeling method which comprises the following steps: firstly, based on electromagnetic transient model data of a direct current transmitting end alternating current system and a direct current receiving end alternating current system of a target power grid, carrying out electromagnetic transient simulation modeling on a high-voltage direct current system of the target power grid; and finally, combining the alternating current system model and the direct current control and protection system model into an alternating current and direct current large power grid model through a full-automatic debugging module, and carrying out electromagnetic transient simulation calculation. The invention provides a full-automatic debugging technology based on a direct-current transmitting and receiving end alternating-current system and a direct-current model, solves the bottleneck that electromagnetic transient simulation modeling of a large-scale alternating-current and direct-current power grid is complicated and the workload is large, can reduce the debugging time of modeling of the large-scale alternating-current and direct-current power grid, quickly enables the model to reach a target stable state, and improves the modeling efficiency. Compared with a manual debugging method, the method has higher accuracy, and the working efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of full electromagnetic transient simulation of AC and DC power grids of power systems, and in particular to a method for fully automatic debugging and modeling of electromagnetic transient simulation of AC and DC power grids. Background Art

[0002] At present, my country's power system has begun to develop towards multiple machines, large power grids, AC / DC combined transmission and large-area interconnected operation, forming the world's largest AC / DC hybrid power grid with the highest voltage level. Electromechanical transient simulation cannot accurately simulate the interaction characteristics of AC and DC at non-fundamental frequencies, AC asymmetric faults, DC line faults, and DC system recovery after disturbances that are closely related to the performance of DC control systems. Electromagnetic transient simulation can accurately simulate the transient characteristics of various components in the power system, especially the switching characteristics of power electronic devices such as HVDC and FACTS, and can accurately analyze various electromechanical and electromagnetic transient phenomena in AC and DC electromagnetic transients.

[0003] The bottleneck of large-scale electromagnetic transient application is that the speed of power system modeling is extremely slow. At the same time, there are many equipment models and large parameter scales, which makes it difficult to complete the modeling work manually and it is also difficult to ensure the correctness of the parameters. The actual domestic power grid data is generally electromechanical transient analysis data, such as BPA, PSASP and online data of PSDB platform. However, the real power grid data is huge, and there are certain differences between the electromechanical transient model and the electromagnetic transient model of power equipment. Therefore, large-scale AC and DC power grid electromagnetic transient simulation modeling and debugging technology has become the key to academic research and engineering application research.

[0004] At present, the electromagnetic transient simulation model of large-scale AC and DC power systems is established by using the principle of conversion between electromechanical transient model and electromagnetic transient model to establish the electromagnetic transient simulation model of AC and DC systems, and the modeling is completed by manual segmentation debugging. Manual debugging of the model is required to make the large AC and DC power grids reach a stable state, and the DC control system adopts the classical control strategy, which cannot fully reflect the operating conditions of the actual project and cannot accurately invert the accident process in production. Summary of the invention

[0005] To solve the above problems, the present invention provides a method for fully automatic debugging and modeling of electromagnetic transient simulation of AC and DC power grids, which improves the efficiency of debugging and modeling of large AC and DC power grids and fills the gap in automatic debugging and modeling methods for electromagnetic transients of AC and DC power grids.

[0006] A method for fully automatic debugging and modeling of electromagnetic transient simulation of AC and DC power grids, comprising the following steps:

[0007] S1, partition the target power grid into a DC partition HVDC and AC partitions R_ac and I_ac, and transfer the electromagnetic transient data of the AC partition to the automatic debugging module;

[0008] S2. Automatically process the boundary power grid of the AC partitions R_ac and I_ac through the Debug module, and calculate the short-circuit ratios Rscr and Iscr at the boundary bus nodes of the AC partitions R_ac and I_ac;

[0009] S3, based on the short-circuit ratios Rscr and Iscr calculated in step S2, perform electromagnetic transient simulation calculation on the AC power grids of the AC partitions R_ac and I_ac, generate calculation result files R_ac.out and I_ac.out, compare them with the electromechanical transient power flow data power.out of the known target power grid, and make the AC partition R_ac and I_ac models reach a stable state;

[0010] S4, through the automatic debugging Debug module, calculate the voltage amplitude, phase angle, sending end reactance value Rxl and receiving end reactance value Ixl of the ideal voltage source of the HVDC sending end and receiving end in S1;

[0011] S5. Manually model the DC partition HVDC in step S1 as an independent power grid, with parameters derived from actual engineering data. Through the automatic debugging module, the voltage amplitude and phase angle of the ideal voltage sources at the sending and receiving ends of the DC partition HVDC calculated in step S4, as well as the sending end reactance value Rx1 and the receiving end reactance value Ix1 are configured to generate the DC partition HVDC electromagnetic transient simulation model HVDC.inf.

[0012] S6, using a large-scale full electromagnetic transient simulation program to perform electromagnetic transient simulation calculations on the DC partition HVDC electromagnetic transient simulation model in step S5, obtaining a DC partition HVDC model simulation result hvdc.out, and debugging the DC partition HVDC model through an automatic debugging module to make the DC partition HVDC model reach a stable state;

[0013] S7, large power grid merging: Through the automatic debugging Debug module, the stable DC partition HVDC model in step S6 and the stable AC partition R_ac and I_ac models on both sides in step S3 are merged into a large power grid, and the boundary grids on both sides are connected with wires to generate a full electromagnetic transient model of the AC and DC large grid.

[0014] Furthermore, step S1 specifically includes:

[0015] The target power grid is divided into two zones: the single DC system is recorded as the HVDC zone, and the AC systems at the DC sending and receiving ends are divided into two zones at the AC connecting bus on both sides, recorded as the R_ac zone and the I_ac zone; the electromagnetic transient data of the R_ac zone and the I_ac zone and the boundary bus node number connected to the DC system are passed into the automatic debugging Debug module as parameters.

[0016] Furthermore, step S2 specifically includes:

[0017] The automatic debugging Debug module automatically adds resistive load and inductive load at the boundary bus of the AC R_ac zone by reading the voltage amplitude and phase angle, active power and reactive power of the AC partition boundary bus node, and automatically adds an ideal voltage source at the boundary bus of the AC I_ac zone. The parameter values ​​are obtained through the data in step S1; the short-circuit ratios Rscr and Iscr at the boundary bus nodes of the AC power grid AC partitions R_ac and I_ac are calculated.

[0018] Furthermore, step S3 specifically includes:

[0019] Perform electromagnetic transient simulation calculations on the AC power grids of AC partitions R_ac and I_ac, and generate calculation result files R_ac.out and I_ac.out. Through the automatic debugging Debug module, compare the node voltage amplitude and phase angle in R_ac.out and I_ac.out with those in power.out. If the relative error is greater than 0.01, it is considered that the power grid state has not reached the same stable state. Adjust the parameter values ​​of the boundary node connections and continue the calculation until the relative error is less than 0.01.

[0020] Furthermore, step S4 specifically includes:

[0021] The voltage amplitude and phase angle, active and reactive values ​​and short-circuit ratios Rscr and Iscr at the bus nodes of the AC power grid of the AC partitions R_ac and I_ac are input into the Debug module to calculate the voltage amplitude and phase angle of the ideal voltage source at the sending and receiving ends of the DC system, the sending end reactance value Rxl, and the receiving end reactance value Ixl.

[0022] Furthermore, step S5 specifically includes:

[0023] Step 1: 1 modeling process of DC partitioned HVDC primary system;

[0024] In the second step, the DC partition HVDC control and protection system is modeled according to the actual engineering data, and the protection system only models the main protection.

[0025] Step 3: The automatic debugging module reads the voltage amplitude and phase angle of the ideal voltage source at both ends of the DC in step S4, and assigns the voltage amplitude and phase angle to the sending and receiving ends of the DC partition HVDC;

[0026] Step 4: Automatic debugging The Debug module reads the DC sending end reactance value Rx1 and the receiving end reactance value Ix1 in step S4, and assigns them to the setting of the parameters of the DC partition HVDC sending end and receiving end AC reactors.

[0027] Step 5: Automatic debugging The Debug module generates a DC partition HVDC electromagnetic transient simulation model HVDC.inf based on the completion of the first four steps.

[0028] Further, step S6 specifically includes:

[0029] A large-scale full electromagnetic transient simulation program is used to calculate the DC partition HVDC model to generate the DC simulation result hvdc.out. Through the automatic debugging Debug module, the voltage, current and power at the AC connection bus in hvdc.out are compared with the electromechanical transient flow data power.out result data of the known target power grid, and the parameters are adjusted until the relative error is less than 0.01, so that the DC system can achieve steady-state operation.

[0030] Furthermore, step S7 specifically includes:

[0031] Through the automatic debugging Debug module, the load is disconnected at the boundary bus node of the AC R_ac zone and connected to the sending-end bus node of the DC system HVDC zone; the voltage source is disconnected at the boundary bus node of the AC I_ac zone and connected to the receiving-end bus node of the DC system HVDC zone, and the AC / DC large network model file is generated, and the large-scale electromagnetic transient calculation program is called for calculation.

[0032] The beneficial effects of the present invention are as follows:

[0033] Aiming at the modeling and debugging of large-scale AC and DC systems, the present invention proposes an automatic debugging modeling method, which can automatically add debugging elements and parameters to the AC and DC power grid according to the input electromagnetic transient model file of the whole network and the boundary bus name and other data, and generate a full electromagnetic transient simulation model of the large AC and DC power grid, providing strong support for the modeling and debugging of large-scale AC and DC transmission systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a flow chart of a method for fully automatic debugging and modeling of electromagnetic transient simulation of AC and DC power grids provided by the present invention;

[0035] Figure 2 This is a schematic diagram of AC and DC partitioning according to an embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of AC partition boundary processing according to an embodiment of the present invention;

[0037] Figure 4 is a schematic diagram of DC partition boundary processing according to an embodiment of the present invention;

[0038] Figure 5 This is a functional schematic diagram of an automatic debugging Debug module according to an embodiment of the present invention;

[0039] Figure 6 It is a fault side bus voltage simulation diagram and a recording comparison diagram of an embodiment of the present invention;

[0040] Figure 7 It is a simulation diagram of the current injected into the fault-side busbar and a comparison diagram of the recorded waveform in an embodiment of the present invention;

[0041] in Figure 6 , Figure 7 In the figure, blue is the recorded data and red is the simulated data. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] See also Figure 1 The embodiment of the present invention provides a method for fully automatic debugging and modeling of electromagnetic transient simulation of AC and DC power grids, comprising the following steps:

[0044] S1. The target power grid is divided into DC and AC systems. A single DC system is recorded as an HVDC area. The AC systems at the DC sending end and the receiving end are divided into two areas at the AC connecting busbars on both sides, which are recorded as R_ac area and I_ac area. Step S1 specifically includes the following steps:

[0045] See also Figure 2 , AC / DC system partition diagram, the AC system at the sending end and the receiving end of the DC system is connected to the AC bus on both sides through the dynamic debugging Debug module (such as Figure 5 As shown in the figure, the system is divided into two partitions, and the electromagnetic transient files R_ac.inf and I_ac.inf of the R_ac zone and the I_ac zone are generated. The boundary bus node numbers of the R_ac zone and the I_ac zone connected to the DC system are passed into the automatic debugging Debug module as parameters.

[0046] S2. Automatically process the boundary grids of the AC grid partitions R_ac and I_ac at the DC sending end and the receiving end through the Debug module, and calculate the short-circuit ratios Rscr and Iscr at the boundary bus nodes of the AC partitions R_ac and I_ac;

[0047] See also Figure 3 , step S2 specifically includes the following steps:

[0048] The automatic debugging Debug module reads the voltage amplitude and phase angle, active and reactive power of the boundary bus nodes of the AC partition, searches for the resistive load and inductive load model data at the boundary bus nodes in the AC R_ac area file R_ac.inf, and automatically adds the ideal voltage source model data at the boundary bus in the AC I_ac area file I_ac.inf, and calculates the short-circuit ratios Rscr and Iscr at the boundary bus nodes of the AC power grid AC partitions R_ac and I_ac.

[0049] The calculation formula of short circuit ratio is shown in (1):

[0050]

[0051] In the formula, S ac is the short-circuit capacity of the AC system, P dN is the system rated power, U N is the rated AC voltage, and Z is the AC system impedance.

[0052] S3, performing electromagnetic transient simulation calculation on the AC power grids of the AC partitions R_ac and I_ac, generating calculation result files R_ac.out and I_ac.out, comparing them with the electromechanical transient power flow data power.out of the known target power grid, and automatically adjusting the parameter values ​​of the boundary nodes so that the AC power grids of the AC partitions R_ac and I_ac reach a stable state; step S3 specifically includes the following steps:

[0053] Through the automatic debugging Debug module, the node voltage amplitude and phase angle in the two output files are compared. If the relative error is greater than 0.01, it is considered that the power grid state is not consistent with the stable state. The parameter values ​​of the voltage source and load connected to the boundary node are adjusted, and the calculation is continued until the relative error is less than 0.01.

[0054] S4. Calculate the voltage amplitude and phase angle of the ideal voltage source at the sending and receiving ends of the DC partition HVDC through the automatic debugging module, as well as the reactance value Rxl at the sending end and the reactance value Ixl at the receiving end;

[0055] S5, artificially modeling the DC partition HVDC in step S1 as an independent power grid, with parameters derived from actual engineering data, and configuring the DC partition HVDC sending and receiving end voltage source and equivalent reactance value parameters based on the voltage amplitude and phase angle of the ideal voltage source at the sending and receiving ends of the DC partition HVDC calculated in step S4, as well as the sending end reactance value Rx1 and the receiving end reactance value Ix1 through the automatic debugging module, to generate the DC partition HVDC electromagnetic transient simulation model HVDC.inf. Step S5 specifically includes the following steps:

[0056] Step 1: 1 modeling process of DC partitioned HVDC primary system;

[0057] In the second step, the DC partition HVDC control and protection system is modeled according to the actual engineering data, and the protection system only models the main protection.

[0058] Step 3: The automatic debugging module reads the voltage amplitude and phase angle of the ideal voltage source at both ends of the DC in step S4, and assigns the voltage amplitude and phase angle to the sending and receiving ends of the DC partition HVDC;

[0059] Step 4: Automatic debugging: The debug module reads the DC sending end reactance value Rx1 and the receiving end reactance value Ix1 in step S4, and assigns them to the setting of the parameters of the DC partition HVDC sending end and receiving end AC reactors;

[0060] Step 5: Automatic debugging The Debug module generates a DC partition HVDC electromagnetic transient simulation model HVDC.inf based on the completion of the first four steps.

[0061] S6, using a large-scale full electromagnetic transient simulation program to perform electromagnetic transient simulation calculations on the DC partition HVDC electromagnetic transient simulation model in step S5, to obtain a DC partition HVDC model simulation result hvdc.out, and debugging the DC partition HVDC model through an automatic debugging module to make the DC partition HVDC model reach a stable state. Step S6 specifically includes the following steps:

[0062] The large-scale full electromagnetic transient simulation program is called to calculate the DC model file HVDC.inf and generate the result file HVDC.out. Through the automatic debugging Debug module, the voltage, current and power at the AC connection bus in hvdc.out are compared with the electromechanical transient flow data power.out result data of the known target power grid, and the parameters are adjusted until the relative error is less than 0.01, so that the DC system can reach steady-state operation.

[0063] S7, merging the large power grid, merging the DC partition and the AC partitions on both sides into a large power grid, and connecting the boundary grids on both sides with wires. Step S7 specifically includes the following steps:

[0064] Through the automatic debugging Debug module, the load model is disconnected at the boundary bus node of the AC R_ac zone and connected to the sending-end bus node of the DC system HVDC zone; the voltage source model is disconnected at the boundary bus node of the AC I_ac zone and connected to the receiving-end bus node of the DC system HVDC zone, the AC / DC large network model file HVDC.inf is generated, and the large-scale electromagnetic transient calculation program is called for calculation.

[0065] To verify the practicality of the present invention, please refer to Figure 6 , Figure 7 , the fault waveform of the electromagnetic transient model of the AC / DC large power grid was compared with the engineering recording data. The fault point was a single-phase grounding fault on the DC receiving valve side: an instantaneous grounding fault of phase A of the AC line on the Hubei side was set at 3.985s, and the fault was eliminated at 4.0172s, and the fault crossing was successful, which was consistent with the waveform of the on-site recording diagram.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for automatic debugging and modeling of full electromagnetic transient simulation of AC and DC power grids, characterized in that: The steps include: S1, partition the target power grid into a DC partition HVDC and AC partitions R_ac and I_ac, and transfer the electromagnetic transient data of the AC partition to the automatic debugging module; S2. Automatically process the boundary power grid of the AC partitions R_ac and I_ac through the Debug module, and calculate the short-circuit ratios Rscr and Iscr at the boundary bus nodes of the AC partitions R_ac and I_ac; S3, based on the short-circuit ratios Rscr and Iscr calculated in step S2, perform electromagnetic transient simulation calculation on the AC power grids of the AC partitions R_ac and I_ac, generate calculation result files R_ac.out and I_ac.out, compare them with the electromechanical transient power flow data power.out of the known target power grid, and make the AC partition R_ac and I_ac models reach a stable state; S4, through the automatic debugging Debug module, calculate the voltage amplitude, phase angle, sending end reactance value Rxl and receiving end reactance value Ixl of the ideal voltage source of the HVDC sending end and receiving end in S1; S5. Manually model the DC partition HVDC in step S1 as an independent power grid, with parameters derived from actual engineering data. Through the automatic debugging module, the voltage amplitude and phase angle of the ideal voltage sources at the sending and receiving ends of the DC partition HVDC calculated in step S4, as well as the sending end reactance value Rx1 and the receiving end reactance value Ix1 are configured to generate the DC partition HVDC electromagnetic transient simulation model HVDC.inf. S6, using a large-scale full electromagnetic transient simulation program to perform electromagnetic transient simulation calculations on the DC partition HVDC electromagnetic transient simulation model in step S5, obtaining a DC partition HVDC model simulation result hvdc.out, and debugging the DC partition HVDC model through an automatic debugging module to make the DC partition HVDC model reach a stable state; S7, large power grid merging: Through the automatic debugging Debug module, the stable DC partition HVDC model in step S6 and the stable AC partition R_ac and I_ac models on both sides in step S3 are merged into a large power grid, and the boundary grids on both sides are connected with wires to generate a full electromagnetic transient model of the AC and DC large grid.

2. The method for automatic debugging and modeling of full electromagnetic transient simulation of AC and DC power grids according to claim 1, characterized in that: Step S1 specifically includes: The target power grid is divided into two zones: the single DC system is recorded as the HVDC zone, and the AC systems at the DC sending and receiving ends are divided into two zones at the AC connecting bus on both sides, recorded as the R_ac zone and the I_ac zone; the electromagnetic transient data of the R_ac zone and the I_ac zone and the boundary bus node number connected to the DC system are passed into the automatic debugging Debug module as parameters.

3. The method for automatic debugging and modeling of full electromagnetic transient simulation of AC and DC power grids according to claim 1, characterized in that: Step S2 specifically includes: The automatic debugging Debug module automatically adds resistive load and inductive load at the boundary bus of the AC R_ac zone by reading the voltage amplitude and phase angle, active power and reactive power of the AC partition boundary bus node, and automatically adds an ideal voltage source at the boundary bus of the AC I_ac zone. The parameter values ​​are obtained through the data in step S1; the short-circuit ratios Rscr and Iscr at the boundary bus nodes of the AC power grid AC partitions R_ac and I_ac are calculated.

4. The method for automatic debugging and modeling of full electromagnetic transient simulation of AC and DC power grids according to claim 1, characterized in that: Step S3 specifically includes: Perform electromagnetic transient simulation calculations on the AC power grids of AC partitions R_ac and I_ac, and generate calculation result files R_ac.out and I_ac.out. Through the automatic debugging Debug module, compare the node voltage amplitude and phase angle in R_ac.out and I_ac.out with those in power.out. If the relative error is greater than 0.01, it is considered that the power grid state has not reached the same stable state. Adjust the parameter values ​​of the boundary node connections and continue the calculation until the relative error is less than 0.

01.

5. The method for automatic debugging and modeling of full electromagnetic transient simulation of AC and DC power grids according to claim 1, characterized in that: Step S4 specifically includes: The voltage amplitude and phase angle, active and reactive values ​​and short-circuit ratios Rscr and Iscr at the bus nodes of the AC power grid of the AC partitions R_ac and I_ac are input into the Debug module to calculate the voltage amplitude and phase angle of the ideal voltage source at the sending and receiving ends of the DC system, the sending end reactance value Rxl, and the receiving end reactance value Ixl.

6. The method for automatic debugging and modeling of full electromagnetic transient simulation of AC and DC power grids according to claim 1, characterized in that: Step S5 specifically includes: Step 1: 1 modeling process of DC partitioned HVDC primary system; In the second step, the DC partition HVDC control and protection system is modeled according to the actual engineering data, and the protection system only models the main protection. Step 3: The automatic debugging module reads the voltage amplitude and phase angle of the ideal voltage source at both ends of the DC in step S4, and assigns the voltage amplitude and phase angle to the sending and receiving ends of the DC partition HVDC; Step 4: Automatic debugging The Debug module reads the DC sending end reactance value Rx1 and the receiving end reactance value Ix1 in step S4, and assigns them to the setting of the parameters of the DC partition HVDC sending end and receiving end AC reactors. Step 5: Automatic debugging The Debug module generates a DC partition HVDC electromagnetic transient simulation model HVDC.inf based on the completion of the first four steps.

7. The method for automatic debugging and modeling of full electromagnetic transient simulation of AC and DC power grids according to claim 1, characterized in that: Step S6 specifically includes: A large-scale full electromagnetic transient simulation program is used to calculate the DC partition HVDC model to generate the DC simulation result hvdc.out. Through the automatic debugging Debug module, the voltage, current and power at the AC connection bus in hvdc.out are compared with the electromechanical transient flow data power.out result data of the known target power grid, and the parameters are adjusted until the relative error is less than 0.01, so that the DC system can achieve steady-state operation.

8. The method for automatic debugging and modeling of full electromagnetic transient simulation of AC and DC power grids as claimed in claim 1, characterized in that: Step S7 specifically includes: Through the automatic debugging Debug module, the load is disconnected at the boundary bus node of the AC R_ac zone and connected to the sending-end bus node of the DC system HVDC zone; the voltage source is disconnected at the boundary bus node of the AC I_ac zone and connected to the receiving-end bus node of the DC system HVDC zone, and the AC / DC large network model file is generated, and the large-scale electromagnetic transient calculation program is called for calculation.

Images