Fault type identification method in power system

Abstract

The present disclosure relates to a method for controlling a protection system of an electrical power system comprising an electrical transmission line, the method comprising: determining a plurality of phase angle deviations based on a network model of the electrical power system during respective faults of at least three faults; determining at least three phase angle ranges based on the plurality of phase angle deviations, where a sum of the at least three phase angle ranges is an angle of full rotation; and controlling a protection system for the power system based on the at least three phase angle ranges.

Description

Technical Field

[0001] The present disclosure relates to methods, apparatus, computer readable media, and systems for use in an electric power system including a transmission line. Background Art

[0002] Current environmental issues require the integration of large converter-interfaced renewable power plants (CIRPPs) into the transmission network, and therefore different control schemes are applied through converters connected to CIRPPs. In order to meet the fault ride-through requirements specified by different grid codes, CIRPPs are connected even during faults. The presence of such converter-interfaced renewable resources in the network modulates the fault voltage and current signals, which are significantly different from those of conventional synchronous generators. These different fault characteristics have a negative impact on the performance of available phase selection or fault classification logic, which are designed for conventional grids dominated by synchronous generators.

[0003] Accurate phase selection may refer to the ability of the protective intelligent electronic device (IED) to identify the faulty phase(s), which is a prerequisite for single-pole autoreclosing. Phase selection or fault classification may be performed by identifying which of the 6 circuits (3 phase-to-ground and 3 phase-to-phase) impedances fall into a predetermined characteristic.

[0004] The first method for phase selection involves the relay comparing the relative angles between the pure fault sequence currents available at the local end and identifying the fault type in the network. This method is not affected by fault resistance and load unbalance and quickly and accurately classifies the fault type. In the second method, the adverse effects of phase angle variations in the positive sequence current are avoided in some relays by utilizing only the angle difference between the negative sequence current and the zero sequence current. In this technique, the fault resistance is estimated to distinguish between single-line-to-ground faults and double-line-to-ground faults. In another method, some relays utilize the phase angle difference of the superimposed sequence voltages along with the current angle characteristics for fault type classification in weak feed conditions.

[0005] All the above mentioned phasor based techniques assume consistency in the system (angles of local and remote currents are close to each other), which is also true for conventional grids connected with conventional generators. However, these methods have limitations when applied to lines connected with converter interfaced renewable resources due to the modulated voltage and current signals during faults and the consistency assumption no longer holds. Another approach adaptively performs fault classification for transmission networks connected with CIRPPs, where the non-consistency factor is calculated assuming that the grid is strongly connected. This technique will not work if the grid is weakly connected.

[0006] Therefore, there is a need for an accurate phase selection method for networks, especially networks connected to CIRPP. Summary of the invention

[0007] The present disclosure relates to a method for a protection system of an electric power system including a transmission line, the method comprising: determining a plurality of phase angle deviations based on a network model of the electric power system during respective faults of at least three faults; determining at least three phase angle ranges based on the plurality of phase angle deviations, wherein the sum of the at least three phase angle ranges is a fully rotated angle.

[0008] According to one embodiment, both ends of the transmission line are terminated at a first end coupled to a first generator and a second end coupled to a second generator, and the method also includes: obtaining a plurality of voltage measurement values ​​at the first end; determining a measured phase angle deviation based on the plurality of voltage measurement values; and determining a fault by identifying in which of at least three phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three phase angle ranges.

[0009] According to one embodiment, the method further comprises: determining a plurality of additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; and determining at least three additional phase angle ranges based on the additional plurality of phase angle deviations, wherein the plurality of phase angle deviations are different from the plurality of additional phase angle deviations, wherein at least three faults are different from at least three additional faults, wherein at least three phase angle ranges are different from at least three additional phase angle ranges, and wherein the sum of the at least three additional phase angle ranges is the angle of full rotation.

[0010] According to one embodiment, the method also includes: obtaining multiple voltage measurement values ​​at the first end; determining an additional measured phase angle deviation based on the multiple voltage measurement values; and determining the fault by identifying in which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges.

[0011] According to one embodiment, the method further comprises: obtaining a plurality of current measurements of the first end; determining a zero-sequence current based on the plurality of current measurements of the first end; and further determining a fault based on the zero-sequence current, in particular by comparing the zero-sequence current with a preset value.

[0012] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is a phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0013] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0014] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0015] According to one embodiment, a transmission line carries multiple phases, and the method includes: obtaining multiple voltage measurement values ​​at a first end measured before and during a fault; and determining an n-phase fault based on voltage differences between respective phases of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1 and corresponds to the number of multiple phases.

[0016] According to one embodiment, the method further comprises: obtaining a plurality of current measurements of the first end; determining a generator type of the first generator based on the plurality of current measurements and / or the plurality of voltage measurements; and when the first generator is determined to be of the first generator type, determining a measured phase angle deviation based on the plurality of voltage measurements; or when the first generator is determined to be of the second generator type, determining a measured phase angle deviation based on the plurality of current measurements.

[0017] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0018] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0019] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0020] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0021] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0022] The present disclosure relates to a method for controlling a protection system of an electric power system including a transmission line, the method comprising: receiving at least three phase angle ranges determined according to any one of the above embodiments; and controlling the protection system for the electric power system based on the at least three phase angle ranges.

[0023] The present disclosure relates to a method for controlling a protection system of an electric power system including a transmission line, the method comprising: determining a plurality of phase angle deviations based on a network model of the electric power system during respective faults of at least three faults; determining at least three phase angle ranges based on the plurality of phase angle deviations, wherein the sum of the at least three phase angle ranges is a fully rotated angle; and controlling the protection system for the electric power system based on the at least three phase angle ranges.

[0024] According to one embodiment, both ends of the transmission line are terminated at a first end coupled to a first generator and a second end coupled to a second generator, and the method also includes: obtaining a plurality of voltage measurement values ​​at the first end; determining a measured phase angle deviation based on the plurality of voltage measurement values; determining a fault by identifying in which of at least three phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three phase angle ranges; and controlling a protection system for the power system based on the determined fault.

[0025] According to one embodiment, the method further comprises: determining a plurality of additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; and determining at least three additional phase angle ranges based on the additional plurality of phase angle deviations, wherein the plurality of phase angle deviations are different from the plurality of additional phase angle deviations, wherein at least three faults are different from at least three additional faults, wherein at least three phase angle ranges are different from at least three additional phase angle ranges, and wherein the sum of the at least three additional phase angle ranges is the angle of full rotation.

[0026] According to one embodiment, the method also includes: obtaining multiple voltage measurement values ​​at the first end; determining an additional measured phase angle deviation based on the multiple voltage measurement values; determining a fault by identifying in which of at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges; and controlling a protection system for the power system based on the determined fault.

[0027] According to one embodiment, the method also includes: obtaining multiple current measurement values ​​of the first end; determining the zero-sequence current based on the multiple current measurement values ​​of the first end; further determining the fault based on the zero-sequence current, in particular by comparing the zero-sequence current with a preset value; and controlling a protection system for the power system based on the determined fault.

[0028] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is a phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0029] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0030] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0031] According to one embodiment, a transmission line carries multiple phases, and the method includes: obtaining multiple voltage measurement values ​​at a first end measured before and during a fault; determining an n-phase fault based on voltage differences between respective phases of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1 and corresponds to the number of multiple phases; and further controlling a protection system based on the determined n-phase fault.

[0032] According to one embodiment, the method further comprises: obtaining a plurality of current measurements of the first end; determining a generator type of the first generator based on the plurality of current measurements and / or the plurality of voltage measurements; and when the first generator is determined to be of the first generator type, determining a measured phase angle deviation based on the plurality of voltage measurements; or when the first generator is determined to be of the second generator type, determining a measured phase angle deviation based on the plurality of current measurements.

[0033] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0034] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0035] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0036] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0037] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0038] The present disclosure also relates to a method for a protection system for an electric power system, the electric power system comprising a transmission line terminating at a first end, the method comprising: determining a plurality of phase angle deviations based on a network model of the electric power system during respective faults of at least three faults; determining at least three phase angle ranges based on the plurality of phase angle deviations, wherein the sum of the at least three phase angle ranges is the angle of complete rotation; obtaining a plurality of voltage and current measurements of the first end; determining a measured phase angle deviation based on the plurality of voltage measurements of the first end, and determining a zero-sequence current based on the plurality of current measurements of the first end; and determining a fault based on the at least three phase angle ranges, the measured phase angle deviation, and the zero-sequence current.

[0039] According to one embodiment, the method also includes: determining multiple additional phase angle deviations based on a network model of the power system during respective faults of at least one additional fault set; determining at least three additional phase angle ranges based on the additional multiple phase angle deviations, wherein the sum of the at least three additional phase angle ranges is the angle of complete rotation; determining additional measured phase angle deviations based on multiple voltage measurements; and determining the fault by identifying in which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges.

[0040] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of the negative sequence voltage measured during the fault and the second phase angle is the phase angle of the zero sequence voltage measured during the fault, or the phase angle difference between the phase angle of the positive sequence voltage measured before the fault and the phase angle of the positive sequence voltage measured during the fault.

[0041] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0042] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0043] According to one embodiment, the transmission line carries multiple phases, and the method further includes: obtaining multiple voltage measurement values ​​of the first end measured before and during the fault; and determining an n-phase fault based on the voltage difference between each phase of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1, corresponding to the number of multiple phases.

[0044] According to one embodiment, the method further comprises: obtaining a plurality of current measurements of the first end; determining a generator type of the first generator based on the plurality of current measurements and / or the plurality of voltage measurements; and when the first generator is determined to be of the first generator type, determining a measured phase angle deviation based on the plurality of voltage measurements; or when the first generator is determined to be of the second generator type, determining a measured phase angle deviation based on the plurality of current measurements.

[0045] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0046] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0047] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0048] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0049] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0050] The present disclosure also relates to a method for controlling a protection system for an electric power system, the electric power system comprising a transmission line terminating at a first end, the method comprising: receiving at least three phase angle ranges, a measured phase angle deviation, a zero-sequence current, and / or a fault determined according to any one of the above-mentioned embodiments; and controlling the protection system for the electric power system based on the determined fault.

[0051] The present disclosure also relates to a method for controlling a protection system for an electric power system, the electric power system comprising a transmission line terminating at a first end, the method comprising: determining a plurality of phase angle deviations based on a network model of the electric power system during respective faults of at least three faults; determining at least three phase angle ranges based on the plurality of phase angle deviations, wherein the sum of the at least three phase angle ranges is an angle of complete rotation; obtaining a plurality of voltage and current measurements of the first end; determining a measured phase angle deviation based on the plurality of voltage measurements of the first end, and determining a zero-sequence current based on the plurality of current measurements of the first end; determining a fault based on the at least three phase angle ranges, the measured phase angle deviation, and the zero-sequence current; and controlling the protection system for the electric power system based on the determined fault.

[0052] According to one embodiment, the method also includes: determining multiple additional phase angle deviations based on a network model of the power system during respective faults of at least one additional fault set; determining at least three additional phase angle ranges based on the additional multiple phase angle deviations, wherein the sum of the at least three additional phase angle ranges is the angle of complete rotation; determining additional measured phase angle deviations based on multiple voltage measurements; determining a fault by identifying in which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges; and controlling a protection system for the power system based on the determined fault.

[0053] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of the negative sequence voltage measured during the fault, wherein the second phase angle is the phase angle of the zero sequence voltage measured during the fault, or the phase angle difference between the phase angle of the positive sequence voltage measured before the fault and the phase angle of the positive sequence voltage measured during the fault.

[0054] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0055] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0056] According to one embodiment, the transmission line carries multiple phases, and the method further includes: obtaining multiple voltage measurement values ​​of the first end measured before and during the fault; determining an n-phase fault based on the voltage difference between each phase of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1 and corresponds to the number of multiple phases; and further controlling the protection system based on the determined n-phase fault.

[0057] According to one embodiment, the method further comprises: obtaining a plurality of current measurements of the first end; determining a generator type of the first generator based on the plurality of current measurements and / or the plurality of voltage measurements; and when the first generator is determined to be of the first generator type, determining a measured phase angle deviation based on the plurality of voltage measurements; or when the first generator is determined to be of the second generator type, determining a measured phase angle deviation based on the plurality of current measurements.

[0058] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0059] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0060] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0061] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0062] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0063] The present disclosure also relates to a device for a protection system of an electric power system including a transmission line, the device including a processor configured to: determine multiple phase angle deviations based on a network model of the electric power system during respective faults of at least three faults; determine at least three phase angle ranges based on the multiple phase angle deviations, wherein the sum of the at least three phase angle ranges is the angle of complete rotation.

[0064] According to one embodiment, both ends of the transmission line terminate at a first end coupled to a first generator and a second end coupled to a second generator, and the processor is further configured to: obtain a plurality of voltage measurement values ​​of the first end; determine a measured phase angle deviation based on the plurality of voltage measurement values; and determine a fault by identifying in which of at least three phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three phase angle ranges.

[0065] According to one embodiment, the processor is further configured to: determine a plurality of additional phase angle deviations based on a network model of the power system during respective ones of at least three additional faults; and determine at least three additional phase angle ranges based on the additional plurality of phase angle deviations, wherein the plurality of phase angle deviations are different from the plurality of additional phase angle deviations, wherein at least three faults are different from at least three additional faults, wherein at least three phase angle ranges are different from at least three additional phase angle ranges, and wherein the sum of the at least three additional phase angle ranges is the angle of full rotation.

[0066] According to one embodiment, the processor is also configured to: obtain multiple voltage measurement values ​​of the first end; determine an additional measured phase angle deviation based on the multiple voltage measurement values; and determine the fault by identifying which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges.

[0067] According to one embodiment, the processor is also configured to: obtain multiple current measurement values ​​of the first end; determine the zero-sequence current based on the multiple current measurement values ​​of the first end; further determine the fault based on the zero-sequence current, in particular by comparing the zero-sequence current with a preset value; and control the protection system for the power system based on the determined fault.

[0068] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of the negative sequence voltage measured during the fault, and the second phase angle is the phase angle of the zero sequence voltage measured during the fault or the phase angle difference between the phase angle of the positive sequence voltage measured before the fault and the phase angle of the positive sequence voltage measured during the fault.

[0069] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0070] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0071] According to one embodiment, the transmission line carries multiple phases, and the processor is further configured to: obtain multiple voltage measurement values ​​of the first end measured before and during the fault; and determine an n-phase fault based on the voltage difference between each phase of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1, corresponding to the number of multiple phases.

[0072] According to one embodiment, the processor is further configured to: obtain a plurality of current measurement values ​​of the first end; determine a generator type of the first generator based on the plurality of current measurement values ​​and / or the plurality of voltage measurement values; and when the first generator is determined to be of the first generator type, determine a measured phase angle deviation based on the plurality of voltage measurement values; or when the first generator is determined to be of the second generator type, determine a measured phase angle deviation based on the plurality of current measurement values.

[0073] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0074] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0075] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0076] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0077] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0078] The present disclosure also relates to a device for controlling a protection system of an electric power system including a transmission line, the device comprising a processor configured to: receive at least three phase angle ranges determined according to any one of the above-mentioned embodiments; and control the protection system for the electric power system based on the at least three phase angle ranges and at least three second phase angle ranges.

[0079] The present disclosure also relates to a device for controlling a protection system of an electric power system including a transmission line, the device including a processor configured to: determine multiple phase angle deviations based on a network model of the electric power system during respective faults of at least three faults; determine at least three phase angle ranges based on the multiple phase angle deviations, wherein the sum of the at least three phase angle ranges is the angle of complete rotation; and control the protection system for the electric power system based on the at least three phase angle ranges.

[0080] According to one embodiment, both ends of the transmission line are terminated at a first end coupled to a first generator and a second end coupled to a second generator, and the processor is also configured to: obtain multiple voltage measurement values ​​of the first end; determine a measured phase angle deviation based on the multiple voltage measurement values; determine a fault by identifying in which of at least three phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three phase angle ranges; and control a protection system for the power system based on the determined fault.

[0081] According to one embodiment, the processor is further configured to: determine a plurality of additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; and determine at least three additional phase angle ranges based on the additional plurality of phase angle deviations, wherein the plurality of phase angle deviations are different from the plurality of additional phase angle deviations, wherein at least three faults are different from at least three additional faults, wherein at least three phase angle ranges are different from at least three additional phase angle ranges, and wherein the sum of the at least three additional phase angle ranges is the angle of full rotation.

[0082] According to one embodiment, the processor is also configured to: obtain multiple voltage measurement values ​​at the first end; determine an additional measured phase angle deviation based on the multiple voltage measurement values; determine a fault by identifying in which of at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges; and control a protection system for the power system based on the determined fault.

[0083] According to one embodiment, the processor is also configured to: obtain multiple current measurement values ​​of the first end; determine the zero-sequence current based on the multiple current measurement values ​​of the first end; further determine the fault based on the zero-sequence current, in particular by comparing the zero-sequence current with a preset value; and control the protection system for the power system based on the determined fault.

[0084] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is a phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0085] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0086] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0087] According to one embodiment, the transmission line carries multiple phases, and the processor is further configured to: obtain multiple voltage measurement values ​​of the first end measured before and during the fault; determine an n-phase fault based on the voltage difference between each phase of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1 and corresponds to the number of multiple phases; and further control the protection system based on the determined n-phase fault.

[0088] According to one embodiment, the processor is further configured to: obtain a plurality of current measurement values ​​of the first end; determine a generator type of the first generator based on the plurality of current measurement values ​​and / or the plurality of voltage measurement values; and when the first generator is determined to be of the first generator type, determine a measured phase angle deviation based on the plurality of voltage measurement values; or when the first generator is determined to be of the second generator type, determine a measured phase angle deviation based on the plurality of current measurement values.

[0089] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0090] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0091] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0092] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0093] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0094] The present disclosure also relates to a device for a protection system of an electric power system including a transmission line, the device including a processor configured to: determine multiple phase angle deviations based on a network model of the electric power system during respective faults of at least three faults; determine at least three phase angle ranges based on the multiple phase angle deviations, wherein the sum of the at least three phase angle ranges is the angle of complete rotation; obtain multiple voltage and current measurement values ​​of a first end; determine the measured phase angle deviation based on the multiple voltage measurement values ​​of the first end, and determine the zero-sequence current based on the multiple current measurement values ​​of the first end; and determine the fault based on the at least three phase angle ranges, the measured phase angle deviation, and the zero-sequence current.

[0095] According to one embodiment, the processor is also configured to: determine multiple additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; determine at least three additional phase angle ranges based on the additional multiple phase angle deviations, wherein the sum of the at least three additional phase angle ranges is the angle of complete rotation; and determine additional measured phase angle deviations based on multiple voltage measurements; determine the fault by identifying in which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges.

[0096] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of the negative sequence voltage measured during the fault, wherein the second phase angle is the phase angle of the zero sequence voltage measured during the fault, or the phase angle difference between the phase angle of the positive sequence voltage measured before the fault and the phase angle of the positive sequence voltage measured during the fault.

[0097] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0098] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0099] According to one embodiment, the transmission line carries multiple phases, and the processor is further configured to: obtain multiple voltage measurement values ​​of the first end measured before and during the fault; determine an n-phase fault based on the voltage difference between each phase of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1, corresponding to the number of multiple phases.

[0100] According to one embodiment, the processor is further configured to: obtain a plurality of current measurement values ​​of the first end; determine a generator type of the first generator based on the plurality of current measurement values ​​and / or the plurality of voltage measurement values; and when the first generator is determined to be of the first generator type, determine a measured phase angle deviation based on the plurality of voltage measurement values; or when the first generator is determined to be of the second generator type, determine a measured phase angle deviation based on the plurality of current measurement values.

[0101] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and wherein the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0102] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0103] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0104] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0105] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0106] The present disclosure also relates to a device for controlling a protection system of an electric power system including a transmission line, the device comprising a processor configured to: receive at least three phase angle ranges, a measured phase angle deviation, a zero-sequence current, and / or a fault determined according to any one of the above-mentioned embodiments; and control the protection system for the electric power system based on the determined fault.

[0107] The present disclosure also relates to a device for controlling a protection system of an electric power system including a transmission line, the device including a processor configured to: determine multiple phase angle deviations based on a network model of the electric power system during respective faults of at least three faults; determine at least three phase angle ranges based on the multiple phase angle deviations, wherein the sum of the at least three phase angle ranges is the angle of complete rotation; obtain multiple voltage and current measurement values ​​of a first end; determine a measured phase angle deviation based on the multiple voltage measurement values ​​of the first end, and determine a zero-sequence current based on the multiple current measurement values ​​of the first end; determine a fault based on the at least three phase angle ranges, the measured phase angle deviation, and the zero-sequence current; and control the protection system for the electric power system based on the determined fault.

[0108] According to one embodiment, the processor is also configured to: determine multiple additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; determine at least three additional phase angle ranges based on the additional multiple phase angle deviations, wherein the sum of the at least three additional phase angle ranges is the angle of complete rotation; determine additional measured phase angle deviations based on multiple voltage measurements; determine the fault by identifying in which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges; and control a protection system for the power system based on the determined fault.

[0109] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of the negative sequence voltage measured during the fault, wherein the second phase angle is the phase angle of the zero sequence voltage measured during the fault, or the phase angle difference between the phase angle of the positive sequence voltage measured before the fault and the phase angle of the positive sequence voltage measured during the fault.

[0110] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0111] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0112] According to one embodiment, the transmission line carries multiple phases, and the processor is further configured to: obtain multiple voltage measurement values ​​of the first end measured before and during the fault; determine an n-phase fault based on the voltage difference between each phase of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1 and corresponds to the number of multiple phases; and further control the protection system based on the determined n-phase fault.

[0113] According to one embodiment, the processor is further configured to: obtain a plurality of current measurement values ​​of the first end; determine a generator type of the first generator based on the plurality of current measurement values ​​and / or the plurality of voltage measurement values; and when the first generator is determined to be of the first generator type, determine a measured phase angle deviation based on the plurality of voltage measurement values; or when the first generator is determined to be of the second generator type, determine a measured phase angle deviation based on the plurality of current measurement values.

[0114] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0115] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0116] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0117] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0118] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0119] The present disclosure also relates to a computer-readable medium for controlling a protection system for an electric power system, which carries instructions for executing the method of any one of the above embodiments.

[0120] The present disclosure also relates to a power system, comprising a power transmission line and the device of any one of the above embodiments.

[0121] Various exemplary embodiments of the present disclosure are intended to provide features that will become apparent by reference to the following description when taken in conjunction with the accompanying drawings. According to various embodiments, exemplary systems, methods, and devices are disclosed herein. However, it should be understood that these embodiments are presented by way of example and not limitation, and that it will be apparent to those of ordinary skill in the art who read this disclosure that various modifications may be made to the disclosed embodiments while remaining within the scope of this disclosure.

[0122] Therefore, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. In addition, the specific order and / or hierarchy of steps in the methods disclosed herein are merely exemplary methods. Based on design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be rearranged while remaining within the scope of the present disclosure. Therefore, it will be understood by those of ordinary skill in the art that the methods and techniques disclosed herein present various steps or actions in an example order, and unless otherwise expressly stated, the present disclosure is not limited to the specific order or hierarchy presented.

[0123] Hereinafter, exemplary embodiments of the present disclosure will be described. It should be noted that, unless otherwise specified or apparent, some aspects of any one of the described embodiments may also be found in some other embodiments. However, in order to improve understandability, each aspect will be described in detail only when first mentioned, and any repeated description of the same aspect will be omitted.

[0124] The above and other aspects and implementations thereof are described in more detail in the drawings, the description, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0125] Figure 1 A flow chart of a method according to an embodiment of the present disclosure is shown.

[0126] Figure 2 A model of a power system according to an embodiment of the present disclosure is shown.

[0127] Figure 3 A model of a power system during a fault according to an embodiment of the present disclosure is shown.

[0128] Figure 4 A model of a power system during a fault according to an embodiment of the present disclosure is shown.

[0129] Figure 5 The phase angle range of a fault in a power system according to an embodiment of the present disclosure is shown.

[0130] Figure 6 The phase angle range of a fault in a power system according to an embodiment of the present disclosure is shown.

[0131] Figure 7 The phase angle ranges of various faults in the power system according to an embodiment of the present disclosure are shown.

[0132] Figure 8 A flow chart of a method according to an embodiment of the present disclosure is shown.

[0133] Fig. 9 A flow chart of a method according to an embodiment of the present disclosure is shown.

[0134] Fig.10 An electric power system under test according to an embodiment of the present disclosure is shown.

[0135] Fig.11 Voltage and current measurements taken during a fault in an electric power system are shown according to an embodiment of the disclosure.

[0136] Fig.12 Graphs showing phase angle, phase angle range, and current calculated according to an embodiment of the present disclosure are shown.

[0137] Fig.13 The phase angle and phase angle range calculated according to an embodiment of the present disclosure are shown.

[0138] Fig.14 Voltage and current measurements taken during a fault in an electric power system are shown according to an embodiment of the disclosure.

[0139] Fig.15 Graphs showing phase angle, phase angle range, and current calculated according to an embodiment of the present disclosure are shown.

[0140] Fig.16 The phase angle and phase angle range calculated according to an embodiment of the present disclosure are shown.

[0141] Fig.17 Voltage and current measurements taken during a fault in an electric power system are shown according to an embodiment of the disclosure.

[0142] Fig.18 A graph showing phase angles and phase angle ranges calculated according to an embodiment of the present disclosure is shown.

[0143] Fig.19 A graph showing current calculated according to an embodiment of the present disclosure is shown.

[0144] Fig. 20 The phase angle and phase angle range calculated according to an embodiment of the present disclosure are shown.

[0145] Fig.21 An electric power system under test according to an embodiment of the present disclosure is shown.

[0146] Fig. 22 A performance summary of a method according to an embodiment of the present disclosure is shown.

[0147] Fig.23 An electric power system under test according to an embodiment of the present disclosure is shown.

[0148] Fig.24 A performance summary of a method according to an embodiment of the present disclosure is shown.

[0149] Fig.25 An electric power system under test according to an embodiment of the present disclosure is shown.

[0150] Fig.26 A performance summary of a method according to an embodiment of the present disclosure is shown.

[0151] Fig. 27 An electric power system under test according to an embodiment of the present disclosure is shown.

[0152] Fig.28 A performance summary of a method according to an embodiment of the present disclosure is shown.

[0153] Fig.29 A performance summary of a method according to an embodiment of the present disclosure is shown.

[0154] Fig.30 Devices, computer-readable media, and systems according to embodiments of the present disclosure are shown. DETAILED DESCRIPTION

[0155] Figure 1 A flow chart of a method according to an embodiment of the present disclosure is shown. At S101, during respective faults of at least three faults, a plurality of phase angle deviations are determined based on a network model of the power system. At S102, at least three phase angle ranges are determined based on the plurality of phase angle deviations, wherein the sum of the at least three phase angle ranges is the angle of full rotation. At S103, a protection system for the power system is controlled based on the at least three phase angle ranges.

[0156] Figure 2A model of a power system according to an embodiment of the present disclosure is shown. The network 200 includes a first power source 221 connected to a second power source 222 via a transmission line 210. In this embodiment, the first power source 221 is an asynchronous power source, in particular a converter interfaced renewable energy power plant (CIRPP), and the second power source 222 is a power grid. According to one embodiment, the first power source and / or the second power source may be a synchronous power source. The equivalent impedances of the CIRPP 221 and the power grid 222 are respectively 231 and Z SN 232. Transmission line 210 is terminated at a first end 251 (busbar M in this embodiment) and a second end 252 (busbar N in this embodiment). According to one embodiment, the transmission line is terminated at another end (such as a third end, a fourth end, etc.). CIRPP 221 is coupled to busbar M 251 via a delta-wye transformer 241. The line impedance of transmission line 210, in particular the protected section between busbar M 251 and busbar N 252, is represented by an impedance Z L (especially the impedance per unit distance) modeling. When a fault occurs at point K, the impedance between busbar M 251 and point K is modeled as xZ L , the impedance between busbar N 252 and point K is modeled as (1-x)Z L . can vary with each moment and can be calculated as follows:

[0157]

[0158] in, and are the fault voltages measured at the local end (i.e. busbar M251) before and during the fault instance, respectively, and are the fault currents measured at the local end (i.e. busbar M251) before and during the fault instance, respectively.

[0159] In the following, phase-to-ground faults, particularly phase-A-to-ground (AG) faults, are considered. Figure 3 The embodiment according to the present disclosure is shown Figure 2 Model of the power system during faults, especially AG faults, especially sequence diagrams. Figure 4 Shows Figure 3 A simplified sequence diagram of . Figure 3 and Figure 4 In The equivalent impedance of the network 200 may be 231. Figure 3 and Figure 4 The remaining parameters can be defined as follows:

[0160] = Positive sequence voltage before fault

[0161] = Positive sequence voltage during fault

[0162] V2 = negative sequence voltage during fault

[0163] V0=zero sequence voltage during fault

[0164] Z 1T = Total positive sequence impedance at the fault point (k)

[0165] Z 2T = Total negative sequence impedance between points a and b

[0166] Z 0T = Total zero sequence impedance between points c and d

[0167] = Equivalent impedance of CIRPP during fault

[0168] Z SN = Equivalent impedance of remote source

[0169] Applying Kirchhoff's current law (KCL) at the fault point k yields:

[0170]

[0171] It can be rearranged as follows:

[0172]

[0173] Further rearranging equation (2) yields:

[0174]

[0175] is equivalent to the following:

[0176]

[0177] because and Equation (5) can be simplified as follows:

[0178]

[0179] against Rearranging equation (6) yields:

[0180]

[0181] because Equation (7) can be simplified as follows:

[0182]

[0183] Because the ratio Much smaller than 1, especially in the case of 1×10 -2 or less, during the fault period, compared with the transmission line impedance and the remote impedance, equation (8) can be further simplified as follows:

[0184]

[0185] The consistency in the traditional transmission network allows the grid equivalent impedance Z SN The impedance of the protected line is Z L In the form of, for each sequence component, that is, positive sequence component, negative sequence component, and zero sequence component, use the real-valued multiplier K 1,2,0 That is, Z SN It can be expressed as follows:

[0186] Z SN =K 1,2,0 Z 1L (10)

[0187] Substituting equation (10) into equation (9) yields:

[0188]

[0189] You can use Z 1T =(1-x+K1)Z 1L Simplifying it like this:

[0190]

[0191] refer to Figure 4 , the positive sequence voltage is divided to obtain the negative sequence voltage, as shown below:

[0192]

[0193] Substituting equation (12) into equation (13), we obtain the following result:

[0194]

[0195] Similarly, the zero-sequence voltage can be expressed as follows:

[0196]

[0197] For AG fault, the superimposed voltage can be written as follows:

[0198]

[0199] Substituting equation (12) into equation (16) yields:

[0200]

[0201] Positive sequence index It can be calculated as the angle difference between the negative sequence fault voltage and the superimposed positive sequence fault voltage as follows:

[0202]

[0203] Zero sequence index It can be calculated as the angle difference between the negative sequence fault voltage and the zero sequence fault voltage as follows:

[0204]

[0205] The phase angle range (also referred to as partition in this article) for AG fault classification can be determined according to equations (18) and (19), as follows: Figure 5 shown.

[0206] Figure 5 The power system (particularly Figure 2 The phase angle range of faults (especially AG faults) in the power system of the power system. In particular, Figure 5 a) and Figure 5 b) shows the phase angle range of AG fault and The partition is a phase angle range with upper and lower limits, where the calculated and According to one embodiment, the difference between the upper limit and the lower limit (i.e., the width of the range) is determined based on a preset value or an adaptive value, in particular based on a calculated and According to one embodiment, the upper limit and / or the lower limit are determined based on a preset value or an adaptive value, in particular based on a calculated and Sure.

[0207] Similar to the AG fault, the superimposed voltage fault of phase-B-to-phase-C-to-ground (BCG) can be expressed as follows:

[0208]

[0209] The negative sequence voltage of BCG fault can be written as follows:

[0210]

[0211] The zero-sequence voltage of a BCG fault can be written as follows:

[0212]

[0213] Therefore, the positive sequence index It can be written as follows:

[0214]

[0215] Zero sequence index It can be written as follows:

[0216]

[0217] The BCG fault classification can be determined based on equations (23) and (24), as Figure 6 shown.

[0218] Figure 6 The power system (particularly Figure 2 The phase angle range of faults (especially BCG faults) in the power system of Figure 6 a) and Figure 6 b) shows the phase angle range of BCG fault and Please note, Figure 6 The partitioning of AG failures in the previous section is based on the Figure 5 Partitions of the AG fault shown in . A partition is a phase angle range with upper and lower limits, where the calculated and According to one embodiment, the difference between the upper limit and the lower limit, i.e. the width of the range, is determined based on a preset value or an adaptive value, in particular based on a calculated and According to one embodiment, the upper limit and / or the lower limit are determined based on a preset value or an adaptive value, in particular based on a calculated and Sure.

[0219] The above is used to calculate and The analysis can be performed for any additional faults including BG faults, CG faults, ABG faults, CAG faults, AB faults, BC faults, and CA faults, where each of the letters A, B, and C respectively represent the A phase, B phase, and C phase carried on the transmission line, and the letter G represents the ground. That is, for example, a CAG fault refers to a C phase to A phase ground fault. Figure 7 shows the phase-to-ground fault and the phase-to-phase fault and According to one embodiment, the phase fault is determined and The result partition.

[0220] Figure 7 The phase angle ranges of various faults in the power system according to the embodiment of the present disclosure are shown. In particular, Figure 6 a) and Figure 6 b) shows the phase angle range of phase-to-phase fault and phase-to-ground fault respectively Figure 7 c) shows the phase angle range of phase-to-phase fault and phase-to-ground fault

[0221] The following instructions are used based on Figure 7 The phase angle range shown is a method for identifying faults, particularly the type of fault.

[0222] First, voltage and current measurements are obtained at the local terminal. According to one embodiment, the local terminal is coupled to an asynchronous power supply. According to one embodiment, the local terminal is Figure 2 The busbar M 251 is then connected to the busbar M 251. Secondly, the positive sequence, negative sequence, and zero sequence voltages are calculated based on the voltage and current measurements obtained, in particular, based on the respective voltage phasors. Thirdly, the positive sequence angle index is calculated. and zero sequence angle index The details are as follows:

[0223]

[0224] in, Fourth, the fault type is based on the calculated and as well as Figure 7 The phase angle range shown, in particular, is calculated by and and Figure 7 The phase angle range shown is compared and the calculated and According to one embodiment, the zero-sequence current is further compared with a preset value, and the criteria are summarized as follows:

[0225] 1. If And I o >I th , the fault is an AG fault.

[0226] 2. If And I o >Ith , the fault is a BG fault.

[0227] 3. If And I o >I th , the fault is a CG fault.

[0228] 4. If And I o >I th , the fault is an ABG fault.

[0229] 5. If And I o >I th , the fault is a BCG fault.

[0230] 6. If And I o >I th , the fault is a CAG fault.

[0231] 7. If And I o th , then the fault is AB fault.

[0232] 8. If And I o th , the fault is a BC fault.

[0233] 9. If And I o th , the fault is a CA fault.

[0234] Fifth, based on ΔV a ,ΔV b ,ΔV c , and I o Identify three-phase faults, especially by converting ΔV a ,ΔV b ,ΔV c , and I o are compared with the respective preset values, more specifically by doing the following:

[0235] If (ΔV a >V th1 And ΔV b >V th2 And ΔV c >V th3 And I o th ), then it is a three-phase fault, where and V​​​​th1 , V th2 , and V th3 are the threshold voltages of phase A, phase B, and phase C, respectively. According to one embodiment, V th1 ,V th2 , and V th3 According to one embodiment, V th1 ,V th2 , and V th3 The protection system for the power system is controlled based on another parameter setting, in particular the rated voltage, more particularly a ratio of the rated voltage, for example 2%. and / or The at least three faults may be a plurality of phase angle deviations determined based on a network model of the power system during respective faults of the at least three faults. The at least three faults may include any combination of at least three of an AG fault, a BG fault, a CG fault, an ABG fault, a BCG fault, a CAG fault, an AB fault, a BC fault, and a CA fault. Figure 7 Any combination of the at least three partitions shown in a)-c) can be at least three phase angle ranges determined based on multiple phase angle deviations, wherein the sum of the at least three phase angle ranges is the angle of complete rotation. The at least three phase angle ranges may include the above criteria 1 to 9 as and / or Set to any one of the phase angle ranges shown. and / or The at least three additional faults may be a plurality of additional phase angle deviations determined based on a network model of the power system during respective faults of the at least three faults. The at least three additional faults may include any combination of at least three of an AG fault, a BG fault, a CG fault, an ABG fault, a BCG fault, a CAG fault, an AB fault, a BC fault, and a CA fault. Figure 7 Any combination of the at least three partitions shown in a)-c) can be at least three additional phase angle ranges determined based on multiple additional phase angle deviations, wherein the sum of the at least three additional phase angle ranges is the angle of full rotation. The at least three additional phase angle ranges may include the above criteria 1 to 9 for and / or Set to any one of the phase angle ranges shown.

[0236] According to an embodiment, the plurality of phase angle deviations is different from the plurality of additional phase angle deviations. According to an embodiment, the at least three faults are different from the at least three additional faults. According to an embodiment, the at least three phase angle ranges are different from the at least three additional phase angle ranges.

[0237] It is understood by those skilled in the art that the term "additional" simply means "extra", and thus can be used interchangeably as "second" as well as "third", "fourth", etc. That is, for example, the plurality of phase angle deviations may be a plurality of first phase angle deviations, and the plurality of additional phase angle deviations may be a plurality of second phase angle deviations. It is worth noting that for each fault, the first phase angle deviation may or may not be the same parameter ( and / or ). It will be further understood by those skilled in the art that the parameters after the first and second phases may be calculated, that is, for example, a plurality of third phase angle deviations, a plurality of fourth phase angle deviations, etc. may be calculated.

[0238] Figure 8 and Fig. 9 Shown is a Figure 7 An additional embodiment of a method for identifying a fault, particularly a fault type, using a phase angle range is shown.

[0239] refer to Figure 8 , at S801, calculate the positive sequence angle index and zero sequence angle index In particular, according to equation (25). Positive sequence angle index or zero sequence angle index can be referred to as a measured phase angle deviation. According to one embodiment, S801 includes obtaining voltage and current measurements of a local terminal. According to one embodiment, the local terminal is coupled to an asynchronous power source. According to one embodiment, the local terminal is Figure 2 According to one embodiment, S801 further comprises calculating positive sequence, negative sequence, and zero sequence voltages based on the acquired voltage and current measurements, in particular based on the respective voltage phasors. At S802, Compare with Set 1 and / or Set 2, where Set 1 is or includes the phase angle range of single-phase-to-ground fault Set 2 is or includes the phase angle range of relative phase-to-ground faults Will Compare with Set 3, where Set 3 is or includes the phase angle ranges for single-phase-to-ground faults and phase-to-phase-to-ground faults According to one embodiment, Set 1, Set 2, and Set 3 are respectively Figure 7 a), Figure 7 b), and Figure 7 According to one embodiment, Compare with set 1 and / or set 2 and Compare with set 3, is or includes determination and The intermediate fault type includes information on whether the fault involves a single phase (i.e., a single phase-to-ground fault) or involves at least two phases (i.e., a phase-to-phase fault or a phase-to-phase fault). and When and Figure 7 a) The comparison shows that the fault may be a BG fault, but and Figure 7 b) The comparison shows that the fault may be an ABG fault. Comparison with Set 3 shows that the fault may be a BG or CAG fault. Compare and When the potential faults determined to be compared overlap each other, a fault is determined, in this case a BG fault. Therefore, at S803, it is determined whether the identified intermediate fault type is a single phase-to-ground fault. If it is positive, the fault is a phase-to-ground fault indicated by the intermediate fault type. However, if it is negative, at S804, the zero sequence current can be compared with a threshold value to distinguish whether the fault is a phase-to-phase fault or a phase-to-phase fault.

[0240] According to one embodiment, both ends of the transmission line are terminated at a first end coupled to a first generator and a second end coupled to a second generator, and the method also includes: obtaining a plurality of voltage measurement values ​​at the first end; determining a measured phase angle deviation based on the plurality of voltage measurement values; and determining a fault by identifying in which of at least three phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three phase angle ranges.

[0241] According to one embodiment, the method further comprises: determining a plurality of additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; and determining at least three additional phase angle ranges based on the additional plurality of phase angle deviations, wherein the plurality of phase angle deviations are different from the plurality of additional phase angle deviations, wherein at least three faults are different from at least three additional faults, wherein at least three phase angle ranges are different from at least three additional phase angle ranges, and wherein the sum of the at least three additional phase angle ranges is the angle of full rotation.

[0242] According to one embodiment, the method also includes: obtaining multiple voltage measurement values ​​at the first end; determining an additional measured phase angle deviation based on the multiple voltage measurement values; and determining the fault by identifying in which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges.

[0243] According to one embodiment, the method further comprises: obtaining a plurality of current measurements of the first end; determining a zero-sequence current based on the plurality of current measurements of the first end; and further determining a fault based on the zero-sequence current, in particular by comparing the zero-sequence current with a preset value.

[0244] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is a phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0245] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0246] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0247] According to one embodiment, a transmission line carries multiple phases, and the method includes: obtaining multiple voltage measurement values ​​of a first end measured before and during a fault; and determining an n-phase fault based on voltage differences between respective phases of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1 and corresponds to the number of multiple phases.

[0248] According to one embodiment, the method further comprises: obtaining a plurality of current measurements of the first end; determining a generator type of the first generator based on the plurality of current measurements and / or the plurality of voltage measurements; and when the first generator is determined to be of the first generator type, determining a measured phase angle deviation based on the plurality of voltage measurements; or when the first generator is determined to be of the second generator type, determining a measured phase angle deviation based on the plurality of current measurements.

[0249] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0250] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0251] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0252] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0253] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0254] According to one embodiment, the transmission line is terminated at both ends at a first end coupled to a first generator and a second end coupled to a second generator, and the method further comprises: obtaining a plurality of voltage measurements at the first end; determining a measured phase angle deviation based on the plurality of voltage measurements; determining a fault by identifying in which of at least three phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three phase angle ranges; and controlling a protection system for the power system based on the determined fault. According to one embodiment, the measured phase angle deviation is a positive sequence angle indicator of equation (25) or zero sequence angle index According to one embodiment, the at least three faults or at least three additional faults are or include faults involving a single phase, in particular phase-to-ground faults, more specifically AG, BG, and CG faults. According to one embodiment, the at least three faults or at least three additional faults are or include faults involving two phases, in particular phase-to-phase faults, more specifically ABG, BCG, and CAG faults, and / or phase-to-phase faults, more specifically AB, BC, and CA faults. According to one embodiment, the at least three faults or at least three additional faults are or include any possible combination of at least three of the above faults. According to one embodiment, the at least three faults are the same as the at least three additional faults. According to one embodiment, the at least three faults are different from the at least three additional faults. According to one embodiment, the at least three phase angle ranges are or include Figure 7 a) Partitions 1, 2, and 3 or Figure 7 According to one embodiment, at least three second phase angle ranges are or include Figure 7 b) Partitions 1, 2, and 3 or Figure 7 c) Partitions 1, 2, and 3.

[0255] According to one embodiment, the method further comprises: determining a plurality of additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; and determining at least three additional phase angle ranges based on the additional plurality of phase angle deviations, wherein the plurality of phase angle deviations are different from the plurality of additional phase angle deviations, wherein at least three faults are different from at least three additional faults, wherein at least three phase angle ranges are different from at least three additional phase angle ranges, and wherein the sum of the at least three additional phase angle ranges is the angle of full rotation.

[0256] According to one embodiment, the method further comprises: obtaining a plurality of voltage measurements at the first end; determining an additional measured phase angle deviation based on the plurality of voltage measurements; determining a fault by identifying in which of at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges; and controlling a protection system for the power system based on the determined fault. According to one embodiment, the additional measured phase angle deviation is a positive sequence angle indicator of equation (25) or zero sequence angle index According to one embodiment, the at least three additional phase angle ranges are or include Figure 7 a) Partitions 1, 2, and 3 or Figure 7 According to one embodiment, at least three second phase angle ranges are or include Figure 7 b) Partitions 1, 2, and 3 or Figure 7 c) Partitions 1, 2, and 3.

[0257] According to one embodiment, the method further comprises: obtaining a plurality of current measurements at the first terminal; determining a zero-sequence current based on the plurality of current measurements at the first terminal; further determining a fault based on the zero-sequence current, in particular by comparing the zero-sequence current with a preset value; and controlling a protection system for the power system based on the determined fault. According to one embodiment, determining that the fault is Figure 8 S804 and / or at least any one of the above numbered standards 1 to 9.

[0258] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is a phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0259] According to one embodiment, the plurality of phase angle deviations, additional plurality of phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of the negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of the zero sequence voltage measured during the fault, or is the phase angle difference between the phase angle of the positive sequence voltage measured before the fault and the phase angle of the positive sequence voltage measured during the fault. According to one embodiment, the plurality of phase angle deviations, additional plurality of phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a first sequence of voltages or currents measured at a point on the transmission line before the fault, and wherein the second phase angle is the phase angle of a second sequence of voltages or currents measured at the point on the transmission line during the fault. According to one embodiment, the first phase angle is ∠V2 of equation (25). According to one embodiment, the second phase angle is ∠ΔV1 or ∠V0 of equation (25).

[0260] According to one embodiment, a transmission line carries multiple phases, and the method includes: obtaining multiple voltage measurement values ​​of a first end measured before and during a fault; determining an n-phase fault based on voltage differences between respective phases of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1 and corresponds to the number of multiple phases; and further controlling a protection system based on the determined n-phase fault.

[0261] According to one embodiment, the method further comprises: obtaining a plurality of current measurements of the first end; determining a generator type of the first generator based on the plurality of current measurements and / or the plurality of voltage measurements; and when the first generator is determined to be of the first generator type, determining a measured phase angle deviation based on the plurality of voltage measurements; or when the first generator is determined to be of the second generator type, determining a measured phase angle deviation based on the plurality of current measurements.

[0262] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0263] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0264] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0265] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0266] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0267] refer to Fig. 9 , at S901, determine the zero sequence current. At S902, compare the zero sequence current with a preset value. If yes, execute S801 and S802 to determine whether the fault type is a phase-to-ground fault or a phase-to-phase-to-ground fault. If no, determine and compare it to set 4, where set 4 is or includes The fault type determined is a phase-to-phase fault.

[0268] According to one embodiment, the method also includes: determining multiple additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; determining at least three additional phase angle ranges based on the additional multiple phase angle deviations, wherein the sum of the at least three additional phase angle ranges is the angle of complete rotation; determining additional measured phase angle deviations based on multiple voltage measurements; and determining the fault by identifying in which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges.

[0269] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is a phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0270] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0271] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0272] According to one embodiment, the transmission line carries multiple phases, and the method further includes: obtaining multiple voltage measurement values ​​of the first end measured before and during the fault; and determining an n-phase fault based on the voltage difference between each phase of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1, corresponding to the number of multiple phases.

[0273] According to one embodiment, the method further comprises: obtaining a plurality of current measurements of the first end; determining a generator type of the first generator based on the plurality of current measurements and / or the plurality of voltage measurements; and when the first generator is determined to be of the first generator type, determining a measured phase angle deviation based on the plurality of voltage measurements; or when the first generator is determined to be of the second generator type, determining a measured phase angle deviation based on the plurality of current measurements.

[0274] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0275] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0276] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0277] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0278] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0279] According to one embodiment, the method further comprises: determining a plurality of additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; determining at least three additional phase angle ranges based on the additional plurality of phase angle deviations, wherein the sum of the at least three additional phase angle ranges is the angle of full rotation; determining the additional measured phase angle deviations based on a plurality of voltage measurements; determining the fault by identifying in which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges; and controlling a protection system for the power system based on the determined fault. According to one embodiment, the at least three faults or the at least three additional faults are or comprise faults involving two phases, in particular relative to phase to ground faults, more particularly ABG, BCG, and CAG faults, and / or relative to phase faults, more particularly AB, BC, and CA faults. According to one embodiment, the at least three faults or the at least three additional faults are or comprise faults involving single phases, in particular relative to ground faults, more particularly AG, BG, and CG faults. According to one embodiment, the at least three faults or the at least three additional faults are or include any possible combination of at least three of the above faults. According to one embodiment, the at least three faults are the same as the at least three additional faults. According to one embodiment, the at least three faults are different from the at least three additional faults. According to one embodiment, the at least three phase angle ranges are or include Figure 7 a) Partitions 1, 2, and 3 or Figure 7 According to one embodiment, at least three second phase angle ranges are or include Figure 7 b) Partitions 1, 2, and 3 or Figure 7 c) Partitions 1, 2, and 3.

[0280] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is a phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0281] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0282] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0283] According to one embodiment, the transmission line carries multiple phases, and the method further includes: obtaining multiple voltage measurement values ​​of the first end measured before and during the fault; determining an n-phase fault based on the voltage difference between each phase of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1 and corresponds to the number of multiple phases; and further controlling the protection system based on the determined n-phase fault.

[0284] According to one embodiment, the method further comprises: obtaining a plurality of current measurements of the first end; determining a generator type of the first generator based on the plurality of current measurements and / or the plurality of voltage measurements; and when the first generator is determined to be of the first generator type, determining a measured phase angle deviation based on the plurality of voltage measurements; or when the first generator is determined to be of the second generator type, determining a measured phase angle deviation based on the plurality of current measurements.

[0285] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0286] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0287] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0288] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0289] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0290] Fig.10A tested power system according to an embodiment of the present disclosure is shown. The network 1000 includes a first power source 1021 connected to a second power source 1022 via a transmission line 1010. In this embodiment, the first power source 1021 is an asynchronous power source, in particular a type IV wind turbine generator (WTG), and the second power source 1022 is a power grid modeled as a Thevenin equivalent circuit (a constant voltage source behind a source impedance) outside a bus N1052. According to one embodiment, the first power source and / or the second power source may be a synchronous power source. The transmission line 1010 is terminated at both ends at a first end 1051 (bus M in this embodiment) and a second end 1052 (bus N in this embodiment). According to one embodiment, the transmission line terminates at another end (e.g., a third end, a fourth end, etc.). The WTG 1021 is coupled to the bus M 1051 via a Y-delta transformer 1091 and a delta-Y transformer 1092. An intelligent electronic device IED may be placed at, in, on, or associated with busbar M 1051. According to one embodiment, the IED measures the voltage and current of busbar M 1051. An intelligent electronic device IED may be placed at, in, on, or associated with busbar N 1052. According to one embodiment, the IED measures the voltage and current of busbar N 1052. According to one embodiment, the IED placed at, in, on, or associated with busbar N 1052 is omitted. Electricity flows from a first power source 1021 through a line 1010 between busbar M 1051 and busbar N 1052, which in this case is a 100 km long line operating at a nominal voltage of 220 kV.

[0291] Three fault conditions and identification methods according to embodiments of the present disclosure are described below.

[0292] Case 1: AG fault at 10 km from busbar M1051, RF = 10Ω, fault initiation angle FIA ​​= 60°:

[0293] For this case, the three-phase voltage and current measurement values ​​of busbar M1051 are as follows: Fig.11 a) and Fig.11 b). The pattern of AG failure can be seen from the figure. The failure occurred at 0.1s and lasted for 0.22s. Fig.12 As shown in a), the positive and zero sequence indicators are calculated at different time points. These indicators fall on and The AG fault partition. Fig.13 a) to Fig.13 It can also be clearly seen in c) that Fig.13 a) to Fig.13c) shows the phase angle range of phase-to-ground fault Phase angle range of phase-to-ground fault Phase angle range for phase-to-ground faults and phase-to-phase-to-ground faults And the calculated and , as indicated by the box points. Fig.13 a) to Fig.13 The position of the black dot in c) corresponds to a certain time point after the failure and Value, for example, 20ms after the fault occurs. The zero-sequence current is greater than the threshold (I0>I th ),like Fig.12 b. Therefore, the fault is determined to be an AG fault.

[0294] Case 2: AB fault 10km away from busbar M1051, RF=50Ω, FIA=60°:

[0295] In this case, the three-phase voltage and current measurement values ​​of busbar M1051 are as follows: Fig.14 a) and Fig.14 b). Fig.15 As shown in a), the positive and zero sequence indicators are calculated at different time points, and these indicators fall into the defined AB fault partition. The zero-sequence current is less than the threshold value (I0 th ),like Fig.15 b. Therefore, the fault is determined to be an AB fault. In this embodiment, the phase angle range of the relative phase fault is Equal to the respective phase angle range of phase-to-ground faults As shown in the above criteria numbered 4 to 6 and 7 to 9. Therefore, Fig.16 shows the phase angle range for phase-to-ground faults And the calculated location.

[0296] Case 3: BCG fault at 10km from busbar M1051, RF=10Ω, FIA=60°:

[0297] In this case, the three-phase voltage and current measurement values ​​of busbar M1051 are as follows: Fig.17 a) and Fig.17 b). The positive sequence and zero sequence indicators are calculated at different time points, such as Fig.18 a) and Fig.18 As shown in b), each indicator falls into the defined BCG fault partition. and Inside. From Fig. 20 a) to Fig. 20 ​It can also be clearly seen in c) that Fig. 20 a) to Fig. 20 c) shows the phase angle range of phase-to-ground fault Phase angle range of phase-to-ground fault Phase angle range for phase-to-ground faults and phase-to-phase-to-ground faults And the calculated and The zero-sequence current is greater than the threshold (I0>I th ),like Fig.19 Therefore, the fault is determined to be a BCG fault.

[0298] Test results for various system configurations are described below, including single circuit, dual circuit, and cable systems with various CIRPP devices (including Type III WTG, Type IV WTG, and solar photovoltaic (PV) generator).

[0299] System configuration: Single-circuit transmission line with Type IV WTG ( Fig.21 )

[0300] The network 2100 includes a first power source 2121 connected to a second power source 2122 via a transmission line 2110. In this embodiment, the first power source 2121 is an asynchronous power source, in particular a type IV wind turbine generator WTG, and the second power source 2122 is a power grid modeled as a Thevenin equivalent circuit (constant voltage source behind source impedance) outside the bus N 2152. According to one embodiment, the first power source and / or the second power source can be a synchronous power source. The transmission line 2110 is terminated at both ends at a first end 2151 (bus M in this embodiment) and a second end 2152 (bus N in this embodiment). According to one embodiment, the transmission line terminates at another end (e.g., a third end, a fourth end, etc.). The WTG 2121 is connected to the bus M 2151 through a Y-delta transformer 2141 and a delta-Y transformer 2142. The intelligent electronic device IED can be placed at, in, on, or associated with the bus M 2151. According to one embodiment, the IED measures the voltage and current of the bus M 2151. Intelligent electronic devices IEDs may be placed at, in, on, or associated with bus N 2152. According to one embodiment, the IEDs measure the voltage and current of bus N 2152. According to one embodiment, the IEDs placed at, in, on, or associated with bus N 2152 are omitted. Power flows from the first power source 2121 through the line 2110 between bus M 2151 and bus N 2152. The test conditions, system parameters, and WTG parameters are listed below.

[0301] Total number of test cases = 660

[0302] Test conditions:

[0303] 1. Fault starting angle: 0°, 60°, 135°

[0304] 2. Fault resistance: 0, 5, 10, 20, 50Ω

[0305] 3. Source-to-line-impedance ratio (SIR) on the grid side: 0.5

[0306] 4. Fault type: Ag, AB, BC-g, ABC-g

[0307] 5. Fault location: 1%, 5%, 10%, 16%, 24%, 36%, 50%, 64%, 76%, 84%, 90%

[0308] System parameters:

[0309] 6. Line MN:

[0310] 7. Source at busbar N

[0311] Source Angle = -17.1°

[0312]

[0313] Fig. 22 The performance summary of the method according to the embodiment of the present disclosure is shown. In particular, the performance summary includes the performance of the first method and the second method for comparison.

[0314] System configuration: Single-circuit transmission line with Type III wind power ( Fig.23 )

[0315] The network 2300 includes a first power source 2321 connected to a second power source 2322 via a transmission line 2310. In this embodiment, the first power source 2321 is an asynchronous power source, in particular a type III wind turbine generator WTG, and the second power source 2322 is a power grid modeled as a Thevenin equivalent circuit (constant voltage source behind source impedance) outside the bus N 2352. According to one embodiment, the first power source and / or the second power source can be a synchronous power source. The transmission line 2310 is terminated at both ends at a first end 2351 (bus M in this embodiment) and a second end 2352 (bus N in this embodiment). According to one embodiment, the transmission line terminates at another end (e.g., a third end, a fourth end, etc.). The WTG 2321 is coupled to the bus M 2351 via a Y-delta transformer 2341 and a delta-Y transformer 2342. The intelligent electronic device IED can be placed at, in, on, or associated with the bus M 2351. According to one embodiment, the IED measures the voltage and current of bus M 2351. The intelligent electronic device IED may be placed at, in, on, or associated with bus N 2352. According to one embodiment, the IED measures the voltage and current of bus N 2352. According to one embodiment, the IED placed at, in, on, or associated with bus N 2352 is omitted. Power flows from the first power source 2321 through the line 2310 between bus M 2351 and bus N 2352. The test conditions, system parameters, and WTG parameters are listed below.

[0316] Total number of test cases = 528

[0317] Test conditions:

[0318] 1. Fault starting angle: 0°, 60°, 135°

[0319] 2. Fault resistance: 0, 10, 20, 50Ω

[0320] 3. Grid side SIR: 0.5

[0321] 4. Fault type: Ag, AB, BC-g, ABC-g

[0322] 5. Fault location: 1%, 5%, 10%, 16%, 24%, 36%, 50%, 64%, 76%, 84%, 90%

[0323] System parameters:

[0324] 6. Line MN:

[0325] 7. Source at busbar N

[0326] Source Angle = -17.1°

[0327]

[0328] Fig.24 The performance summary of the method according to the embodiment of the present disclosure is shown. In particular, the performance summary includes the performance of the first method and the second method for comparison.

[0329] System configuration: Single circuit transmission line with solar PV generator ( Fig.25 )

[0330] The network 2500 includes a first power source 2521 connected to a second power source 2522 via a transmission line 2510. In this embodiment, the first power source 2521 is an asynchronous power source, in particular a solar PV, and the second power source 2522 is a power grid modeled as a Thevenin equivalent circuit (constant voltage source behind source impedance) outside the bus N 2552. According to one embodiment, the first power source and / or the second power source can be a synchronous power source. The transmission line 2510 is terminated at both ends at a first end 2551 (bus M in this embodiment) and a second end 2552 (bus N in this embodiment). According to one embodiment, the transmission line terminates at another end (e.g., a third end, a fourth end, etc.). The solar PV 2521 is coupled to the bus M 2551 through a Y-delta transformer 2541 and a delta-Ye transformer 2542. An intelligent electronic device IED can be placed at, in, on, or associated with the bus M 2551. According to one embodiment, the IED measures the voltage and current of the bus M 2551. Intelligent electronic devices IEDs may be placed at, in, on, or associated with bus N 2552. According to one embodiment, the IEDs measure the voltage and current of bus N 2552. According to one embodiment, the IEDs placed at, in, on, or associated with bus N 2552 are omitted. Power flows from the first power source 2521 through the line 2510 between bus M 2551 and bus N 2552. Test conditions, system parameters, and solar PV parameters are listed below.

[0331] Total number of test cases = 528

[0332] Test conditions:

[0333] 1. Fault starting angle: 0°, 60°, 135°

[0334] 2. Fault resistance: 0, 10, 20, 50Ω

[0335] 3. Grid side SIR: 0.5

[0336] 4. Fault type: Ag, AB, BC-g, ABC-g

[0337] 5. Fault location: 1%, 5%, 10%, 16%, 24%, 36%, 50%, 64%, 76%, 84%, 90%

[0338] System parameters:

[0339] 6. Line MN:

[0340] 7. Source at busbar N

[0341] Source Angle = -17.1°

[0342]

[0343] Fig.26 The performance summary of the method according to the embodiment of the present disclosure is shown. In particular, the performance summary includes the performance of the first method and the second method for comparison.

[0344] System configuration: Transmission line with Type IV wind power ( Fig. 27 )

[0345] The network 2700 includes a first power source 2721 connected to a second power source 2722 via a transmission line 2710. The transmission line 2710 is a double-circuit transmission line. In this embodiment, the first power source 2721 is an asynchronous power source, in particular a type IV wind turbine generator WTG, and the second power source 2722 is a power grid modeled as a Thevenin equivalent circuit (constant voltage source behind the source impedance) outside the bus N 2752. According to one embodiment, the first power source and / or the second power source can be a synchronous power source. The transmission line 2710 is terminated at both ends at a first end 2751 (in this embodiment, bus M) and a second end 2752 (in this embodiment, bus N). According to one embodiment, the transmission line terminates at another end (e.g., a third end, a fourth end, etc.). WTG 2721 is coupled to bus M 2751 via a Y-delta transformer (in particular, a grounded Y-delta transformer 2741) and a delta-Y transformer (in particular, a grounded delta-Y transformer 2742). An intelligent electronic device, IED, may be placed at, in, on, or associated with bus M 2751. According to one embodiment, the IED measures the voltage and current of bus M 2751. An intelligent electronic device, IED, may be placed at, in, on, or associated with bus N 2752. According to one embodiment, the IED measures the voltage and current of bus N 2752. According to one embodiment, the IED placed at, in, on, or associated with bus N 2752 is omitted. Electricity flows from a first power source 2721 through line 2710 between bus M 2751 and bus N 2752. Test conditions, system parameters, and Type IV WTG parameters are listed below.

[0346] Total number of test cases = 528

[0347] Test conditions:

[0348] 1. Fault starting angle: 0°, 60°, 135°

[0349] 2. Fault resistance: 0, 10, 20, 50Ω

[0350] 3. Grid side SIR: 0.5, 2

[0351] 4. Fault type: Ag, AB, BC-g, ABC-g

[0352] 5. Fault location: 1%, 5%, 10%, 16%, 24%, 36%, 50%, 64%, 76%, 84%, 90%

[0353] System parameters:

[0354] 6. Line MN:

[0355]

[0356] 7. Source at busbar N

[0357] Source Angle = -17.1°

[0358]

[0359] Fig.28 The performance summary of the method according to the embodiment of the present disclosure is shown. In particular, the performance summary includes the performance of the first method and the second method for comparison.

[0360] Fig.29 The performance summary of the method according to the embodiment of the present disclosure is shown. In particular, the performance summary includes the performance of the first method and the second method for comparison.

[0361] Fig.30 Devices, computer-readable media, and systems according to embodiments of the present disclosure are shown. Device 3010 is a device for controlling a protection system of a power system including a transmission line. Computer-readable media 3020 is a device for controlling a protection system of a power system including a transmission line, which carries instructions for executing the method of any of the above embodiments. Power system 3000 includes device 3010 of any of the above embodiments and computer-readable media 3020 of any of the above embodiments.

[0362] According to one embodiment, both ends of the transmission line are terminated at a first end coupled to a first generator and a second end coupled to a second generator, and the processor is also configured to: obtain multiple voltage measurement values ​​of the first end; determine a measured phase angle deviation based on the multiple voltage measurement values; determine a fault by identifying in which of at least three phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three phase angle ranges; and control a protection system for the power system based on the determined fault.

[0363] According to one embodiment, the processor is further configured to: determine a plurality of additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; and determine at least three additional phase angle ranges based on the additional plurality of phase angle deviations, wherein the plurality of phase angle deviations are different from the plurality of additional phase angle deviations, wherein at least three faults are different from at least three additional faults, wherein at least three phase angle ranges are different from at least three additional phase angle ranges, and wherein the sum of the at least three additional phase angle ranges is the angle of full rotation.

[0364] According to one embodiment, the processor is also configured to: obtain multiple voltage measurement values ​​at the first end; determine an additional measured phase angle deviation based on the multiple voltage measurement values; determine a fault by identifying in which of at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges; and control a protection system for the power system based on the determined fault.

[0365] According to one embodiment, the processor is also configured to: obtain multiple current measurement values ​​of the first end; determine the zero-sequence current based on the multiple current measurement values ​​of the first end; further determine the fault based on the zero-sequence current, in particular by comparing the zero-sequence current with a preset value; and control the protection system for the power system based on the determined fault.

[0366] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is a phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0367] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0368] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0369] According to one embodiment, the transmission line carries multiple phases, and the processor is further configured to: obtain multiple voltage measurement values ​​of the first end measured before and during the fault; determine an n-phase fault based on the voltage difference between each phase of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1 and corresponds to the number of multiple phases; and further control the protection system based on the determined n-phase fault.

[0370] According to one embodiment, the processor is further configured to: obtain a plurality of current measurement values ​​of the first end; determine a generator type of the first generator based on the plurality of current measurement values ​​and / or the plurality of voltage measurement values; and when the first generator is determined to be of the first generator type, determine a measured phase angle deviation based on the plurality of voltage measurement values; or when the first generator is determined to be of the second generator type, determine a measured phase angle deviation based on the plurality of current measurement values.

[0371] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0372] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0373] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0374] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0375] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0376] According to one embodiment, the processor is also configured to: determine multiple additional phase angle deviations based on a network model of the power system during respective faults of at least three additional faults; determine at least three additional phase angle ranges based on the additional multiple phase angle deviations, wherein the sum of the at least three additional phase angle ranges is the angle of complete rotation; determine additional measured phase angle deviations based on multiple voltage measurements; determine the fault by identifying in which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges; and control a protection system for the power system based on the determined fault.

[0377] According to one embodiment, the measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a phase angle of a negative sequence voltage measured during a fault, and wherein the second phase angle is a phase angle of a zero sequence voltage measured during the fault, or a phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0378] According to one embodiment, the multiple phase angle deviations, additional multiple phase angle deviations, measured phase angle deviations, or additional measured phase angle deviations are or include a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during the fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

[0379] According to one embodiment, a plurality of phase angle deviations, an additional plurality of phase angle deviations, a measured phase angle deviation, or an additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is a first sequence of phase angles of a voltage or current measured at a point on the transmission line before a fault, and wherein the second phase angle is a second sequence of phase angles of a voltage or current measured at the point on the transmission line during the fault.

[0380] According to one embodiment, the transmission line carries multiple phases, and the processor is further configured to: obtain multiple voltage measurement values ​​of the first end measured before and during the fault; determine an n-phase fault based on the voltage difference between each phase of the multiple voltage measurement values ​​measured before the fault and the multiple voltage measurement values ​​measured during the fault, wherein n is a natural number greater than 1 and corresponds to the number of multiple phases; and further control the protection system based on the determined n-phase fault.

[0381] According to one embodiment, the processor is further configured to: obtain a plurality of current measurement values ​​of the first end; determine a generator type of the first generator based on the plurality of current measurement values ​​and / or the plurality of voltage measurement values; and when the first generator is determined to be of the first generator type, determine a measured phase angle deviation based on the plurality of voltage measurement values; or when the first generator is determined to be of the second generator type, determine a measured phase angle deviation based on the plurality of current measurement values.

[0382] According to one embodiment, the first power source is one of a grid, a synchronous power source, an unconventional power source, in particular an inverter-based resource, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

[0383] According to one embodiment, the phase angle ranges of the at least three phase angle ranges do not overlap with each other.

[0384] According to one embodiment, the phase angle ranges of the at least three additional phase angle ranges do not overlap with each other.

[0385] According to one embodiment, each of the at least three phase angle ranges comprises a respective phase angle deviation of the plurality of phase angle deviations.

[0386] According to one embodiment, each of the at least three additional phase angle ranges comprises a respective phase angle deviation of the plurality of additional phase angle deviations.

[0387] Although various embodiments of the present disclosure have been described above, it should be understood that they are given as examples only and not as limitations. Similarly, various diagrams may depict example architectures or configurations, which are provided to enable those of ordinary skill in the art to understand the exemplary features and functions of the present disclosure. However, these people will understand that the present disclosure is not limited to the example architectures or configurations shown, but can be implemented using various alternative architectures and configurations. In addition, as will be understood by those of ordinary skill in the art, one or more features of an embodiment may be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of the present disclosure should not be limited by any of the exemplary embodiments described above.

[0388] It should also be understood that any reference to an element using names such as "first", "second", etc. herein does not generally limit the number or order of these elements. Instead, these names can be used herein as a convenient means of distinguishing two or more elements or element instances. Therefore, referring to a first and a second element does not mean that only two elements can be used, nor does it mean that the first element must precede the second element in some way.

[0389] In addition, those skilled in the art will appreciate that information and signals may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, and symbols that may be referenced in the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0390] Those skilled in the art will further understand that any of the various illustrative logical blocks, units, processors, devices, circuits, methods, and functions described in conjunction with the aspects disclosed herein may be implemented by electronic hardware (e.g., digital implementations, analog implementations, or a combination of both), firmware, various forms of programs or design codes containing instructions (for convenience, may be referred to herein as "software" or "software units"), or any combination of these techniques.

[0391] In order to clearly illustrate this interchangeability of hardware, firmware, and software, various illustrative components, blocks, units, circuits, and steps have been generally described above according to their functions. Whether this function is implemented as hardware, firmware, or software or a combination of these technologies depends on the specific application and the design constraints imposed on the entire system. Those skilled in the art can implement the described functions in various ways for each specific application, but such implementation decisions will not deviate from the scope of this disclosure. According to various embodiments, processors, devices, components, circuits, structures, machines, units, etc. can be configured to perform one or more functions described herein. The term "configured to" or "configured for" used herein with respect to a specified operation or function refers to a processor, device, component, circuit, structure, machine, unit, etc. that is physically constructed, programmed, and / or arranged to perform a specified operation or function.

[0392] In addition, it will be understood by those skilled in the art that the various illustrative methods, logic blocks, units, devices, components, and circuits described herein may be implemented or performed within an integrated circuit (IC), which may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, or any combination thereof. The logic blocks, units, and circuits may also include antennas and / or transceivers to communicate with various components within a network or device. The general-purpose processor may be a microprocessor, but may also be any conventional processor, controller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other suitable configuration for performing the functions described herein. If implemented in software, the functions may be stored as one or more instructions or codes on a computer-readable medium. Therefore, the steps of the method or algorithm disclosed herein may be implemented as software stored on a computer-readable medium.

[0393] Computer-readable media include computer storage media and communication media, including any medium capable of transferring a computer program or code from one place to another. Storage media can be any available medium that a computer can access. As an example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, magnetic disk storage devices, or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of instructions or data structures and can be accessed by a computer.

[0394] In addition, memory or other storage devices and communication components may be used in embodiments of the present disclosure. It should be understood that, for clarity, the above description has described embodiments of the present disclosure with reference to different functional units and processors. However, it will be apparent that any suitable functional distribution between different functional units, processing logic elements or domains may be used without detracting from the present disclosure. For example, functions shown as being performed by separate processing logic elements or controllers may be performed by the same processing logic unit or controller. Therefore, references to specific functional units are only references to suitable means for providing the functions, rather than indications of strict logical or physical structures or organizations.

[0395] Various modifications to the implementations described in this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations without departing from the scope of this disclosure. Therefore, the present disclosure is not intended to be limited to the embodiments shown herein, but should be given the widest scope consistent with the novel features and principles disclosed herein, as described in the following claims.

Claims

1. A method of controlling a protection system for an electric power system, the electric power system comprising a transmission line, the method comprising: determining a plurality of phase angle deviations based on a network model of the power system during respective ones of the at least three faults; determining at least three phase angle ranges based on the plurality of phase angle deviations, wherein a sum of the at least three phase angle ranges is an angle of full rotation; as well as A protection system of the power system is controlled based on the at least three phase angle ranges.

2. The method according to claim 1, wherein: The transmission line is terminated at both ends at a first end coupled to a first generator and a second end coupled to a second generator, the method further comprising: obtaining a plurality of voltage measurements at the first terminal; determining a measured phase angle deviation based on the plurality of voltage measurements; determining a fault by identifying in which of the at least three phase angle ranges the measured phase angle deviation lies, in particular by comparing the measured phase angle deviation with at least one of the at least three phase angle ranges; and A protection system of the power system is controlled based on the determined fault.

3. The method according to claim 1 or 2, further comprising: determining a plurality of additional phase angle deviations based on a network model of the power system during respective ones of at least three additional faults; as well as At least three additional phase angle ranges are determined based on the plurality of additional phase angle deviations, wherein a sum of the at least three additional phase angle ranges is an angle of complete rotation.

4. The method according to claim 3, further comprising: obtaining a plurality of voltage measurements at the first terminal; determining an additional measured phase angle deviation based on the plurality of voltage measurements; determining the fault by identifying in which of the at least three additional phase angle ranges the measured phase angle deviation is located, in particular by comparing the measured phase angle deviation with at least one of the at least three additional phase angle ranges; as well as A protection system of the power system is controlled based on the determined fault.

5. The method according to any one of claims 1 to 4, further comprising: obtaining a plurality of current measurements at the first terminal; determining a zero sequence current based on a plurality of current measurements at the first terminal; further determining the fault based on the zero-sequence current, in particular by comparing the zero-sequence current with a preset value; as well as A protection system of the power system is controlled based on the determined fault.

6. The method according to any one of claims 1 to 5, wherein: The measured phase angle deviation is a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during a fault, and wherein the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or is a phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

7. The method according to any one of claims 4 to 6, wherein: The multiple phase angle deviations, the multiple additional phase angle deviations, the measured phase angle deviation, or the additional measured phase angle deviation is or includes a phase angle difference between a first phase angle and a second phase angle, wherein the first phase angle is the phase angle of a negative sequence voltage measured during a fault, and the second phase angle is the phase angle of a zero sequence voltage measured during the fault, or the phase angle difference between a phase angle of a positive sequence voltage measured before the fault and a phase angle of the positive sequence voltage measured during the fault.

8. The method according to any one of claims 2 to 7, wherein: The transmission line carries a plurality of phases, and the method comprises: obtaining a plurality of voltage measurements at the first terminal measured before a fault and during the fault; determining an n-phase fault based on voltage differences between respective phases of a plurality of voltage measurements measured before the fault and a plurality of voltage measurements measured during the fault, wherein n is a natural number greater than 1 corresponding to the number of the plurality of phases; and The protection system is further controlled based on the determined n-phase fault.

9. The method according to any one of claims 2 to 8, comprising: obtaining a plurality of current measurements at the first terminal; determining a generator type of the first generator based on the plurality of current measurements and / or the plurality of voltage measurements; as well as determining the measured phase angle deviation based on the plurality of voltage measurements when it is determined that the first generator is a first generator type; or When it is determined that the first generator is of a second generator type, the measured phase angle deviation is determined based on the plurality of current measurements.

10. The method according to any one of claims 2 to 6, wherein: The first power source is one of a grid, a synchronous power source, and an unconventional power source, in particular a resource based on an inverter, and the second power source is a synchronous power source or a grid having at least one synchronous power source and / or at least one unconventional power source.

11. The method according to any one of claims 1 to 7, wherein: The phase angle ranges of the at least three phase angle ranges do not overlap with each other.

12. The method according to any one of claims 1 to 9, wherein: Each of the at least three phase angle ranges includes a respective phase angle deviation of the plurality of phase angle deviations.

13. A method of controlling a protection system for an electric power system, the electric power system comprising a transmission line terminating at a first end, the method comprising: determining a plurality of phase angle deviations based on a network model of the power system during respective ones of the at least three faults; determining at least three phase angle ranges based on the plurality of phase angle deviations, wherein a sum of the at least three phase angle ranges is an angle of full rotation; obtaining a plurality of voltage and current measurements at the first terminal; determining a measured phase angle deviation based on a plurality of voltage measurements at the first terminal, and determining a zero sequence current based on a plurality of current measurements at the first terminal; determining a fault based on the at least three phase angle ranges, the measured phase angle deviation, and the zero sequence current; and A protection system of the power system is controlled based on the determined fault.

14. An apparatus for controlling a protection system for an electric power system, the electric power system comprising a transmission line, the apparatus comprising a processor, the processor being configured to: determining a plurality of phase angle deviations based on a network model of the power system during respective ones of the at least three faults; At least three phase angle ranges are determined based on the multiple phase angle deviations, wherein: The sum of the at least three phase angle ranges is the angle of complete rotation; as well as A protection system of the power system is controlled based on the at least three phase angle ranges.

15. An apparatus for controlling a protection system for an electric power system, the electric power system comprising a transmission line, the apparatus comprising a processor, the processor being configured to: determining a plurality of phase angle deviations based on a network model of the power system during respective ones of the at least three faults; At least three phase angle ranges are determined based on the multiple phase angle deviations, wherein: The sum of the at least three phase angle ranges is the angle of complete rotation; obtaining a plurality of voltage and current measurements at the first terminal; determining the measured phase angle deviation based on a plurality of voltage measurements at the first terminal, and determining a zero sequence current based on a plurality of current measurements at the first terminal; determining a fault based on the at least three phase angle ranges, the measured phase angle deviation, and the zero sequence current; as well as A protection system of the power system is controlled based on the determined fault.

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