A method and system for real-time simulation and result statistics of HVDC commutation failure based on script-automated execution.

Abstract

This invention provides a method and system for real-time simulation and result statistics of HVDC commutation failure based on script-driven automatic execution. The method includes: building an HVDC transmission system in a real-time simulation system; writing a batch processing program in a script file; simulating various simulation conditions through the batch processing program; and automatically controlling the real-time simulation system to simulate fault conditions under different operating conditions. After the simulation, based on the characteristics of commutation failure and related state variables, the script file automatically generates simulation waveforms and state variable reports required for analyzing commutation failure. The state variable reports include the minimum effective value of the inverter-side AC voltage, the minimum value of the inverter-side arc extinction angle, the maximum value of the synchronous condenser excitation current, whether commutation failure occurred, and the number of times commutation failure occurred. This invention controls the real-time simulation system to simulate fault conditions under different operating conditions through script program files, achieving repeatable and batch processing effects, thus improving the efficiency and accuracy of the simulation.

Description

Technical Field

[0001] This invention relates to the field of power system safety and stability technology, specifically to a method and system for real-time simulation and result statistics of HVDC commutation failure based on script automatic execution. Background Technology

[0002] RTDS (Real-Time Digital Simulation) is a real-time, fully digital electromagnetic transient simulation device for power systems. Its component models and simulation accuracy have gained high recognition in the simulation field and are widely used in electrical equipment simulation experiments, especially relay protection equipment verification tests. It is an important verification tool for studying and analyzing power system characteristics and conducting closed-loop tests on relay protection.

[0003] For typical power system RTDS simulation models, depending on the combination of different test items such as system operating status, fault location, and fault type, there are often hundreds or even thousands of test operation steps. The repetitiveness and complexity of the tests are relatively high, and the final test results, such as the storage of test waveforms, feedback from the tested object, and records of action behavior, are also very large and scattered. If relying solely on manual judgment and processing, it is time-consuming, labor-intensive, and inefficient. Therefore, the automated testing of RTDS simulation systems is essential.

[0004] Currently, the main method for automated testing is through the script editing function of RTDS simulation systems. Existing RTDS script editing technology often determines whether the system has reached steady state by starting the simulation and waiting for a sufficiently long time, without providing specific criteria. Furthermore, existing script editing is not designed for commutation failures in UHVDC transmission systems, lacking relevant scripts for judging commutation failures and counting the number of failures. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for real-time simulation and result statistics of HVDC commutation failure based on script-automated execution.

[0006] The method for real-time simulation and result statistics of HVDC commutation failure based on script-driven automatic execution provided by the present invention includes:

[0007] Step 1: Build a model of the UHVDC transmission system in the real-time simulation system, and use script files to determine whether the operation of the UHVDC transmission system has reached a steady state;

[0008] Step 2: Write a batch program in the script file to set different fault types. When the HVDC DC transmission system reaches steady state, the automatic control real-time simulation system will simulate different simulation conditions.

[0009] Step 3: After the simulation is completed, use the script file to write a program to automatically generate the simulation waveform and state variable report required for analyzing the commutation failure, based on the characteristics of the commutation failure and the relevant state variables.

[0010] Preferably, in step 1:

[0011] The script file references the state variables of the HVDC transmission system, including: the arc extinction angle on the inverter side, the firing angle on the rectifier side, the effective value of the AC voltage on the inverter side, the DC voltage on the rectifier side, and the DC voltage on the inverter side.

[0012] A function program is written using a script file. After the HVDC transmission system has been running for a period of time during initialization, the function calculates the referenced state variables and obtains the maximum and minimum values ​​of the arc extinction angle pk_gama and vy_gama on the inverter side, the maximum and minimum values ​​of the firing angle pk_alpha and vy_alpha on the rectifier side, the maximum and minimum values ​​of the effective AC voltage pk_Urms and vy_Urms on the inverter side, the maximum and minimum values ​​of the DC voltage pk_UdcR and vy_UdcR on the rectifier side, and the maximum and minimum values ​​of the DC voltage pk_UdcI and vy_UdcI on the inverter side.

[0013] When the following equations are simultaneously satisfied, the HVDC direct current transmission system is considered to have reached steady state:

[0014]

[0015] Wherein, c1, c2, c3, c4, and c5 are the upper limits of the fluctuation of the state variables referenced when the HVDC DC transmission system reaches a steady state;

[0016] The script file contains a program to make the HVDC transmission system reach a steady state. After the DC transmission system has been running for a period of time since initialization, the steady-state judgment formula mentioned above is used to determine whether each state variable meets the requirements. If all the introduced state variables meet the requirements, the DC transmission system is judged to have reached a steady state. If not all the introduced state variables meet the requirements, the DC transmission system is made to run for a period of time, and the steady-state formula is used again for judgment. This process is repeated until the requirements are met.

[0017] Preferably, in step 2, different fault resistances, fault durations, fault types, short-circuit ratios of the inverter-side AC system, and whether a synchronous condenser is engaged are set to analyze commutation failures under different simulation conditions.

[0018] Preferably, the fault resistance is selected from multiple sets of values ​​from low to high, ranging from 0.1 ohms to 20 ohms; the fault duration is selected from multiple sets of values, ranging from 100ms to 500ms; the AC system short-circuit ratio is selected from multiple sets of values, ranging from 3 to 15; the fault type is selected from two sets of values, choosing from three-phase fault, two-phase ground fault, and single-phase fault; and the synchronous condenser activation status is selected from two sets, namely, synchronous condenser activated and synchronous condenser not activated.

[0019] Preferably, step 3 includes:

[0020] After the simulation is completed, according to the need to analyze commutation failure, select the simulation waveforms to be stored for each simulation, use a script file to write a program to save the required simulation waveforms as JPG and MPB files, and place the saved JPG and MPB files in the folder specified by the program.

[0021] A program is written using a script file to cyclically name the simulation waveforms stored in the simulation. The program sets the fault resistance to be i types, the fault type to t types, the fault duration to k types, the short-circuit ratio of the inverter-side AC system to m types, and the synchronous condenser engagement / disengagement status to n types. The simulation waveforms stored in each simulation are named TPt_Ri_Tk_SCRm, representing the simulation waveforms under the t-th fault type, the i-th fault resistance, the k-th fault duration, and the m-th short-circuit ratio.

[0022] To analyze commutation failure, a program is written in the script file to store the state variables required for analysis in the form of a report. The state variables required for analysis include: the minimum effective value of the inverter side AC voltage, the minimum value of the inverter side arc extinction angle, the maximum value of the synchronous condenser excitation current, the maximum value of the synchronous condenser excitation voltage, whether commutation failure has occurred, and the number of times commutation failure has occurred.

[0023] The minimum effective value of the inverter-side AC voltage, the minimum value of the inverter-side arc extinction angle, the maximum value of the synchronous condenser excitation current, and the maximum value of the synchronous condenser excitation voltage are calculated by writing program functions in the script file; the formulas for judging whether commutation failure has occurred and the number of commutation failures are as follows:

[0024]

[0025] When there is a situation where the inverter-side arc extinction angle gama(t) at the current time t is zero, and the inverter-side arc extinction angle gama(t+1) at the next time is greater than zero, this is recorded as a commutation failure. If this situation occurs again, the number of commutation failures is incremented by one. If this situation does not occur, it is considered that no commutation failure fault has occurred.

[0026] The real-time simulation and result statistics system for HVDC commutation failure based on script automatic execution provided by the present invention includes:

[0027] Module M1: Build a model of the UHVDC transmission system in the real-time simulation system and use script files to determine whether the operation of the UHVDC transmission system has reached a steady state;

[0028] Module M2: Write a batch program in the script file to set different fault types. When the HVDC DC transmission system reaches steady state, the automatic control real-time simulation system will simulate different simulation conditions.

[0029] Module M3: After the simulation is completed, a program is written using a script file to automatically generate the simulation waveforms and state variable reports needed to analyze the commutation failure, based on the characteristics of the commutation failure and the relevant state variables.

[0030] Preferably, in module M1:

[0031] The script file references the state variables of the HVDC transmission system, including: the arc extinction angle on the inverter side, the firing angle on the rectifier side, the effective value of the AC voltage on the inverter side, the DC voltage on the rectifier side, and the DC voltage on the inverter side.

[0032] A function program is written using a script file. After the HVDC transmission system has been running for a period of time during initialization, the function calculates the referenced state variables and obtains the maximum and minimum values ​​of the arc extinction angle pk_gama and vy_gama on the inverter side, the maximum and minimum values ​​of the firing angle pk_alpha and vy_alpha on the rectifier side, the maximum and minimum values ​​of the effective AC voltage pk_Urms and vy_Urms on the inverter side, the maximum and minimum values ​​of the DC voltage pk_UdcR and vy_UdcR on the rectifier side, and the maximum and minimum values ​​of the DC voltage pk_UdcI and vy_UdcI on the inverter side.

[0033] When the following equations are simultaneously satisfied, the HVDC direct current transmission system is considered to have reached steady state:

[0034]

[0035] Wherein, c1, c2, c3, c4, and c5 are the upper limits of the fluctuation of the state variables referenced when the HVDC DC transmission system reaches a steady state;

[0036] The script file contains a program to make the HVDC transmission system reach a steady state. After the DC transmission system has been running for a period of time since initialization, the steady-state judgment formula mentioned above is used to determine whether each state variable meets the requirements. If all the introduced state variables meet the requirements, the DC transmission system is judged to have reached a steady state. If not all the introduced state variables meet the requirements, the DC transmission system is made to run for a period of time, and the steady-state formula is used again for judgment. This process is repeated until the requirements are met.

[0037] Preferably, in module M2, different fault resistances, fault durations, fault types, short-circuit ratios of the inverter-side AC system, and whether a synchronous condenser is engaged are set to analyze commutation failures under different simulation conditions.

[0038] Preferably, the fault resistance is selected from multiple sets of values ​​from low to high, ranging from 0.1 ohms to 20 ohms; the fault duration is selected from multiple sets of values, ranging from 100ms to 500ms; the AC system short-circuit ratio is selected from multiple sets of values, ranging from 3 to 15; the fault type is selected from two sets of values, choosing from three-phase fault, two-phase ground fault, and single-phase fault; and the synchronous condenser activation status is selected from two sets, namely, synchronous condenser activated and synchronous condenser not activated.

[0039] Preferably, the module M3 includes:

[0040] After the simulation is completed, according to the need to analyze commutation failure, select the simulation waveforms to be stored for each simulation, use a script file to write a program to save the required simulation waveforms as JPG and MPB files, and place the saved JPG and MPB files in the folder specified by the program.

[0041] A program is written using a script file to cyclically name the simulation waveforms stored in the simulation. The program sets the fault resistance to be i types, the fault type to t types, the fault duration to k types, the short-circuit ratio of the inverter-side AC system to m types, and the synchronous condenser engagement / disengagement status to n types. The simulation waveforms stored in each simulation are named TPt_Ri_Tk_SCRm, representing the simulation waveforms under the t-th fault type, the i-th fault resistance, the k-th fault duration, and the m-th short-circuit ratio.

[0042] To analyze commutation failure, a program is written in the script file to store the state variables required for analysis in the form of a report. The state variables required for analysis include: the minimum effective value of the inverter side AC voltage, the minimum value of the inverter side arc extinction angle, the maximum value of the synchronous condenser excitation current, the maximum value of the synchronous condenser excitation voltage, whether commutation failure has occurred, and the number of times commutation failure has occurred.

[0043] The minimum effective value of the inverter-side AC voltage, the minimum value of the inverter-side arc extinction angle, the maximum value of the synchronous condenser excitation current, and the maximum value of the synchronous condenser excitation voltage are calculated by writing program functions in the script file; the formulas for judging whether commutation failure has occurred and the number of commutation failures are as follows:

[0044]

[0045] When there is a situation where the inverter-side arc extinction angle gama(t) at the current time t is zero, and the inverter-side arc extinction angle gama(t+1) at the next time is greater than zero, this is recorded as a commutation failure. If this situation occurs again, the number of commutation failures is incremented by one. If this situation does not occur, it is considered that no commutation failure fault has occurred.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] This invention is simple and easy to implement, and has practical applications. It uses script program files to determine whether the UHVDC transmission system has reached a steady state, eliminating the need for manual observation. By controlling the real-time simulation system through script program files, it can simulate fault conditions under different operating conditions, achieving repeatable and batch processing effects, thus improving the efficiency and accuracy of simulation. After the simulation is completed, the graph is automatically saved, and the script program files record data such as the number of commutation failures, making the operation more convenient and the results more intuitive. Attached Figure Description

[0048] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0049] Figure 1 This is a flowchart of a real-time simulation and result statistics method for HVDC commutation failure based on automatic script execution proposed in an embodiment of the present invention;

[0050] Figure 2 This is a flowchart illustrating the steady-state operation of the HVDC direct current transmission system proposed in this embodiment of the invention.

[0051] Figure 3 This is a logic diagram for determining the number of commutation failures as proposed in an embodiment of the present invention;

[0052] Figure 4 This is a diagram of the report file generated in an embodiment of the present invention. Detailed Implementation

[0053] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0054] Example 1

[0055] like Figure 1 This invention proposes a real-time simulation and result statistics method for HVDC commutation failure based on automatic script execution, comprising the following steps:

[0056] Step 1: Build a model of the HVDC transmission system in the real-time simulation system, and use script files to determine whether the ultra-high voltage DC transmission system has reached a steady state.

[0057] Step 2: Write a batch program in the script file to set different fault types. When the HVDC DC transmission system reaches a steady state, the automatic control real-time simulation system will simulate different simulation conditions.

[0058] Step 3: After the simulation is completed, use the script file to write a program to automatically generate the simulation waveform and state variable report required for analyzing the commutation failure, based on the characteristics of the commutation failure and the relevant state variables.

[0059] Step 1 includes:

[0060] A model of the HVDC direct current transmission system is built in a real-time simulation system, and a script file is used to determine whether the HVDC direct current transmission system has reached a steady state.

[0061] The script file references state variables in the HVDC transmission system, including: the arc extinction angle on the inverter side, the firing angle on the rectifier side, the effective value of the AC voltage on the inverter side, the DC voltage on the rectifier side, and the DC voltage on the inverter side, which are variables closely related to commutation failure.

[0062] Write a function program in the script file. After the HVDC transmission system has been running for a certain period of time during initialization, use the function to calculate the referenced state variables and obtain the maximum and minimum values ​​of the arc extinction angle pk_gama and vy_gama on the inverter side, the maximum and minimum values ​​of the firing angle pk_alpha and vy_alpha on the rectifier side, the maximum and minimum values ​​of the effective AC voltage pk_Urms and vy_Urms on the inverter side, the maximum and minimum values ​​of the DC voltage pk_UdcR and vy_UdcR on the rectifier side, and the maximum and minimum values ​​of the DC voltage pk_UdcI and vy_UdcI on the inverter side.

[0063] When the following equations are satisfied simultaneously, the HVDC direct current transmission system is considered to have reached a steady state.

[0064]

[0065] Where c1, c2, c3, c4, and c5 are the upper limits of the fluctuations of the state variables referenced when the HVDC direct current transmission system reaches a steady state.

[0066] The script file contains a program that enables the HVDC transmission system to reach a steady state. After the system initializes and runs for a certain period, the steady-state determination formula is used to check whether each state variable meets the requirements. If all introduced state variables meet the requirements, the system is considered to have reached a steady state. If not, the system runs for another T seconds, and the steady-state formula is used again. This process is repeated until the requirements are met. The flowchart for determining whether the HVDC transmission system has reached a steady state is shown below. Figure 2 As shown.

[0067] Step 2 includes:

[0068] A batch program is written in the script file to set different fault types. When the UHVDC transmission system reaches a steady state, the automatic control real-time simulation system simulates different simulation conditions.

[0069] To analyze the impact of different factors on commutation failure, different fault resistances, fault durations, fault types, short-circuit ratios of the inverter-side AC system, and whether or not a synchronous condenser is engaged were set to analyze the commutation failure under different simulation conditions.

[0070] Step 3 includes:

[0071] After the simulation, a program is written using a script file to automatically generate the simulation waveforms and state variable reports needed for analyzing commutation failure, based on the characteristics and related state variables. After the simulation, according to the needs of analyzing commutation failure, the program selects the simulation waveforms to be stored for each simulation, and saves the required simulation waveforms as JPG and MPB files using a script file. The saved JPG and MPB files are then placed in the folder specified by the program.

[0072] A program is written using a script file to cyclically name the simulation waveforms stored in the simulation. The program sets the fault resistance to be of type i, the fault type to be type t, the fault duration to be type k, the short-circuit ratio of the inverter-side AC system to be type m, and the synchronous condenser engagement / disengagement status to be type n. The simulation waveforms stored in each simulation are named TPt_Ri_Tk_SCRm, representing the simulation waveforms under the t-th fault type, the i-th fault resistance, the k-th fault duration, and the m-th short-circuit ratio.

[0073] To analyze commutation failures, a program is written in the script file to store the required state variables in report form. The required state variables include: the minimum effective value of the inverter-side AC voltage, the minimum value of the inverter-side arc extinction angle, the maximum value of the synchronous condenser excitation current, the maximum value of the synchronous condenser excitation voltage, whether commutation failure has occurred, and the number of times commutation failure has occurred.

[0074] The minimum effective value of the inverter-side AC voltage, the minimum value of the inverter-side arc extinction angle, the maximum value of the synchronous condenser excitation current, and the maximum value of the synchronous condenser excitation voltage are calculated by writing program functions in the script file. The formulas for determining whether commutation failure has occurred and the number of commutation failures are as follows:

[0075]

[0076] That is, if the current inverter-side arc-extinguishing angle is zero, and the next moment the inverter-side arc-extinguishing angle is greater than zero, this is recorded as a commutation failure. If this situation occurs again, the commutation failure count is incremented by one. If this situation does not occur, it is considered that no commutation failure has occurred. The logic diagram for determining the number of commutation failures is as follows: Figure 3 As shown.

[0077] To verify the proposed method for real-time simulation and result statistics of HVDC commutation failure based on automatic script execution, a script was written in RTDS to perform real-time simulation and result statistics of commutation failure in an HVDC transmission system, using an RTDS simulation example. The script program was designed with 72 simulation conditions, including: 3 fault resistances (0.5 ohms, 5 ohms, 15 ohms), 2 fault durations (100ms, 500ms), 2 fault types (single-phase grounding, three-phase grounding), and 3 AC system short-circuit ratios (15, 8, 5).

[0078] The naming convention for stored operating conditions is as follows: TPt_Ri_Tk_SCRm represents the simulation waveform under the following conditions: fault type t, fault resistance ith, fault duration k, and short-circuit ratio m. TP0 and TP1 represent three-phase fault and single-phase fault, respectively; R0, R1, and R2 represent fault resistances of 5 ohms, 0.5 ohms, and 15 ohms, respectively; T0 and T1 represent fault durations of 100ms and 500ms, respectively; and SCR0, SCR1, and SCR2 represent AC system short-circuit ratios of 15, 8, and 5, respectively. For example, R0TP0T1_SCR2 represents a simulation condition with a fault resistance of 5 ohms, a three-phase fault type, a fault duration of 1500ms, and an AC system short-circuit ratio of 5.

[0079] The naming convention for report files is as follows: vy_volts represents the minimum effective value of the inverter-side AC bus voltage; vy_gama represents the minimum arc extinction angle on the inverter side; pk_volts represents the maximum effective value of the inverter-side AC bus voltage; pk_If represents the maximum value of the phase condenser excitation current; pk_Ef represents the maximum value of the phase condenser excitation voltage; and NoCF represents the number of commutation failures. The generated report files are as follows: Figure 4 As shown.

[0080] Example 2

[0081] This invention also provides a real-time simulation and result statistics system for HVDC commutation failure based on automatic script execution. The real-time simulation and result statistics system for HVDC commutation failure based on automatic script execution can be implemented by executing the process steps of the real-time simulation and result statistics method for HVDC commutation failure based on automatic script execution. That is, those skilled in the art can understand the real-time simulation and result statistics method for HVDC commutation failure based on automatic script execution as a preferred embodiment of the real-time simulation and result statistics system for HVDC commutation failure based on automatic script execution.

[0082] The real-time simulation and result statistics system for HVDC commutation failure based on script automatic execution provided by the present invention includes: Module M1: building a model of the HVDC DC transmission system in the real-time simulation system, and using a script file to determine whether the ultra-high voltage DC transmission system has reached a steady state; Module M2: writing a batch processing program in the script file to set different fault types, and automatically controlling the real-time simulation system to simulate different simulation conditions when the HVDC DC transmission system reaches a steady state; Module M3: after the simulation is completed, using a script file to write a program to automatically generate the simulation waveform diagram and state variable report required for analyzing the commutation failure based on the characteristics of the commutation failure and related state variables.

[0083] In module M1:

[0084] The script file references the state variables of the HVDC transmission system, including: the arc extinction angle on the inverter side, the firing angle on the rectifier side, the effective value of the AC voltage on the inverter side, the DC voltage on the rectifier side, and the DC voltage on the inverter side.

[0085] A function program is written using a script file. After the HVDC transmission system has been running for a period of time during initialization, the function calculates the referenced state variables and obtains the maximum and minimum values ​​of the arc extinction angle pk_gama and vy_gama on the inverter side, the maximum and minimum values ​​of the firing angle pk_alpha and vy_alpha on the rectifier side, the maximum and minimum values ​​of the effective AC voltage pk_Urms and vy_Urms on the inverter side, the maximum and minimum values ​​of the DC voltage pk_UdcR and vy_UdcR on the rectifier side, and the maximum and minimum values ​​of the DC voltage pk_UdcI and vy_UdcI on the inverter side.

[0086] When the following equations are simultaneously satisfied, the HVDC direct current transmission system is considered to have reached steady state:

[0087]

[0088] Wherein, c1, c2, c3, c4, and c5 are the upper limits of the fluctuation of the state variables referenced when the HVDC DC transmission system reaches a steady state;

[0089] The script file contains a program to make the HVDC transmission system reach a steady state. After the DC transmission system has been running for a period of time since initialization, the steady-state judgment formula mentioned above is used to determine whether each state variable meets the requirements. If all the introduced state variables meet the requirements, the DC transmission system is judged to have reached a steady state. If not all the introduced state variables meet the requirements, the DC transmission system is made to run for a period of time, and the steady-state formula is used again for judgment. This process is repeated until the requirements are met.

[0090] In module M2, different fault resistances, fault durations, fault types, short-circuit ratios of the inverter-side AC system, and whether a synchronous condenser is engaged are set to analyze commutation failures under different simulation conditions.

[0091] The fault resistance is selected from multiple sets of values, ranging from 0.1 ohms to 20 ohms, from low to high; the fault duration is selected from multiple sets of values, ranging from 100ms to 500ms; the AC system short-circuit ratio is selected from multiple sets of values, ranging from 3 to 15; the fault type is selected from two sets of values, choosing from three-phase fault, two-phase ground fault, and single-phase fault; the synchronous condenser activation status is selected from two sets, namely synchronous condenser activated and synchronous condenser not activated.

[0092] The module M3 includes:

[0093] After the simulation is completed, according to the need to analyze commutation failure, select the simulation waveforms to be stored for each simulation, use a script file to write a program to save the required simulation waveforms as JPG and MPB files, and place the saved JPG and MPB files in the folder specified by the program.

[0094] A program is written using a script file to cyclically name the simulation waveforms stored in the simulation. The program sets the fault resistance to be i types, the fault type to t types, the fault duration to k types, the short-circuit ratio of the inverter-side AC system to m types, and the synchronous condenser engagement / disengagement status to n types. The simulation waveforms stored in each simulation are named TPt_Ri_Tk_SCRm, representing the simulation waveforms under the t-th fault type, the i-th fault resistance, the k-th fault duration, and the m-th short-circuit ratio.

[0095] To analyze commutation failure, a program is written in the script file to store the state variables required for analysis in the form of a report. The state variables required for analysis include: the minimum effective value of the inverter side AC voltage, the minimum value of the inverter side arc extinction angle, the maximum value of the synchronous condenser excitation current, the maximum value of the synchronous condenser excitation voltage, whether commutation failure has occurred, and the number of times commutation failure has occurred.

[0096] The minimum effective value of the inverter-side AC voltage, the minimum value of the inverter-side arc extinction angle, the maximum value of the synchronous condenser excitation current, and the maximum value of the synchronous condenser excitation voltage are calculated by writing program functions in the script file; the formulas for judging whether commutation failure has occurred and the number of commutation failures are as follows:

[0097]

[0098] When there is a situation where the inverter-side arc extinction angle gama(t) at the current time t is zero, and the inverter-side arc extinction angle gama(t+1) at the next time is greater than zero, this is recorded as a commutation failure. If this situation occurs again, the number of commutation failures is incremented by one. If this situation does not occur, it is considered that no commutation failure fault has occurred.

[0099] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0100] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A real-time simulation and result statistics method for HVDC commutation failure based on automatic script execution, characterized in that, include: Step 1: Build a model of the UHVDC transmission system in the real-time simulation system, and use script files to determine whether the operation of the UHVDC transmission system has reached a steady state; Step 2: Write a batch program in the script file to set different fault types. When the HVDC DC transmission system reaches steady state, the automatic control real-time simulation system will simulate different simulation conditions. Step 3: After the simulation is completed, use the script file to write a program to automatically generate the simulation waveform and state variable report required for analyzing the commutation failure based on the characteristics of the commutation failure and the relevant state variables. In step 1: The script file references the state variables of the HVDC transmission system, including: the arc extinction angle on the inverter side, the firing angle on the rectifier side, the effective value of the AC voltage on the inverter side, the DC voltage on the rectifier side, and the DC voltage on the inverter side. A function program is written using a script file. After the HVDC transmission system has been running for a period of time during initialization, the function calculates the referenced state variables and obtains the maximum and minimum values ​​of the arc extinction angle pk_gama and vy_gama on the inverter side, the maximum and minimum values ​​of the firing angle pk_alpha and vy_alpha on the rectifier side, the maximum and minimum values ​​of the effective AC voltage pk_Urms and vy_Urms on the inverter side, the maximum and minimum values ​​of the DC voltage pk_UdcR and vy_UdcR on the rectifier side, and the maximum and minimum values ​​of the DC voltage pk_UdcI and vy_UdcI on the inverter side. When the following equations are simultaneously satisfied, the HVDC direct current transmission system is considered to have reached steady state: Wherein, c1, c2, c3, c4, and c5 are the upper limits of the fluctuation of the state variables referenced when the HVDC DC transmission system reaches a steady state; The script file contains a program to make the HVDC transmission system reach a steady state. After the DC transmission system has been running for a period of time since initialization, the steady-state judgment formula mentioned above is used to determine whether each state variable meets the requirements. If all the introduced state variables meet the requirements, the DC transmission system is judged to have reached a steady state. If not all the introduced state variables meet the requirements, the DC transmission system is made to run for a period of time, and the steady-state formula is used again for judgment. This process is repeated until the requirements are met.

2. The method for real-time simulation and result statistics of HVDC commutation failure based on script automatic execution according to claim 1, characterized in that, In step 2, different fault resistances, fault durations, fault types, short-circuit ratios of the inverter-side AC system, and whether a synchronous condenser is engaged are set to analyze commutation failures under different simulation conditions.

3. The method for real-time simulation and result statistics of HVDC commutation failure based on automatic script execution according to claim 2, characterized in that, The fault resistance is selected from multiple sets of values, ranging from 0.1 ohms to 20 ohms, from low to high; the fault duration is selected from multiple sets of values, ranging from 100ms to 500ms; the AC system short-circuit ratio is selected from multiple sets of values, ranging from 3 to 15; the fault type is selected from two sets of values, choosing from three-phase fault, two-phase ground fault, and single-phase fault; the synchronous condenser activation status is selected from two sets, namely synchronous condenser activated and synchronous condenser not activated.

4. The method for real-time simulation and result statistics of HVDC commutation failure based on automatic script execution according to claim 1, characterized in that, Step 3 includes: After the simulation is completed, according to the need to analyze commutation failure, select the simulation waveforms to be stored for each simulation, use a script file to write a program to save the required simulation waveforms as JPG and MPB files, and place the saved JPG and MPB files in the folder specified by the program. A program is written using a script file to cyclically name the simulation waveforms stored in the simulation. The program sets the fault resistance to be i types, the fault type to t types, the fault duration to k types, the short-circuit ratio of the inverter-side AC system to m types, and the synchronous condenser engagement / disengagement status to n types. The simulation waveforms stored in each simulation are named TPt_Ri_Tk_SCRm, representing the simulation waveforms under the t-th fault type, the i-th fault resistance, the k-th fault duration, and the m-th short-circuit ratio. To analyze commutation failure, a program is written in the script file to store the state variables required for analysis in the form of a report. The state variables required for analysis include: the minimum effective value of the inverter side AC voltage, the minimum value of the inverter side arc extinction angle, the maximum value of the synchronous condenser excitation current, the maximum value of the synchronous condenser excitation voltage, whether commutation failure has occurred, and the number of times commutation failure has occurred. The minimum effective value of the inverter-side AC voltage, the minimum value of the inverter-side arc extinction angle, the maximum value of the synchronous condenser excitation current, and the maximum value of the synchronous condenser excitation voltage are calculated by writing program functions in the script file; the formulas for judging whether commutation failure has occurred and the number of commutation failures are as follows: When there is a situation where the inverter-side arc extinction angle gama(t) at the current time t is zero, and the inverter-side arc extinction angle gama(t+1) at the next time is greater than zero, this is recorded as a commutation failure. If this situation occurs again, the number of commutation failures is incremented by one. If this situation does not occur, it is considered that no commutation failure fault has occurred.

5. A real-time simulation and result statistics system for HVDC commutation failure based on automatic script execution, characterized in that, include: Module M1: Build a model of the UHVDC transmission system in the real-time simulation system and use script files to determine whether the operation of the UHVDC transmission system has reached a steady state; Module M2: Write a batch program in the script file to set different fault types. When the HVDC DC transmission system reaches steady state, the automatic control real-time simulation system will simulate different simulation conditions. Module M3: After the simulation is completed, a program is written using a script file to automatically generate the simulation waveforms and state variable reports needed to analyze the commutation failure, based on the characteristics of the commutation failure and the relevant state variables. In module M1: The script file references the state variables of the HVDC transmission system, including: the arc extinction angle on the inverter side, the firing angle on the rectifier side, the effective value of the AC voltage on the inverter side, the DC voltage on the rectifier side, and the DC voltage on the inverter side. A function program is written using a script file. After the HVDC transmission system has been running for a period of time during initialization, the function calculates the referenced state variables and obtains the maximum and minimum values ​​of the arc extinction angle pk_gama and vy_gama on the inverter side, the maximum and minimum values ​​of the firing angle pk_alpha and vy_alpha on the rectifier side, the maximum and minimum values ​​of the effective AC voltage pk_Urms and vy_Urms on the inverter side, the maximum and minimum values ​​of the DC voltage pk_UdcR and vy_UdcR on the rectifier side, and the maximum and minimum values ​​of the DC voltage pk_UdcI and vy_UdcI on the inverter side. When the following equations are simultaneously satisfied, the HVDC direct current transmission system is considered to have reached steady state: Wherein, c1, c2, c3, c4, and c5 are the upper limits of the fluctuation of the state variables referenced when the HVDC DC transmission system reaches a steady state; The script file contains a program to make the HVDC transmission system reach a steady state. After the DC transmission system has been running for a period of time since initialization, the steady-state judgment formula mentioned above is used to determine whether each state variable meets the requirements. If all the introduced state variables meet the requirements, the DC transmission system is judged to have reached a steady state. If not all the introduced state variables meet the requirements, the DC transmission system is made to run for a period of time, and the steady-state formula is used again for judgment. This process is repeated until the requirements are met.

6. The real-time simulation and result statistics system for HVDC commutation failure based on script automatic execution according to claim 5, characterized in that, In module M2, different fault resistances, fault durations, fault types, short-circuit ratios of the inverter-side AC system, and whether a synchronous condenser is engaged are set to analyze commutation failures under different simulation conditions.

7. The real-time simulation and result statistics system for HVDC commutation failure based on script automatic execution according to claim 6, characterized in that, The fault resistance is selected from multiple sets of values, ranging from 0.1 ohms to 20 ohms, from low to high; the fault duration is selected from multiple sets of values, ranging from 100ms to 500ms; the AC system short-circuit ratio is selected from multiple sets of values, ranging from 3 to 15; the fault type is selected from two sets of values, choosing from three-phase fault, two-phase ground fault, and single-phase fault; the synchronous condenser activation status is selected from two sets, namely synchronous condenser activated and synchronous condenser not activated.

8. The real-time simulation and result statistics system for HVDC commutation failure based on script automatic execution according to claim 5, characterized in that, The module M3 includes: After the simulation is completed, according to the need to analyze commutation failure, select the simulation waveforms to be stored for each simulation, use a script file to write a program to save the required simulation waveforms as JPG and MPB files, and place the saved JPG and MPB files in the folder specified by the program. A program is written using a script file to cyclically name the simulation waveforms stored in the simulation. The program sets the fault resistance to be i types, the fault type to t types, the fault duration to k types, the short-circuit ratio of the inverter-side AC system to m types, and the synchronous condenser engagement / disengagement status to n types. The simulation waveforms stored in each simulation are named TPt_Ri_Tk_SCRm, representing the simulation waveforms under the t-th fault type, the i-th fault resistance, the k-th fault duration, and the m-th short-circuit ratio. To analyze commutation failure, a program is written in the script file to store the state variables required for analysis in the form of a report. The state variables required for analysis include: the minimum effective value of the inverter side AC voltage, the minimum value of the inverter side arc extinction angle, the maximum value of the synchronous condenser excitation current, the maximum value of the synchronous condenser excitation voltage, whether commutation failure has occurred, and the number of times commutation failure has occurred. The minimum effective value of the inverter-side AC voltage, the minimum value of the inverter-side arc extinction angle, the maximum value of the synchronous condenser excitation current, and the maximum value of the synchronous condenser excitation voltage are calculated by writing program functions in the script file; the formulas for judging whether commutation failure has occurred and the number of commutation failures are as follows: When there is a situation where the inverter-side arc extinction angle gama(t) at the current time t is zero, and the inverter-side arc extinction angle gama(t+1) at the next time is greater than zero, this is recorded as a commutation failure. If this situation occurs again, the number of commutation failures is incremented by one. If this situation does not occur, it is considered that no commutation failure fault has occurred.

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